bioclimatic belts of sierra madre occidental (mexico):a preliminary approach

International Journal of Geobotanical Research, Vol. nº 3. 2013. pp. 19-35

Corresponding author: Joaquín Giménez de Azcárate. Higher Politecnic School. University of Santiago de Compostela. Spain, e-mail: [email protected]. Telf. 34 98282362 Fax: 34 982285887 ISSN: 2253-6302 (print)/ISSN: 2253-6515 (on line) ©Editaefa DOI: 10.5616/ijgr 130002

Bioclimatic belts of Sierra Madre Occidental (México): A preliminary approach.

Joaquín GIMÉNEZ DE AZCÁRATE (1), Miguel Ángel MACÍAS RODRÍGUEZ(2) y Fernando GOPAR MERINO(3)

(1) Department of Botany. Higher Politechnic School. University of Santiago de Compostela. E-27002 Lugo. Spain. (2) Department of Environmental Sciences. University Center of Biological and Agricultural Sciences- University of Guadalajara, Jalisco. México. (3) Centre for Research in Environmental Geography. Campus Morelia. National Autonomous University of México. Michoacán. México.

Abstract

A bioclimatic synthesis of the Sierra Madre Occidental (SMO) based on the diagnosis of data from 159 meteorological stations, the floral and vegetation data collected in field surveys, and in the bibliographic revision. The considered area is above the altitude of 1800 m included in the physiographical province of SMO, which entirely belongs to Tropical macrobioclimate, being represented by the biocli-mates Tropical Pluviseasonal and Tropical Xeric. Broadly speaking, the first is distributed in the highlands and on the western slope of the range, while the second is sited in the dry mountain ravines and on the eastern slope. Fourteen isobioclimates were recognised, 5 for the bioclimate Tropical Xeric (Thermotropical Dry, Mesotropical Semiarid, Mesotropical Dry, Supratropical Semiarid and Supratropical Dry) and 9 for the Tropical Pluviseasonal (Thermotropical Subhumid Mesotropical Subhumid, Mesotropical Humid, Supratropical Subhumid, Supratropical Humid, Supratropical Hyperhumid, Orotropical Subhumid, Orotropical Humid and Orotropical Hyperhumid). Each one has its corresponding vegetation belt, with emphasis in the structure of its potential natural vegetation, its main bioindicators and its catenal distribution. These results are complemented by distribution maps of the bioclimates, thermotypes and ombrotypes pre-sent, and by three vegetation transects recognised along both routes made at different latitudes.

Keywords: Bioindicators, distribution, isobioclimates, México, Sierra Madre Occidental.

Abreviations used

AGS: Aguascalientes. CHIH: Chihuahua, CONABIO: Nacional Comision for the Knoweldege and Use of the Biodiversity. DGO: Durango. GIS: Geographical Infor-mation System. INIFAP: Instituto Nacional de Investiga-ciones Forestales y Agropecuarias. JAL: Jalisco. IUCN: International Union for the Natural Conservancy. NAY: Nayarit. SIN: Sinaloa. SMO: Sierra Madre Occidental. SON: Sonora. WGS: World Geodesic System ZAC: Zacatecas.

Introduction

The science of bioclimatology is based in the formu-lation of fundamentals that relate climate to the distribu-tion of plants and their plant communities; in this way, the index and parameters used are related or delimited by living organisms and, particularly by the plants and ve-getation (Müller, 1982; Breckle, 2002). Climatic dates and their parameters and index, as well as floristic and phytosociological data, are very useful tools in the analy-sis of those links, and allow one to draw the biogeogra-

phic boundaries in relatively homogeneous floristic ter-ritories (Tuhkanen, 1980). Over recent decades this has motivated a remarkable advance in the development of Bioclimatology. On a continental and regional level, the macrobioclimate is the main environmental regulatory factor of the distribution of global vegetation (Larcher, 2003), while the edaphic or geomorfologic factors play a secondary role. Among the most widely used approaches to relate climate and vegetation is the Walter model, with its concept of zonobioma (Breckle, op cit.); other appro-aches deriving from it have been proposed by Bailey (1995, 1996), Brown et al. (1998), Olson et al. (2001) y

Schultz (2005). At a regional level the considerations obtained from climatic models of Gaussen (Walter & Lieth, 1960-67; Lieth et al. 1999; Rivas-Martínez, 2004, 2008), have demonstrated great effectiveness in dis-criminating macroclimates and bioclimates, and in rela-ting climate and vegetation accordingly, to establish the physical parameters (thermotypes and ombrotypes). The ever-more detailed knowledge of the distribution and composition of the vegetation, along with the availability of climate data and computer tools for management and

https://www.researchgate.net/publication/37903893_Selected_Climatic_Data_for_a_Global_Set_of_Standard_Stations_for_Science?el=1_x_8&enrichId=rgreq-b199e196-05d4-470c-b42f-8e1b53f06c2b&enrichSource=Y292ZXJQYWdlOzI3MTA1NDU1NDtBUzoxOTMwNzYxNTM4NTE5MzFAMTQyMzA0NDM1MTA0Nw==

J. Giménez de Azcárate , M.Á. Macías Rodríguez & F. Gopar Merino

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ordering, provide criteria and objectivity to the biocli-matic models and their relationship with the vegetation. This has led to bioclimatology being regarded as one of the foundations for classifying and defining the earth's ecosystems and its boundaries in a standardized, robust, predictive and practical way (Sayre et al. 2007). In addi-tion it has been implemented in programs of study and conservation of habitats and biodiversity, in obtaining predictions for agricultural and forestry resources, and to determine future climate and vegetation scenarios (Ri-vas-Martínez, 2007).

The geographical distribution and the orography of the Sierra Madre Occidental (afterwards referred to as SMO), favour the appearance of ecosystems with an origin and nature antagonistic as deserts, woodland, grasslands and shrublands. Its geographical position along western Mexico has determined the diversity and distribution of species and plant communities to act as a barrier to the flora and vegetation coming from high plateaux and both Coastal and Sonoran plains. It also functions as migratory corridor of the holartic species and plant communities coming from higher latitudes to Mesoamerica. Also note the remarkable importance of the endemic component in the region (Rzedowski, 1978; González-Elizondo et al. 2012), and its role as a source of environmental goods and services for society (Bye, 1995; Descroix et al. 2004). It also includes 32 of the 152 Prioriti Terrestrial Regions of México as defined by CONABIO institution (Arriaga et al. 2000). Among the dominant plant formations are pine-oak forests, adapted to a wide variety of habitats and possessing the highest floral diversity of Mexico (Rzedowski, op. cit.), encou-raging the wealth of plant communities it hosts. In this sense the IUCN has recognized two hotspots of biodiver-sity within the SMO: the north of SMO and the upper basin of Mezquital river (Felger & Wilson, 1995; Gon-zález-Elizondo, 1997). On the other hand SMO is a rele-vant territory for its biocultural heritage, linked to the body and vitality of the seven indigenous groups that live there (Bye, op. cit.; Boege, 2008).

Studies on the vegetation and flora of the SMO cor-respond mostly to contributions made in particular terri-tories of its geography; and of these the following are noteworthy: Lumholtz (1902), Gentry (1942), LeSueur (1945), White (1948), Gordon (1968), McVaugh (1987, 1989, 1992, 2001), Búrquez et al. (1992), González-Eli-zondo & González-Elizondo (1992), González-Elizondo et al. (1993), Laferrière (1994), Casas et al. (1995), Fel-ger & Wilson (1995), Fisher et al. (1995), Martin et al. (1998), Reina et al. (1999), Lebgue Keleng (2002, 2005), Enríquez et al. (2003), Estrada et al. (2003), García-Aré-valo & González-Elizondo (2003), García-Arévalo et al. (2004), Koleff et al. (2004), Vázquez-García et al. (2004), González-Elizondo et al. (2009, 2011), Reina & Van Devender (2005), García-Arévalo (2008), Mathiasen et al. (2008), Herrera et al. (2009), Aragón et al. (2010) and Van Devender et al. (2010). The study of González-Elizondo et al. (2012) stands out as an integrated synthe-sis of the vegetation throughout the SMO. In the field of cartography the studies showing the distribution of the vegetation units are: Anonymous (1973, 1997, 2002, 2007a); Rzedowski, 1978; Brown et al. 1998; González-Elizondo et al. 2007 and González-Elizondo et al. 2012.

