LOPEZ FERNANDEZ, MARIA LUISA – mllopez@unav.es (Departamento de Biología Ambiental, Facultad de Ciencias, Universidad de Navarra), 31008 Pamplona.

LOPEZ, SOLEDAD – solpfernandez@gmail.com (Instituto de Estudios Manchegos), 13002 Ciudad Real, España.

(English version, made by M.L. Lopez Fernandez, of "Manual y Guía de Bioclimatología Mundial, 2017", http://www.naturalezenhispania.com, by the same authors).

ABSTRACT:

López, Fernández, M.L.& López Fernández, M.S. (2018). “Worldwide Bioclimatology Manual and Guide”. Documentos Aljibe “on-line”, vol. V, n.8., 26 de junio de 2018. Ciudad Real. Edita Sociedad Surcos. Depósito Legal: CR 820-1986- - ISBN 84-398-6347-0 ISSN 2445-1304. http://www.naturalezenhispania.com.

A summary exposition of Rivas-Martínez & al. (2011) “Worldwide Bioclimatic Classification System, Global Bioclimatics", is given. We comment, usually in their own words, on the originality of its premises, its basic elements, its hierarchical levels, its Isobioclimates, the Ombroclimographes (or Ombrolimogrames), and the Synoptic Table of the Bioclimatic Classification of the Earth. With the help of the information contained in the web: “http://www.globalbioclimatics.org”, Rivas-Mart. & Rivas-Sáenz (1996-2017), an approach to World Bioclimatic Diversity is given. Also, as a complement to the theoretical exposition, a practical example of how to perform the Bioclimatic Classification of a weather station is provided. Finally, the possibility of performing bioclimatic thematic maps, is commented, with bibliographical mention of the most recent maps. As for us, we have expanded the Bioclimatic Variants of Rivas-Mart. et al. (2011), with the concept of Normal Variant. We have also added some precisions to their concept of Steppic Variant. We give a glossary of concepts, which, in the offered pdf file, indicates the pages in which each of the terms is used.

Key words: Macrobioclimates, Bioclimates, Bioclimatic Variants, Bioclimatic Belts, Thermotypes, Ombrotypes, Isobioclimates, Ombroclimograms, Continentality, Steppicity, Submediterraneity, Global Bioclimatic Diversity, Bioclimatic Maps.

RESUMEN

Se realiza una exposición resumida de la Clasificación Bioclimática Mundial, "Global Bioclimatics", de Rivas-Martínez & al. (2011), comentando, muchas veces con sus mismas palabras, la originalidad de sus premisas, sus elementos básicos, sus niveles jerárquicos, los Isobioclimas, los Ombroclimografos (u Ombroclimogramas), y la Tabla Sinóptica de la Clasificación Bioclimática de la Tierra. Con ayuda de la información contenida en “http://www.globalbioclimatics.org”, Rivas-Mart. & Rivas-Sáenz (1996-2017), se hace una aproximación a la Diversidad Bioclimática Mundial. Así mismo se ofrece un ejemplo práctico de cómo realizar la clasificación bioclimática de una estación meteorológica, que complementa la exposición teórica. Para terminar, se comenta la posibilidad de realizar mapas temáticos bioclimáticos, con mención bibliográfica de los más recientes. Por nuestra parte, hemos ampliado las Variantes Bioclimáticas de Rivas-Mart. et al. (2011), con el concepto de Variante Normal, así como también hemos añadido algunas precisiones a su concepto de Variante Esteparia. El trabajo se acompaña de un glosario de conceptos, que, en la versión PDF que se ofrece, indica la página en que se utiliza cada uno de ellos.

Palabras clave: Macrobioclimas, Bioclimas, Variantes Bioclimáticas, Pisos Bioclimáticos, Termotipos, Ombrotipos, Isobioclimas, Ombroclimograma, Continentalidad, Estepicidad, Submediterraneidad, Diversidad Bioclimática Mundial, Mapas Bioclimáticos.

General Index

1.- Introduction

2.- Premises of the classification

3.- Basic Elements for the Global Bioclimatic Classification

4.- Worldwide Bioclimatic Classification

5.- Bioclimatic Synopsis of the Earth

6.- Isobioclimates

7.- Bioclimograms

8.- Approach to Global Bioclimatic Diversity

9.- Assessment of Summer Aridity, with examples

10.- ITC and Ci Calculations

11.- Practical example of complete bioclimatic characterization of a meteorological station, and of the use of the synoptic table

12.- Bioclimatic Cartography

13.- Paginated glossary

14.- Table of contents

15.- Bibliography

1.- INTRODUCTION

Bioclimatology is the science that studies the relationship between climate and the distribution of living beings and their communities on Earth.

Since approximately 1987, Rivas-Martínez has developed a new "Bioclimatic Classification of the Earth", the "GLOBAL BIOCLIMATICS" of Rivas-Martínez (1987, 2004, 2008). Precisely, also in 2008, López Fernández & López Fernández published a "Guide to Recognizing and Classifying Bioclimatic Units", with the aim of facilitating the understanding and use of Rivas-Martínez's "Global Bioclimatics".

Recently, Rivas-Martínez & al., 2011, have remodeled and completed the "Global Bioclimatics", also called "Worldwide Bioclimatic Classification System", which exclusively uses climatic data. The Worldwide Bioclimatic Classification, by Rivas Martínez & al., is hierarchical and recognizes three levels: Macrobioclimate, Bioclimate / Variant, and Bioclimatic Belt - consisting of a Thermotype and a Ombrotype.This new Bioclimatic Classification recognizes in the Earth 5 Macrobioclimates, to which are subordinated 28 Bioclimates - in each one of which operate one or more of the nine recognized Bioclimatic Variants, and, in addition, 31 Thermotypes and 9 Ombrotypes: Altogether, over 400 elemental bioclimatic combinations, known as Isobioclimates, each of one consisting of a Macrobioclimate, a Bioclimate / Variant and a Bioclimatic Belt (a Thermotype plus an Ombrotype), which have territorial representation in the Geobiosphere.

With this "Manual and Guide to World Bioclimatology", we aim to facilitate the understanding and use of this bioclimatic classification tool, so useful to explain and understand Biogeography.

2.- PREMISES OF THE BIOCLIMATIC CLASSIFICATION OF THE EARTH, RIVAS-MARTÍNEZ & al. (2011)

The following eight premises bring together the main lines of force that condition the distribution of life, as interpreted by Rivas-Martínez (2008) and Rivas-Martínez & al. (2011), so they are at the basis of their Earth's Bioclimatic Classification.

2.1. Reciprocity: In Bioclimatology, it has been shown that there is an adjusted and reciprocal relationship between climate, vegetation and geographical territories, ie, between Isobioclimates, biocenosis and biogeographical units. This is because the distribution of vegetation, as well as the evolution of the biocenosis, have accompanied and accompany the climatic oscillations and the geological variations of the earth, which have taken place in the past. (Exceptionally, some high alpine ridges have prevented vegetation migrations and that reciprocity: see premise 8: Orogenies, below)

2.2. Photoperiod / Latitude: In the distribution of life have great influence, both the photoperiod and its variation throughout the year, as well as the angle with which the sun's rays affect the surface of the Earth, both phenomena controlled by latitude. Therefore, latitude is the first factor used to characterize and differentiate Macrobioclimates.

2.3. Continentality / Oceanicity - Annual thermal amplitude: The annual thermal amplitude has an influence of first magnitude in the distribution of the biocenosis and, consequently, in the borders of many Bioclimates. In the Synoptic Table of the Earth's Bioclimatic Classification (see Figure 7, below), it can be seen how the Continentality is used to differentiate the Temperate Macrobioclimate from the Boreal Macrobioclimate, as well as all the Bioclimates from each other except the Tropical.

2.4. Seasonality of Precipitation: The annual rhythm of precipitation has as much or more importance, in the composition and distribution of the biocenosis, than the amount of rain itself. The annual rhythm is the distribution of precipitation throughout the year. Seasonality differentiates bioclimatic units of several ranges: Macrobioclimates, Bioclimates and Bioclimatic Variants.

2.5. Mediterraneity: There is a large Mediterranean Macrobioclimate, latitudinally extratropical, ombrically antithetical to the Tropical, Temperate and Boreal Macrobioclimates, showing a summer aridity (or summer drought) of at least two consecutive months: That is to say, in which the sum of the precipitations of the two consecutive driest months of the summer quarter is less than or equal to twice the sum of the average monthly temperatures of those same months: (Psi + Psii) 2 ( Tsi + Tsii), being si and sii the two consecutive months drier of the summer. Such a shortage of rain during the summer, which can last up to the twelve months of the year, is a brake for life, just during the months thermally more favorable to growth. This circumstance is reflected in deep physiognomic changes of the biocenosis, with respect to other Bioclimates with precipitations of similar quantity, but without summer drought.

2.6. Deserts: The deserts are the response of life to extremely unfavorable climatic conditions, either by cold, or by aridity, or by both. That is why there is no single type of desert bioclimate for all the deserts of the world, but there are cold deserts, in all Macrobioclimates, and warm deserts, in the Tropical and Mediterranean Macrobioclimates. In warm deserts, the rate of precipitation is decisive, with maximums in summer - tropical deserts - or in autumn and spring – Mediterranean deserts. The flora and vegetation of both types of deserts are clearly different and are phenologically adapted to the precipitation rhythms.

2.7. Oroclimates (Mountain climates): In the mountains, the Bioclimate, except for temperature and precipitation values, shows a close relationship, in the photoperiod values, with that of its piedmont. Therefore, in the mountains, just as there is a certain vertical zonation of the biocenosis, there is also, for each Macrobioclimate, a particular sequence of thermotypic and ombrotypic combinations, that is to say, a particular sequence of Bioclimatic Belts. So that the altitudinal succession of vegetation floors is explained by thermal and ombric changes due to altitudinal and / or exposure-orientation changes.

2.8. Orogenies: In some regions of the Earth, paleogeological, orographic and paleoclimatic circumstances have prevented the free migration of the biocenosis, in correspondence with the climatic variations that were occurring. Therefore, in those regions, the reciprocal relationship between climate and distribution of the biocenosis, announced in the first Premise, can not be met. One such circumstance has been the Alpine orogeny, which gave rise to an almost continuous set of high mountain systems oriented East-West (Hindu Kush, Himalayan, Tibet and Karakorum, etc.) on the Asian continent. These reliefs, of considerable altitude, have acted as a barrier, greatly limiting the migratory movements of life forms, during the great climatic changes that followed. Thus, in addition to the severe extinctions during arid or glacial periods, these large Central Asian transverse ridges have prevented the biocenotic recolonizations from the adjacent subtropical belt during the interglacial and, ultimately, during the Holocene periods. As a consequence, between the meridians 70º and 110º E, and between the 25º and 35º N parallels, it was necessary to establish the altitudinal limit of 2,000 meters, as an approximate border between the Tropical Macrobioclimate on the one hand, and the Mediterranean and Temperate Macrobioclimates, on the other.

3.- BASIC COMPONENTS FOR THE WORLDWIDE BIOCLIMATIC CLASSIFICATION

After having seen the Premises that underpin this Worldwide Bioclimatology, we will now comment on its basic elements, namely: Latitude, Annual distribution of rainfall, Bioclimatic Parameters, and Bioclimatic Indices.

All the necessary data for the Bioclimatic Classification of the Earth are offered even by the simplest thermopluviometric stations. These are the following data: Name and Country; Latitude, Longitude and Altitude; period of temperature and precipitation observations; monthly averages of maximum and minimum temperatures; and monthly rainfall. In total, 43 data are needed from each meteorological station.

However, let us note that the great work of Rivas-Martínez and his team has been the double selection they have achieved: First, they have selected the parameters and indices that are significant for the distribution of life and which are easily obtained from the 43 basic data provided by the meteorological stations; And secondly, they have once again made a successful selection by assigning, at each step of the bioclimatic hierarchical classification, those parameters and indices that make it possible to differentiate these levels. All these selections are not subjective, but have been made by relating the different types of ecosystems to the climatological data offered by the stations (more than 20,000, worldwide, collected by Rivas Martínez, in the database of his Phytosociological Research Center, Spain, http://globalbioclimatics.org/).

In doing so, the predictive value of the result, that is, of the World Bioclimatic Classification, is truly astounding. But in reality, what should astound us is the knowledge of the different forms of life and their distribution-geographic positioning at world-wide level, and the work of relating that knowledge with the climatic data.

Next, we will discuss the following five topics:

3.1.- Latitude: Latitudinal Zones and Bands.

3.2.- Seasonality of temperatures and rainfall. Period of plant activity. Types of frost.

3.3.- Parameters

3.3.1.- Seasonal Parameters

3.3.2.- Temperature Parameters

3.3.3.- Precipitation Parameters

3.4.- Bioclimatic Indexes

3.4.1.- Continentality / Oceanicity Index: Annual thermal amplitude - lc -

3.4.2.- Index of Thermicity It and Index of Compensated Thermicity Itc

3.4.3.- Ombrothermal Indexes - Io -

3.5.- Alphabetical list of the abbreviations that designate the Parameters and the Bioclimatic Indexes.

3.1.- Latitude: Latitudinal Zones and Waists.

The three factors that most influence the distribution of life - the photoperiod and its annual variation, the temperature and its seasonal variation, and the amount of precipitation along with its annual rhythm - have a close correlation with the values of latitude. It is therefore not surprising that the limits of the superior bioclimatic units in World Bioclimatology show a close correspondence with the latitudinal zones and bands traditionally proposed by geographers. In figure 1 we show the latitudinal Zones and Bands, for later, in figure 3, to point out and comment their correlations with the Macrobioclimates.

Latitudinal Zones. -In terms of latitude, at any altitude above sea level, large latitudinal zones are distinguished on Earth (see Rivas-Mart et al., 2011): one Warm – between the 35º North and South; two Temperate - between the 35º-66º N and S; and two Cold- between 66º-90º N and S.

Figure 1. Amplitude of latitudinal Zones and Belts recognized on Earth (according to Rivas-Mart et al., 2011):

	Latitudinal Zones	Latitudinal Belts
N	3. Cold 66º-90º	3a. Arctic 66º-90º

	2. Temperate 35º-66º	2b. Subtemperate 51º-66º
		2a. Eutemperate 35º-51º


	1. Warm 0º-35º	1c. Subtropical 23º-35º
		1b. Eutropical 7º-23º
		1a. Equatorial 7ºN-7ºS
S	1. Warm 0º-35º
		1b. Eutropical 7º-23º
		1c. Subtropical 23º-35º
	2. Temperate 35º-66	2a. Eutemperate 35º-51º

		2b. Subtemperate 51º-66º

	3. Cold 66º-90º	3a. Antartic 66º-90º

Latitudinal Belts. - Depending on the latitude, at any altitude above sea level, 11 wide latitudinal belts are distinguished on Earth:

In the Warm Zone, the following 5 latitudinal Belts are recognized: one Equatorial Belt, 7º North - 7º South; two Eutropical Belts, 7º-23º North and 7º- 23º South; and two Subtropical Belts, 23º-35º North and 23º-35º South.

In the Temperate Zones, which contact north and south with the warm zone, 4 latitudinal belts are recognized: two Eutemperate Belts, 35º-51º North and 35º-51º South; and two Subtemperate Belts, 51º-66º North and 51º-66º South.

In the Cold Zones, which contact both in the North and the South with the Temperate zones, only two latitudinal belts are recognized, one Arctic belt, 66º-90º North and another Antarctic belt, 66º-90º South.

3.2.- Seasonality of temperatures and rainfall. Period of plant activity. Types of frost.

Seasonality refers to variations in temperature and precipitation occurring throughout the year. In tropical climates, seasonality is marked by precipitation, while, in the extratropical climates, seasonality is marked by temperatures.

The seasonality of temperatures and of precipitations is involved in the definition and formulation of most of the Parameters and Indexes used in this Worldwide Bioclimatic Classification, as we will see below. In fact, the seasonality of temperatures and the amount of monthly precipitation, as well as its annual rhythm, are data of great diagnostic value in the recognition and delimitation of Macrobioclimates, Bioclimates

One aspect of the seasonality of temperatures is the concept of "Plant activity period". "Plant activity period" is the number of months whose average monthly temperature exceeds a certain threshold to allow the biochemical activity of plants. The most accepted threshold is Ti> 3ºC. Another aspect of the seasonality of temperatures is the concept of "Types of frost", which may be: absent, probable or sure, depending on the magnitude of the parameters mi and m'i. It is said that a month has frost absent, when its m'i> 0; it is said that a month has probable frost, when it simultaneously fulfills mi> 0, and m'i ≤ 0; and finally, it is said that one month has sure frost, if mi ≤ 0.

3.3.- Parameters

We understand by Parameters the data or significant values of those climatic variables that are considered necessary to analyze a bioclimatic situation.

In order to establish this Worldwide Bioclimatic Classification, climatic data that are easily accessible have been used - average monthly temperatures of the maximum and minimum, and average monthly temperatures, expressed in degrees centigrade (ºC), and monthly precipitations expressed in millimeters (mm). All these data, which we consider as Parameters in this classification, are offered even by the simplest weather stations, which, altogether, form a wide network around the world.

The main Parameters of seasonality, temperature and precipitation used in this "Bioclimatic Classification of the Earth" are listed below by their acronyms and notations. (For more information, see Rivas-Mart et al., 2011):

3.3.- Parameters

3.3.1. – Seasonal Parameters

3.3.2.- Temperature Parameters

3.3.3.- Precipitation Parameters

3.3.1.- Seasonal Parameters

The sequence of atmospheric changes, and their duration, are of paramount importance to life. Therefore, in Bioclimatology, it is interesting to take into account the following periods of time - Seasonal parameters - during which vegetation and flora are especially sensitive to certain climatic values of temperature and precipitation.

We list the main Seasonal Parameters used in this Classification. From each one its acronym and its contents are indicated:

Tr1 Winter solstice trimester. Season: Winter (W, Winter). Dec-Jan-Feb, latitude N; Jun-Jul-Aug, latitude S.

Tr2 Spring equinox trimester. Season: Spring (P, Spring). Mar-Abr-May, latitude N; Sep-Oct-Nov, latitude S.

Tr3 Summer solstice trimester. Season: Summer (S, Summer). Jun-Jul-Aug, latitude N; Dec-Jan-Feb, latitude S.

Tr4 Autumn equinox trimester. Season: Autumn (F, Fall, Automn). Sep-Oct-Nov, latitude N; Mar-Abr-May, latitude S.

Cm1 The warmest four-month period of the year.

Cm2 Four-month period following the Cm1.

Cm3 Four-month period prior to the Cm1.

Pav Period of plant physiological activity: number of months whose average monthly temperature equals or exceeds 3.5ºC: Ti ≥ 3,5ºC.

Pf Periods of frost: number of months with frost absent, probable or safe.

Ss Warmer semester of the year

Sw Warmer semester of the year

3.3.2.- Temperature Parameters

Are data, annual or monthly, of temperatura. We list them by their initials, indicating their content. Average temperatures are expressed in degrees centigrade and positive temperatures, in tenths of a degree centigrade.

T Average annual temperature

Ti Average monthly temperature, standing: 1 = January, ..., 12 = December

Tmax Average monthly temperature of the warmest month of the year

Tmin Average monthly temperature of the coldest month of the year.

Tp Positive Annual Temperature: Quantifies, for each place, the thermal energy available for life. It is the sum, expressed in tenths of degree centigrade, of the average monthly temperatures of those months that exceed 0ºC: Tp=

Tps Positive Temperature of the warmest trimester of the year (Tropical Macrobioclimate), or summer trimester (Macrobioclimates extratropical), expressed in tenths of degree centigrade.

Tpw Positive Temperature of the coldest trimester of the year, expressed in tenths of degree centigrade.

Tsi Monthly Medium Temperature of any Summer month

M Average temperature of the maximum temperatures of the coldest month in the year, ie, the month with the lowest Ti.

m Average temperature of the minimum temperatures of the coldest month in the year, that is, the month with the lowest Ti.

mi Average monthly temperature of the mínimum temperatures, where i: 1 = January, ..., 12 = December.

m’i Average monthly temperature of absolute minimum temperatures, where i: 1 = January, ..., 12 = December.

3.3.3.- Precipitation Parameters.

They are expressed in mm (or liters per square meter):

P Annual precipitation.

Pi Monthly precipitation, where i: 1 = January, ..., 12 = December.

Pss Precipitation of the six warmest months of the year

Psw Precipitation of the coldest six months of the year

Pcm1 Precipitation of the warmest four-month period of the year.

Pcm2 Precipitation of the four months period following the warmest four-month period of the year.

Pcm3 Precipitation of the four months period previous to the warmest four months period of the year.

P Tr1 Precipitation of the winter solstice trimester. Season: Winter (W, Winter). Dec-Jan-Feb, latitude N; Jun-Jul-Ago, latitude S.

P Tr2 Precipitation of the spring equinox trimester. Season: Spring (P, Spring). Mar-Abr-May, latitude N; Sep-Oct-Nov, latitude S.

P Tr3 Precipitation of the summer solstice trimester. Season: Summer (S, Summer). Jun-Jul-Aug, latitude N; Dec-Jan-Feb, latitude S.

P Tr4 Precipitation of the automn equinox trimester. Season: Autumn (F, Fall, Automn). Sep-Oct-Nov, latitude N; Mar-Abr-May, latitude S.

Ps Precipitation of the summer trimester -S, Summer. Jun-Jul-Aug, latitude N; Dec-Jan-Feb, latitude S.

Psi Monthly precipitation of any Summer month

Pw Winter trimester precipitation -W, Winter. Dec-Jan-Feb, latitude N; Jun-Jul-Ago, latitude S.