The absence of geobotanical and bioclimatic studies in this territory has driven this study, the aim being to identify the bioclimatic belts and establish their relation-ship with the vegetation through the implementation of a Global Bioclimatics model (Rivas-Martínez, 2008, 2011a). Here we try to support a consistent, predictive and universal classification system of terrestrial ecosys-tems of SMO, with bioclimatology as the cornerstone for its description and systematization of differents scales (Sayre et al. 2008, 2009; Cress et al. 2009; Rivas-Martí-nez et al. 2011b).

Background

In North America the geobotanical contributions for ordering and describing the plant communities, based on bioclimatology and phytosociology, were first used al-most 20 years ago (Peinado et al., 1994a, 1997a, 1997b; Rivas-Martínez, 1997; Peinado et al. 1998; Rivas-Martí-nez et al., 1999; Peinado et al., 2006, 2007, 2010, 2011). In México the geobotanical research that incorporates bioclimatology as a tool for geospatial analysis of eco-systems, have been developed in specific territories and had little impact. This is due to the criteria traditionally followed in the studies of vegetation, based on a physio-gnomyc and ecological diagnosis, supported by Kö-ppen´s classification amended by García (Miranda & Hernández X., 1963; González-Quintero, 1974; García, 1973, 2004; González-Medrano, 2003; Anonymous, 2013), and to the taxonomic challenges surrounding a very diverse flora (Rzedowski, 1978, 1991; Mittermeier & Goettsch, 1992; Villaseñor, 2004). All of the above have prevented the adoption of a hierarchical and syste-matic proposal. Despite this, some studies have been carried out which contribute to the knowledge of the relationships among vegetation, distribution and climate, such as those carried out in Northwest México (Peinado et al. 1994b, 1995, 2008, 2010), Transmexican Volcanic Belt (Almeida et al., 1994, 2004; Escamilla et al. 1998, 2002; Giménez de Azcárate & Escamilla, 1999; Giménez de Azcárate et al., 1997, 2003; Giménez de Azcárate & Ramírez, 2004; Medina et al., 2012), Potosino Highpla-teau (Giménez de Azcárate & González-Costilla, 2011) and Yucatán Península (Barber & Crespo, 2001).

Territory description

The SMO is the longest mountain range in México starting at the border with Arizona and New Mexico (USA) to the north (30º 35' N) and running SSE to Jalis-co where it meets with the Mexican Volcanic Belt (21º 00' N). It runs through the states of SON, CHIH, DGO, SIN, ZAC, NAY, AGS and JAL. The main peaks are Cerro Gordo (3,347 m), Barajas (3,310 m), Mohinora (3,307 m), Huehuento (3,262 m) and “Cerro de las Ante-nas” (3,224 m), all of them located in Durango except Mohinora located in the SW of Chihuahua; other minor summits and ranges have an altitude between 2500 m and 3000 m. The rivers from it drain into the Pacific Ocean and toward the Mexican Highplateau. In this last instance some streams flow to endorheic basins and others to the Mexican Gulf through the rivers Conchos and Bravo. Both sides of the watershed show a marked asymmetry; thus the western aspect is scoured by deep ravines that can reach 1,800 m in depth: the Urique, Cobre, Sinforosa Tamazula, San Lorenzo, Presidio, Ba-

Bioclimatic belts of Sierra Madre Occidental (México):A preliminary approach

21

luarte, Mezquital, Santiago and Bolaños being the most outstanding. Its eastern flank, however, presents a gra-dual transition to the Mexican Highplateau.

The extent of the SMO coupled with its floral and physiographic complexity, has motivated this study con-cerning analysis of the territories belonging to the SMO which are located above 1,800m (Figure 1). This area covers 177,593 km2 and corresponds to 50.1% of the total area of the physiographic province of the SMO; this unit shares borders with the following provinces: “Llanura Sonorense” and “Planicie Costera del Pacífico” to the west, “Sierras y Llanuras del Norte” to the east and north, “Mesa del Centro” to the south-east, and “Eje Neovolcánico” to the south (Cervantes et al. 1990; CONABIO, 1997). The territories excluded from the present study are undergoing preliminary analysis and will be the subject of a future publication.

From a biogeographic point of view, the area consi-dered belongs mostly to the floral province of SMO, which is included in the region “Mesoamericana de mon-taña”. This region is a transitional zone between the Holartic and Neotropical kingdoms, characterized by the convergence of boreal affinity woody flora, tropical affi-nity herbaceous flora and endemic elements. (Rzedo-wski, 1978, 1991, 1996; Rzedowski & Reina, 1990). The remainder area belongs to the Altiplanicie floral province (Xerofitica-Mexicana region).

Following the biogeographic classification of Rivas-Martínez et al. (1999), the territory is included in the Madreana Occidental province (Madreana region); in specific areas of its periphery, taxa coming from the Mexicano-Xerofítica region, and particularly in the northern area of study from the Gran Cuenca region, are present.

The factors that determine the climatic traits and the

diversity and distribution of the climates in the territory are conditioned by the geographical position between the subtropical high pressure belt and the intertropical con-vergence zone (latitudinal bands eutropical and subtropi-cal); the exposure to the entry of warm and humid Paci-fic ocean winds; the broad altitudinal and latitudinal range; and the physiographical complex that determines an asimmetry of slopes due to the effect of the orogra-phic barrier. All of this determines the thermic regime, with average monthly values getting a low or medium fluctuation, and ombric with a markedly summer cha-racter determined by the convective mass causing the so-called "Mexican Front", along the western aspect of the SMO (Mosiño-Alemán & García, 1974; Douglas et al. 1993). Moreover, the climate is going to be affected by tropical storms and hurricanes occurring in the Pacific toward the end of summer and autumn (Hastings & Turner, 1965). The rough slopes on the western side play a decisive role in the range of precipitation and tempe-rature. These climatic features coupled with its biogeo-graphic position between the Neartic and Neotropical

kingdoms (Rzedowski, 1978), make the region of study an exceptional location to put into practice the metho-dology of bioclimatic analysis.

Methods

The diagnosis has followed the proposal of Global Bioclimatic classification system (Rivas-Martínez, 2007, 2008; Rivas-Martínez et al. 2011a) based on the reciprocal relationship between the values of climate models and the distribution of vegetation, explained through the altitudinal zonation of the bioclimatic belts. The system includes basic aspects related to the limitations that the climate creates on vascular plants and plant communities. The basic parameters and index used in the analysis have been: Ti, mi, Mi, m, M, Tp, Pi, Pp, It, Io, Iod2 and Ic; their definitions can be found in previous papers.

As climatic information was taken into account, data coming from meteorological stations located in the area of study and published in the Basic Climatological Sta-tistics of INIFAP for the states of: AGS (Medina et al., 2006b), CHIH (Medina et al., 2006a), DGO (Medina et

Figure 1: Location of the study area


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al., 2005), JAL (Ruiz et al., 2003); SIN (Ruiz et al., 2005) and ZAC (Medina & Ruiz, 2004). NAY and SON have not been considered because their meteorological sta-tions are located below the benchmark followed in this study. To complete the territorial representation infor-mation from others stations available in the National Meteorological Service of Mexico (Anonymous, 2011) was incorporated. In total there were 159 stations whose breakdown by states is: AGS 14, CHIH 48, DGO 46, JAL 7, SIN 1 and ZAC 43. For each one, in addition to considering its geographic location, basic climate infor-mation averaged monthly from the different parameters of precipitation and temperature was used. Based on this information the values of the different bioclimatic index were obtained using the Bioclima program (Alcaraz, 2013) which generates the diagnosis and the bioclimo-gram for each station. These results were supplemented with those obtained in the field trips carried out during the years 2009, 2010 and 2011, in which the climate-vegetation relationships were checked and adjusted considering the dynamic-catenal phytosociological con-cepts (Rivas-Martínez, 2005). The field work was based on the selection of representative and well preserved patches of natural potential vegetation from all over the territory. Also the recommendations of Beard (1973)

were taken into account focused on the analysis of the structure and the physical appearance of the vegetation, and on the presence of forest indicator species. In addi-tion, when complexity of flora allowed it, phytosociolo-gical releves were carried out (Braun-Blanquet, 1979; Westhoff & van der Maarel, 1980), in order to accurately back up the field work. In a complementary way three transects of potential natural vegetation were established along the range (Box, 1981; Rivas-Martínez, 2007). For floristic determinations, regional and taxonomical floras were consulted, as well as floristic lists (Farjon et al. 1997; González-Elizondo et al. 1991, 2007; González-Elizondo & González-Elizondo, 1995; García-Arévalo & González-Elizondo, 2003; González-Villareal, 1986, 1990; McVaugh, 1987, 1989, 1992, 2001; Vazquez-Gar-cía et al. 2004). The Tropicos database (2013) was used as the nomenclatural reference model. The spatial con-text used in the description of the vegetation units was based on geographical and physiographical aspects (Cer-vantes et al. 1990; CONABIO, 1997).