Psb1 Precipitation of the first two months after the summer solstice (July-August in latitude N, January-February in latitude S)

Psb2 Precipitation of the two subsequent months to Psb1 (September-October in latitude N, March-April in latitude S)

Pp Annual Positive Precipitation: Pp = ∑Pi (Ti>0ºC). Pp is the sum of Pi of all months of the year, whose Ti is greater than 0ºC. Pp=∑Pi (Ti>0), being i: 1 = January, ..., 12 = December.

Pps Positive Precipitation of the three warmest months period of the year (tropical zones), or of the summer trimester (extratropical zones).

Ppw Positive Precipitation of the three coldest months period of the year (tropical zones), or of the winter trimester (extratropical zones).

> W> Winter precipitation.

> P> Spring precipitation.

> S> Summer precipitation.

> F> Fall precipitation.

3.4.- Bioclimatic Indexes

3.4.1.- Continentality / Oceanicity Index: Annual thermal amplitude -lc-

3.4.2.- Thermicity Index -It- and Compensated Thermicity Index -Itc-

3.4.3.- Ombrothermic Indexes -Io-

The indexes are the result of applying simple arithmetic formulas to various parameters of rainfall and / or temperature, selected by seasonal criteria or by criteria of specific biological requirements.

For this classification, Rivas-Martínez (2008) and Rivas-Martínez et al. (2011) have selected some Indexes, such as Continentality Index, already proposed by other authors, but, above all, they have created other new Indexes -the Thermicity Index as well as the Ombrothermic Indexes- which have great prediction capacity with respect to the distribution of the life.

It is precisely in the discovery of new Bioclimatic Indexes that the most brilliant part of the bioclimatic system of Rivas-Martínez (2008) and Rivas-Martínez et al. (2011), as we have already said. To discover and establish them, interpreting and following the dictation of the distribution of life and its dynamism, they have used all the ideas and demands contained in the Premises and the Basic Elements, already commented. They have also handled climate data from 20,000 stations around the world, which obviously reduces the subjectivism of choice.

3.4.1.- Continentality / Oceanicity Index: Annual thermal amplitude -lc-

The Continentality / Oceanity Index quantifies the amplitude of the annual thermal oscillation by calculating the thermal interval between the highest and lowest monthly average temperatures of the year. Although the index is called "Continentality Index", if its values are between 0 and 21, traditionally we talk about Oceanity, while, if they are high, over 21, we talk about Continentality. This Continentality Index, despite its simplicity, shows an excellent correlation with life. In addition, the data required for its calculation are provided by all weather stations, even the simplest ones.

The Continentality / Oceanity index expresses the difference, in degrees centigrade, between the highest and lowest monthly average temperatures of the year:

Ic = Tmax – Tmin

The Continentality Types and Subtypes recognized in the "Bioclimatic Classification of the Earth, together with their Ic intervals, are shown in Figure 1A.

Figura 1A. Types and Subtypes of Continentality, and their intervals of Ic.

TYPES	Ic VALUES	SUBTYPES	Ic VALUES
Hyperoceanic	0≤Ic≤11	1.1 Ultrahyperoceanic	0≤Ic≤4
		1.2 Euhyperoceanic	4<Ic≤8
		1.3 Subhyperoceanic	8<Ic≤11
Oceanic	11<Ic≤21	2.1 Semihyperoceanic	11<Ic≤14
		2.1 Euoceanic	14<Ic≤17
		2.3 Semicontinental	17<Ic≤21
Continental	21<Ic≤66	3.1 Subcontinental	21<Ic≤28
		3.2 Eucontinental	28<Ic≤46
		3.3 Hypercontinental	46<Ic≤66

3.4.2.- Index of Thermicity -It- and Index of Thermicity Compensated -Itc-

The Thermicity Index weighs and quantifies the intensity of the winter cold, a limiting factor for many types of life. It is calculated by summing T (mean annual temperature), M (mean temperature of the maximum of the coldest month), and m (mean temperature of the minimum of the coldest month), and expressed in tenths of a degree centigrade:

It = (T + M + m) 10

It is, therefore, an Index that considers together the intensity of the winter cold and the average annual temperature.

But since (M + m) is approximately, ≈2Tmin (Tmin = average temperature of the coldest month of the year), it is not necessary to know neither M nor m, to calculate It:

It ≈ (T + 2 Tmin) 10

The correlation of this Thermicity Index with vegetation is very satisfactory in countries with warm and temperate climates. However, in cold countries, or in countries with a continental tendency, the relationship with vegetation is more precise if the Annual Positive Temperature (Tp) is used. For this reason, it is a very useful Index to distinguish the Tropical Macrobioclimate from the Mediterranean and Temperate Macrobioclimetes, in those latitudes in which the three Macrobioclimates coincide (latitudes above 23 N and S). In the Mediterranean and Temperate Macrobioclimates, unlike in the Tropical, there is the winter: therefore, their lt is necessarily lower than in the Tropical.

Compensated Termicity Index.

As the Thermicity Index is greatly affected by the annual thermal amplitude - Continental Index, lc-, it needs a certain compensation, to make possible the comparisons between localities, regardless of the excesses of temperance or cold, that occur in hyperoceanic climates, or in the hypercontinental ones. It has been thus arrived at the Compensated Thermicity Index - Itc - which is no more than the value of It plus a compensation value, Ci:

Itc = It + Ci

Value of Ci. Ci is the compensation value to correct for the excess "temperance" or "cold" occurring in extratropical areas (more than 23 ° N and S), when the Continental Index is extremely low (Ic ≤ 8), or high (Ic> 17), compared to cases where Ic has mean values: In this way, the effect of an "excess" Ocean / Continental, on the measure of the climate thermal comfort, is neutralized. The value of Ci is calculated according to latitude and Continentality. Chapter 10 details the procedure for calculating Itc and Ci, with the help of several examples of stations with different Continental Indexes. (See Chapter 10).

As the truly meaningful Index is the Compensated Thermicity Index, Itc, we will always speak, in this work, of Itc. (In their study of the world's weather stations, see www.globalbioclimatics.org (Rivas-Mart. & Rivas-Sáenz, 1996-2017), authors indicate both It and Itc).

3.4.3.- Ombrothermic Indexes -Io-

They serve to measure the moisture comfort that life enjoys in the different terrestrial zones. The Ombrothermic Index relates the precipitation to the temperature, but using the Parameters of Positive Precipitation and Positive Temperature, already discussed. The value of an Ombrothermic Index is the quotient between Positive Precipitation and Positive Temperature of the considered period, multiplied by ten:

Io = (Pp/Tp) 10.

Certain intervals of Io reflect faithfully changes in biocenosis. The Ombrothermic Indexes are so determinant and significant that their intervals are used in all hierarchical levels of the Bioclimatic Classification of the Earth of Rivas-Martínez (2008) and Rivas-Martínez et al. (2011).

In addition to the Io, Annual Ombrothermic Index, many other Ombrothermic Indices can be calculated, for various periods that are considered significant, of 1, 2, 3, or more months.

In tropical territories, it is sometimes necessary to know the index:

Iod2 Ombrothermic Index of the driest bimester within the driest four-month period of the year.

Among the various Ombrothermic Indexes used in extratropical territories, the following are very significant:

Ios, Iosi Ombrothermic Index of any month of the summer trimester (Tr3)

Ios1 Ombrothermic Index of the hottest month of the summer trimester (Tr3)

Ios2 Ombrothermic Index of the hottest bimester of the summer trimester (Tr3)

Iosc Summer compensable Ombrothermic Indexes. Two of them are considered:

Iosc3 (= Ios3): Compensable Ombrothermic Index of the summer trimester (Tr3), necessary to evaluate the summer aridity

Iosc4 (= Ios4): Compensable Summer Ombrothermic Index for the four-month period resulting from adding, to the summer trimester (Tr3), the month immediately preceding. This index is also used to assess summer aridity.

All these Summer Ombrothermic Indexes are very important, since they measure the summer aridity and its possible compensation: They are essential to differentiate the Mediterranean Macrobioclimate, from the Temperate and Boreal Macrobioclimates (see these, sections 4.1.2, 4.1.3, and 4.1.4). For the correct use of all these Indexes, see chapter 9.

3.5.- Alphabetical list of the abbreviations that designate the Parameters and the Bioclimatic Indexes.

We have found it necessary to list, in alphabetical order, all the Parameters and Indices mentioned in the previous headings (See Figure 2).

Figure 2. Alphabetical list of Parameters and Bioclimatic Indexes acronyms.

Para-meter /Index	Descripción
Ci	Continentality compensation value
Cm1	The warmest four-month period of the year.
Cm2	Four-month period following the Cm1
Cm3	Four-month period prior to the Cm1
Ic	Continentality / Oceanicity Index: Annual thermal amplitude.
Io	Annual Ombrothermal Index: (Pp/Tp) x 1O.
Iod2	Ombrothermal Index of the driest bimester within the driest four-month period of the year.
Ios, Iosi	Ombrothermal Index of any month of the summer trimester
Ios1	Ombrothermal Index of the hottest month of the summer trimester (Tr3)
Ios2	Ombrothermal Index of the hottest bimester of the summer trimester (Tr3)
Iosc	Summer compensable Ombrothermal Indexes
Iosc3(= Ios3)	Compensable Ombrothermic Index of the summer trimester, necessary to evaluate the summer aridity
Iosc4(= Ios4)	Compensable Summer Ombrothermal Index for the four-month period resulting from adding, to the summer trimester, the month immediately preceding. This index is also used to assess summer aridity.
It	Thermicity Index
Itc	Compensated Thermicity Index
M	Average temperature of the maximum temperatures of the coldest month in the year, ie, the month with the lowest Ti. (Seasonal Temperature Index)
m	Average temperature of the minimum temperatures of the coldest month in the year, that is, the month with the lowest Ti. (Seasonal Temperature Index)
mi	Average monthly temperature of the mínimum temperatures, where i: 1 = January, ..., 12 = December.
m´i	Average monthly temperature of absolute minimum temperatures, where i: 1 = January, ..., 12 = December
P	Annual precipitation
Pav	Period of plant physiological activity
Pcm1	Precipitation of the warmest four-month period of the year.
Pcm2	Precipitation of the four months period following the warmest four-month period of the year
Pcm3	Precipitation of the four months period previous to the warmest four months period of the year
Pf	Periods of frost
Pi	Monthly precipitation, where i: 1 = January, ..., 12 = December. (Weather parameter)
Pp	Annual Positive Precipitation
Pps	Positive Precipitation of the three warmest months period of the year (tropical zones), or of the summer trimester (extratropical zones).
Ppw	Positive Precipitation of the three coldest months period of the year (tropical zones), or of the winter trimester (extratropical zones).
Ps	Precipitation of the summer trimester
Psb1	Precipitation of the first two months after the summer solstice (July-August in latitude N, January-February in latitude S)
Psb2	Precipitation of the two subsequent months to Psb1 (September-October in latitude N, March-April in latitude S)
Psi	Monthly precipitation of any Summer month
Pss	Precipitation of the six warmest months of the year
Psw	Precipitation of the coldest six months of the year
PTr1	Precipitation of the winter solstice trimester
PTr2	Precipitation of the spring equinox trimester
PTr3	Precipitation of the summer solstice trimester
PTr4	Precipitation of the automn equinox trimester
Pw	Winter trimester precipitation
Ss	Warmer semester of the year
Sw	Warmer semester of the year
T	Average annual temperature. (Weather parameter)
Ti	Average monthly temperature, standing: 1 = January, ..., 12 = December. (Weather parameter)
Tmax	Average monthly temperature of the warmest month of the year.
Tmin	Average monthly temperature of the coldest month of the year.
Tp	Positive Annual Temperature
Tps	Positive Temperature of the warmest trimester of the year (Tropical Macrobioclimate), or summer trimester (Macrobioclimates extratropical)
Tpw	Positive Temperature of the coldest trimester of the year
Tr1	Winter solstice trimester
Tr2	Spring equinox trimester
Tr3	Summer solstice trimester
Tr4	Autumn equinox trimester
Tsi	Monthly Medium Temperature of any Summer month
>W>	Winter precipitation.
>P>	Spring precipitation.
>S>	Summer precipitation.
>F>	Fall precipitation.

4.- WORLDWIDE BIOCLIMATIC CLASSIFICATION

The Worldwide Bioclimatic Classification (Rivas-Mart, 2008, Rivas-Mart et al., 2011) is necessarily hierarchical, because it has to reflect the different range of influence of climatic factors on the distribution of life. The hierarchical bioclimatic units of the Classification are: 1-Macrobioclimates, 2-Bioclimates / Variants, and 3-Bioclimatic Belts.

Latitude has a decisive influence on the distribution of living beings and, for that reason, it is used in the first hierarchical step of classification, that of the Macrobioclimates. Indeed, latitude determines the photoperiod, the inclination of the sun's rays, the distribution of high and low atmospheric pressures, the general circulation of the atmosphere and its effect on the amount and distribution of rainfall, etc.,

Likewise, in each Macrobioclimate, the distribution patterns of the plant communities are governed by combinations of Continentality levels, together with humidity comfort levels: Ic and Io. Bioclimates and their variants are thus defined.

And in each Bioclimate / Variant unit, the combination of one level of ltc, -or of Tp - (Thermotype) with another of Io (Ombrotipo), reflects the actual distribution of vegetation types and, thus, define the third hierarchical level of the classification, the Bioclimatic Belts.

4.1.- First hierarchical level of the Classification: Macrobioclimates

4.2.- Second hierarchical level of the Classification: Bioclimates / Variants

4.3.- Third hierarchical level of the Classification: Bioclimatic Belts -Thermotypes and Ombrotypes-

4.1. First hierarchical level of the Classificacion: Macrobioclimates

The Macrobioclimates are the greater rank typological units of this Bioclimatic Classification. These are synthetic biophysical models, delimited by certain latitudinal and climatic values, that have a wide territorial jurisdiction and that are related to the great types of climates, biomes, and biogeographic regions, of the Earth. The five Macrobioclimates that are accepted in this classification are: Tropical, Mediterranean, Temperate, Boreal and Polar.

To distinguish the Macrobioclimates, the latitudinal values are the first to be taken into account, and their limits are shown in figure 3: Tropical Macrobioclimate fits the latitudinal warm zone (35 N & S); Mediterranean Macrobioclimate participates in the warm and temperate zones (23º-52º N & S); Temperate Macrobioclimate also participates in the warm zone and extends through almost all the temperate zone (23º-66ºN and 23º-55º S); Boreal Macrobioclimate is distributed throughout almost all the temperate zone and the cold zone, but has an asymmetric latitudinal distribution (42º-72º N and 49º-56º S); finally, the Polar Macrobioclimate is almost symmetrically distributed in the temperate zone and throughout the cold zone (51º-90ºN and 53º-90ºS).

Figure 3. Width of latitudinal zones and belts recognized on Earth, and their relationship to the distribution of Macrobioclimates. As can be seen, the limits of the Macrobioclimates do not coincide exactly with the corresponding belts, although they show close correspondences.

	Latitudinal Zones	Latitudinal Belts	Macrobioclimates
N	3. Cold 66º-90º	3a. Arctic 66º-90º					Polar 51º-90º
						Boreal 42º-72º
	2. Temperate 35º-66º	2b. Subtemperate 51º-66º			Temperate 23º-66º
		2a. Eutemperate 35º-51º		Medite-rranean 23º-52º


	1. Warm 0º-35º	1c. Subtropical 23º-35º	0º-35º Tropical 0-35º
		1b. Eutropical 7º-23º
		1a. Equatorial 7ºN-7ºS
S	1. Warm 0º-35º
		1b. Eutropical 7º-23º
		1c. Subtropical 23º-35º		Medite-rranean 23º-52º	Temperate 23º-55º
	2. Temperate 35º-66	2a. Eutemperate 35º-51º
						Boreal 49º-56º
		2b. Subtemperate 51º-66º
							Polar 53º-90º

	3. Cold 66º-90º	3a. Antarctic 66º-90º

As shown in Figure 3, and despite their denominations, the boundaries of the Macrobioclimates do not correspond exactly to the Latitudinal Zones and Belts, but the comparison with them helps to locate the areas of each Macrobioclimate on the continents.

1.-In the latitudinal belts equatorial - 7ºN-7ºS - and eutropical - 7º-23ºN and S-, as the solar radiation is practically zenith and the duration of the day and of the night vary little along the year, the Macrobioclimate, at any altitude, regardless of temperature, is considered tropical.

2.- In the subtropical latitudinal belts - 23º-35º N and S -, depending on the temperature and the rhythm of the precipitations throughout the year, the territory is divided between the Tropical, Mediterranean and Temperate Macrobioclimates.

3.-In the eu-temperate latitudinal belts -35º-52ºN and S-, the seasonal photoperiods and the less energy received represent a severe border for plant and animal life, which have to adapt to drought and cold of the Mediterranean, Temperate or Boreal Macrobioclimates, depending on the rainfall rhythms and thermal levels.

4.-In the latitudinal subtemperate belts -52º-66ºN and 52º-60ºS-, the photoperiod and the thermicity establish new limits to the life, by the necessary adaptations to the intense photoperiod and the intense cold, typical of the Macrobioclimates Temperate, Boreal and Polar .

5.-In the latitudinal Arctic -66º-90ºN-and Antarctic -60º-90ºS- belts, due to the great difference in the duration of day and night, and the little thermal energy that is received during the solstices, life finds very severe limitations. Therefore, at any latitude and altitude, the Macrobioclimate is considered Polar.

In addition to the latitude, in the differentiation of the Macrobioclimas several thermal indices are used, in some cases related to the Continental Index, as well as certain rainfall rhythms. Thus, the Compensated Thermicity Index, Itc, which accurately measures the winter cold intensity - a true barrier for many living beings - is very discriminant to differentiate tropical, Mediterranean and temperate Macrobioclimates.

In the Earth's Bioclimatic Synopsis, Figure 7, in the Macrobioclimates column, we find all the necessary values to distinguish the Macrobioclimates from each other. Figure 4 is a copy of that first column of the Earth's Bioclimatic Synopsis, which facilitates its consultation.

Note: According to the Orobioclimates premise, to analyze the Macrobioclimate of a meteostation located at a certain height above sea level, it is necessary to theoretically calculate the thermal values that would have in its base, that is, between 0 and 200 meters above sea level. For that, it is necessary to increase T, M, Itc and Tp in certain values, for every 100 m that the weather station exceeds 200m. The amount of the increments vary somewhat with the latitude, so they are given, as a note, at the bottom of the summary table "Bioclimatic Synopsis of the Earth". (See Figure 7)

Figure 4.- Column of Macrobioclimates, extracted from the Bioclimatic Synopsis of the Earth

Macrobioclimates ⁽¹⁾

Name, Acronym and Differential Characters

Tropical Tr

Warm Zone: Equatorial, Eutropical and Subtropical Belts (0º - 35º N & S). In Subtropical (23º - 35º N & S) at < 200 m, at least two values: T ≥ 25º, m ≥ 10º, Itc ≥ 580; or, if Pss > Psw, or Pcm₂< Pcm₁ > Pcm₃,at least two values: T ≥ 21º, M ≥ 18º, Itc ≥ 470. In Eurasia, from 25º to 35º N, height ≥ 2000 m: it is not tropical.

Mediterranean Me

Subtropical Warm Zone (23º to 35º N & S) and Eutemperate Temperate Zone (35º to 52º N & S), with summer aridity at least bimonthly after the summer solstice: Ios₂ ≤ 2, Iosc₄ ≤ 2. In the Subtropical, at least two of the three thermal values: T < 25º, m < 10º, Itc < 580.

Temperate Te

Subtropical Warm Zone (23º to 35º N & S) and Temperate Zone (35º to 66º N & 35º a 54º S). Without summer aridity: Ios₂>2, Iosc₄>2. At <200 m, Tp≥380. Besides: a), from 23º to 35º N & S, at <200 m, at least two values: T<21º, M<18º, Itc<470; or b), against Boreal, at <200 m: if Ic≤11: T>6º, Tmax>10º and Tps>320; if 11<Ic≤21: Tp>720 and T>5.3º; if 21<Ic≤28: Tp>740 and T>4.8º; if 28<Ic≤46: Tp>800 and T>3.8º; and if 46<Ic: Tp>800 and T>0º.

Boreal Bo

Temperate and Cold Zones (42º to 72º N, 49º to 56º S). Without summer aridity: Ios₂>2, Iosc₄>2. At <200 m, Tp≥380. If Ic≤11: T≤6º, Tmax≤10º, 380≤Tp≤720 and Tps≤320; if 11<Ic≤21: 380≤Tp≤720 and T≤5.3º; if 21<Ic≤28: 380≤Tp≤740 and T≤4.8º; if 28<Ic≤46: 380≤Tp≤800 and T≤3,8; and if 46<Ic: 380≤Tp£800 and T≤0º.

Polar Po

Temperate and Cold Zones (51º a 90º N & S).

Altitude < 100m: Tp < 380.

(Rivas-Mart. et al., 2011)

(Modified M.L. López y M.S. López, 26 Dec. 2016)

(1) Between 23º - 48º N and 23º - 51º S, if the locality is 200 m, or more, of altitude, it is necessary to theoretically calculate the thermal values at such a height by increasing T by 0.6 °; M and m, by 0.5º; and Itc by 13 units, for every 100 m that exceeds said altitude. More than 48º N ó 51º S, it is necessary to calculate the theoretical values of the average annual temperature, of the average of the maximums temperature of the coldest month, and of the annual positive temperature, increasing T by 0.4º, M by 0.5º and Tp by 12 units, for every 100 m that exceeds said altitude.

4.1.1.- Tropical Macrobioclimate

The Tropical Macrobioclimate is distributed between latitudes 35º N & S, corresponding to the latitudinal belts equatorial, eutropical and subtropical, this last latitudinal belt, 23º-35º N and S, also occupied by the Mediterranean and Temperate Macrobioclimates. It should be remembered here the reciprocity premise, that in Eurasia, between 25º and 35º N and 70º-120º E, territories at 2,000m, or higher, are not tropical.

The territories with Tropical Macrobioclimate have very low Continentality, since the temperatures remain almost constant throughout the year. However, the ombric rhythms of the 6-months periods, or 4-months periods, are very important here, as well as a high level of certain thermal parameters and indices. (See Figure 4, or also, the Synopsis of the World Bioclimatic Classification, figure 7).

The optimum of vegetation in the Tropical Macrobioclimate is the rainforest, or equatorial forest, which is the terrestrial vegetation with the greatest biodiversity, structural complexity, biomass and productivity, with three or more layers of trees, with abundant woody lianas and numerous epiphytes. However, depending on the amount of precipitation, the structure of tropical potential vegetation corresponds to other types: semi-deciduous forests, open forests, shrub vegetation, semi-deserts, deserts, or hyper-deserts. In addition, the phytochenosis ruled by the Tropical Macrobioclimate have a very original flora and vegetation, rich and diverse, and, therefore, radically different from those of the territories with Mediterranean or Temperate Macrobioclimates, with precipitations of similar quantity.

The Tropical Macrobioclimate is present in all the continents, except in Antarctica.

4.1.2.- Mediterranean Macrobioclimate

The Mediterranean Macrobioclimate is distributed between the 23º-52º N & S, latitudes in which it coincides with the Tropical (23º-35º N & S), Temperate (23º-52º N & S) and Boreal (42º-52º N and 49º -52 S) Macrobioclimates. It should be remembered here the reciprocity premise, that in Eurasia, between 25º and 35º N and 70º-120º E, territories at 2,000m, or higher, are either Mediterranean or Temperate (not tropical).

Territories with a Mediterranean Macrobioclimate have a non-compensable summer aridity (see Chapter 9), ie, Ios2 2, with Iosc3 2, or Iosc4 2, in addition to a lower level than the Tropical in certain thermal Parameters and Indices. (See Figure 4, or also, the Synopsis of the World Bioclimatic Classification, figure 7).

The optimum of vegetation in the Mediterranean Macrobioclimate are the durisilva, sclerophyll forests of modest size, low biodiversity and productivity, with few lianas and almost no epiphytes. However, depending on the amount of rainfall, the structure of Mediterranean potential vegetation corresponds to very different types: further to durisilva, there are closed deciduous forests, conifer forests, shrub vegetation, semi-deserts, deserts or hyper-deserts. In addition, phytochenosis of the Macrobioclimate Mediterranean, have a very original flora and vegetation, rich and diverse, and, therefore, radically different from those of the territories with Tropical, Temperate, or Boreal Macrobioclimates, with precipitations of similar amount.

The Mediterranean Macrobioclimate has its greatest territorial representation in the center and in the western part of all continents, and does not exist in Antarctica.

4.1.3. Temperate Macrobioclimate

Temperate Macrobioclimate is distributed between latitudes 23º to 66º N and 23º to 54º S, latitudes in which it coincides, in whole or in part, with the Tropical, Mediterranean and Boreal Macrobioclimates. The lack of summer aridity, by itself, distinguishes the Temperate Macrobioclimate of the Mediterranean Macrobioclimate, but, to distinguish it from the Tropical and the Boreal, it is necessary to specify well its thermal thresholds:

a) Summer aridity: The Temperate Macrobioclimate, at any altitude and value of Continentallity, lacks summer aridity: that is, the two consecutive warmer months of the summer trimester (or warmer period of the year) have Ios2>2; or, if there were two arid months, with: Ios2 2, this aridity is compensated by the rains of the previous month, or of the previous two months: losc3>2, or losc4>2. (See Figure 4, or also the Synopsis of the World Bioclimatic Classification, figure 7).

b) Thermal thresholds of Temperate Macrobioclimate in front of Tropical Macrobioclimate. Between 23º to 35º N & S, theoretically calculated at 200 m altitude, two of the three thermal values mentioned must meet the following conditions: T<2lº, M<l8º, ltc<470.

c) Thermal thresholds of Temperate Macrobioclimate versus Boreal Macrobioclimate. Between 43º to 66º N and 49º to 54º S, values theoretically calculated at an altitude of 200 m, or those at lower altitudes, must be greater than the threshold values that limit Temperate and Boreal Macrobioclimates. Those thresholds, which depend on the Continentality Index values, can be seen in figure 4, or also in the Synopsis of the World Bioclimatic Classification, figure 7.

The optimum of vegetation in the Temperate Macrobioclimate are the evergreen laurisilva rich in arborescent ferns, as well as the deciduous aestisilva; in the cold extremes of the Temperate Macrobioclimate are characteristic the aciculisilvas; and, finally, in the xeric extremes of the Temperate Macrobioclimate, the deciduous woodland becomes discontinuous and easily transformed into extensive pastures, or steppes, under the pressure of grazing and of fires.

The Temperate Macrobioclimate is represented on all continents, except in Antarctica.

4.1.4.- Boreal Macrobioclimate

The Boreal Macrobioclimate extends from latitudes 42º to 72º N and from 49º to 56º S, latitudes in which it coincides, to a greater or lesser extent, with the Mediterranean, Temperate and Polar Macrobioclimates. The following characteristics allow to define the Boreal Macrobioclimate and to differentiate it from the other three: the lack of summer aridity, by itself, distinguishes between Macrobioclimates Boreal and Mediterranean; the lower thermal threshold separates it from the Polar Macrobioclimate; but in order to distinguish it from the Temperate Macrobioclimate, its thermal thresholds must be well defined in dependance with Continentality.

a). - Lack of summer aridity. In the Boreal Macrobioclimate, at any altitude and value of Continentality, there are no two consecutive arid months during the summer or warmer period of the year; that is, Ios2>2; or, if there were two arid months, Ios2 2, these are compensated with Iosc3>2, or Iosc4>2. (See Chapter 9).

b). - Thermal thresholds of Boreal Macrobioclimate versus Temperate Macrobioclimate. Between latitudes 42º to 72º N and 49º to 56º S, thermo-climatic values theoretically calculated at an altitude of 200 m, or those at lower altitudes, must be lower than the threshold values between the Boreal and Temperate Macrobioclimates. Those thresholds, which depend on the Continentality Index values, can be seen in figure 4, or also in the Synopsis of the World Bioclimatic Classification, figure 7.

c). - Lower thermal threshold compared to Polar Macrobioclimate. The Boreal Macrobioclimate has a lower thermal threshold, calculated to less than 200 m, of Tp380. This threshold distinguishes it from the Polar Macrobioclimate.

The optimum of vegetation in the Macrobioclimate Boreal are acciculisilvas, conifer or taiga forests, with low understory but, at the thermal limits of the Macrobioclimate, the Tundra of nanofanerófitos, nanocaméfitos and hemicryptophytes appear.

The Boreal Macrobioclimate is represented in the continents of Eurasia, North America and South America, but is lacking in Africa, Australia and Antarctica.

4.1.5.- Polar Macrobioclimate

It is considered that all territories between the parallels 51º to 90º N & S, with a Positive Annual Temperature, theoretically calculated at 200 m altitude, lower than 380 (Tp <380), have a Polar Macrobioclimate. (See Figure 4, or also, the Synopsis of the World Bioclimatic Classification, figure 7).

The optimum of vegetation in the Macrobioclimate Polar are the nanofanerophytes and nanocamephytes tundras, and the graminoids lawns with more or less mosses and lichens, all of them communities of little productivity and slow growth.

The Polar Macrobioclimate is the only Macrobioclimate present in Antarctica and is also represented in the continents of Eurasia and North America, but it does not exist in Africa, South America or Australia.

4.1.6.- Macrobioclimates Continental Distribution

We show, in Figure 5, the continental distribution of Macrobioclimates.

Figure 5. Continental distribution of the Macrobioclimates

Continents / Macrobioclimates	North America	South America	Eurasia	Africa	Australia-Polynesia	Antarctica	Total, by Continents
Tropical	+	+	+	+	+	---	5
Mediterranean	+	+	+	+	+	---	5
Temperate	+	+	+	+	+	---	5
Boreal	+	+	+	---	+	---	4
Polar	+	+ (Insular)	+	---	---	+	4
Total Macrobioclimates	5	5	5	3	4	1

4.2.- Second hierarchical level of the Classification: Bioclimates / Variants

Bioclimates constitute the second rank of the Rivas-Mart. (2008) and Rivas-Mart. & al. (2011) hierarchical Bioclimatic Classification.In the wide territories of each Macrobioclimate, life detects climate scenarios related to certain thresholds lo and lc, mainly, but also, in certain cases, with the precipitation rhythms (in the Tropical Macrobioclimate), or with the Tp (in Polar Macrobioclimate): those sets of climatic-environmental scenarios, indicated by changes vegetation, and subordinated to the Macrobioclimas, are the Bioclimates. 28 Bioclimates are recognized, distributed in the five Macrobioclimates. (See Synoptic Table, second column, figure 7). Each Bioclimate possesses vegetal formations, biomas, biocenosis and vegetal communities, of its own.

Regarding the Variants, in all the Bioclimates, certain peculiarities and variations of the seasonal rhythms of precipitation and / or temperature, tolerable within their defining intervals, allow to recognize the Bioclimatic Variants. Globally, nine Bioclimatic Variants are recognized.

Coming up next we will comment in detail: in 4.2.1, the distinguishable Bioclimates within each Macrobioclimate; and in 4.2.2, the recognized Bioclimatic Variants, their peculiarities, and the Bioclimates to which they affect:

4.2.- Second hierarchical level of the Classification: Bioclimates / Variants

4.2.1. Bioclimates

4.2.1.a) Tropical Bioclimates

4.2.1.b) Mediterranean Bioclimates

4.2.1.c) Temperate Bioclimates

4.2.1.d) Boreal Bioclimates

4.2.1.e) Polar Bioclimates

4.2.2.- Bioclimatic Variants

4.2.2.a) Pluviserotin Variant (Pse).

4.2.2.b) Antitropical Variant (Ant).

4.2.2.c) Bixeric Variant (Bix).

4.2.2.d) Tropical Drought Variants (Str).

4.2.2.e) Semitropical Hyperdesertic Variant (Strhd).

4.2.2.f) Steppic Variant (Stp).

4.2.2.g) Submediterranean Variant (Sbm).

4.2.2.h) Polar Semiboreal Variant (Pose).

4.2.2.i) Normal Variant (Nor).

4.2.1. Bioclimates

In the Tropical Macrobioclimate, which maintains a very constant temperature throughout the year, the amount and the seasonal rhythm of the precipitations are the criteria that delimit its Bioclimates. In the rest of the Macrobioclimates there are already seasonal variations, both rainfall and temperature, throughout the year, so that, in addition to the humidity comfort - Ombrothermal Index, lo-, also the annual thermal amplitude - Continentality Index, lc -, differentiate bioclimatic ambits. However, in the Mediterranean Macrobioclimate, with summer aridity, in which by definition water acts as a limiting factor of life, especially during summer, the vegetation perceives up to four levels of Io and two levels of Ic. As for Temperate, Boreal and Polar Macrobioclimates, without summer aridity, the most discriminating factor for life is the annual thermal amplitude -lc-, followed in importance by the humidity comfort -lo-: the vegetation itself marks three levels of Ic in the Temperate and Polar Macrobioclimates, and five levels in the Boreal Macrobioclimate; while, with respect to lo, the vegetation only distinguishes two levels in all the three Macrobioclimates.

4.2.1.a) Tropical Bioclimates

Within the vast territories occupied by the Tropical Macrobioclimate, five Bioclimas are recognized, which correspond with the five large caesuras, related to both the annual Ombrothermal Index, Io, and the rainfall regime, Iod2. (See figure 7, Synopsis of the Worldwide Bioclimatic Classification).

Thus, the tropical bioclimatic space distinguishes three thresholds of Io, delimiting four intervals, in the wettest of which, the rainfall regime, Iod2, separates, in turn, two other intervals: in total, five Bioclimates The threethreshold values of Io are: 3.6, 1.0 and 0.2, and the threshold value of Iod2 is 2.5. The five Tropical Bioclimates are thus defined: Tropical Pluvial, with Io ≥3,6 and Iod2> 2,5; Tropical Pluviseasonal, with Io ≥3,6 and Iod2≤2,5; Tropical Xeric, with 1.0lo<3,6; Tropical Desertic, with 0,2lo<1,0; and Tropical Hyperdesertic, with Io <0.2.

The optimum of vegetation in each of the Tropical Bioclimates are the following formations: in the Tropical Pluvial, the rainforests; In the Tropical Pluviseasonal, the hiemisilva; in the Tropical Xeric, the open hyemifruticeta in mixture with the terriherbosa; in the Tropical Desertic, the sicidesertas; and in the Tropical Hyperdesertic, the absence of rooted vascular plants, since they are regions without vascular plants.

4.2.1.b) Mediterranean Bioclimates

In the territories of Mediterranean Macrobioclimate, located in the center and in the western façades of the continents, eight Mediterranean Bioclimates are recognized, which correspond to as many changes in vegetation, and which are related to the combination of four levels of humidity comfort -lo-, with two levels of Continentality -lc-. (See figure 7, Synopsis of the Worldwide Bioclimatic Classification).

And so, in the Mediterranean Macrobioclimate, life distinguishes three thresholds of Io, delimiting the following four intervals of humidity comfort: with 2.0lo, two Mediterranean Pluviseasonal Bioclimates; with 1.0lo < 2, two Mediterranean Xeric Bioclimates; with 0.2lo < 1.0, two Mediterranean Desertic Bioclimates; and with lo<0.2, two Mediterranean Hyperdesertic Bioclimates. At each of those four intervals, two levels of Continentality can be recognized: with lc21, four Mediterranean Oceanic Bioclimates; with lc>21, four Mediterranean Continental Bioclimates. The eight Mediterranean Bioclimates are thus characterized: Mediterranean Pluviestacional Oceanic, Me. Pluviestacional Continental, Me. Xeric Oceanic, Me. Xeric Continental, Me. Desert Oceanic, Me. Desert Continental, Me. Hyperdesertic Oceanic and Me. Hyperdesertic Continental.

The optimum of vegetation in each of the Mediterranean Bioclimates are the following formations: in the Pluviestational Mediterranean Bioclimates, the optimum of vegetation are sclerophyllous forests and, to a lesser extent, laurifolia semipervirent forests, deciduous forests and needle-leaves forests; in the Xeric Mediterranean Bioclimates, the optimum of vegetation are closed microforests and shrubs; in the Mediterranean Desertic Bioclimates, the optimum of vegetation are semi-deserts, open shrubs and scatered thickets; and in the Hyperdesertic Mediterranean Bioclimates, the characteristic feature is the absence of climatophile woody vegetation.

4.2.1.c) Temperate Bioclimates

In Temperate Macrobioclimate life distinguishes two intervals of humidity comfort: thus, with lo3.6, Xeric Temperate Bioclimate, and with lo>3.6, three Bioclimates, distinguishable by two Continentality thresholds, 11 and 21: with lc11, Hypercoceanic Temperate Bioclimate; with 11<lc21, Oceanic Temperate Bioclimate; and with Ic>21, Continental Temperate Bioclimate. In this way, four Bioclimas have been recognized within the Temperate Macrobioclimate. (See figure 7, Synopsis of the Worldwide Bioclimatic Classification).

The optimum of vegetation in each of the Temperate Bioclimates are: in the Hyperoceanic Temperate Bioclimate, the optimum of vegetation are the lauroid forests; in the Oceanic Temperate and Continental Temperate Bioclimates, the optimum of vegetation are the winter deciduous forests, as well as, in the mountains, conifer forests; and in the Xeric Temperate Bioclimate the optimum of vegetation are the laurifruticeta and the aestifruticeta.

4.2.1.d) Boreal Bioclimates

In the Boreal Macrobioclimate territories, six Bioclimates are recognized, characterized by their levels of Continentality, in combination with the Ombrothermal Index. In this Macrobioclimate, life has great sensitivity to Continentality, recognizing four thresholds that delimit five intervals: lc11, 11<lc21, 21<lc28, 28<lc46, 46<lc. With respect to Io, only two intervals, separated by a threshold, are recognized: : lo>3.6, or lo3.6 (See figure 7, Synopsis of the Worldwide Bioclimatic Classification).

So, when Continentality is extremely high, lc>46, the Bioclimate is Boreal Hypercontinental, regardless of the Ombrothermal Index of the place. However, with Continentality Index below 46, Ic46, if the Ombrothermic Index is less than, or equal to, 3.6 -lo 3.6-, the Bioclimate is Boreal Xeric; But if the Ombrothermic Index is greater than 3.6 -lo>3.6-, the Bioclimate goes in function of the lc, as follows: with lc11, Boreal Hiperoceanic Bioclimate; with Ic between 11 y 21 -11<lc2l-, Boreal Oceánico Bioclimate; with Ic between 21 y 28 -2l<lc 28-, Boreal Subcontinental Bioclimate; and if Ic between 28 y 46 -28<lc46-, Boreal Continental Bioclimate.

The optimum vegetation in the Boreal Bioclimates are coniferous forests, and shrub and Ericaceae tundra.

4.2.1.e) Polar Bioclimates

In the territories with Polar Macrobioclimate, due to the intrinsic difficulties that represent the low temperatures, life distinguishes: in addition to a threshold and two ranges of Positive Temperature -Tp =0, or Tp>0-, two thresholds and three intervals of Continentality, -Ic : 11 y 21-, as well as one threshold and two intervals of Io, -3,6-, thus defining, in total, five Bioclimates: Polar Hyperoceanic, Polar Oceanic, Polar Continental, Polar Xeric and Polar Pergelid (See figure 7, Synopsis of the Worldwide Bioclimatic Classification).

The optimum vegetation in the Boreal Bioclimates are coniferous forests, and shrub and Ericaceae tundra.

4.2.2.- Bioclimatic Variants

The amplitude of the intervals defining each Bioclimate, allows certain variations in the rhythms of humidity and/or temperature (such as advance / delay of rains, or of high / low temperatures). The vegetation reflects these variations, which are bioclimatically expressed by the Variants.

In the set of five Macrobioclimates, nine Bioclimatic Variants have been recognized (See Figure 6). (It should be noted that the Variant of Tropical Drought includes, in fact, seven Variants):

Pluviserotin (late-summer rains), Antitropical, Bixeric (two droughts), Tropical Drought, Semitropical Hyperdesertic, Steppic, Submediterranean, Polar Semiboreal, and Normal.

4.2.2.a) Pluviserotin Variant (Pse). Tropical Bioclimatic Variant in which the precipitation of the first two months of the summer solstice (June-July, in latitudes N, and December-January, in latitudes S) is less than 1.3 times that corresponding to the two months that follow (August-September in latitudes N, and February-March, in latitudes S): Psb1<l.3Psb2. This Variante does not take place in either the Tropical Pluvial Bioclimate or the Tropical Hyperdesertic Bioclimate.

This Bioclimatic Variant is due to the monsoon activity that, in Africa, Indostan and North America, delays the summer rains until the autumn. Its plant communities have the same structure as the normal tropical ones with equivalent Ombrotype, although their floristic element differs, due to the phenological isolation.

4.2.2.b) Antitropical Variant (Ant). Tropical Bioclimatic Variant, practically restricted to the equatorial waist and adjacent territories, where rainfall corresponding to the winter solstice trimester (December, January and February, in latitude N, and June, July and August, in latitude S) are higher than those of the summer trimester (June, July and August, in latitude N, and December, January and February, in latitude S): PTr1>PTr3. This Variant does not take place in either the Tropical Pluvial Bioclimate or the Tropical Hyperdesertic Bioclimate.

The Antitropical plant formations are very similar, in their structure, to those of the Tropical Pluviserotin Variant and of the Normal Variant, with equivalent Ombrotype, although their floristic element has a high number of endemisms, obviously caused by a phenological period practically antithetical, which has favored their isolation and, therefore, their speciation

4.2.2.c) Bixeric Variant (Bix). Tropical Bioclimatic Variant, in which there are two annual periods of aridity, with at least one month of P2T, in both solstices, separated by two more rainy periods in both equinoxes, in which at least one month is P>2T. This Variant does not take place in either the Tropical Pluvial Bioclimate or the Tropical Hyperdesertic Bioclimate.

The Bixeric Tropical plant formations have structural, and sometimes phylogenetic, relationships with those Mediterranean pluviestational, xeric and desertic.

Figure 6. Distribution of the Bioclimatic Variants in the Macrobioclimates of the Earth. Tr = Tropical, Me = Mediterranean; Te = Temperate; Bo = Boreal; And Po = Polar. (According to Rivas-Mart et al., 2011, modified by the authors).

Bioclimatic Variants	("drought" levels)	Tr	Me	Te	Bo	Po
Pluviserotin (Pse)		•
Antitropical (Ant)		•
Bixeric (Bix)		•
Tropical Drought (Str), (7 Humidity-Variants of)	Pluvial Hygrophytic	•
	Pluvial Subhigrophytic	•
	Pluvial Submesophytic	•
	Pluviseasonal Mesophytic	•
	Pluviseasonal Submesophytic	•
	Pluviseasonal Subxerophytic	•
	Pluviseasonal Xerophytic	•
Semitropical Hyperdesertic (Strhd)			•
Steppic (Stp)			•	•	•	•
Submediterranean (Sbm)				•	•	•
Polar Semiboreal (Pose)					•
Normal (Nor)		•	•	•	•	•

4.2.2.d) Tropical Drought Variants (Str). Bioclimatic Variants that operate in the Tropical Pluvial and Tropical Pluviestational Bioclimes, when the monthly Io, in one or several months, is lower than 2.5, circumstance that gives rise to a period, more or less prolonged and / or more or less intense, of relative drought. Three Variants ("drought" levels) are recognized in the Tropical Pluvial Bioclimate, and four other Variants in the Pluviseasonal Tropical Bioclimate. (Figure 6). (For more information, see Rivas-Mart et al., 2011, pp. 15).