To carry out the mapping, the information included in the Digital Climatic Atlas of México (version 2.0) was used for reference; monthly and annual averages of maximum temperature, minimum temperature and pre-cipitation were considered (Hijmans et al. 2005; Fernán-dez-Eguiarte et al., 2012). The layers of climatic infor-mation are available in raster format with pixels around 1 Km2. The period considered was 109 years (1902 - 2012). These layers were analyzed in a GIS (ArcGIS 9.3) thus obtaining the bioclimatic index values. Based on these results and through the process of algebraic map-ping, a raster series with the different values obtained for each pixel was made, which gave rise to the correspon-ding maps of bioclimates, thermotypes and ombrotypes. The overlap of these layers allowed us to identify the isobioclimates present in the territory. To homogenize the information contained in the raster layers, these were

converted in vector format giving the corresponding polygons. The maps were made to a scale 1:500,000 and a Lambert conical projection and WGS-84 datum were considered. The minimum scale for cartography was 2 mm2 on the map, so those polygon areas smaller than 100 Ha were eliminated.

The bioclimatic characterization was supplemented with the analysis of potential natural vegetation. For this, the data collected in the field and the vegetation and land use vegetation map (Anonymous 2007b) were taken into account. From this last map only the types related to cli-matophylous vegetation were considered, in order to link them with their corresponding bioclimatic belt. It also took into account the descriptions of vegetation related in lite-rature (RzedowskI 1978; González-Elizondo et al. 2007, 2012). Finally bioclimatic contributions reported in neig-hbouring territories were considered (Peinado et al. 1994b, Rivas-Martínez et al. 1999; Macías, 2009; Peinado et al. 2010, 2011; Giménez de Azcárate & González-Costilla, 2011).

Results

This diagnosis places the SMO within the macrobio-climate Tropical with the presence of a marked rainy season (June to October) coinciding with the warmer half of the year. With regard to bioclimate, are represented the Tropical Xeric (1 ≤ Io ≤ 3.6) and the Tropical Pluvi-seasonal (Io ≥ 3.6; Iod2 ≤ 2.5); its distributions are showed in Map 1. Within the first, five bioclimatic belts are recognized (in brackets the number of stations assig-ned): thermotropical dry (0), mesotropical semiarid (7), mesotropical dry (90), supratropical semiarid (0) and supratropical dry (7). With respect to the Bioclimate Tropical Pluviseasonal presents five bioclimatic belts: thermotropical subhumid (0), mesotropical subhumid (8), mesotropical humid (1), supratropical subhumid (21), supratropical humid (18), supratropical hyperhumid (2), orotropical subhumid (0), orotropical humid (5) and orotropical hyperhumid (0). The presence of bioclimatic belts without representative meteorological stations is justified on the basis of the results of the extrapolations made for map making and the analysis of the vegetation. The distribution of thermotypes and ombrotypes is re-flected in the maps 2 and 3 respectively. Supratropical subhumid and Supratropical humid are the bioclimatic belts better represented within Tropical pluviseasonal bioclimate, mainly along the highlands of SMO. Within Tropical xeric boclimate, the more representative belt is Mesotropical dry, mainly toward the southeastern portion (ZAC); also Supratropical dry has an important presence in the northeastern area, bordering the Chihuahuan De-sert. The Thermotropical and Orotropical thermotypes, and the Arid and Hyperhumid ombrotypes are both vir-tually unrepresented due to problems of scale.

The correspondence between bioclimates (isobiocli-mates) and the 15 types of climatophilous vegetation types, selected from INEGI Serie IV (Anonymous 2007b), is showed in Table 1. Other vegetation types like edaphoxerophylous, hygrophilous or secondary vegeta-tion types, are not considered within the table, as they are not condicioned by weather, but by other factors such as the lithological, soil nature or anthropical influence.


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Map 2: Thermotypes of Sierrra Madre Occidental

Map 1: Bioclimates of Sierrra Madre Occidental


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VEGETATION TYPE

ISOBIOCLIMATES

TROPICAL XERIC TROPICAL PLUVISEASONAL

Mes

otro

pica

l S

emia

rid

Sup

ratr

opic

al

Sem

iari

d

The

rmot

ropi

cal

Dry

Mes

otro

pica

l D

ry

Sup

ratr

opic

al

Dry

The

rmot

ropi

cal

Sub

hum

id

Mes

otro

pica

l S

ubhu

mid

Sup

ratr

opic

al

Sub

hum

id

Oro

trop

ical

S

ubhu

mid

Mes

otro

pica

l H

umid

Sup

ratr

opic

al

Hum

id

Oro

trop

ical

H

umid

Sup

ratr

opic

al

Hyp

erum

id

Oro

trop

ical

H

yper

umid

Bosque de Ayarín x x x

Bosque de Cedro x X

Bosque de Encino x x x x x x x x

Bosque de Encino-Pino x x x x

Bosque de Oyamel x x

Bosque de Pino x x

Bosque de Pino-Encino x x

Bosque de Tascate x

Bosque Mesófilo de Montaña x

Chaparral x x

Matorral Crassicaule x x x x x

Matorral Desértico Micrófilo x x

Matorral Desértico Rosetófilo x x x

Selva Baja Caducifolia x x x

Selva Baja Subcaducifolia x x x

Table 1. Correspondence among vegetation types selected of INEGI (Anonymous 2007b) and the isobioclimates recogniced. The intersections ✔ link the vegetation types with the isobioclima (s); if that intersection is marked with x, shows that the vegetation type has an azonal or marginal nature.

For each isobioclimate recognized a selection of me-

teorological stations with its corresponding diagnosis is shown in Table 2. In this regard Figure 2 shows six bio-climatic diagrams of some of these stations; a complete diagnosis of which is presented in Table 3.

Correspondence with vegetation belts

The extent of the area and its geomorphological and physiographic complexity condition the biota growing there, which also presents an enormous taxonomic and syntaxonomical difficulties. Therefore, the proposition and description of the phytocoenoses that correspond to each situation is very complicated and is outside of the scope of this paper. Nevertheless, taking into account the bioclimates existing in the study area (Tropical xeric and Tropical pluviseasonal) and their bioclimatic belts, the more representative types of potential natural vegeta-tion have been defined and characterized, without going into the peculiarities of the phytocoenoses hosting. For this reason the diagnosis is focused on the dominant structure and physiognomy, its main bioindicators, its distribution and catenal position; when there was infor-mation available, dynamic and ecological aspects are discussed in order to complement the analysis. It should be added that a number of the bioindicators recognized for each belt are not present in the whole of it, especially in the largest ones; also some of those bioindicators are able to fluctuate towards neighboring horizons by phy-siographic and edaphic compensatory accommodations.