4.2.2.e) Semitropical Hyperdesertic Variant (Strhd). In the subtropical latitudinal zone (23º-35º N & S), a territory of Mediterranean Macrobioclimate and Ombrotype from Hyperarid to Ultrahyperarid (Io = 0.0 - 0.4) should be considered as a Hyperdesertic Semitropical Variant, when the trimester precipitation corresponding to the solstice of Summer (Tr3) is only 0.7 times lower than the winter solstice trimester (Tr1) precipitation: PTr3 <0.7 PTr1. This occurs in the hottest deserts of California, in North America, in the deserts of Antofagasta or Atacama in South America, and in the deserts of the oceanic Sahara and Namibia in Africa. (For more information, see Rivas-Mart et al., 2011, pp. 15).

4.2.2.f) Steppic Variant (Stp). Steppicity is a bioclimatic characteristic that, in the extratropical Macrobioclimates (Mediterranean, Temperate, Boreal and Polar), indicates the existence of two breakes off (or pauses) in the vital activity during both solstices, in summer (June, July and August, in latitudes N, And December, January and February, in latitudes S) and in winter (December, January and February, in latitudes N, and June, July and August, in latitudes S), due to drought and/or cold.The steppic character only appears in Bioclimates with tendencies to drought and to Continentality, and is emphasized by the appearance of xerophytic types of vegetation, due to the water limitation and / or the low temperatures, existing in both solstices.

For the Steppic Variant to appear, the Bioclimate must have a lc at least of Semicontinentality, lc> l7, and a Io low, between the Lower Hyperarid and the Upper Sub-humid, 6.0≥lo>0.2. The brakes on vegetative activity, characteristic of the Steppic Variant, imply the following: a), The braking of the steppic summer requires at least one month of summer whith the precipitation, in mm, less than three times its temperature, in degrees centigrade: Psi < 3Tsi; b), The braking of the steppic winter is recognized because the positive precipitation of the summer trimester is higher to the positive precipitation of the winter trimester: Pps>Ppw.

The steppic character is highlighted in very diverse continental or semicontinental plant formations, due to the appearance of types of xerophytic vegetation, as well as for the fragility of the forests, due to the water limitation existing in both solstices. The most characteristic steppic plant formations of the Earth, corresponding to this Bioclimatic Variant, are: the micro-forests, shrubland and Mediterranean xeric steppe grasslands of the Northern Hemisphere; the steppes and temperate steppic forests of Eurasia; the broad grasslands, wooded or not, of North America; and also the taiga and tundra steppic formations, boreal and polar, restricted to areas of low summer precipitation, in Asia and North America.

4.2.2.g) Submediterranean Variant (Sbm). Bioclimatic variant frequent in Temperate Macrobioclimate, and scarce in Boreal and Polar Macrobioclimates, in which, at least during one summer month (June, July or August, in latitudes N, and December, January or February, in latitudes S), the precipitation in millimeters is less than two and eight tenths the average temperature in degrees centigrade of that same period: Iosi <2.8, or Psi<2.8Tsi

The most characteristic submediterranean temperate plant formations are those of transition or ecotone between Temperate Bioclimates, lacking summer aridity, and the genuinely Mediterranean, where the summer drought lasts for at least two months. In the Hollartic Kingdom, the most representative plant formations are usually those formed, in the mature stage, by sclerophyllous or deciduous forests, as well as certain types of xerophytic coniferous forests and xerophytic tundra.

4.2.2.h) Polar Semiboreal Variant (Pose). A Boreal Macrobioclimate territory, with Ic28 -Bioclimates Boreal Hyper-oceanic, Boreal Oceanic and Boreal Subcontinental-, and Termotype Oroboreal, Tp between 380-480, should be considered as a Polar Semiboreal variant, if it is a mountain completely surrounded by forest at its base and, in addition, the Tmax11º (average monthly temperature of the warmest month of the year) and Tps320 (positive temperature of the summer trimester, in tenths of degree), since the natural potential vegetation in these bioclimatic conditions are deforested tundras, instead of micro-forests: that is the case in North America - on the western shores and reliefs of the Alaska Peninsula towards the Bering Strait, or on the Aleutian Peninsula and Islands -, and in other artoboreal and antiboreal territories of the Earth. (For more information, see Rivas-Mart et al., 2011, pp. 15).

4.2.2.i) Normal Variant (Nor). In this hierarchical level "Bioclimate / Variant", the portion of a Bioclima that does not present any of the thermal or ombric peculiarities of any of the other eight variants described above, is considered to have Normal Variant. It is essential to name as Normal Variant the rest of the Bioclima not included in any of the other eight Variants, because using the name of the Bioclima for both the Bioclima and for what remains after assigning Variant to some parts of it, would be a cause of confusion, especially when making Bioclimatic Maps (because we would be giving the same name to two different hierarchical levels). So the Normal Variant occurs in all of the Bioclimates, alone or accompanied by one or more of the other Variants, except in the Tropical Pluvial and Tropical Pluviseasonal. (See Figure 6).

4.3.- Third hierarchical level of the Classification: Bioclimatic Belts -Thermotypes and Ombrotypes-

Bioclimatic Belts are each one of the environments that follow each other in a latitudinal, longitudinal or altitudinal cliserie. Each Bioclimatic Belt is defined by a thermal interval together with a humidity comfort interval: that is, by a Thermotype and a Ombrotype. Each Bioclimatic Belt corresponds to certain formations and plant communities: a vegetation belt. The phenomenon of plant zoning has universal jurisdiction. The Thermotypic threshold values (Itc, Tp) differ somewhat from one Macrobioclimate to another (see figure 7, Bioclimatic Belts, column 3), but Ombroclimatic threshold values (Io) are the same in all Macrobioclimates (see figure 7: Bioclimatic Belts, column 4).

Sometimes it is convenient to distinguish, within the Bioclimatic Belts, the lower and upper halves of their thermal and ombric intervals: thus appear the subordinate units of Bioclimatic belts, the so-called Bioclimatic Horizons, Termotypic and Ombrotypic. Bioclimatic Horizons are named by adding the word "lower" or "upper" to the corresponding name of the Thermotype or the Ombrotype: Upper Termomediterranean Horizon; Lower Subhumid Horizon.

Expressing the Thermotypes and the Ombrotypes as Belts, or as Horizons, depends on the territorial scale to which we work.

Explanatory note:

It is important to remark a peculiarity in the names of the Termotypic Horizons: the upper / lower adjectives refer to the actual values of thermal comfort (Thermotypes), precisely to the hotter half, or cooler half, of the thermal belt. But it is necessary to take into account that, in Nature, the upper thermal Horizon, hotter, is found, paradoxically, at the lower height. So, in nature, and contrary to what their names indicate, the higher, hotter Horizon is situated at a lower altitude than the lower, colder Horizon, which stands higher.

4.3.1.- Thermotypes. These are thermal categories of the climate, which take into account certain intervals of Itc and / or Tp, and that occurring in latitudinal, longitudinal or altitudinal sequence -thermobelts - in each of the Macrobioclimates of the Earth. Generally speaking, seven thermobelts are recognized: Infra-, Thermo-, Meso-, Supra-, Oro-, Crioro- and Gelid-, although not all seven are recognized in each Macrobioclimate. Besides, as thermo-threshold values vary slightly from one Macrobioclimate to another, the Thermotypes of each Macrobioclimate need to be named by adding, to the general word that indicates the belt, the name of the Macrobioclimate itself: Termotropical, Suprapolar, etc. Thus, the Thermotypes recognized in the Bioclimatic Classification of the Earth amount to 31. In the fourth and fifth column -Thermotypes- of the table "Bioclimatic Synopsis of the Earth" (Figure 7), the names of all the Thermotypes in each Macrobioclimate, and the intervals of Itc and Tp that delimit them in each Macrobioclimate, are indicated, as well as the acronyms that designate them. At any altitude, or latitude, when the Thermicity Compensated Index (Itc) is lower than 120, or when the Continentality Index (Ic) is equal to or higher than 21, to recognize the Thermotype, the value of the Annual Positive Temperature (Tp) is used.

To express the Upper and Lower Horizons of each Thermotype, the upper / lower words are added to the Thermotype name, or the letters "s" or "i", to the corresponding acronym. Thus, for example: Upper Mesomediterranean Horizon - Mmes; Lower Mesomediterranean Horizon - Mmei. (Thermo-Horizons are not recognized in the Gelid Thermotypes or the Infratemperate Thermotype).

4.3.2.- Ombrotypes. They are climate categories, which express the level of humidity comfort, or discomfort, through intervals of the Annual Ombrothermal Index, lo. The Ombrotyps follow each other in the latitudinal, longitudinal or altitudinal sequence - ombro-belts - in each of the Macrobioclimates of the Earth. Given the high predictive value and the high correlation that the annual ombrothermal values show with the climatophilic potential vegetation structures in the whole Earth, Rivas-Martínez & al. (2011) have used humidity confort intervals to establish their Омбрotypes.

The Ombrotypes recognized in the Bioclimatic Classification of the Earth are the following nine: Ultrahyperarid, Hyperarid, Arid, Semi-arid, Dry, Sub-humid, Humid, Hyper-humid and Ultrahyper-humid. The threshold values that diagnose the Ombrotypes are always the same in all Macrobioclimates and their intervals, as well as the abbreviations abbreviations that designate them, are shown in the fourth column - Ombrotypes- of the table "Bioclimatic Synopsis of the Earth" (see figure 7).

To express the Upper and Lower Horizons of each Ombrotype, the upper / lower / lower word is added to the Ombrotype name, or the letters "s" or "i", to the corresponding acronym. Thus, for example: Upper Dry Horizon – Drys/Secs; Lower Dry Horizon - Dryi/Seci.

5.- BIOCLIMATIC SYNOPSIS OF THE EARTH

It is a table, compacted into a page, that summarizes the whole of the Bioclimatic world hierarchical Classification, with an indication of the characters and thresholds that distinguish each one of its three levels: Macrobioclimates, Bioclimates / Variants (these only mentioned), and Bioclimatic Belts. (See Figure 7).

Figure 7: Bioclimatic Synopsis of the Earth. (Link to its quality file).

6.- ISOBIOCLIMATE

An Isobioclimate is a unique bioclimatic space, defined by a Bioclimate / Variant, together with a Bioclimatic Belt - Thermotype + Ombrotype-. Each Isobioclimate is an elemental bioclimatic unit, as perceived and distinguished by living beings. We can consider each Isobioclimate as a natural culture chamber, a Phytotron, whose "walls" are the lower and upper thresholds that define each one of its components: Macrobioclimate, Bioclimate / Variant and Bioclimatic Belt-Thermotype and Ombrotype-. Considering fixed other environmental variables - such as mother rock, soil, geological history, evolutionary history of living beings, etc. - each Isobioclimate harbors, in a climax position, a single vegetation series.

Isobioclimates are useful for identifying bioclimatically analogous territories on any of the five Continents, as well as for recognizing equivalent types of vegetation. The representation on the map of the areas occupied by each Isobioclima allows very precise bioclimatic maps to be obtained. (See figure 116, Isobioclimatic Map of Peninsular Spain).

To name each Isobioclimate is used a phrase that includes: Bioclimate / Bioclimatic Variant, together with a Bioclimatic Belt - Thermotype + Ombrotype-. Thus, for example: Mepo Nor Tme Dry is the Isobioclimate "Mediterranean Pluviseasonal Oceanic, Normal Variant, Thermomediterranean, Dry", which is found, for example, in much of Andalusia, Spain; or Boxe Stp Tbo Dry is the Isobioclimate "Boreal Xeric Steppic, Termoboreal, Dry", which operates, for example, in Petropavlovsk, Kazakhstan.

7.- BIOCLIMOGRAMS

Bioclimograms, also called Bioclimographs, or Ombro-Termoclimograms, are the graphical representation of Isobioclimates. Bioclimograms used by Rivas-Martínez (2008) and Rivas-Martínez & al. (2011), are based on those of Gaussen & Bagnouls (1952) and also on those of Walter & Lieth (1967). These graphs, very expressive, represent, in a Cartesian coordinate system with two ordinates and one abscissa, the temperature and rainfall data of a meteorological station, throughout the year. In the left ordinate, the temperature is represented, and in the right ordinate, the rainfall: their scales are adjusted to the ratio 2T (ºC) = P (mm). On the abscissa, the months of the year are represented: in the first place appears the month following the winter solstice: January in the Northern Hemisphere, and July in the Southern Hemisphere.

The graph of Figure 8 is accompanied by a data panel, which includes:

name of the station (1); its altitude in meters (2); its latitude, longitude, and the number of years of meteorological observations (3); P (4), T (5), m (6), Ic (7), M (8), Tp (9), Itc (10), Tn (11), Io (12); trimesterly precipitation in decreasing order (13): Pn=spring, S=summer, F=automn, and W=winter; M '(14); m' (15); temperature scale (16); precipitation scale (17).

Figure 8.- Structure of the Bioclimogram (Rivas-Mart, 2008, Rivas-Mart et al., 2011, somewhat modified by the authors). (Explanation of numbers, in the text).

In order to accommodate, in a single type of Bioclimograma, all the variations of Ti and Pi occurring in the world, the temperature scale (16) starts at zero on the dotted line and advances five degrees by five degrees above zero; with respect to negative temperatures, the scale is modified and each interval represents the following temperatures: -10, -20 y – 60ºC. As for the precipitations (17), each segment represents 10mm of rainfall until reaching 90mm, because, from this rainfall, the values are doubled for each interval: 180, 360 y 720mm of Pi (18). The surface of the rainfall curve, that exceeds the 90 mm line, is colored in blue (18) (in this diagram we have put it in yellow), to indicate the change of scale. When the temperature curve exceeds that of the precipitation, the area enclosed between the two curves, drought expression (19), is colored red (in this scheme we have put it in blue); But, if the rainfall curve exceeds that of the temperature, that surface is striped, to indicate period with available humidity (20). Monthly frost periods: sure or probable (21); and absent (22). The period of plant activity, Pav, (23): months with Ti ≥ 3,5 °; NORTH HEMISPHERE: months in the Northern Hemisphere, and HEMISPHERE SUR: months in the Southern Hemisphere: E, January; ...; X, July; ...; (24): at the bottom of the graph, the complete bioclimatic diagnosis, the Isobioclimate, -including Macrobioclimate (named in the Bioclimate), Bioclimate, Bioclimatic Variant and Bioclimatic Belt, expressed as Thermotype and Ombrotype horizons-, is given.

8.- APPROACH to the GLOBAL BIOCLIMATIC DIVERSITY

Global Bioclimatic Diversity can be considered at each of the three hierarchical levels of the World Bioclimatic Classification:

8.1.- At the first hierarchical level, that of the Macrobioclimates, total World Diversity is 5 Macrobioclimates.

8.2.- For the second hierarchical level, that of the Bioclimates/Variants, we have collected, in figure 9, almost the whole totality of the World Diversity at this level, 74 Bioclimate / Variant units, distributed by Bioclimates and by Variants.

As for Macrobioclimates, at this Bioclimate / Variant level, the most diversified is the Tropical Macrobioclimate, with 18 Bioclimate/Variant units, followed by the Boreal Macrobioclimate, with 17. By variants, the best represented are: the Normal Variant, which is present in each Bioclimate, except in Tropical Pluvial and Tropical Pluviseasonal; the Steppic Variant, present in 18 of the Bioclimates; and the Submediterranean Variant, present in 15 Bioclimates.

8.3.- And, in the third hierarchical level, that of the Bioclimatic Belts -Thermotypes and Ombrotypes-,the World Bioclimatic Diversity, at this level of Isobioclimates, is almost 400 Isobioclimates, although only about 300 Isobioclimates have a significant territorial entity worldwide. (Rivas-Mart. & Rivas-Sáenz, 1996-2017; Rivas-Mart. et al., 2011).

Figure 10 lists, for each Macrobioclimate, the number of its Bioclimates, its Variants, its combined units Bioclimate + Variant, and of the Thermotypes and Ombrotypes that operate in it. And, in its last column, appears the approximate number of its Isobioclimates

The world 's largest bioclimatic diversity, at Isobioclimates level, is offered by Temperate Macrobioclimate, with more than 97 Isobioclimates, followed by Tropical Macrobioclimate, with more than 91.

Figure 9.- Almost all the possible combinations of Bioclimate / Variant, in the 28 Bioclimates, of the five Macrobioclimates, distributed by Bioclimates and by Variants.

Bioclimates	Pse	Ant	Bix	Str	Stp	Sbm	Nor	Total	Total
Trpl				Pluvial Hygrophytic				3
				Pluvial Subhigrophytic
				Pluvial Submesophytic
Trps	•	•	•	Pluviseasonal Mesophytic				7
				Pluviseasonal Submesophytic
				Pluviseasonal Subxerophytic
				Pluviseasonal Xerophytic
Trxe	•	•	•				•	4
Trde	•	•					•	3
Trhd							•	1
Total Tropical									18
Mepo					•		•	2
Mepc					•		•	2
Mexo					•		•	2
Mexc					•		•	2
Medo					•		•	2
Medc					•		•	2
Meho							•	1
Mehc							•	1
Total Mediterranean									14
Teho						•	•	2
Teoc					•	•	•	3
Teco					•	•	•	3
Texe					•	•	•	3
Total Temperate									11
Boho						•	•	2
Booc					•	•	•	3
Bosc					•	•	•	3
Boco					•	•	•	3
Bohc					•	•	•	3
Boxe					•	•	•	3
Total Boreal									17
Poho						•	•	2
Pooc					•	•	•	3
Poco					•	•	•	3
Poxe					•	•	•	3
Popg					•	•	•	3
Total Polar									14
TOTAL	3	3	2	7	18	15	26	74	74

Figure 10.- The almost totality of World Bioclimatic Diversity at Isobioclimates level.

Macro-bioclimate	Bio-climates	Operating Variants	Bioclimates + Variants	Operating Thermo-types	Operating Ombro-types	Isobio-climates
Tropical	5	11	18	7	9	Más de 91
Mediterra-nean	8	2	14	7	9	Más de 68
Temperate	4	3	11	7	6	Más de 97
Boreal	6	3	17	6	6	Más de 66
Polar	5	3	14	4	6	Más de 29
Total	28	13 in the world	74	31	9 in the world	Almost 400

8.4.- As illustrative examples of World Bioclimatic Diversity, next we give 59 climatic-bioclimatic examples, from as many meteorological stations, which represent the majority of the existing combinations of Macrobioclimate, Bioclimate and Bioclimatic Variant. Moreover, this information is available in: Worldwide Bioclimatic Classification System, 1996-2017, S. Rivas-Martínez & S. Rivas-Sáenz, Phytosociological Research Center, Spain, http://www.globalbioclimatics.org. In order to facilitate access to those examples, in Figure 11 we give the list of the 59 selected stations, ordered according to the Bioclimatic Synopsis of the Earth (see Figure 7, Chapter 5); and in figure 12, the list of those same selected stations, sorted alphabetically by country. After the figures 11 and 12, appear each of the climatic-bioclimatic examples, ordered by Bioclimate / Variant, figures 13-71.

Figure 11.- List of climate-bioclimatic representative examples of almost every combination of Macrobioclimate and Bioclimate / Bioclimatic Variant, with territorial representation on Earth, in bioclimatic order.

	Bioclimate / Variant	Country	Weather Station
1	Trpl Hygrophytic	Japan	Ishigaki
2	Trpl Subhigrophytic	Suriname	Zanderij
3	Trpl Submesophytic	China	Wucho/Tsang-Wu
4	Trps Mesophytic	Indonesia	Achmad Yani
5	Trps Submesophytic	Bahamas Islands	Nassau Intl
6	Trps Subxerophytic	Madagascar	Tananarive
7	Trps Xerophytic	Mexico	Zapopán
8	Trps Pse	Vietnam	Donghoi
9	Trps Ant	Sri Lanka	Trincomalee
10	Trps Bix	Ivory Coast	Port Bouet
11	Trxe Pse	Chad	Ati
12	Trxe Ant	Saudi Arabia	Khamis Mushait
13	Trxe Bix	Ethiopia	Diredawa
14	Trxe Normal	Botswana	Ghanzi
15	Trde Pse	Peru	Arequipa
16	Trde Ant	Iran	Jask
17	Trde Normal	Pakistan	Karachi
18	Trhd Normal	Namibia	Mowebaai
19	Mepo Stp	Spain	Tudela
20	Mepo Normal	Chile	Hualpencillo
21	Mepc Stp	Ukraine	Bolgrad
22	Mepc Normal	Tajikistan	Dushanbe
23	Mexo Stp	Argentina	Coronel J.J.Gómez
24	Mexo Normal	Libya	Idris
25	Mexc Stp	Kazakhstan	Pavlodar
26	Mexc Normal	Armenia	Jerevan
27	Medo Stp	Australia	Farina
28	Medo Normal	Egypt	Salum
29	Medc Stp	Kazakhstan	Dzhezkazgan
30	Medc Normal	Uzbekistan	Ak-Baytal
31	Meho Normal	Libya	Gialo
32	Mehc Normal	Iran	Yazd
33	Teho Sbm	New Zealand	Wigram
34	Teho Normal	Ireland	Valentia
35	Teoc Stp	China	Matsu
36	Teoc Sbm	Croatia	Rab
37	Teoc Normal	Uruguay	Artigas
38	Teco Stp	Hungary	Pecs
39	Teco Sbm	India	Srinagar
40	Teco Normal	Byelarus	Brest
41	Texe Stp	Mongolia	Altai
42	Texe Sbm	Ukraine	Kharkov
43	Texe Normal	Argentina	Villa Mercedes
44	Boho Normal	Chile	Navarino
45	Booc Normal	Iceland	Husavik
46	Bosc Stp	Sweden	Bjuroklubb
47	Bosc Normal	Finland	Oulu
48	Boco Stp	Russia	Anavgay Kamchatk
49	Boco Normal	Mongolia	Bulgan
50	Bohc Stp	Russia Yakutskaya	Verkhoyansk
51	Bohc Normal	Russia Yakutskaya	Komara
52	Boxe Stp	USA Alaska	Fort Yukon
53	Poho Normal	Norway	Jan Mayen
54	Pooc Normal	Greenland -DNK-	Ivigtut
55	Poco Stp	Canada	Cambridge Bay
56	Poco Normal	Russia	Yamsk
57	Poxe Stp	Russia Yakutia	Sredne-Kolymsk
58	Poxe Normal	Greenland-Dnk	Umanak
59	Popg Normal	Antarctica	Mcmurdo Station

Figure 12.- List of climate-bioclimatic representative examples of almost every combination of Macrobioclimate and Bioclimate / Bioclimatic Variant, with territorial representation on Earth, in alphabetical order of countries.