Tropical Xeric Bioclimate

Thermotropical Dry

It is distributed mainly below the benchmark conside-red here (1,800 m), although it can extend above this level when local physiographic and climatic conditions are favourable, as in the case of the warmest and most sheltered ravines. The ombrotype Dry is the most wides-pread, and is located on the lower slopes of the western of SMO, as well as in the deeper intermontane ravines crossing it (Yaqui, Mayo, Fuerte, Mezquitic, Acaponeta, Chapalagana, Bolaños, etc); through these ravines its associated woodland may ascend to around the 2,000m level. (González-Elizondo et al. 2012). The structure of the potential vegetation is a plurispecific deciduous mi-croforest, tropical deciduous forest sensu Rzedowski (1978). Its floral composition shows no clearly dominant species, being shared among the representative bioindi-cators of this bioclimatic belt: Amphipterygium adstrin-gens, Bursera benthamii, B. fagaroides, B. graveolens, B. multijuga, B. schlechtendalli, Cedrela odorata, Ceiba acuminata, C. aesculifolia, Cochlospermum vitifolium, Cordia alliodora, Haematoxyllum brasiletto, Leucaena esculenta, L. lanceolata, Lonchocarpus spp., Lysiloma spp., Pachycereus pecten-aboriginum, Pseudobombax palmeri, Stenocereus queretaroensis, S. turberi, Tabe-buia impetiginosa, etc. Disruption of this forest leads to the development of a replacement plant community which holds some of the previous trees and secondary species like Erythrina flabelliformis, Guazuma ulmifolia, Ipomoea arborescens, I. murucoides, Lysiloma acapul-cense, Plumeria acutifolia, Tecoma stans, Vachellia spp


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Figure 2: Bioclimatic diagrams of six representative stations of the isobioclimates recogniced: Campo nº 5 (CHIH), La Ciudad (DGO), Vascogil (DGO), Cuahutemoc (CHIH),


26

The steepness and irregularity of the thermotropical areas favours the contact with the different Pinus spp. and / or Quercus spp plant formations found in the upper bioclimatic belt (Mesotropical), which is reflected in contrasting mosaics of vegetation. Sometimes these forests can appear in the thermotropical belt, where they are linked to exceptional soil conditions such as stony outcrops, nutrient poverty and abundance of heavy me-tals (Penington & Sarukan, 2005; Macías, 2009).

As we further away from the SMO to the Chihuahuan or Sonoran Deserts the aridity increases leading to the presence of Arid and Semiarid ombrotypes (Rivas-Mar-tínez et al.1999; Peinado et al. 2010).

Mesotropical Semiarid

Its location is restricted to the driest places in the in-tramountain valleys and eastern foothills of the adjacent physiographical subprovinces: “Sierras y Llanuras de Durango”, “Gran Meseta y Cañones Duranguenses”, “Mesetas y Cañadas del Sur” and “Sierras y Valles Zaca-tecanos”. Its potential vegetation corresponds to brush communities abundant in microphyllous and thorny spe-cies, growing mainly on well-drained alluvial soils. As representative bioindicators, Celtis iguannea, Eysen-dhardtia polystachya, Flourensia cernua, Fouquieria splendens, Forestiera angustifolia, Koeberlinia spinosa, Lantana camara, Larrea tridentata, Prosopis laevigata, Yucca decipiens, Y. torey and Y. rigida, can all be recog-nised. Toward the more southern and warmer areas the appearance of Bursera fagaroides, B. bipinnata, Ipomoea intrapilosa and I. murucoides is more noticeable. Its alteration or transformation by livestock rearing favours the domain of brush with mimosas (Mimosa aculeticar-pa, Mimosa biuncifera, M. dysocarpa, M. monancistra), acacias (Vachellia constricta, V. neovernicosa, V. schaffneri), magueyes (Agave asperrima, A. lechuguilla) prickly pears (Cylindropuntia imbricata, Opuntia duran-guensis, O. leucotricha, O. streptacantha) and sotoles

(Dasylirion duranguense), in addition to numerous grasses (Aristida spp., Bouteloua spp. Chloris gayana, Cynodon dactylon, Megathyrsus maximus, Melinis re-pens, Pennisetum ciliare, etc). These grasses are present as well in other belts of Xeric bioclimate. In the flat valleys with deep alluvial soils, the potential plant for-mation prevailing is a thorny and phreatophilous micro-forest dominated by Prosopis laevigata, which is often found alongside Cercidium praecox, Eysenhardtya po-lystachya, Ipomoea spp., and Vachellia spp., among other species.

Mesotropical Dry

It extends to almost all the physiographic subprovin-ces of SMO, especially in the intramontaine valleys, in the eastern slopes and in their adjacent plains. Its poten-tial vegetation is made up of different semi-open micro-forest dominated by sunshaded and stunted evergreen or deciduous oaks (Quercus chihuahuensis, Q. eduardii, Q. emory, Q. grisea, Q. radiata, Q. resinosa, Q. viminea, etc. ), which often incorporates other trees and shrubs, sometimes with a secondary role, as Juniperus deppeana, J. duranguensis, J. erythrocarpa, J. flaccida, Opuntia spp., Lycium berlandieri, Rhus microphylla, R. virens, Vachellia constricta, V. pennatula, V. schaffneri, etc. At its upper limit frequently we find the presence of pines (Pinus leiophylla var. chihuahuana or P. cembroides mainly), that came from Supratropical Dry belt. At its lower limit, bordering the intramontaine dry ravines, may appear species suited to thermophillous conditions which grow up from the bottom of the valleys, like Bursera copalifera, B. fagaroides, B. multijuga, Croton sp., Ipo-moea intrapilosa, I. murucoides, Lysiloma divaricatum or Randia sp. among others species. In habitats altered by fire or overgrazing a secondary thicket of Dasylirion duranguensis and Dodonaea viscosa has expanded, whose extension has been increasing in recent years aided by this degraded environment.

Figure 2 (cont.): Bioclimatic diagrams of six representative stations of the isobioclimates recogniced: Malpaso (ZAC) and El Palmito (SIN).


27

Meteorological stations Parameters and indexes Isobioclimate

Alt T P It Io Bioclimate Thermotype Ombrotype

Malpaso (ZAC)

2135 16.9 367.5 418 1.82 TrXe Mtr Low Sar Up

Santa Anita (CHIH)

1891 16.7 381.1 324 1.92 TrXe Mtr Up Sar Up

Venadero (AGS)

2026 17.8 538.7 444 2.52 TrXe Mtr Low Dry Low

Balleza (CHIH)

1920 17.8 491.0 377 2.30 TrXe Mtr Up Dry Low

Durango (DGO)

1885 17.1 475.6 390 2.32 TrXe Mtr Up Dry Low

Canatlán (DGO)

2000 15.8 536.0 363 2.82 TrXe Mtr Up Dry Up

Aguazarca (AGS)

2417 15.5 582.0 388 3.13 TrXe Mtr Up Dry Up

Cd. Cuauhtémoc (CHIH)

2010 14.2 478.1 280 2.80 TrXe Str Low Dry Low

Rosario (DGO)

1800 15.1 458.3 311 2.53 TrXe Str Low Dry Low

Monte Escobedo (ZAC)

2190 15.4 719.2 370 3.88 TrPs Mtr Up Shu Low

El Palmito (SIN)

1875 16.6 1181.6 428 5.92 TrPs Mtr Low Shu Up

El Cantil (DGO)

2035 15.1 1469.4 368 8.11 TrPs Mtr Up Hum Low

Otinapa (DGO)

2400 12.9 666.0 271 4.31 TrPs Str Low Shu Low

Madera (CHIH)

2092 10.7 734.6 168 5.70 TrPs Str Up Shu Up

Guachochi (CHIH)

2420 10.2 780.0 185 6.36 TrPs Str Up Hum Low

Vascogil (DGO)

2400 11.3 1366.8 236 10.05 TrPs Str Up Hum Up

La Ciudad (DGO)

2580 10.0 1531 208 12.83 TrPs Str Up Hhu Low

O. de Camellones (DGO)

2180 10.7 1603.0 219 12.52 TrPs Str Up Hhu Low

Campo No. 5 (CHIH)

2700 9.5 978.7 144 8.65 TrPs Otr Low Hum Low

Tres Ojitos (DGO)

2600 8.4 981.0 134 9.76 TrPs Otr Low Hum Up

Table 2: Meteorological stations with their parameters associated, bioclimatic indexes and diagnosis. Acronyms used: Alt: Altitude (meters). T: Average annual temperature (° C). P: average annual precipitation (mm). It: Thermicity index. Io: Annual ombrothermic index. TrXe: Tropical Zeric. TrPs: Tropical Pluviseasonal. Mtr: Mesotropical. Str: Supratropical. Otr: Orotropical. Sar: Semiarid. Shu: Subhumid. Hum: Humid. Hhu: Hyperhumid. Low: Lower. Up: Upper


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Index

Station

Campo N° 5 La Ciudad Vascogil Cd.

Cuahutémoc Malpaso El Palmito

M 8.4 14.2 14.6 16.3 21.3 18

m -3.4 -3.3 -2.3 -2.3 3.7 8.2

It 144 208 236 280 418 428

Ic 14.1 8.7 9.9 14.2 7.9 6.2

Id 15 19.8 19.6 20.6 18.3 11.9

Io 8.65 12.83 10.05 2.8 1.82 5.92

Ios1 4.3 13.3 8.2 2.0 2.3 6.3

Ios2 8.48 19.6 13.34 4.05 3.64 10.45

Ios3 9.58 20.69 14.15 4.66 3.69 11.25

Ios4 7.83 16.69 11.57 3.88 2.88 8.61

Tp 1131 1193 1359 1704 2023 1995

Ts 479 419 477 614 589 563

Pp 978 1531 1366 478 367 1181

Cont EuOc Up ShOc Up ShOc Up EuOc Up EuhOc Low EuhOc Low

Table 3: Bioclimatic diagnosis of the six stations of reference selected. Acronyms used: M: Average temperature of the maximums of the coldest month. m: Average temperature of the minimums of the coldest month. It: Thermicity index. Ic: Simple continentality index. Id: Diurnality index or daily thermal interval. Io: Annual ombrothermic index. Ios1: Ombro-thermic index of the hottest month of the summer quarter. Ios2: Ombrothermic index of the hottest two month of the summer quarter. Ios3: Ombrothermic index of the summer quarter. Ios4: Ombrothermic index of the four month period resulting from adding the summer quarter and the month inmediately preceding it. Tp: Positive annual temperature. Ts: Average tempera-ture of summer quarter. Pp: Positive annual precipitation. Cont: Continentality. EuhOc: Euhyperoceanic ShOc: Subhiper-oceanic. EuOc: Euoceanic. Low: Lower. Up: Upper.

Supratropical Semiarid

It has a very small area, restricted to the physiogra-phic subprovince of “Sierras y Llanuras Tarahumaras”, in the northeastern SMO. It is usually found on underde-veloped soils characterised as xerosoils, responsible, together with the climate, for the xerophytic character of the vegetation. Its potential vegetation is dominated by rosetophyllous and microphyllous scrublands, which sometimes to go with crasicaule species, most of them endemics of the Chihuahuan Desert. The height of these shrubs ranges between 1 and 3m, with variable densities as a function of grazing intensity. These plant formations are dominated by Agave lechuguilla, Cercocarpus mon-tanus, Euphorbia antisiphylitica, Garrya wrightii, Larrea tridentata, Opuntia spp. Parthenium argentatum, Prosopis sp., Quercus depressipes, Vachellia spp. and Yucca carnerosana. The herbaceous stratus is composed of grasses, mainly of Bouteloua genus.

Supratropical Dry

It roughly corresponds with the area of mid mountain located in the northern portion of SMO with a marked effect of rain shadow because of its location to leeward of the humid winds. It is distributed discontinuously throughout the subprovinces of “Sierras y Cañadas del Norte”, “Sierras y Llanuras Tarahumaras”, “Gran Meseta y Cañones Chihuahuenses”, “Sierras y Llanuras de Du-rango”, “Gran Meseta y Cañones Duranguenses” and “Mesetas y Cañadas del Sur”. Its potential plant forma-tions are preferably formed by mixed coniferous and deciduous (oak) microforests; sometimes a particular

group of them can dominate the plant formation. The most conspicuous indicator elements are: Garrya wri-ghtii, Juniperus deppeana, Pinus cembroides, Quercus chihuahuensis, Q. emoryi and Q. grisea. Towards its upper horizon the presence of Arbutus arizonica, Cupre-ssus arizonica, Pinus engelmannii, P. leiophylla var. chihuahuana, Quercus arizonica, Q. eduardii, Q. durifo-lia or Q. laeta becomes more noticeable. As serial ele-ments associated with the disturbance by livestock F-orestiera angustifolia, Lindleya mespiloides, Mimosa aculeaticarpa, M. biuncifera, Quercus eduardii and Vachellia schaffnerii usually occur, as well as different grasses.

Tropical pluviseasonal

Thermotropical Subhumid

Its presence is restricted to small scattered areas of the Pacific slope (subprovince of “Pié de la Sierra”) in the states of Sinaloa, Nayarit and Durango, bordering on the Thermotropical dry belt, which has a wider area of distribution. Its potential vegetation consists of subde-ciduous mesoforests dominated by Astronium gravelo-lens, Brosimium allicastrum, Bursera simarouba, Ente-rolobium cyclocarpum, Swietenia humilis among others. Occasionally appear elements from pine-oak forest making up patches more or less pure with the previous species; between them can be presents Pinus devonian, P. duouglasiana, P. herrerae, P. lumholtzii, P. luzma-riae, P. maximinoi, P. oocarpa, and other species such as Arbutus madrensis, A. tesallata, A. xalapensis, Clethra rosei, Quercus crassifolia, Q. praineana, Q. resinosa,


29

etc. The floristic composition and the proportion of trees changes depending on various environmental factors such as orientation, altitude, soil type, etc. The alteration of these potential forests favours the appearance of se-condary deciduous forest with elements coming from Thermotropical dry belt and its serial stages, taking ad-vantage of the new xeric and heliophilous conditions for its development.

Mesotropical Subhumid

This belt is present extensively throughout the study area, mainly occupying mid-mountain areas both on the western slopes of the range and on the internal slopes without a marked effect of rain shadow. This broad dis-tribution is the reason that the potential vegetation co-rresponds with different mixed conifer and oak mesofo-rests which often incorporate other broadleaf trees. As important bioindicators of the belt are: Arbutus xalapen-sis, Bocconia arborea, Juniperus deppeana, Pinus devo-niana, P. engelmannii, P. lumholtzii, P. luzmariae, P. oocarpa, Quercus coccolobifolia, Q. gentryi, Q. magno-liifolia, Q. oblongifolia, Q. resinosa, Q. rugosa and Q. viminea. The replacement serial brush incorporates some thorny elements in its lower horizon (Vachellia spp., and Mimosa spp.), shrubs of Compositae plant family like Baccharis, Eupatorium, Roldana, Senecio, Stevia, Verbe-sina, and ericaceaous shrubs as Arctostaphyllos pungens, Befaria mexicana and Vaccinium caespitosum. Many of these species are often introduced into the undergrowth showing indications of disturbance, mainly associated with the movement of livestock and fire damage.

Mesotropical Humid

Its distribution area is restricted to specific patches of the physiographic subprovinces “Gran Meseta y Cañones Duranguenses” and “Mesetas y Cañadas del Sur”, located around 2,000 masl in ravines and steep slopes facing the humid winds and therefore with high precipitation re-cords. The potential vegetation corresponds with mixed subperennial macroforests. The Mesotropical lower hori-zon are dominating by mesophytic forests, where are frequent Alnus acuminata, Arbutus xalapensis, Brahea aculeata, Carpinus caeroliniana, Cedrela odorata, Cle-yera integrifolia, Ceanothus depressus, Clethra spp., Cornus disciflora, Garrya laurifolia, Ilex quercetorum, Litsea glaucescens, Magnolia pacifica ssp. tarahumara Oreopanax xalapensis, Ostrya virginiana, Oreopanax spp., Persea liebmannii, Tilia americana, and pines and oaks as Pinus herrerae, P. maximinoi, P. oocarpa, Quer-cus candicans, Q. castanea, Q. diversifolia, Q. obtusata, Q. splendens and Q. subespathulata. Toward the upper horizon some of these species, especially the most ther-mophillous, tend to disappear; at the same time as other species appear such as Abies neoduranguensis, Clethra rosei, Pinus ayacahuite, P. douglasiana, P. pseudostro-bus, Quercus scytophylla and Styrax ramirezii, acquiring the plant formation more typical of pine-oak forests. The alteration of these forests boost the development of a dense border substitution brush with Cercocarpus ma-crophyllus, Coriaria ruscifolia, Monnina wrightii, Prunus spp., Rhamnus betulifolia, Rhus aromatica, Ternstroemia lineata, Triumfetta discolor, Verbesina spp. and Waltheria indica.