	Country	Weather Station	Bioclimate/ Variant
59	Antarctica	Mcmurdo Station	Popg Normal
23	Argentina	Coronel J.J. Gómez	Mexo Stp
43	Argentina	Villa Mercedes	Texe Normal
26	Armenia	Jerevan	Mexc Normal
27	Australia	Farina	Medo Stp
5	Bahamas Islands	Nassau Intl	Trps Submesophytic
14	Botswana	Ghanzi	Trxe Normal
40	Byelarus	Brest	Teco Normal
55	Canada	Cambridge Bay	Poco Stp
11	Chad	Ati	Trxe Pse
20	Chile	Hualpencillo	Mepo Normal
44	Chile	Navarino	Boho Normal
3	China	Wucho/Tsang-Wu	Trpl Submesophytic
35	China	Matsu	Teoc Stp
36	Croatia	Rab	Teoc Sbm
28	Egypt	Salum	Medo Normal
13	Ethiopia	Diredawa	Trxe Bix
47	Finland	Oulu	Bosc Normal
54	Greenland -DNK-	Ivigtut	Pooc Normal
58	Greenland-Dnk	Umanak	Poxe Normal
38	Hungary	Pecs	Teco Stp
45	Iceland	Husavik	Booc Normal
39	India	Srinagar	Teco Sbm
4	Indonesia	Achmad Yani	Trps Mesophytic
16	Iran	Jask	Trde Ant
32	Iran	Yazd	Mehc Normal
34	Ireland	Valentia	Teho Normal
10	Ivory Coast	Port Bouet	Trps Bix
1	Japan	Ishigaki	Trpl Hygrophytic
25	Kazakhstan	Pavlodar	Mexc Stp
29	Kazakhstan	Dzhezkazgan	Medc Stp
24	Libya	Idris	Mexo Normal
31	Libya	Gialo	Meho Normal
6	Madagascar	Tananarive	Trps Subxerophytic
7	Mexico	Zapopán	Trps Xerophytic
41	Mongolia	Altai	Texe Stp
49	Mongolia	Bulgan	Boco Normal
18	Namibia	Mowebaai	Trhd Normal
33	New Zealand	Wigram	Teho Sbm
53	Norway	Jan Mayen	Poho Normal
17	Pakistan	Karachi	Trde Normal
15	Peru	Arequipa	Trde Pse
48	Russia	Anavgay Kamchatk	Boco Stp
56	Russia	Yamsk	Poco Normal
57	Russia Yakutia	Sredne-Kolymsk	Poxe Stp
50	Russia Yakutskaya	Verkhoyansk	Bohc Stp
51	Russia Yakutskaya	Komara	Bohc Normal
12	Saudi Arabia	Khamis Mushait	Trxe Ant
19	Spain	Tudela	Mepo Stp
9	Sri Lanka	Trincomalee	Trps Ant
2	Suriname	Zanderij	Trpl Subhigrophytic
46	Sweden	Bjuroklubb	Bosc Stp
22	Tajikistan	Dushanbe	Mepc Normal
21	Ukraine	Bolgrad	Mepc Stp
42	Ukraine	Kharkov	Texe Sbm
37	Uruguay	Artigas	Teoc Normal
52	USA Alaska	Fort Yukon	Boxe Stp
30	Uzbekistan	Ak-Baytal	Medc Normal
8	Vietnam	Donghoi	Trps Pse

Next, the 59 stations, as examples of the bioclimatic diversity at the level of Macrobioclima - Bioclima / Variant, ordered by that concept, following figure 11.

Note: At the computer exits, from the web http://www.globalbioclimatics.org, the stations in which no variant is specified, must be considered as Normal Variant (Nor) (See Normal Variant, above). We add this indication in each of the stations with Variante Nor.

Figure 13

Tropical Pluvial Bioclimate,

Hygrophytic Variant

Figure 14

Tropical Pluvial Bioclimate,

Subhigrophytic Variant

Figure 15

Tropical Pluvial Bioclimate,

Submesophytic Variant

Figure 16

Tropical Pluviseasonal Bioclimate,

Mesophytic Variant

Figure 17

Tropical Pluviseasonal Bioclimate,

Submesophytic Variant

Figure 18

Tropical Pluviseasonal Bioclimate,

Subxerophytic Variant

Figure 19

Tropical Pluviseasonal Bioclimate,

Xerophytic Variant

Figure 20

Tropical Pluviseasonal Bioclimate,

Pluviserotin Variant

Figure 21

Tropical Pluviseasonal Bioclimate,

Antitropical Variant

Figure 22

Tropical Pluviseasonal Bioclimate,

Bixeric Variant

Figure 23

Tropical Xeric Bioclimate,

Pluviserotin Variant

Figure 24

Tropical Xeric Bioclimate,

Antitropical Variant

Figure 25

Tropical Xeric Bioclimate,

Bixeric Variant

Figure 26

Tropical Xeric Bioclimate,

Normal Variant

Figure 27

Tropical Desertic Bioclimate,

Pluviserotin Variant

Figure 28

Tropical Desertic Bioclimate,

Antitropical Variant

Figure 29

Tropical Desertic Bioclimate,

Normal Variant

Figure 30

Tropical Hyperdesertic Bioclimate,

Normal Variant

Figure 31

	19

	Mediterranean Pluviseasonal Oceanic Bioclimate, Steppic Variant

Figure 32

	20

	Mediterranean Pluviseasonal Oceanic Bioclimate, Normal Variant

Figure 33

Mediterranean Pluviseasonal Continental Bioclimate,

Steppic Variant

Figure 34

	22

	Mediterranean Pluviseasonal Continental Bioclimate, Steppic Variant

Figure 35

Mediterranean Xeric Oceanic Bioclimate,

Steppic Variant

Figure 36

Mediterranean Xeric Oceanic Bioclimate,

Normal Variant

Figure 37

	25

	Mediterranean Xeric Continental Bioclimate, Steppic Variant

Figure 38

	26

	Mediterranean Xeric Continental Bioclimate, Normal Variant

Figure 39

	27

	Mediterranean Desertic Oceanic Bioclimate, Steppic Variant

Figure 40

	28

	Mediterranean Desertic Oceanic Bioclimate, Normal Variant

Figure 41

	29

	Mediterranean Desertic Continental Bioclimate, Steppic Variant

Figure 42

	30

	Mediterranean Desertic Continental Bioclimate, Normal Variant

Figure 43

	31

	Mediterranean Hyperdesertic Oceanic Bioclimate, Normal Variant

Figure 44

Mediterranean Hyperdesertic Continental Bioclimate,

Normal Variant

Figure 45

	33

	Temperate Hyperoceanic Bioclimate, Submediterranean Variant

Figure 46

Temperate Hyperoceanic Bioclimate,

Normal Variant

Figure 47

Temperate Oceanic Bioclimate,

Steppic Variant

Figure 48

Temperate Oceanic Bioclimate,

Submediterranean Variant

Figure 49

Temperate Oceanic Bioclimate,

Normal Variant

Figure 50

Temperate Continental Bioclimate,

Steppic Variant

Figure 51

	39

	Temperate Continental Bioclimate, Submediterranean Variant

Figure 52

Temperate Continental Bioclimate,

Normal Variant

Figure 53

Temperate Xeric Bioclimate,

Steppic Variant

Figure 54

Temperate Xeric Bioclimate,

Submediterranean Variant

Figure 55

Temperate Xeric Bioclimate,

Normal Variant

Figure 56

Boreal Hyperoceanic Bioclimate,

Normal Variant

Figure 57

Boreal Oceanic Bioclimate,

Normal Variant

Figure 58

Boreal Subcontinental Bioclimate,

Steppic Variant

Figure 59

Boreal Subcontinental Bioclimate,

Normal Variant

Figure 60

Boreal Continental Bioclimate,

Steppic Variant

Figure 61

Boreal Continental Bioclimate,

Normal Variant

Figure 62

Boreal Hypercontinental Bioclimate,

Steppic Variant

Figure 63

Boreal Hypercontinental Bioclimate,

Normal Variant

Figure 64

Boreal Hypercontinental Bioclimate,

Normal Variant

Figure 65

Polar Hyperoceanic Bioclimate,

Normal Variant

Figure 66

Polar Oceanic Bioclimate,

Normal Variant

Figure 67

Polar Continental Bioclimate,

Steppic Variant

Figure 68

Polar Continental Bioclimate,

Normal Variant

Figure 69

Polar Xeric Bioclimate,

Steppic Variant

Figure 70

Polar Xeric Bioclimate,

Normal Variant

Figure 71

Polar Pergelid Bioclimate,

Normal Variant

9.- ASSESSMENT OF SUMMER ARIDITY, WITH EXAMPLES

Summer aridity, Ios2 ≤ 2 (see Chapter 3, Ombrothermal Indexes, and Chapter 4, Mediterranean, Temperate and Boreal Macrobioclimates), differentiates the Mediterranean Macrobioclimate from the Temperate and Boreal Macrobioclimates, which do not have such summer aridity. However, there are circumstances where the soil field capacity supplements this summer aridity, If the month, or the two months, prior to the summer drought, provide enough rain, to have the soil recharged: in those cases, neither the vegetation nor the Macrobioclimate are Mediterranean. In order to evaluate this possible soil compensation for summer aridity, Summer Compensatory Ombrothermal Indexes, Iosc3 e Iosc4, are used (see Chapter 3). The values of these Compensable Summer Ombrothermal Indices, Iosc3 e Iosc4, have a high discriminatory value in the Mediterranean-Temperate and Mediterranean-Boreal border territories.

9.1.- Assessment of summer aridity.

From what has been said, if the Ios2 of our weather station is less than or equal to 2, Ios2 ≤ 2, we can not categorically state that our weather station has summer aridity, but we must study the possible edaphic compensation to this summer aridity, with the help of Iosc3 and Iosc4 values. However, the possible compensatory effect of precipitation falling in the month, or in the two months preceding the summer drought, is related to three factors: a), the annual water comfort, measured by the annual Io; b), the magnitude of Ios2; and c), the own value of the compensable Ombrothermal Indices, Iosc3 and Iosc4. Which is understandable: Not any value of Io allows the compensation, but this can only occur with an Io annual greater than 2. But, in addition, and depending on the magnitude of the annual Io, the possibly compensable values of Ios2 vary. In figures 72 and 73, the values of Io and Ios2, which allow for compensation, are given. If our weather station allows the compensation of a deficient Ios2, three cases may occur: 1), that our Iosc3 value were greater than two, which would suppose directly that the summer aridity is compensated, that is to say, there is no summer aridity; 2), that our Iosc3 value were below the corresponding intervals in the table, which would indicate, directly, that there is no compensation to summer aridity; and 3), that our Iosc3 value were in between the intervals shown in the table to allow compensation with Iosc4. Already in the column of Iosc4, there are only two possibilities: 1), that our Iosc4 were greater than two, which indicates that there is edaphic compensation of summer aridity; and 2), that our Iosc4 were less than or equal to 2, which finally indicates that there is no edaphic compensation of summer aridity. (The reading and interpretation of Figure 72 is explained in Figure 73).

Figure 72.- Compensation table to evaluate summer aridity, as a function of Io, Ios2, Iosc3 and Iosc4.

Io	Ios2	Iosc3	Iosc4
2.0 < Io ≤ 2.8	1.9 ≤ Ios2 ≤ 2.0	Iosc3 = 2.0	- Iosc4 > 2.0: Compensable aridity - Iosc4 ≤ 2.0: Non-compensable aridity
2.8 < Io ≤ 3.6	1.8 ≤ Ios2 ≤ 2.0	1.9 ≤ Iosc3 ≤ 2.0
3.6 < Io ≤ 4.8	1.8 ≤ Ios2 ≤ 2.0	1.9 ≤ Iosc3 ≤ 2.0
4.8 < Io ≤ 6.0	1.7 ≤ Ios2 ≤ 2.0	1.9 ≤ Iosc3 ≤ 2.0
6.0 < Io ≤ 7.0	1.5 ≤ Ios2 ≤ 2.0	1.8 ≤ Iosc3 ≤ 2.0
7.0 < Io ≤ 8.0	1.4 ≤ Ios2 ≤ 2.0	1.8 ≤ Iosc3 ≤ 2.0
8.0 < Io ≤ 9.0	1.3 ≤ Ios2 ≤ 2.0	1.8 ≤ Iosc3 ≤ 2.0
9.0 < Io ≤ 10.0	1.2 ≤ Ios2 ≤ 2.0	1.8 ≤ Iosc3 ≤ 2.0
10.0 < Io ≤ 11.0	1.1 ≤ Ios2 ≤ 2.0	1.7 ≤ Iosc3 ≤ 2.0
11.0 < Io ≤ 12.0	1.0 ≤ Ios2 ≤ 2.0	1.7 ≤ Iosc3 ≤ 2.0
12.0 < Ioaaaaa	0.9 ≤ Ios2 ≤ 2.0	1.7 ≤ Iosc3 ≤ 2.0

Figure 73: Reading and interpretation of figure 72.

Ios2

Iosc3

Iosc4

2.0 < Io ≤ 2.8

With Ios2 from 1.9 to 2.0, the meteorological station is compensable with Iosc3

If Ios2 is less than 1.9, the meteorological station is Mediterranean

If Iosc3 is higher than 2.0, the weather station is Temperate, or Boreal

If Iosc3 equals 2.0, the weather station is compensable with Iosc4

If Iosc3 is less than 2.0, the meteorological station is Mediterranean

If Iosc4 is greater than 2.0, the weather station is Tempe-rate, or Boreal

If Iosc4 is less than or equal to 2.0, the weather station is Mediterranean

2.8 < Io ≤ 3.6

With Ios2 from 1.8 to 2.0, the meteorological station is compensable with Iosc3

If Ios2 is less than 1.8, the meteorological stationis Mediterranean

If Iosc3 is higher than 2.0, the weather station is Temperate, or Boreal

If Iosc3 goes from 1.9 to 2.0, the weather station is compensable with Iosc4

If Iosc3 is less than 1.9, the meteorological station is Mediterranean

If Iosc4 is greater than 2.0, the weather station is Tempe-rate, or Boreal

If Iosc4 is less than or equal to 2.0, the weather station is Mediterranean

3.6 < Io ≤ 4.8

With Ios2 from 1.8 to 2.0, the meteorological station is compensable with Iosc3

If Ios2 is less than 1.8, the meteorological station is Mediterranean

If Iosc3 is higher than 2.0, the weather station is Temperate, or Boreal

If Iosc3 goes from 1.9 to 2.0, the weather station is compensable with Iosc4

If Iosc3 is less than 1.9, the meteorological station is Mediterranean

If Iosc4 is greater than 2.0, the weather station is Temperate, or Boreal

If Iosc4 is less than or equal to 2.0, the weather station is Mediterranean

4.8 < Io ≤ 6.0

With Ios2 from 1.7 to 2.0, the meteorological station is compensable with Iosc3

If Ios2 is less than 1.7, the meteorological station is Mediterranean

If Iosc3 is higher than 2.0, the weather station is Temperate, or Boreal

If Iosc3 goes from 1.9 to 2.0, the weather station is compensable with Iosc4

If Iosc3 is less than 1.9, the meteorological station is Mediterranean

If Iosc4 is greater than 2.0, the weather station is Temperate, or Boreal

If Iosc4 is less than or equal to 2.0, the weather station is Mediterranean

6.0 < Io ≤ 7.0

With Ios2 from 1.5 to 2.0, the meteorological station is compensable with Iosc3

If Ios2 is less than 1.5, the meteorological station is Mediterranean

If Iosc3 is higher than 2.0, the weather station is Temperate, or Boreal

If Iosc3 goes from 1.8 to 2.0, the weather station is compensable with Iosc4

If Iosc3 is less than 1.8, the meteorological station is Mediterranean

If Iosc4 is greater than 2.0, the weather station is Temperate, or Boreal

If Iosc4 is less than or equal to 2.0, the weather station is Mediterranean

7.0 < Io ≤ 8.0

With Ios2 from 1.4 to 2.0, the meteorological station is compensable with Iosc3

If Ios2 is less than 1.4, the meteorological station is Mediterranean

If Iosc3 is higher than 2.0, the weather station is Temperate, or Boreal

If Iosc3 goes from 1.8 to 2.0, the weather station is compensable with Iosc4

If Iosc3 is less than 1.8, the meteorological station is Mediterranean

If Iosc4 is greater than 2.0, the weather station is Temperate, or Boreal

If Iosc4 is less than or equal to 2.0, the weather station is Mediterranean

8.0 < Io ≤ 9.0

With Ios2 from 1.3 to 2.0, the meteorological station is compensable with Iosc3

If Ios2 is less than 1.3, the meteorological station is Mediterranean

If Iosc3 is higher than 2.0, the weather station is Temperate, or Boreal

If Iosc3 goes from 1.8 to 2.0, the weather station is compensable with Iosc4

If Iosc3 is less than 1.8, the meteorological station is Mediterranean

If Iosc4 is greater than 2.0, the weather station is Temperate, or Boreal

If Iosc4 is less than or equal to 2.0, the weather station is Mediterranean

9.0 < Io ≤10.0

With Ios2 from 1.2 to 2.0, the meteorological station is compensable with Iosc3

If Ios2 is less than 1.2, the meteorological station is Mediterranean

If Iosc3 is higher than 2.0, the weather station is Temperate, or Boreal

If Iosc3 goes from 1.8 to 2.0, the weather station is compensable with Iosc4

If Iosc3 is less than 1.8, the meteorological station is Mediterranean

If Iosc4 is greater than 2.0, the weather station is Temperate, or Boreal

If Iosc4 is less than or equal to 2.0, the weather station is Mediterranean

10.0< Io ≤11.0

With Ios2 from 1.1 to 2.0, the meteorological station is compensable with Iosc3

If Ios2 is less than 1.1, the meteorological station is Mediterranean

If Iosc3 is higher than 2.0, the weather station is Temperate, or Boreal

If Iosc3 goes from 1.7 to 2.0, the weather station is compensable with Iosc4

If Iosc3 is less than 1.7, the meteorological station is Mediterranean

If Iosc4 is greater than 2.0, the weather station is Temperate, or Boreal

If Iosc4 is less than or equal to 2.0, the weather station is Mediterranean

11.0<Io ≤12.0

With Ios2 from 1.0 to 2.0, the meteorological station is compensable with Iosc3

If Ios2 is less than 1.0, the meteorological station is Mediterranean

If Iosc3 is higher than 2.0, the weather station is Temperate, or Boreal

If Iosc3 goes from 1.7 to 2.0, the weather station is compensable with Iosc4

If Iosc3 is less than 1.7, the meteorological station is Mediterranean

If Iosc4 is greater than 2.0, the weather station is Temperate, or Boreal

If Iosc4 is less than or equal to 2.0, the weather station is Mediterranean

12.0 < Io

With Ios2 from 0.9 to 2.0, the meteorological station is compensable with Iosc3

If Ios2 is less than 0.9, the meteorological station is Mediterranean

If Iosc3 is higher than 2.0, the weather station is Temperate, or Boreal

If Iosc3 goes from 1.7 to 2.0, the weather station is compensable with Iosc4

If Iosc3 is less than 1.7, the meteorological station is Mediterranean

If Iosc4 is greater than 2.0, the weather station is Temperate, or Boreal

If Iosc4 is less than or equal to 2.0, the weather station is Mediterranean

9.2.- Examples for the valuation of summer aridity

Using the tables in figures 72 and 73, the possible compensation of the summer aridity, Ios2 ≤ 2, is evaluated, analyzing the values of Io, Ios2, Iosc3 and Iosc4. To explain the use of the compensation tables, we will use figures 74-79, whose information is taken from Rivas Martínez website: www.globalbioclimatics.org.

The possible edaphic compensation of the summer aridity has to be evaluated only when the Ios2 of our station is between 2 and 0.9, 0.9≤ Ios2 ≤ 2, because if the station's Ios2 is greater than two (Ios2 > 2), the station has no summer aridity, and does not need any compensation (figure 74): Smithers, Canada; however, if the station's Ios2 is less than 0.9, Ios2 <0.9, the station, with such a low Ios2, does not allow compensation for summer aridity (figure 75: Dzhalal-Abad, Kyrgyzstan); but if the station's Ios2 is greater than or equal to 0.9, and equal to or less than two: 0.9 ≤ Ios2 ≤ 2, the existing summer aridity may, or may not, be compensable, and in order to elucidate it, one must go again to the two tables in Figures 72 and 73, that show how a deficient Ios2 can be compensated according to the value of the annual Io, the Ios2 itself, and the Iosc3 and Iosc4. (See Figures 76 and 78, non-compensable, and figures 77 and 79, compensable).