Supratropical Subhumid

Its distribution area include most of the physiogra-phic subprovinces, with the exception of the most sout-hern ones, at lower altitude. It extends along the high mountain areas in the lee of the wet Pacific winds. The potential vegetation corresponds mainly with different pine and oak mixed mesoforests, whose more noticeable species are Arbutus arizonica, A. madrensis, A. tessella-ta, Garrya ovata, Juniperus deppeana, Pinus engel-mannii, P. leiophylla, P. teocote, Quercus arizonica, Q. castanea and Q. durifolia. In topographically favorable locations, such as hydromorphic plains, Pinus arizonica var. cooperi is often incorporated and becomes dominant in this biotope. When its undergrowth and contiguous deforested areas are affected by fire, a replacement bunchgrass, zacatonal, is settled; It is constituted by grasses of the genus Aristida, Bouteloua, Bromus, Festuca, Stipa and Muhlenbegia. In places with shallow soils or rocky outcrops are characterised by thickets dominated by Arctostaphylos pungens.

Supratropical Humid and hyperumid

Both types show a similar distribution to the previous belt, although they occupy smaller areas, mainly asso-ciated with ravines strongly influenced by the wet winds; this explains the high rainfall records, particularly in the hyperhumid ombrotype. Its potential vegetation is cons-tituted for different conifer macroforests, pures or mixed, of Abies duranguensis, Hesperocyparis lusitanica var. lindley, Picea chihuahuaza, Pinus spp. and Pseudotsuga menziesii; at the lower horizon, some oaks make an appearance. The main bioindicators of these supratropi-cal environments, as well as the previous species, are Arbutus bicolor, A. madrensis, Pinus arizonica var. cooperi, P. ayacahuite, P. leiophylla, P. duranguensis, P. strobiformis, Populus tremuloides, Prunus serotina, Quercus crassifolia, Q. macvaughii, Q. scytophylla and Q. sideroxyla. Abies duranguensis and Picea chihuahua-na dominate the sciophyllous biotopes covering the wet-ter ravines and slopes of the range, belonging to hyperumid ombrotype. The replacement fringes of these forests are dominated by Asteraceae and Labiatae bushes with an emphasis on genus like Eupatorium, Hyptis, Roldana, Salvia, Stevia and Senecio.

Orotropical Subhumid

Its distribution is restricted to patches on the highest areas of the northeastern SMO, in the physiographic subprovince of “Sierras y Valles del Norte”, where there is a noticeable decrease in the influence of humidity from the Pacific Ocean, and a prevalence of xeric conditions typical of the western edge of Chihuahuan Desert. The potential vegetation corresponds with pure forests of Pinus spp. or mixed forests adding Quercus spp. and Juniperus deppeana. The main representative species encountered are Pinus arizonica, P. chihuahuana and P. teocote, some oaks like Quercus arizonica, Q. depressi-pes and Q. laeta, and arbutus, Arbutus bicolor. The lack of meteorological stations, coupled with the marginal geographical situation of this belt, hampers the interpre-tation of data and the establishment of clear criteria that would differentiate it from the other two orotropical belts found on the main summits.


30

Figure 3: Transect of potential natural vegetation and its relationship with thermotypes along the itinerary between Yécora(SON), Cerro Mohinora (CHIH) and Ciudad Cuahutémoc (CHIH) at 27ºN and 29ºN. 1). Thermo- and low Mesotropical,

Figure 4: Transect of potential natural vegetation and its relationship with the thermotypes along the itinerary between El Palmito (SIN), Espinazo del Diablo (DGO), Cerro Huehuento (DGO) and Durango City (DGO) at 23ºN and 25º N. 1).

Figure 5: Transect of potential natural vegetation and its relationship with thermotypes along the itinerary between Mesa del Nayar (NAY), Río Chapalagana (JAL), Siera de Cardos (ZAC) and Zacatecas city (ZAC) at 21ºN and 22ºN. 1).


31

Orotropical humid and hyperhumid

Both belts are restricted to the highest peaks of the range, mainly over 3,000 m, as well as some high land located at the northern end of SMO in the state of CHIH. These enclaves are scattered throughout the physiogra-phic subprovinces of “Sierras y Cañadas del Norte”, “Gran Meseta y Cañones Chihuahuenses”, “Gran Meseta y Cañones Duranguenses” and “Mesetas y Cañadas del Sur”. Its potential vegetation consists of different conifer meso-macroforests with sporadic incidence of broadleaf trees. The main biomarkers are Arbutus bicolor, Pinus ayacahuite, P. arizonica var. cooperi, P. teocote, Pseudotsuga menziesii, Quercus crassifolia, Q. depress-ipes and Q. sideroxyla. The harshness of the climate in these areas, along with the stony and poorly developed soils, leads to forest communities which are not very diverse and often show signs of fire damage, fallen and dead trees etc. This accelerates the open aspect of these forests and the abundance of herbaceous plants, mostly of Gramineae and Compositae families, (typical of this next stage) owns of the serial stages, as Bouteloua, Draba, Muhlenbergia, Poa, Primula, Sedum and Sene-cio, among others. In edaphoxerophyllous locations, around some of the summits there is a scrub community dominated by Quercus depressipes, Arctostaphylos pungens and Helianthemum glomeratum.

As an integral synthesis of the previous results, three transects are displayed showing both gradients, latitudinal and altitudinal. These illustrate the arrangement of the bioclimatic belts and their corresponded potential natural vegetation, to agree with data, interpretations and extra-polations realised (Figures 3, 4 and 5). The footnotes describe the vegetation types related within each biocli-matic belt and their dominating byotipes. The asymmetry in the limits of thermotypes in western and eastern slopes are due to the moderating and refreshing action of the humid winds coming from the Pacific coast.

Discussion and conclusions

The location and range of the SMO determines its funcion as a biological corridor, especially for holartic affinity flora, which along with the tropical component, presents towards the foothills, has favoured a high floral and phytocenotic diversity. The large physiographic and climatic complexity has contributed greatly to the diver-sity and originality of its biota, and therefore its conside-ration as a well distinct ecoregion. From the bioclimatic point of view all the territory is Tropical, distinguishing between the Tropical Pluviseasonal and Tropical Xérico bioclimates; the former has greater distribution throu-ghout of the range´s highlands and the western flank, where the better represented thermotypes and ombroty-pes are Mesotropical, Supratropical and Orotropical, and the Subhumid, Humid and Hyperumid, respectively. The potential natural vegetation of these belts is related to different forests dominated by Pinus spp. and Quercus spp.; the preceding taxa reliably combine with other conifers (Abies, Hesperocyparis, Juniperus, Picea, Pseu-dotsuga). The Tropical Xeric bioclimate shows a more restricted distribution toward the eastern flank and the dry mountain ravines, where the floral influence from the Chihuahuan Desert increases. The more prevalent ther-

motypes are Mesotropical and Supratropical, the Dry ombrotype being the most abundant. The potential ve-getation is made up by forests and sclerophyllous bushes of Quercus spp. and Pinus spp. that can incorporate xerophitic taxa of Chihuahuan affinity (Lycium, Proso-pis, Opuntia, Vachellia, Yucca) or of Neotropical Pacific affinity (Ceiba, Ipomoea, Bursera, Lysiloma).The struc-ture, the size and the composition (family and genus) of the potential natural vegetation encountered along the range (coniferous forests, oak forests mixed forests and shrublands), fit the bioclimatic belt model in a true, re-current and predictable way, and they are in tune with those identified in other analogous tropical territories.