Procedure: Specifically, in order to analyze the possible edaphic compensation of summer aridity, we look at the first column of Figures 72 and 73, to locate in which interval of their first columns is our Io, and to work, then, on that row. Already in the Ios2 column, two things can happen: or that our Ios2 is less than the indicated interval, which would automatically qualify the station as summer arid, without possible compensation (figure 76: Skopje, Macedonia); or that our Ios2 is included in the indicated interval, which allows to try the compensation with Iosc3. Then we go to the Iosc3 column: if our Iosc3 is greater than two, the summer aridity is compensated (figure 77: Alustante, Guadalajara, Spain); if our Iosc3 is less than the indicated interval, the summer aridity is definitely not compensable (Figure 78: Pounds Field, Texas); but if our Iosc3 is within the indicated range, the summer aridity can still be compensated with the Iosc4. In the Iosc4 column, two things can happen: or that our Iosc4 is greater than two, which indicates that summer aridity is compensated by edaphic moisture (Figure 79: Atlanta, Georgia, USA); or that our Iosc4 is equal to or less than two, indicating that the summer aridity would be, definitely, not compensable (we have not found on the website of Rivas Martínez, www.globalbioclimatics.org, any station of these characteristics).

As we have said above, the values of the Ombrothermic Indexes used in the compensation - Iosc3 and Iosc4 -, have a high discriminatory value in the Mediterranean-Temperate and Mediterranean-Boreal border territories.

Figure 74

Bioclimatic Diagnosis: Temperate Continental Bioclimate,

Submediterranean Variant

Figure 75

Diagnosis Bioclimática: Mediterráneo Pluviestacional Continental,

Variante NORMAL

Figure 76

Bioclimatic Diagnosis: Mediterranean Pluviseasonal Continental Bioclimate,

Normal Variant

Figure 77

Bioclimatic Diagnosis: Temperate Oceanic Bioclimate,

Submediterranean Variant

Figure 78

Bioclimatic Diagnosis: Mediterranean Pluviseasonal Oceanic Bioclimate,

Normal Variant

Figure 79

Bioclimatic Diagnosis: Temperate Oceanic Bioclimate,

Submediterranean Variant

10.- Itc and Ci CALCULATIONS

The Compensated Thermicity Index is used to distinguish the Tropical, Mediterranean and Temperate Macrobioclimates, as well as their Thermotypes. For its calculation it is necessary to take into account the Latitude and the Continentality, since it is necessary to apply a progressive correction factor, fi, according to the excess of cold or or heat due to the Continentality / Oceanicity of the meteorological station under study. To facilitate Itc calculation and knowledge, we will explain here, in detail, the procedure to be used.

In Chapter 3 we saw that the Compensated Thermicity Index is:

Itc = It + Ci = (T + M + m) 10 + Ci

Expression convertible into:

Itc ≈ (T + 2 Tmin) 10 + Ci

The first part of the expression offers no calculation difficulties. But, as the compensation value, Ci, varies according to Latitude and Continentality, in Figure 80, we have collected, the Latitude and Continentality intervals, as well as the progressive correction factor, fi, to be applied at each of their intervals, and, finally, we have collected the calculations of Ci. The Continentality progressive correction factor - fi - reaches values between (-10) and (+30).

Figure 80. - Calculation of the compensation values, Ci, to obtain the Compensated Thermicity Index - Itc -, according to the Latitude and thresholds of Continentality, according to Rivas-Martínez.

Latitude	-lc- Thresholds of Continentality	fi	Ci	Ci Calculations
Up to 23º N and S	--- ---	---	Ci = 0	--- --- --- --- ---
Higher than 23ºN or 23ºS	Ic≤8	f0 = (-10)	Ci=C0;	C0=f0 (8 - Ic)
	8<Ic≤17	fi = 0	Ci = 0	--- --- --- --- ---
	17<Ic≤ 21	f1 = 5	Ci =Cl;	C1=f1 (Ic - 17)
	21< Ic≤ 28	f2 = 15	Ci = Cl + C2	C1=f1 (21 - 17) =20; C2=f2 (Ic - 21)
	28 < Ic ≤ 46	f3 = 25	Ci =Cl + C2 + C3	C1=20; C2=f2 (28 - 21) = 105; C3=f3 (Ic - 28)
	46 < Ic ≤ 65	f4 = 30	Ci =Cl + C2 +C3 + C4;	C1=20; C2=105; C3=f3 (46 - 28) =450; C4=f4 (Ic - 46)

In figures 81-87, we can see some case studies, with specific meteorological stations, of the results for the Itc calculations, shown in figure 80, as detailed below:

.) Between 23º N and S, the compensation value, Ci, is equal to 0, because, at those latitudes, it is not necessary to compensate neither the excess of cold nor the heat, due to low or high Continentality. So in those latitudes: It = Itc (See figure 81, Ghanzi, Botswana).

.) At more than 23º N and S,

A) in the strongly hyperoceanic areas (Ic ≤ 8), the compensation value, C0, is calculated by multiplying by f0 = (-10) the difference between 8.0 and the Ic of the locality: C0 = (-10) x (8.0 - Ic). (See Figure 82, Ushuaia, Argentina).

B) in low Continental areas (8<Ic≤17), the value of Ci is considered equal to 0, so, in these cases: It = Itc (See figure 83, Torgilsbu, Greenland-DNK).

C) in intermediate Continental areas (17<Ic≤ 21), the compensation value, C1, is calculated by multiplying by fi (f1 = 5) the difference between the Ic of the locality and the value 17: C1=f1 (Ic – 17). (See Figure 84, Pingwu, China).

D) in the high Continental areas (21<Ic≤ 28), the compensation value Ci is calculated by a sum whose partial values Ci = C1 + C2, are as follows: C1=f1 (21 - 17) =20; y C2=f2 (Ic - 21). See figure 85, Teheran-Doshant, Iran).

E) in very high Continental areas (28 <Ic≤ 46), the compensation value Ci is calculated by a sum whose partial values Ci = Cl + C2 + C3, are as follows: C1=f1 (21 - 17) =20; C2=f2 (28 - 21) =105; y C3 = f3 (Ic - 28). (See Figure 86, Lamaiin Huryee, Mongolia).

F) in extremely high Continental areas (46<Ic≤ 65), the compensation value Ci is calculated by a sum whose partial values Ci  = Cl + C2 + C3 + C4, are as follows: C1=f1 (21 - 17) =20; C2=f2 (28 - 21) =105; C3 = f3 (46 - 28) = 450; y C4 = f4 (Ic - 46). (See figure 87, Vakjanka, Russia).

Figure 81

Bioclimatic Diagnosis: Tropical Xeric Bioclimate,

Normal Variant

Figure 82

Bioclimatic Diagnosis: Boreal Hyperoceanic Bioclimate,

Normal Variant

Figure 83

Bioclimatic Diagnosis: Polar Oceanic Bioclimate,

Normal Variant

Figure 84

Bioclimatic Diagnosis: Temperate Oceanic Bioclimate,

Normal Variant

Figure 85

Bioclimatic Diagnosis: Mediterranean Xeric

Continental Bioclimate, Normal Variant

Figure 86

Bioclimatic Diagnosis: Boreal Continental Bioclimate,

Normal Variant

Figure 87

Bioclimatic Diagnosis: Boreal Hypercontinental Bioclimate,

Normal Variant

11.- PRACTICAL EXAMPLE of a meteorological station complete bioclimatic characterization, with the use of the Synoptic Table.

In order to facilitate the bioclimatic characterization of a meteorological station, we will carry out, in detail, all the steps and calculations necessary for that study, taking as a model the station of DZHEZKAZGÁN, located in the center of Kazakstan. All the climatic data in this section are taken from Prof. Rivas-Martínez's website: http://www.globalbioclimatics.org. (2008), but the classification follows Rivas-Mart. & al., 2011.

We will do the practical example according to the following scheme:

11.1.- Climatic data of departure

11.2.- Bioclimatic diagnosis of a weather station

11.2.a.- Location of the weather station: Latitude, longitude and altitude

11.2.b.- Calculation of the necessary values and indexes.

Three THERMAL INDEXES:

Ic Continentality / Oceanicity Index

Tp Positive Annual Temperature

Itc Compensated Thermicity Index

One OMBRIC (Rainfall) INDEX

Pp Annual positive precipitation

Four OMBROTHERMIC INDEXES

Io Annual Ombrothermic Index, Io = (Pp/Tp)10. 

Ios2 Ombrothermic Index of the hottest bimester of the summer trimester

Iosc3 (= Ios3), Compensable Ombrothermic Index of the summer trimester, necessary to evaluate the summer aridity

Iosc4 (= Ios4), Compensable Summer Ombrothermic Index for the four-month period resulting from adding, to the summer trimester, the month immediately preceding. This index is also used to assess summer aridity

11.2.c.- Recognition of the bioclimatic units of the station, using the General Synoptic Table.

MACROBIOCLIMATE

BIOCLIMATE AND BIOCLIMATIC VARIANT

. BIOCLIMATE

. BIOCLIMATIC VARIANT

BIOCLIMATIC BELT: Thermotype and Ombrotype

11.2.d.- Expression of the complete bioclimatic diagnosis -Isobioclimate-.

11.3.- Synthesis and graphic expression of bioclimatic study: Bioclimograph

11.1.- Climatic data of departure

Figure 88 collects the information provided by a weather station, in this case, DZHEZKAZGAN, Kazakhstan. It contains: a) latitude, longitude and altitude geographic data; b), chronological data: temperatures and precipitation observation periods; And c), climatic data: for the considered periods, the average monthly values of Ti (monthly average temperature), Mi (average of the maximums of each month), mi (average of the minimum of each month), M'i (average monthly temperature of absolute maximums), m'i (average monthly temperature of the absolute minimums), and of Pi (mean of the monthly precipitations). Of all these data, those columns that we need for our study, and that we are going to use are: Ti, Mi, mi, and Pi.

Figure 88.- Necessary data for the bioclimatic study of a meteorological station: DZHEZKAZGAN

DZHEZKAZGAN, Kazakhstan
Latitude: 47º 48'N Longitude: 067º 43'E Altitude: 345m
Temperature observation period: 1968 -1994 (27)
Rainfall observation period . . . . : 1984 -1994 (11)
	Ti	Mi	mi	M'i	m'i	Pi
Jan	-16,1	-11,1	- 21,0	7,8	-50,0	14,5
Feb	-14,7	- 9,4	-20,0	10,0	-41,1	16,0
Mar	-7,2	-1,7	-12,8	25,0	-38,9	25,9
Apr	6,4	13,3	-0,6	28,9	-22,8	6,6
May	15,0	23,3	6,7	67,8	- 8,9	14,0
Jun	20,8	29,4	12,2	41,1	-1,1	22,6
Jul	23,1	31,7	14,4	42,8	3,9	19,8
Aug	20,8	29,4	12,2	41,1	0,0	8,1
Sep	13,9	22,8	5,0	37,2	-10,0	8,4
Oct	5,0	12,2	- 2,2	30,0	- 20,0	17,0
Nov	- 4,7	0,6	-10,0	18,9	- 38,9	9,7
Dec	-13,1	-7,8	-18,3	6,1	- 41,1	13,2
Year	---	---	---	---	---	---

Note: The data source can already give us the annual values, but if not, we ourshelves calculate them: the annual temperature values are the arithmetic mean of the corresponding monthly mean values; with respect to annual rainfall, simply add up all the monthly values: Figure 89.

Figure 89.- Mean annual data of temperatures and average total rainfall calculated for the DZHEZKAZGAN Meteorological Station:

DZHEZKAZGAN, Kazakhstan
Latitude: 47º 48'N Longitude: 067º 43'E Altitude: 345m
Temperature observation period: 1968 -1994 (27)
Rainfall observation period . . . . : 1984 -1994 (11)
	Ti	Mi	mi	M'i	m'i	Pi
Jan	-16,1	-11,1	- 21,0	7,8	-50,0	14,5
Feb	-14,7	- 9,4	-20,0	10,0	-41,1	16,0
Mar	-7,2	-1,7	-12,8	25,0	-38,9	25,9
Apr	6,4	13,3	-0,6	28,9	-22,8	6,6
May	15,0	23,3	6,7	67,8	- 8,9	14,0
Jun	20,8	29,4	12,2	41,1	-1,1	22,6
Jul	23,1	31,7	14,4	42,8	3,9	19,8
Aug	20,8	29,4	12,2	41,1	0,0	8,1
Sep	13,9	22,8	5,0	37,2	-10,0	8,4
Oct	5,0	12,2	- 2,2	30,0	- 20,0	17,0
Nov	- 4,7	0,6	-10,0	18,9	- 38,9	9,7
Dec	-13,1	-7,8	-18,3	6,1	- 41,1	13,2
Year	T = 4,1	---	---	---	---	P = 175,8

11.2.- Bioclimatic diagnosis of a weather station

From the climatic data emitted by the meteorological station, collected and synthesized in Figures 88 and 89, four are the necessary steps to perform the bioclimatic diagnosis of the locality: a, take into account the geographic location - latitude, longitude and altitude - of the weather station; b, calculation of the necessary values and indexes; c, recognition of the bioclimatic units of the station, with the help of the Synoptic General Table; and d, complete formulation of Isobioclimate.

11.2.a.- Location of the weather station: Latitude, longitude and altitude

When starting the bioclimatic study of a station / locality, since that geographical position conditions the monthly distribution of the seasons spring, summer, autumn and winter. The table, as it is usually written, always starts in January. If the station was located inthe Southern Hemisphere, it is convenient to draw, in the data table, a horizontal line of separation between May and June, because in that hemisphere the winter begins in June.

11.2.b.- Calculation of the necessary values and indexes.

For more ease, we are going to first compute three Thermal Indices, then one Index of rainfall, to end up with four Ombrothermal Indexes.

Three THERMAL INDEXES:

Continentality / Oceanicity Index: Annual thermal amplitude - Ic - The Index expresses the difference, in degrees centigrade, between the highest and lowest monthly average temperatures of the year:

Ic = Tmax – Tmin

To calculate it at our station - Figure 90- we go to the Ti column, of average monthly temperatures, and we look for the months with the highest and lowest values, which are those of July and January.

Figure 90.- The data for the calculation of the Continental Index are marked

DZHEZKAZGAN, Kazakhstan
Latitude: 47º 48'N, Longitude: 067º 43'E Altitude: 345m
Temperature observation period: 1968 -1994 (27)
Rainfall observation period: 1984 -1994 (11)
	Ti	Mi	mi	M'i	m'i	Pi
Jan	-16,1	-11,1	- 21,0	7,8	-50,0	14,5
Feb	-14,7	- 9,4	-20,0	10,0	-41,1	16,0
Mar	-7,2	-1,7	-12,8	25,0	-38,9	25,9
Apr	6,4	13,3	-0,6	28,9	-22,8	6,6
May	15,0	23,3	6,7	67,8	- 8,9	14,0
Jun	20,8	29,4	12,2	41,1	-1,1	22,6
Jul	23,1	31,7	14,4	42,8	3,9	19,8
Aug	20,8	29,4	12,2	41,1	0,0	8,1
Sep	13,9	22,8	5,0	37,2	-10,0	8,4
Oct	5,0	12,2	- 2,2	30,0	- 20,0	17,0
Nov	- 4,7	0,6	-10,0	18,9	- 38,9	9,7
Dec	-13,1	-7,8	-18,3	6,1	- 41,1	13,2
Year	T = 4,1	---	---	---	---	P = 175,8

Ic=+23,1 – (-16,1) = 39,2

Positive Annual Temperature - Tp -: It is the sum, expressed in tenths of degree centigrade, of the average monthly temperatures of those months that exceed 0ºC: Ti > 0ºC. Tp = ∑ Ti (Ti > 0) x 10, being i: 1 = January, ..., 12 = December.

Figure 91.- The data for the calculation of the Annual Positive Temperature in the station of DZHEZKAZGAN are marked

DZHEZKAZGAN, Kazakhstan
Latitude: 47º 48'N, Longitude: 067º 43'E Altitude: 345m
Temperature observation period: 1968 -1994 (27)
Rainfall observation period: 1984 -1994 (11)
	Ti	Mi	mi	M'i	m'i	Pi
Jan	-16,1	-11,1	- 21,0	7,8	-50,0	14,5
Feb	-14,7	- 9,4	-20,0	10,0	-41,1	16,0
Mar	-7,2	-1,7	-12,8	25,0	-38,9	25,9
Apr	6,4	13,3	-0,6	28,9	-22,8	6,6
May	15,0	23,3	6,7	67,8	- 8,9	14,0
Jun	20,8	29,4	12,2	41,1	-1,1	22,6
Jul	23,1	31,7	14,4	42,8	3,9	19,8
Aug	20,8	29,4	12,2	41,1	0,0	8,1
Sep	13,9	22,8	5,0	37,2	-10,0	8,4
Oct	5,0	12,2	- 2,2	30,0	- 20,0	17,0
Nov	- 4,7	0,6	-10,0	18,9	- 38,9	9,7
Dec	-13,1	-7,8	-18,3	6,1	- 41,1	13,2
Year	T = 4,1	---	---	---	---	P = 175,8

In our station - Figure 91- we have to add Ti from April to October inclusive and multiply the result by 10, to express it in tenths of a degree, so our

Tp = (6,4 + 15,0 + 20,8 + 23,1 + 20,8 + 13,9 + 5,0) 10 = 1050

Compensated Thermicity Index -Itc-

It is the sum, in tenths of a degree, of T (annual mean temperature), M (average temperature of the maximum of the coldest month, ie of the month with the lowest Ti) and m (average temperature of the minimums of the coldest month, that is the month with the lowest Ti), plus a compensation value, Ci:

Itc = (T + M + m)10 + Ci

The compensation value Ci must be applied to correct the excess of "temperance" or "cold" that occurs when the Continentality Index is extremely low (Ic ≤ 8), or high (Ic>18), compared to cases where the lc has mean values, between 8-18: thus, the values obtained with the ltc are comparable.

Performing the calculations:

1st stage: Calculation of the first part of the formula: (T + M + m) 1O. At our DZHEZKAZGAN station, the coldest month-the one with the lowest monthly average temperature-is January, Figure 92, so that

(T + M + m) 1O = [(+4,1) + (-11,1) + (-21)]10 = (-28,1x10) = - 281

Figure 92.- The data for the calculation of the Compensated Termicity Index, in the DZHEZKAZGAN station, are marked

DZHEZKAZGAN, Kazakhstan
Latitude: 47º 48'N, Longitude: 067º 43'E Altitude: 345m
Temperature observation period: 1968 -1994 (27)
Rainfall observation period: 1984 -1994 (11)
	Ti	Mi	mi	M'i	m'i	Pi
Jan	-16,1	-11,1	- 21,0	7,8	-50,0	14,5
Feb	-14,7	- 9,4	-20,0	10,0	-41,1	16,0
Mar	-7,2	-1,7	-12,8	25,0	-38,9	25,9
Apr	6,4	13,3	-0,6	28,9	-22,8	6,6
May	15,0	23,3	6,7	67,8	- 8,9	14,0
Jun	20,8	29,4	12,2	41,1	-1,1	22,6
Jul	23,1	31,7	14,4	42,8	3,9	19,8
Aug	20,8	29,4	12,2	41,1	0,0	8,1
Sep	13,9	22,8	5,0	37,2	-10,0	8,4
Oct	5,0	12,2	- 2,2	30,0	- 20,0	17,0
Nov	- 4,7	0,6	-10,0	18,9	- 38,9	9,7
Dec	-13,1	-7,8	-18,3	6,1	- 41,1	13,2
Year	T = 4,1	---	---	---	---	P = 175,8

2nd stage: Ci calculation. As we saw in Chapter 10, Ci value is calculated according to the latitude and to the different thresholds of Continentality, established by Rivas-Martínez (see Figure 93). Latitude thresholds: up to 23º N and S, and greater than 23º N and S. Continentality thresholds: from 0 to 8, up to 17, up to 21, up to 28, up to 46 and up to 65. The last column gives the highest values of Ci that can be reached at each Continental threshold.

For our weather station of DZHEZKAZGAN, we have to take into account the Index of Continentality previously calculated: lc = 39.2. That is why we have to apply the content of the threshold line 28 <Ic≤46. (Figure 93), in which our Ci= C1 + C2 + C3, being C1=20; C2=105; and C3=f3 (lc - 28) = 25(39,2-28) =25 x 11,2 = 280. With it Ci =C1 + C2 + C3 = 15+ 105 + 280 = +405. So:

Ci = +405

Figure 93. Calculation of compensation values Ci needed for the Compensated Thermicity Index - Itc, according to the thresholds of Continentality of Rivas Martínez. The calculation of the Compensated Thermicity Index for the DZHEZKAZGAN station has been indicated.

Latitude	-lc- Thresholds of Continen-tality	fi	Ci	Ci Calculations	Valores Extremos de Ci
Up to 23º N and S	--- ---	---	Ci = 0	--- --- --- --- ---	Ci = 0
Higher than 23ºN or 23ºS	Ic≤8	f0 = (-10)	Ci=C0;	C0=f0 (8 - Ic)	C0 = - 80
	8<Ic≤17	fi = 0	Ci = 0	--- --- --- --- ---	Ci = 0
	17<Ic≤ 21	f1 = 5	Ci i=Cl;	C1=f1 (Ic - 17)	C1 = + 20
	21< Ic≤ 28	f2 = 15	Ci = Cl + C2	C1=f1 (21 - 17) =20; C2=f2 (Ic - 21)	C2 = + 105
	28 < Ic ≤ 46	f3 = 25	Ci =Cl + C2 + C3	C1=20; C2=f2 (28 - 21) = 105; C3=f3 (Ic - 28)	C3 = + 450
	46 < Ic ≤ 65	f4 = 30	Ci =Cl + C2 +C3 + C4;	C1=20; C2=105; C3=f3 (46 - 28) =450; C4=f4 (Ic - 46)	C4 = +570

3rd stage: Calculation of Itc. Finally, we only need, in this third stage, to make the final calculation:

Itc = (T + M + m)10 + Ci = -281 + 405 = 124

Note: Itc can be calculated, even if the averages of the monthly maximums and minimums are not available, because (M + m) is approximately 2Tmin (Tmin: Monthly average temperature of the coldest month of the year):

Itc ≈ (T + 2Tmin)10 + Ci = [4,1 +2(-16,1)]10 + 405 = -281 + 405 = 124

One RAINFALL INDEX

Annual Positive Precipitation –Pp- is the sum of Pi of all months of the year, whose Ti is greater than 0ºC. Pp=∑Pi (Ti>0), being i: 1 = January, ..., 12 = December.