The meteorological stations (159) cover the territory in an heterogeneous and uneven manner. Most of them are sited between 1,800 m and 2,500 m in altitude. This did not prevent the completion of the bioclimatic diagno-sis of the higher areas, through the extrapolations and algebra of maps made in the mapmaking, and the identi-fication of the vegetation belts made in the field. In any case an adequate reference was obtained and adjusted to the scale of the work and the territory, based on the re-ciprocal relationships between the bioclimatic diagnosis and its corresponding climatophyllous vegetation. The territorial division of the bioclimatic units obtained, bioclimas, thermotypes and ombrothypes (Maps 1, 2 and 3), reflects greater precision in the areas surrounding the stations, whilst in remote areas without stations and with access problems, the adjustment is less accurate. It is in these areas that new field works needs undertaken to check the relationships between the bioclimatic extrapo-lations and the vegetation shown here. Moreover it should be considered that the scale used is determined by the extent of the territory. Thus in those territories without reference stations, the bioclimatic diagnosis is more strongly supported by the analysis of the corres-ponding potential vegetation. In any case the cartography obtained, together with its geobotanic diagnosis, besides providing a spatial dimension to the results of this work, constitutes a useful tool for future investigations of an ecological nature that tackle applied aspects of characte-rization, evolution, restoration and management of habi-tats and ecosystems, as well as studies of ecological and territorial management.

As a complement to maps 1, 2 and 3, three transects accompany them (Figures 3, 4 and 5) generated from the bioclimatic information and the fieldwork. These tran-sects cut transversally through the SMO at different latitudes, and they illustrated the layout of the bioclima-tic belts and their corresponding potential vegetation types. The huge extent of the study area, combined with the low density of meteorological stations and their irregular distribution, with some territories lacking refe-rence stations, the bioclimatic diagnosis must lean with more emphasis on the analysis of the corresponding vegetation potential. This is particularly important for future works of a local or regional character that deal with the methodological approach used here.

The results presented must be used to establish the foundations of further investigations aimed at a better understanding of distribution, composition and ecosys-tem functioning, as well as the dynamics and possible response to new scenarios of global change. In spite of


32

the extent and complexity of the territory, this proposal advances the establishment of a bioclimatic classification based on the intimate relationship between climate and vegetation. As it becomes available a better geobotanic diagnosis of the different ecosystems will be more accu-rately adapted and the relationship between the dynamic, ecological and biogeographics aspects of phytocenosis and its bioclimatic belts that define them. Likewise the advances and contributions will favour the establishment of a classification system getting progressively more solid and better structured, that gives clarity and judg-ment to the difficult stage of the classification of the vegetation of Mexico within a global context.

Acknowledgements

The authors would like to thank to Ángel Pérez Za-mora of the Department of Environmental Sciences (University of Guadalajara), for his help in the organiza-tion of the climatic information and in the preparation of the maps; to Socorro and Martha González-Elizondo of the Interdisciplinary Research Centre for Regional Inte-gral Development, Durango unit (CIIDIR-IPN), for their support in the fieldwork and for their contributions to the manuscript. This work has been backed by the projects of the AECID A/012635 and A/024250/09.

References

Alcaraz F, 2013. Bioclimatología con R. Universidad de Mur-cia. Available from: http://www.um.es/docencia/geobotanica/ficheros/practica1.pdf.

Almeida L, Cleef AM, Herrera A, Velázquez A, Luna I. 1994. El zacatonal alpino de la vertiente NW del volcán Popocaté-petl, México y su posición en las montañas tropicales de América. Phytocoen. 22:391-346.

Almeida L, Giménez de Azcárate J, Cleef AM, González-Trá-paga A. 2004. Las comunidades vegetales del zacatonal alpi-no de los volcanes Popocatépetl y Nevado de Toluca, Región Central de México. Phytocoen. 34(1):91-132.

Anonymous. 1973. International classification and mapping of vegetation. United Nations Educational, Scientific and Cultural Organization. París, Francia. 35 p.

Anonymous. 1997. Regiones ecológicas de América del Norte. Hacia una perspectiva común. Comisión para la Cooperación Ambiental de América del Norte. Quebec, Canadá. 63 pp.

Anonymous. 2002. Conjunto de datos vectoriales de la carta de uso del suelo y vegetación: escala 1: 250 000. Serie III (continuo nacional). Instituto Nacional de Estadística, Geografía e Informática. Aguascalientes, México.

Anonymous. 2007a. Ecorregiones terrestres de México. Escala 1: 1,000,000. Instituto Nacional de Estadística, Geografía e Informática; Comisión Nacional para el Conocimiento y Uso de la Biodiversidad e Instituto Nacional de Ecología. México, D.F., México.

Anonymous 2007b Conjunto de datos vectoriales de la Carta de Uso de Suelo y Vegetación, Escala 1:250,000, Serie IV. Conjunto Nacional. Instituto Nacional de Estadística, Geogra-fía e Informática. Aguascalientes, México.

Anonymous 2011. Normales climatológicas. Servicio Meteorológico Nacional y Comisión Nacional del Agua. Available from: http://www.smn.cna.gob.mx.

Anonymous. 2013. Uso de Suelo y Vegetación. Instituto Na-cional de Estadística y Geografía. Aguascalientes, México. Available from: http://www.inegi.org.mx/geo/contenidos/recnat/usosuelo/De-fault.aspx

Aragón E, Garza A, González-Elizondo S, Luna I. 2010. Composición y estructura de las comunidades vegetales del rancho El Durangueño, en la Sierra Madre Occidental, Durango, México. Rev. Mex. Biodiv. 81: 771-787.

Arriaga C, Espinoza JM, Aguilar C, Martínez E, Gómez-Men-doza L, Loa Loza E. (coords.). 2000. Regiones terrestres prio-ritarias de México. Comisión Nacional para el Conocimiento y Uso de la Biodiversidad. México D.F. México. 609 p.

Bailey RG. 1995. Description of the ecoregions of the United States, 2nd ed. US Dept. of Agriculture, Forest Service. Washington DC, USA. 108p.

Bailey RG. 1996. Ecosystem Geography. From ecoregions to sites. Springer-Verlag. New York, USA. 243 p.

Barber A, Crespo M. 2001. A new approach on the bioclima-tology and potencial vegetation of Yucatán peninsula México. Phytocoen. 311:1-31.

Beard J. 1973. The Physiognomic Approach. In: Wittaker RH, editor. Ordination and Classification of Communities. Dr. W. Junk Pub. The Hague, pp. 355-387.

Boege 2008. El patrimonio biocultural de los pueblos indígenas de México. Hacia la conservación in situ de la biodiversidad y agrodiversidad en los territorios indígenas. INAM-CNDI. 344 p.

Box E. 1981. Macroclimate and plant forms: An introduction to predictive modelling in Phytogeography. Dr. W. Junk Publi-shers. The Hague. 243 p.

Braunt-Blanquet J. 1979. Fitosociología. Bases para el estudio de las comunidades vegetales. Ed. Blume. Madrid. 820p.

Breckle SW. 2002. Walter vegetation of the Earth. The ecolo-gical systems of the geobiosphere. Springer. Berlín. 527 p.

Brown DE, Reichenbancher F, Franson SE. 1998. A classifica-tion on North American Biotic Communities. University of Utah Press. Salt Lake City. 342 p.

Búrquez M, Martínez A, Martin PS. 1992. From the high Sierra Madre to the coast: changes in vegetation along highway 16, Maycoba-Hermosillo. In: Clark KF, Roldán J, Schmidt RH, editors. Geology and mineral resources of the northern Sierra Madre Occidental, Mexico. Guidebook. El Paso Geological Survey Publication 24. El Paso, Texas, USA. pp. 239-252.