In our case - Figure 94 - we must add the monthly precipitations from April to October: Pp = 97. (rounding off 96.5).

Pp = 6,6 + 14,0 + 22,6 + 19,8 + 8,1 + 8,4 + 17,0 = 97

Figure 94.- The data for the calculation of the Positive Precipitation in the meteorological station of DZHEZKAZGAN are marked.

DZHEZKAZGAN, Kazakhstan
Latitude: 47º 48'N, Longitude: 067º 43'E Altitude: 345m
Temperature observation period: 1968 -1994 (27)
Rainfall observation period: 1984 -1994 (11)
	Ti	Mi	mi	M'i	m'i	Pi
Jan	-16,1	-11,1	- 21,0	7,8	-50,0	14,5
Feb	-14,7	- 9,4	-20,0	10,0	-41,1	16,0
Mar	-7,2	-1,7	-12,8	25,0	-38,9	25,9
Apr	6,4	13,3	-0,6	28,9	-22,8	6,6
May	15,0	23,3	6,7	67,8	- 8,9	14,0
Jun	20,8	29,4	12,2	41,1	-1,1	22,6
Jul	23,1	31,7	14,4	42,8	3,9	19,8
Aug	20,8	29,4	12,2	41,1	0,0	8,1
Sep	13,9	22,8	5,0	37,2	-10,0	8,4
Oct	5,0	12,2	- 2,2	30,0	- 20,0	17,0
Nov	- 4,7	0,6	-10,0	18,9	- 38,9	9,7
Dec	-13,1	-7,8	-18,3	6,1	- 41,1	13,2
Year	T = 4,1	---	---	---	---	P = 175,8

Four OMBROTHERMIC INDEXES

Their values areten times the quotient between Positive Precipitation and Positive Temperature of the considered period, Io = (Pp / Tp) 10. In addition to the Io, Annual Ombrothermal Index, it is necessary to calculate the Ombrothermal Indexes for the summer period - Jun-Jul-Aug, in the Northern Hemisphere; Dec-Jan-Feb, in the Southern Hemisphere:

Io Annual Ombrothermic Index

Ios2 Ombrothermic Index of the hottest bimester of the summer trimester (Tr3)

Iosc3 (= Ios3) Compensable Ombrothermic Index of the summer trimester (Tr3)

Iosc4 (= Ios4) Compensable Summer Ombrothermic Index for the four-month period resulting from adding, to the summer trimester (Tr3), the month immediately preceding.

We calculate each of them: Figure 95.

Figure 95.- The data for the calculation of the Summer Ombrothermal Indexes are marked in the meteorological station of DZHEZKAZGAN.

DZHEZKAZGAN, Kazakhstan
Latitude: 47º 48'N, Longitude: 067º 43'E Altitude: 345m
Temperature observation period: 1968 -1994 (27)
Rainfall observation period: 1984 -1994 (11)
	Ti	Mi	mi	M'i	m'i	Pi
Jan	-16,1	-11,1	- 21,0	7,8	-50,0	14,5
Feb	-14,7	- 9,4	-20,0	10,0	-41,1	16,0
Mar	-7,2	-1,7	-12,8	25,0	-38,9	25,9
Apr	6,4	13,3	-0,6	28,9	-22,8	6,6
May	15,0	23,3	6,7	67,8	- 8,9	14,0
Jun	20,8	29,4	12,2	41,1	-1,1	22,6
Jul	23,1	31,7	14,4	42,8	3,9	19,8
Aug	20,8	29,4	12,2	41,1	0,0	8,1
Sep	13,9	22,8	5,0	37,2	-10,0	8,4
Oct	5,0	12,2	- 2,2	30,0	- 20,0	17,0
Nov	- 4,7	0,6	-10,0	18,9	- 38,9	9,7
Dec	-13,1	-7,8	-18,3	6,1	- 41,1	13,2
Year	T = 4,1	---	---	---	---	P = 175,8

Annual Ombrothermic Index, Io = (Pp/Tp)10.

With the values of Pp and Tp, calculated above, Pp = 97; Tp = 1050:

Io = (Pp/Tp)10 = (97 / 1050)10 = 0,92

Ombrothermic Index of the hottest bimester of the summer trimester (Tr3):

Ios2: = (Pp2/Tp2) 10

As Pp2 = 19,8+8,1=27,9; and Tp2 = (23,1+20,8) x 10 =439:

Ios2: = (Pp2/Tp2) 10 = (27,9 / 439)10 = 0,64

Compensable Ombrothermic Index of the summer trimester (Tr3): Iosc3 = (Pp3/Tp3) 10:

As Pp3 = 19,8+8,1+22,6=50,5; and Tp3 = (20,8+23,1+20,8) 10 =647:

Iosc3 = (50,5 / 647) 10 = 0,78

Compensable Summer Ombrothermic Index for the four-month period resulting from adding, to the summer trimester (Tr3), the month immediately preceding.

Iosc4 = (Pp4/Tp4) 10: 

As Pp4=19,8+8,1+22,6+14=64,5; and Tp4= (20,8+23,1+20,8+15) x 10 =797:

Iosc4 = (64,5 / 797) 10 = 0,81

11.2.c.- Recognition of the bioclimatic units of the station, using the General Synoptic Table.

Once the latitude, longitude and height data are recognized, and the calculations of the indices of our DZHEZKAZGAN station are carried out, we will identify its Bioclimatology having in view the General Synoptic Table of the Bioclimatic Classification of the Earth (figure 7). We have to find out what Macrobioclimate, what Bioclimate and Bioclimatic Variant, and what Bioclimatic Belt correspond to it, to finally define the Isobioclimate of DZHEZKAZGAN.

MACROBIOCLIMATE

In the Macrobioclimates column of the Synoptic General Table, the first thing we encounter is the call: (1). And is that to identify the Macrobioclimate, in addition to latitude, thermal thresholds T, M, m, Itc and Tp are used, all of them highly conditioned by the altitude of the meteorological station. As the Synoptic Table gives the thresholds of those indices referred to 200m, if our station exceeds that altitude, we must add a certain amount for every 100m that exceeds 200m. The amount to be added to each index is indicated in the call (1) of the Synoptic Table, column of Macrobioclimates, column shown in figure 96.

Figure 96. Recognition of the Macrobioclimate at the DZHEZKAZGAN station. First column of the Synoptic Table

M a c r o b i o c l i m a t e s(1)

Name, Acronym and Differential Characters

Tropical Tr

Warm zone: equatorial, eutropical and subtropical (0º-35º N & S). In subtropical (23º - 35º N & S) at < 200 m, at least two values: T ≥ 25º, m ≥ 10º, Itc ≥ 580; or, if Pss > Psw, or Pcm2 < Pcm1 > Pcm3, at least two values: T ≥ 21º, M ≥ 18º, Itc ≥ 470. In Eurasia, from 25º to 35º N, height ≥ 2000 m: it is not tropical.

Mediterranean Me

Subtropical warm zone (23º-35º N & S) and eutemperate temperate zone (35º-52º N & S), with summer aridity at least bimonthly after the summer solstice: Ios₂ ≤ 2, Iosc₄ ≤ 2. In Subtropical, at least two of the three thermal values: T < 25º, m < 10º, Itc < 580.

Temperate Te

Subtropical warm zone (23º-35º N & S) and temperate zone (35º-66º N & 35º-54º S). Without summer aridity: Ios2>2, Iosc4>2. A <200 m, Tp≥380. Besides: a), 23º-35º N & S, at <200m, at least two values: T<21º, M<18º, Itc<470; or b), In contrast to Boreal, at <200m: if Ic≤11: T>6º, Tmax>10º and Tps>320; if 11<Ic≤21: Tp>720 and T>5.3º; if 21<Ic≤28: Tp>740 and T>4.8º; if 28<Ic≤46: Tp>800 and T>3.8º; and if 46<Ic: Tp>800 and T>0º.

Boreal Bo

Temperate and cold zones (42º-72º N, 49º-56º S). Without summer aridity: Ios2>2, Iosc4>2. A <200 m, Tp≥380. If Ic≤11: T≤6º, Tmax≤10º, 380≤Tp≤720 and Tps≤320; if 11<Ic≤21: 380≤Tp≤720 and T≤5.3º; if 21<Ic≤28: 380≤Tp≤740 and T≤4.8º; if 28<Ic≤46: 380≤Tp≤800 and T≤3,8º; and if 46<Ic: 380≤Tp≤800 and T≤0º.

Polar Po

Temperate and cold zones (51º-90º N & S). Altitude < 100m: Tp < 380.

(Rivas-Mart. et al., 2011)

(Modificado M.L. López y M.S. López, 26 diciembre 2016)

(1) Between 23º - 48º N and 23º - 51º S, if the locality is to 200 m, or more, of altitude, the thermal values must theoretically be calculated at such a height increasing T by 0.6º; M and m, by 0.5 °; and Itc by 13 units, per every 100 m that exceeds that altitude. At more than 48 ° N or 51 ° S, it is necessary to calculate the theoretical values of the average annual temperature, the average of the maximums of the coldest month, and the annual positive temperature, increasing T by 0.4 °, M by 0.5 ° and Tp by 12 units, for every 100 m exceeding said altitude.

DZHEZKAZGAN is located at 345m s.n.m., so that exceeds in 145m the 200m of reference. In Figure 97, the real values of de T, M, Itc and Tp are collected, as well as the theoretical values that result from theoretically positioning the station at 200m.

Figure 97.- Calculation of the theoretical values of the station of DZHEZKAZGAN, at 200m.

Increase per every 100m	DZHEZKAZGAN, at 345m	DZHEZKAZGAN, at 200m
T + 0,6º/100m	T = 4,1	T + 0,6º = 4,7
M + 0,5º/100m	M = -11,1	M + 0,5º = -10,6
Itc + 13/100m	Itc = 119	Itc + 13 = 132
Tp + 55/100m	1050	Tp + 55 = 1105

Once we have met the call (1), we can begin to analyze the Macrobioclimate of our meteostation. We look at the Macrobioclimates column of Figure 96: The first character mentioned is latitude. Latitude of Dzhezkazgán, 47º48'N. We have shaded the latitudes of the three possible Macrobioclimates, which could fit Dzhezkazgan: Mediterranean, Temperate and Boreal.

To distinguish now between these three Macrobioclimates, we analyze the following character: summer aridity, that is, if Ios2 is less than or equal to 2, or greater than 2. As our Ios2 = 0.64, it seems that our meteostation is Mediterranean: but before giving it as definitive, we have to check for a possible compensation by the moisture retained in the soil, due to rainfall in the month, or in the previous two months, by using the values of Iosc3, Iosc4.

To analyze the possible compensation, we look at figure 72. It is clear that, in order to assess the possible compensation of the summer aridity of an Ios2≤2, the annual Io must be equal to or greater than 2. In our case of DZHEZKAZGAN, its Io = 0.92, less than 2, does not even allow us to start the query of possible compensation, so our station has, definitely, summer aridity and is, therefore, Mediterranean.

From the Macrobioclimates column, figure 96, it follows that, of the three possible Macrobioclimates by latitude, only the Mediterranean Macrobioclimate has summer aridity, which leads us to conclude that:

Dzhezkazgán has a Mediterranean Macrobioclimate

BIOCLIMATE AND BIOCLIMATIC VARIANT

Once we know the Macrobioclimate of our station as Mediterranean, we proceed as follows for the identification of the Bioclimate / Bioclimatic Variant:

Figure 98. Differential characteristics of the Mediterranean Bioclimates, according to the Bioclimatic Synopsis of the Earth.

Mediterranean Bioclimates	Bioclimatic intervals		Acronyms
Mediterranean Bioclimates	Io	Ic	Acronyms
Me. Pluviseasonal Oceanic	2.0≤Io	≤ 21	Mepo
Me. Pluviseasonal Continental	2.0≤Io	> 21	Mepc
Me. Xeric Oceanic	1.0≤Io<2.0	≤ 21	Mexo
Me. Xeric Continental	1.0≤Io<2.0	> 21	Mexc
Me. Desertic Oceanic	0.2≤Io<1.0	≤ 21	Medo
Me. Desertic Continental	0.2≤Io<1.0	> 21	Medc
Me. Hyperdesertic Oceanic	Io<0.2	≤ 21	Meho
Me. Hyperdesertic Continental	Io<0.2	> 21	Mehc

For the BIOCLIMATE, we go to the second column-second row of the General Synopsis (Figure 7), which is reproduced in Figure 98. Analyzing the bioclimatic intervals that define each of the Mediterranean Bioclimates, we see that the Ombrothermal Index of our station, Io = 0.92, is in between 0.2 and 1.0, making it a Mediterranean Desertic Bioclimate. As there are two Bioclimates with that denomination, we now look at the Station's Continentality Index, which is Ic = 39.2, continental. So that:

Dzhezkazgán has a Mediterranean Desertic Continental Bioclimate

Regarding the BIOCLIMATIC VARIANT, in the General Synoptic Table, (figure 7), we found that, in that Bioclimate, only two variants - Steppe and Normal-, have been observed. We now check if our meteostation meets the requirements of the Steppic Variant, because otherwise, it would be the Normal Variant.

Figure 99.- The data to be used fot analyzing the possible existence of a Steppic Variant in DZHEZKAZGAN, are marked.

DZHEZKAZGAN, Kazakhstan
Latitude: 47º 48'N, Longitude: 067º 43'E Altitude: 345m
Temperature observation period: 1968 -1994 (27)
Rainfall observation period: 1984 -1994 (11)
	Ti	Mi	mi	M'i	m'i	Pi
Jan	-16,1	-11,1	- 21,0	7,8	-50,0	14,5
Feb	-14,7	- 9,4	-20,0	10,0	-41,1	16,0
Mar	-7,2	-1,7	-12,8	25,0	-38,9	25,9
Apr	6,4	13,3	-0,6	28,9	-22,8	6,6
May	15,0	23,3	6,7	67,8	- 8,9	14,0
Jun	20,8	29,4	12,2	41,1	-1,1	22,6
Jul	23,1	31,7	14,4	42,8	3,9	19,8
Aug	20,8	29,4	12,2	41,1	0,0	8,1
Sep	13,9	22,8	5,0	37,2	-10,0	8,4
Oct	5,0	12,2	- 2,2	30,0	- 20,0	17,0
Nov	- 4,7	0,6	-10,0	18,9	- 38,9	9,7
Dec	-13,1	-7,8	-18,3	6,1	- 41,1	13,2
Year	T = 4,1	---	---	---	---	P =175,8

The Steppic Variant implies: 1, a medium or high Continentaity: Ic > 17; 2, an Ombrothermal Index between the lower hyperarid and the upper sub-humid: 6.0 ≥ Io > 0.2; 3, at least one summer month whith the precipitation, in mm, less than three times its temperature, in degrees centigrade: Psi < 3Ti; -; and 4, the summer trimester positive precipitation needs to be higher than the winter trimester positive precipitation: Pps>Ppw.

According to the results of our previous calculations, in Dzhezkazgan: lc = 39.2; and lo = 0.92: we see that it fulfills those two conditions. For the relation of the precipitation of each summer month with its corresponding temperature, we take the data selected in figure 99, and analyze them in figure 100.

Figure 100.- Calculations to check if the Psi < 3Ti relation is fulfilled in the DZHEZKAZGAN station.

Mes	Psi	Ti	Ti x 3	Relation Psi - 3Ti
Jun	22,6	20,8	62,4	22,6 < 62,4
Jul	19,8	23,1	69.3	19,8 < 69.3
Aug	8,1	20,8	62.4	8,l < 62.4

We find that not only one, but all the summer months have Psi < 3Ti. That is, the station fulfills the third condition. Let us see that the fourth condition is also fulfilled, that PpS>PpW. To check this fourth condition, we also take the data from Figure 98, and analyze them in Figure 99, where we see how PpS>PpW: see figure 101.

Figure 101.- Calculations to check the relation PpS>PpW, in the station of DZHEZKAZGAN

Summer Trimester Positive Precipitation, Pps		Winter Trimester Positive Precipitation, Ppw		Relation Pps: Ppw
Jun	22,6	Dec	0,0
Jul	19,8	Jan	0,0
Aug	8,1	Feb	0,0
Total	50,5	Total	0,0	Pps > Ppw

As our station fulfills the four conditions of the Steppic Variant, we can state that Dzhezkazgán has the following Bioclimate and Variant:

Mediterranean Desertic Continental, Steppic Variant

BIOCLIMATIC BELT -Thermotype and Ombrotype-

Bioclimatic Belts are each one of the environments that follow each other in a latitudinal, longitudinal or altitudinal cliserie. Each Bioclimatic Belt corresponds to certain formations and plant communities: a vegetation belt. Each one of those environments delimits values intervals of Itc, Tp -Termotypes-, and of Io -Ombrotypes-.

To determine the Bioclimatic belt we have to go to the General Synopsis (figure 7) and observe the columns corresponding to Bioclimatic Belts of the row Mediterranean Macrobioclimate, columns that we have copied in Figures 102 and 103. In Termotypes there is a call, clarified in the last lines of the table, which warns us that, if the Continentality is high, Ic ≥ 21, or if the Compensated Thermicity Index is low, Itc <120, the Thermotype is evaluated as a function of Tp.

Recall that Dzhezkazgán has lc = 39.2, ltc = 119, Tp = 1050 and lo = 0.92. As our lc is high and, in addition, our ltc is low, we turn to the value of Tp =1050, between 900 and 1500, so our Thermotype is Supramediterranean. As for the Ombrotype, our lo=0.92 falls into the range 0.4 - 1.0, that is, the meteostation is Arid.

Thus, the Bioclimatic Belt corresponding to Dzhezkazgán is:

Supramediterranean Arid

Figure 102.- Bioclimatic Belts -Termotypes- of the Mediterranean Macrobioclimate, extracted from the General Synopsis.

Bioclimatic Belt	Thermotype (2)		Acronym
Bioclimatic Belt	Itc	Tp (2)	Acronym
1 Inframediterranean	450<ltc≤580	2400<Tp	lme
2 Termomediterranean	350<ltc≤450	2100<Tp≤2400	Tme
3 Mesomediterranean	220<ltc≤350	1500<Tp≤2100	Mme
4 Supramediterranean	Itc ≤ 220	900<Tp≤1500	Sme
5 Oromediterranean		450<Tp≤900	Ome
6 Crioromediterranean		0<Tp≤450	Cme
7 Gelid-mediterranean		Tp=0	Gme
(2) When Ic ≥ 21 (Continental) or when the values of Itc <120, the Thermotype is calculated as a function of Tp, and the theoretical values of Tp at 200 are calculated by increasing 55 units per each 100m that exceeds said altitude.

Figure 103.- Bioclimatic Belts -Ombrotypes- of the Mediterranean Macrobioclimate, extracted from the General Synopsis

Bioclimatic Belt	Ombrotype Io	Acronym
1 Ultrahyperarid	Io < 0.2	Uha
2 Hyperarid	0.2 ≤ Io < 0.4	Har
3 Arid	0.4 ≤ Io < 1.0	Ari
4 Semiarid	1.0 ≤ Io < 2.0	Sar
5 Dry	2.0 ≤ Io < 3.6	Dry
6 Subhumid	3.6 ≤ Io < 6.0	Shu
7 Humid	6.0 ≤ Io < 12.0	Hum
8 Hyperhumid	12.0 ≤ Io < 24.0	Hhu
9 Ultrahyperhumid	24.0 ≤ Io	Uhh

If we wanted to express the Bioclimatic Belt as Termotypic and Ombrotypic Bioclimatic Horizons, we would look at whether the values of Tp and Io are in the lower half, or in the upper half, of the thermal and ombric intervals of the Bioclimatic Belt.

In our meteostation of Dzhezkazgan, the Bioclimatic Horizons are:

Upper Supra-Mediterranean, Upper Arid

11.2.d.- Expression of the complete bioclimatic diagnosis -Isobioclimate-.

The Isobioclimate, the basic unit of "Global Bioclimatics", expresses all the climatic factors that operate in an area, and factors that explain the presence in such area of a certain type of life. To name each Isobioclimate is used a phrase that includes: Bioclimate / Bioclimatic Variant, together with a Bioclimatic Belt - Thermotype + Ombrotype-.

With all the known data we can, therefore, express the Isobioclimate of our station of Dzhezkazgán, like this:

Mediterranean Desertic Continental, Steppic Variant, Supramediterranean, Arid

In addition to words, the Isobioclimate can also be expressed by acronyms, recorded in the General Synoptic Table:

Medc Stp Sme Ari

If more detail is needed, for a finer approximation to the distribution of vegetation, We have discussed above that the Bioclimatic Belt can be expressed as Bioclimatic Horizons, the upper half or the lower half of the Thermotype and the Ombrotype. It is how Rivas-Martínez names the Isobioclimate in his web, and as it also appears named in Rivas-Mart. et al. 2011:

Mediterranean Desertic Continental, Steppic Variant, Upper Supramediterranean, Upper Arid,

which, if we express it in acronyms, results:

Medc Stp USme Uari

11.3.- Synthesis and graphic expression of bioclimatic study: Bioclimograph

Everything done in this practical example for the bioclimatic characterization of a meteorological station appears in figure 104 (page 140), which is how the climatic stations studied in the web "globalbioclimatics.org", of Rivas-Mart. & Rivas-Sáenz (1996-2017), appear.

Figure 104 has three parts: The first one contains the climatic data emitted by the station in question, as well as its name, its geographic location and its periods of observation. The second part shows the results of the necessary calculations to know the Bioclimatic Indexes, as well as the resulting Bioclimatic Diagnosis. And in the third part, the graphical representation of the Isobioclimate is given, that is to say, its Bioclimogram (Ombro-Thermoclimograph or Ombro-Thermoclimogram).

Figure 104.- Bioclimatic study of Dzhezkazgán



	Mediterranean Desertic Continental Bioclimate, Steppic Variant

12.- BIOCLIMATIC CARTOGRAPHY

Knowing the bioclimatic diagnosis of the meteorological stations of a continent, a region, or a nation, etc., It is possible to draw the boundaries of their Macrobioclimates, their Bioclimates, their Bioclimatic Variants, their Continentality, their Thermotypes, their Ombrotypes and their Isobioclimates, on the map, by interpolating the values of its Parameters and corresponding Indexes, from the data of the available meteorological stations, and taking into account prevailing winds and geographical features such as topography and orientation, which influence the climate in the study area (López, López & Piñas, 2009).

In order to illustrate the possibilities of Bioclimatic Cartography, carried out with the results of applying the "Worlwide Bioclimatic Classification System", by Rivas-Mart. & Rivas-Sáenz (1996-2017), to our climate data, next we reproduce some maps realized by the authors, in collaboration with other investigators, always based on our own climatic and bioclimatic data, or provided by Prof. Rivas-Martínez (contained in his worldwide climatic and bioclimatic database).

In 2000 we worked on the Macrobioclimates - Bioclimates and theTermotypes maps of Australia, together with Rivas-Martínez and P. Cantó, maps published by the University of León Cartographic Service (Rivas-Mart., López & Cantó, 2000a and b) (Figures 105-106).

Figure 105.- Macrobioclimates and Bioclimates Maps of Australia. (Link to its quality file).

AustrBiocl

Figure 106. Thermotypes Map of Australia. (Link to its quality file).

Austrtermo

In 2002, Rivas-Martínez, Ogar, Raskovskaja, López Fernández, Marinish, López, Amezketa and Gelidief presented to Congress "Itogi i perspektivi rasvitia botanicheskoi nauki v Kazajstane. Alma-Ata, "the Bioclimates Map of Kazakhstan (Figure 107). Also from Kazakhstan, Rivas-Mart., López, Amezqueta and López made a Continentality Map (Figure 108), which López Fernández & López Fernández have just published (Documentos Aljibe "on line", vol. IV, n7, 16 julio 2017).

Figure 107.- Bioclimatic Map of Kazakhstan. (Link to its quality file).

Kz_biocli2003

Figure 108. Continentality Map of Kazakhstan. Most of the country is Eucontinental, while the levels of Semicontinentality and Subcontinentality only appear in the southeastern mountainous border of the country. (Link to its quality file).

Kz_continental

Figure 109.- Far East Russian Macrobioclimates Map. (Link to its quality file).

1FE_MaBio

Figure 110. Far East Russian Continentality Map. (Link to its quality file).

5fe_continental

Between 2007 and 2015, a very complete bioclimatic study of Peninsular and Balear Spain, has been published: we offer it fully in Figures 111-116 - Maps of Macrobioclimates, of Bioclimates, of Bioclimates / Variants, of Thermotypes, of Ombrotypes, of Continentality and of Isobioclimates-(Piñas, 2007; López & al., 2008; Piñas, López et al., 2008 a y b; López, Marco et al., 2015). This cartographic study is completed with the Continental Map of the same territory, figure 117, which López Fdez & López Fdez have just published (Documentos Aljibe "on line", vol. IV, n7, 16 julio 2017).

Figure 111.- Macrobioclimates of Peninsular and Balearic Spain. (Link to its quality file).

1%20Macrobio_EtiquetSinN

Figure 112.- Bioclimates of Peninsular and Balearic Spain. (Link to its quality file).

2%20BioclimasEtiqueta

Figure 113.- Bioclimates/Variants Map of Peninsular and Balearic Spain. Note: if the name of the Bioclimate appears alone, it is understood to mean the Normal Variant. (Thus: if it is written "Mepo", it means "Mepo Nor", that is to say, “Bioclimate Mepo Normal Variant”; “Teho” means “Bioclimate Teho Normal Variant”. (Link to its quality file).

3%20Bio-Var%202

Figure 114.- Thermotypes Map of Peninsular and Balearic Spain. (Link to its quality file).

4%20Ter

Figure 115.- Ombrotypes Map of Peninsular and Balearic Spain. (Link to its quality file).

5%20Ombrotipos_Etique

Figure 116.- Isobioclimates Map of Peninsular and Balearic Spain, and its legend. (Note: in the Isobioclimates without mention of variant Steppic -Stp-, nor Submediterranean -Sbm-, it is understood that it is the Normal Variant -Nor-). (Link to its quality map file and its quality legend file).

6%20Fig3aisobioclimaMAPA2015ag

6%20Fig3bisobioclimaLEYENDA2015ag

Figure 117.- Continentality Map of Peninsular and Balearic Spain. (Link to its quality file).

TiposContinLOPIL

And finally, in 2011, Rivas-Mart. et al. published maps of the worldwide distribution of Bioclimates, Thermotypes, Ombrotypes and Continentality. It can be very instructive to see them in the original publication: Rivas-Martínez, S., Rivas Sáenz, S., Penas, Á. & col. (2011).

13.- PAGINATED GLOSSARY. (Warning: The page numbers refer to the .pdf document, which can be downloaded from the Web, either at the beginning or at the end of this work).

CONCEPTO	Page
Angle of incidence of sun rays	4
Annual Positive Precipitation -Pp-	11
Annual thermal amplitude	4, 11, 12
Antitropical Variant (Ant).	25, 28,
Biocenosis	3
Bioclimates	24, 25,
Bioclimates / Variants	17, 24,
Bioclimates Maps	141, 142, 145,
Bioclimates/Variants Map	146,
Bioclimatic Belts	17, 31,
Bioclimatic Cartography	139,
Bioclimatic Horizons	32, 33,
Bioclimatic Indexes	6, 11,
Bioclimatic Synopsis of the Earth	33,
Bioclimatic Variants	17, 24, 25, 28,
Bioclimatology	3
Bioclimograms	34, 139
Bioclimographs	34, 139
Bixeric Variant (Bix).	25, 28,
Boreal Bioclimates	25, 27,
Boreal Continental Bioclimate	27,
Boreal Hiperoceanic Bioclimate	27,
Boreal Hypercontinental Bioclimate	27,
Boreal Macrobioclimate	18, 20, 22, 24,
Boreal Oceánico Bioclimate	27,
Boreal Subcontinental Bioclimate	27,
Boreal Xeric Bioclimate	27,
Ci: compensation value	13, 15, 113,
Compensable summer aridity	102, 105
Compensated Thermicity, Index of	6, 11, 12, 13,
Continental Temperate Bioclimate	27,
Continentality / Oceanicity Index	6, 11, 12, 14
Continentality / Oceanicity, Premise of	4
Continentality Map	142, 144, 148,
Deserts Premise	4
Frost Periods –Pf-	9, 15,
Frost, Types of	8
Global Bioclimatic Diversity	36,
Hierarchical	1, 3, 5, 17, 24, 31,
Hypercoceanic Temperate Bioclimate	27,
Ic,	6, 11, 12,
Index of Compensated Thermicity	6, 11, 12, 13,
Index of Thermicity	6, 11, 12,
Io	6, 11, 13, 14, 15
Iod2	14, 15
Ios	14, 15,
Ios2	14, 15,
Iosc	14, 15,
Iosc3	14, 15,
Iosc4	14, 15,
Isobioclimate	34,
Isobioclimates Map	147,
It	6, 11, 12, 15,
Itc	6, 11, 12, 15, 113,
Latitude	6, 19,
Latitude, Premise of Photoperiod/Latitude	4,
Latitudinal Belts	6, 7
Latitudinal Zones	6, 7
Macrobioclimates	17, 18, 20, 24,
Macrobioclimates Map	141, 143, 145,
Mediterranean Bioclimates	25, 26,
Mediterranean Macrobioclimate	18, 20, 21, 24,
Mediterranean Pluviestacional Oceanic Bioclimate	26,
Mediterranean. Desert Continental Bioclimate	26,
Mediterranean. Desert Oceanic Bioclimate	26,
Mediterranean. Hyperdesertic Continental Bioclimate	26,
Mediterranean. Hyperdesertic Oceanic Bioclimate	26,
Mediterranean. Pluviestacional Continental Bioclimate	26,
Mediterranean. Xeric Continental Bioclimate	26,
Mediterranean. Xeric Oceanic Bioclimate	26,
Mediterraneity, Premise of	4
Normal Variant (Nor).	25, 31,
Oceanic Temperate Bioclimate	27,
Ombro-Thermoclimograph	139
Ombro-Thermoclimogram	34, 139
Ombrothermal Indexes	6, 11, 13,
Ombrotype	17, 31, 33
Ombrotypes Map	147,
Oroclimates (Mountain climates), Premise of	4
Orogenies, Premise of	5
Paginated glossary	149
Parameters	6, 8, 9, 10
Pav	15,
Photoperiod / Latitude, Premise of	4,
Phytotron	34,
Plant Activity Period	6, 8, 9, 15,
Pluvial Hygrophytic, “drought" level, Variant (Str)	29, 37
Pluvial Subhigrophytic, “drought" level, Variant (Str)	29, 37
Pluvial submesophytic, “drought" level, Variant (Str)	29, 37
Pluviseasonal Mesophytic, “drought" level, Variant (Str)	29, 37
Pluviseasonal Submesophytic, “drought" level, Variant (Str)	29, 37
Pluviseasonal Subxerophytic, “drought" level, Variant (Str)	29, 37
Pluviseasonal Xerophytic	29, 37
Pluviserotin Variant (Pse).	25, 28,
Polar Bioclimates	25, 27,
Polar Continental Bioclimate	27,
Polar Hyperoceanic Bioclimate	27,
Polar Macrobioclimate	18, 20, 23, 24,
Polar Oceanic Bioclimate	27,
Polar Pergelid Bioclimate	27,
Polar Semiboreal Variant (Pose).	25, 31,
Polar Xeric Bioclimate	27,
Positive Annual Temperature -Tp-	10, 16,
Positive Precipitation, Anual -Pp-	11
Pp, Annual Positive Precipitation	11, 15,
Precipitation Parameters	6, 9, 10,
Premises of the Classification	3
Reciprocity, Premise of	3
Rhythm of precipitation, annual	4
Seasonal Parameters	6, 9,
Seasonal temperature Variation	9
Seasonality of Precipitations	6, 8,
Seasonality of Precipitations, Premise of	4,
Seasonality of Temperatures	6, 8,
Semitropical Hyperdesertic Variant (Strhd)	25, 30,
Steppic Variant (Stp).	25, 30,
Submediterranean Variant (Sbm).	25, 30,
Summer aridity	21, 22, 23, 102, 105
Temperate Bioclimates	25, 26,
Temperate Macrobioclimate	18, 20, 22, 24,
Temperature Parameters	6, 9,
Thermal and Ombric Variations	6,
Thermicity, Index of	6, 11, 12,
Thermotype	17, 31, 32,
Thermotypes Map	141, 146,
Tp, Positive Annual Temperature	10, 16,
Tropical Bioclimates	25,
Tropical Desertic Bioclimate	26,
Tropical Drought Variants (Str).	25, 29,
Tropical Hyperdesertic Bioclimate	26,
Tropical Macrobioclimate	18, 20, 21, 24,
Tropical Pluvial Bioclimate	26,
Tropical Pluviseasonal Bioclimate	26,
Tropical Xeric Bioclimate	26,
Types of Frost	8
Types of frost.	6, 8,
Variants, Bioclimatic	17, 24, 25, 28,
Xeric Temperate Bioclimate	27,

14.- TABLE OF CONTENTS

1.- INTRODUCTION

2.- PREMISES OF THE BIOCLIMATIC CLASSIFICATION OF THE EARTH, RIVAS-MARTÍNEZ & al. (2011)

2.1.- Reciprocity

2.2.- Photoperiod / Latitude

2.3.- Continentality / Oceanicity - Annual thermal amplitude

2.4.- Seasonality of Precipitation

2.5.- Mediterraneity

2.6.- Deserts

2.7.- Oroclimates (Mountain climates)

2.8.- Orogenies

3.- BASIC COMPONENTS FOR THE WORLDWIDE BIOCLIMATIC CLASSIFICATION

3.1.- Latitude: Latitudinal Zones and Waists

3.2.- Seasonality of temperatures and rainfall. Period of plant activity. Types of frost.

3.3.- Parameters:

3.3.1.- Seasonal Parameters

3.3.2.- Temperature Parameters

3.3.3.- Precipitation Parameters

3.4.- Bioclimatic Indexes

3.4.1.- Continentality / Oceanicity Index: Annual thermal amplitude -lc-

3.4.2.- Index of Thermicity -It- and Index of Thermicity Compensated -Itc-

3.4.3.- Ombrothermic Indexes -Io-

3.5.- Alphabetical list of the abbreviations that designate the Parameters and the Bioclimatic Indexes,

4.- WORLDWIDE BIOCLIMATIC CLASSIFICATION

4.1.- First hierarchical level of the Classificacion: Macrobioclimates

4.1.1.- Tropical Macrobioclimate

4.1.2.- Mediterranean Macrobioclimate

4.1.3.- Temperate Macrobioclimate

4.1.4.- Boreal Macrobioclimate

4.1.5.- Polar Macrobioclimate

4.1.6.- Macrobioclimates Continental Distribution

4.2.- Second hierarchical level of the Classification: Bioclimates / Variants

4.2.1. Bioclimates

4.2.1.a) Tropical Bioclimates

4.2.1.b) Mediterranean Bioclimates

4.2.1.c) Temperate Bioclimates

4.2.1.d) Boreal Bioclimates

4.2.1.e) Polar Bioclimates

4.2.2.- Bioclimatic Variants

4.2.2.a) Pluviserotin Variant (Pse)

4.2.2.b) Antitropical Variant (Ant)

4.2.2.c) Bixeric Variant (Bix)

4.2.2.d) Tropical Drought Variants (Str)

4.2.2.e) Semitropical Hyperdesertic Variant (Strhd)

4.2.2.f) Steppic Variant (Stp)

4.2.2.g) Submediterranean Variant (Sbm)

4.2.2.h) Polar Semiboreal Variant (Pose)

4.2.2. I) Normal Variant (Nor)

4.3.- Third hierarchical level of the Classification: Bioclimatic Belts -Thermotypes and Ombrotypes-

4.3.1.- Thermotypes

4.3.2.- Ombrotypes

5.- BIOCLIMATIC SYNOPSIS OF THE EARTH

6.- ISOBIOCLIMATE

7.- BIOCLIMOGRAMS

8.- APPROACH to the GLOBAL BIOCLIMATIC DIVERSITY

8.1.- Diversity at Macrobioclimate level 36

8.2.- Diversity at Bioclimate/Variant level 36

8.3.- Diversity at Bioclimatic-Belt level 36

8.4.- Examples of Global Bioclimatic Diversity at the Macrobioclimate / Bioclimate / Bioclimatic Varian levels 39

9.- ASSESSMENT OF SUMMER ARIDITY, WITH EXAMPLES

9.1.- Assessment of summer aridity

9.2.- Examples for the valuation of summer aridity

10.- Itc and Ci CALCULATIONS

11.- PRACTICAL EXAMPLE of a meteorological station complete bioclimatic characterization, with the -use of the Synoptic Table.

11.1.- Climatic data of departure

11.2.- Bioclimatic diagnosis of a weather station

11.2.a.- Location of the weather station: Latitude, longitude and altitude

11.2.b.- Calculation of the necessary values and indexes

11.2.c.- Recognition of the bioclimatic units of the station, using the General Synoptic Table

11.2.d.- Expression of the complete bioclimatic diagnosis -Isobioclimate-.

11.3.- Synthesis and graphic expression of bioclimatic study: Bioclimograph

12.- CARTOGRAFÍA BIOCLIMÁTICA

13.- PAGINATED GLOSSARY

14.- TABLE OF CONTENTS

15.- BIBLIOGRAPHY

15.- BIBLIOGRAPHY

Gaussen, H. et F. Bagnouls (1952). L’indice xérothermique. Bull. de l’Assoc. de géographes français. 1952, pp. 10-16.

López Fernández, ML & López Fernández, MS. (2008) Ideas básicas de “Global Bioclimatics”, del Prof. Rivas-Martínez: Guía para reconocer y clasificar las unidades bioclimáticas. Publ. Biol. Univ. Navarra, Ser. Bot., 17:3-188.

López Fernández, M.L.& López Fernández, M.S. (2017). “Manual y Guía de Bioclimatología Mundial”. Documentos Aljibe “on-line”, vol. IV, n.6, 13 de abril de 2017. Ciudad Real. Edita Sociedad Surcos. Depósito Legal: CR 820-1986- - ISBN 84-398-6347-0 ISSN 2445-1304. http://www.naturalezenhispania.com.

López Fernández, M.L., López F., M.S., Piñas, S. (2009). “A Bioclimatic & Cartographic Formulation of Climate for Biogeography”. Poster Presentation, 4rd. Biennal Conferen. of IBS. Mérida, México

López Fernández, M.L., Marco, R., Piñas, S., López, S. (2015). “Mapa Isobioclimático de la España Peninsular y Balear”. Documentos Aljibe “on line”, vol. II, nº 4. Ciudad Real, España. Edita Sociedad Surcos. Depósito Legal: CR 820-1986- - ISBN 84-398-6347-0 ISSN 2445-1304. http://www.naturalezenhispania.com.

López Fernández, M.L., Piñas, S., López F., M.S. (2008). “Macrobioclimas, Bioclimas y Variantes Bioclimáticas de España Peninsular y Balear”. Publicaciones de Biología, Universidad de Navarra, Serie Botánica, 17, 229-236.

López Fernández, M.S. & López Fernández, M.L. (2017). “Bioclimatología: Estudio comparado de Continentalidad en España Peninsular, Kazakjistán y Lejano Oriente de Rusia”. Documentos Aljibe “on-line”, vol. IV, n.7, 16 julio 2017. Ciudad Real. Edita Sociedad Surcos. Depósito Legal: CR 820-1986- ISBN 84-398-6347-0 ISSN 2445-1304. http://www.naturalezenhispania.com

Piñas, S. (2007). Bioclimatología de la España Peninsular y Balear, y su Cartografía. Tesis Doctoral. 110 pp. y anexos. Universidad de Navarra. Manuscrito inédito.

Piñas, S., López F., M.S., López Fernández, M.L. (2008a). “Termotipos de la España Peninsular y Balear, y su cartografía”. Publicaciones de Biología, Universidad de Navarra, Serie Botánica, 17, 237-242.

Piñas, S., López F., M.S., López Fernández, M.L. (2008b). “Ombrotipos de la España Peninsular y Balear, y su cartografía”. Publicaciones de Biología, Universidad de Navarra, Serie Botánica, 17, 243-248

Rivas-Martínez, S. (1987). Nociones sobre Fitosociología, Biogeografía y Bioclimatología. In: Peinado, M & S. Rivas-Martínez (eds.) La vegetación de España: 19-45. Ed.

Rivas-Martínez, S. (2004). Global Bioclimatics (Clasificación Bioclimática de la Tierra) (Versión 27-08-2004). www.globalbioclimatics.org.

Rivas-Martínez, S. (2008). Global Bioclimatics (Clasificación Bioclimática de la Tierra). www.globalbioclimatics.org.

Rivas-Martínez, S., López, M.L. & Cantó, P. (2000a). Bioclimatic Map of Australia: Macrobioclimate and Bioclimate. Cartographic Service, University of León, Spain.

Rivas-Martínez, S., López, M.L. & Cantó, P. (2000b). Bioclimatic Map of Australia. Thermoclimatic Belts. Cartographic Service, University of León, Spain

Rivas-Martínez, S., López Fernández, M.L., Amezketa, A., López, M.S., Aquerreta, S., Piñas, S. (2003). “Macrobioclimates, Bioclimates, Thermotypes, Ombrotypes and Continentality Maps of Far East Russia”. En Phytogeography of Northeast Asia: task for the 21st century. Vladivostok (Rusia).

Rivas-Martínez, S., Ogar, N., Raskovskaja, E., López Fernández, M.L., Marinish, O., López, M., Amézketa Ibero, A., & Gelidief, B. (2002). Bioclimaticheskaja Karta Kazakhstaja. (Mapa Bioclimático de Kazakhstán). En Itogi i perspektivi rasvitia botanicheskoi nauki v Kazajstane (Materiali mezdunarodoi nauchnoi konferencii, pocviachshenou 70-letiiu Instituta Botaniki i Fitointrodukcii), Alma-Ata (Kazakhstán), 259-261.

Rivas-Martínez, S. & Rivas-Saenz, S. (1996-2017). Worldwide Bioclimatic Classificacion System. Phytosociological Research Center, Spain. http://globalbioclimatics.org/

Rivas-Martínez, S., Rivas Sáenz, S., Penas, Á. & col. (2011). Worldwide Bioclimatic Classification System. Global Geobotany, 1: 1-634 + 4 Maps

Walter, H. & Lieth, H. (1967). Klimadiagramm-Weltatlas. Gustav Fischer Verlag, Jena 1967.

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Tropical Tr

Mediterranean Me

Temperate Te

Boreal Bo

Polar Po

Subtropical warm zone (23º-35º N & S) and eutemperate temperate zone (35º-52º N & S), with summer aridity at least bimonthly after the summer solstice: Ios2 ≤ 2, Iosc4 ≤ 2. In Subtropical, at least two of the three thermal values: T < 25º, m < 10º, Itc < 580.

Temperate and cold zones (51º-90º N & S). Altitude < 100m: Tp < 380.

(Rivas-Mart. et al., 2011)

Subtropical warm zone (23º-35º N & S) and eutemperate temperate zone (35º-52º N & S), with summer aridity at least bimonthly after the summer solstice: Ios₂ ≤ 2, Iosc₄ ≤ 2. In Subtropical, at least two of the three thermal values: T < 25º, m < 10º, Itc < 580.