Bye, R. 1995. Prominence of the Sierra Madre Occidental in the biological diversity of Mexico. In: DeBano LF, Ffolliott PF, Ortega Rubio A, Gottfried GJ, Hamre RH, Edminster CB, coords. Biodiversity and management of the Madrean archi-pelago: The sky islands of Southwestern United States and Northwestern Mexico. United States Department of Agricul-ture Forest Service, General Technical Report RM 264: 19-27.

Casas S, González-Elizondo S, Tena JA. 1995. Estructura y tendencias sucesionales en bosques de clima templado semi-seco en Durango, Mexico. Madroño 42(4): 501-515.

Cervantes Y, Cornejo SL, Lucero R, Espinoza JM, Miranda E, Pineda A. 1990. Provincias Fisiográficas de México. Extraído de Clasificación de Regiones Naturales de México II, IV.10.2. Atlas Nacional de México. Instituto de Geografía, UNAM/CONABIO, México, D.F.

CONABIO, 1997. Provincias Biogeográficas de México. Es-cala 1: 4,000,000. Comisión Nacional para el Conocimiento y Uso de la Biodiversidad, México. Available from: http://conabioweb.conabio.gob.mx/metacarto/metadatos.

Cress J, Sayre R, Comer P, Warner H. 2009. Terrestrial Eco-systems. Isobioclimates of the conterminous United States: U. S. Geological Survey Scientific Investigations Map 3084, scale 1:5,000,000, 1 sheet. Available from http://pubs.usgs.gov/sim/3084.

Descroix L, González Barrios JL, Estrada J. 2004. La Sierra Madre Occidental, una fuente de agua amenazada. Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecua-rias-Institut de Recherche pour le Développement. Gómez Palacio, Durango, México. 300 p.


33

Douglas MW, Maddox RA, Howard K, Reyes S. 1993. The Mexican Monsoon. J. Climate 6: 1665–1677.

Enríquez E, Koch SD, González-Elizondo S. 2003. Flora y Vegetación de la Sierra de Órganos, municipio de Sombrerete, Zacatecas. México. Acta Bot. Mex. 64: 45-89.

Escamilla M, Giménez de Azcárate J, Vázquez L, Almeida L. 1998. La vegetación de la alta montaña del volcán Iztaccí-huatl, México, y su relación con el medio. Resúmenes del VII Congreso Latinoamericano de Botánica. México D. F.

Escamilla M, Almeida L, Giménez de Azcárate J. 2002. Las comunidades tropoalpinas del volcán Popocatépetl, y su rela-ción con el medio. In: Gómez, F, Mota J, editors. Vegetación y Cambios Climáticos. Servicio de Publicaciones de la Uni-versidad de Almería. Almería, pp. 71-84.

Estrada-Castillón A, Jurado E, Návar J, Jiménez-Pérez J, Garza-Ocañas F. 2003. Plant associations of Cumbres de Majalca National Park, Chihuahua, Mexico. The Southw. Nat. 48(2): 177-187.

Farjon A, Pérez de la Rosa JA, Styles BT. 1997. A field guide to the pines of México and Central America. The Royal Bota-nic Gardens. Kew. U.K.

Felger RS, Wilson MF. 1995. Northern Sierra Madre Occidental and its Apachian outliers: A neglected center of biodiversity. In: DeBano LF, Ffolliott PF, Ortega Rubio A, Gottfried GJ, Hamre RH, Edminster CB, coords. Biodiversity and management of the Madrean archipelago: The sky islands of southwestern United States and northwestern Mexico. USDA Forest Service, General Technical Report RM 264, pp. 36-59.

Fisher JT, Glass PA, Harrington JT. 1995. Temperate pines of northern Mexico: their use, abuse and regeneration. In: DeBano LF, Ffolliott PF, Ortega Rubio A, Gottfried GJ, Hamre RH, Edminster CB, coords. Biodiversity and management of the Madrean archipelago: The sky islands of southwestern United States and northwestern Mexico. USDA Forest Service, General Technical Report RM 264, pp. 165-173.

Fernández-Eguiarte A, Zavala J, Romero R. 2012. Atlas Cli-mático Digital de México (versión 2.0). Centro de Ciencias de la Atmósfera. UNAM. México DF. Available from http://uniatmos.atmosfera.unam.mx/ACDM/

García E. 1973. Modificaciones al Sistema de clasificación climática de Köppen (para adaptarlo a las condiciones de la Republica Mexicana). Offset Larios. México DF. 246 p.

García E. 2004. Modificaciones al Sistema de Clasificación Climática de Köppen. Serie Libros No. 6. Instituto de Geogra-fía. Universidad Nacional Autónoma de México. México, D.F. 90 p.

García Arévalo A. 2008. Vegetación y flora de un bosque relictual de Picea chihuahuana Mart. del norte de México. Polibot. 25: 45-68.

García Arévalo A, González-Elizondo M. 2003. Pináceas de Durango. Comisión Nacional Forestal e Instituto de Ecología, A.C. 2a. ed. México DF. 187 p.

García-Arévalo A, González-Elizondo S. 2003. Pináceas de Durango. CONAFOR e Instituto de Ecología, A. C. 2ª edi-ción. México DF. 187 p.

García Arévalo A, Mendoza J, Nocedal J. 2004. Asociaciones vegetales de los bosques del municipio de Guanaceví, Durango. Madera y Bosques 10: 21-34.

Gentry HS. 1942. Rio Mayo plants. A study of the flora and vegetation of the Valley of the Rio Mayo, Sonora. Carnegie Institution of Washington Publication 527. Washington, DC, USA. 328 p.

Giménez de Azcárate J, Escamilla M, Velázquez A. 1997. Fitosociología y sucesión en el volcán Paricutín (Michoacán, México). Caldasia 19(3):487-505.

Giménez de Azcárate J, Escamilla M. 1999. Las comunidades edafoxerófilas (enebrales y zacatonales) en las montañas del centro de México. Phytocoen. 29(4): 449-468.

Giménez de Azcárate J, Ramírez I, Pinto M. 2003. Las comu-nidades vegetales de la Sierra de Angangueo (Estados de Mi-choacán y México, México): clasificación, composición y distribución. Lazaroa 24:87-111.

Giménez de Azcárate J, Ramírez I. 2004. Análisis fitosocioló-gico de los bosques de oyamel Abies religiosa (H.B.K.) Cham. y Schlecht. de la sierra de Angangueo, región central de México. Fitosociología 41 (1) suppl. 1:91-100.

Giménez de Azcárate J, González-Costilla O. 2011. Pisos de vegetación de la Sierra de Catorce y territorios circundantes (San Luis Potosí, México). Acta Bot. Mex. 94:91-123.

González-Elizondo S, González-Elizondo M, Herrera-Arrieta Y. 1991. Listados Florísticos de México. IX. Flora de Durango. Universidad Nacional Autónoma de México. México DF. 167 p.

González-Elizondo S, González-Elizondo M. 1992. El género Arbutus (Ericaceae) en la Sierra Madre Occidental. Con-sideraciones sobre su taxonomía y distribución. Bol. Inst. Bot. Univ. Guadalajara 1(2): 39-41.

González-Elizondo S, González-Elizondo M. Cortés A. 1993. Vegetación de la Reserva de la Biosfera La Michilía, Durango, Mex. Acta Bot. Mex. 22: 1-104.

González-Elizondo S, González-Elizondo M. 1995. Los enci-nos de Durango, México. III Seminario Nacional sobre utili-zación de encinos. Reporte Científico Especial No. 15. Fac. C. Forestales U.A.N.L. pp.28-33.

González-Elizondo S. 1997. Upper Mezquital River region, Sierra Madre Occidental, Mexico, In: Davis SD, Heywood VH, Herrera-McBryde O, Villa-Lobos J. Hamilton AC, editors. Centres for plant diversity: a guide and strategy for their conservation. Vol. III: The Americas. The World Wide Fund for Nature & International Union for the Conservation of Nature - The World Conservation Union. Cambridge, UK. pp. 157-160.

González-Elizondo S, González-Elizondo M, Márquez MA. 2007. Vegetación y Ecorregiones de Durango. Plaza y Val-dez, México, D. F. 219 p.

González-Elizondo M, Galván, R, López-Enriquez IL, Reséndiz L, González-Elizondo S. 2009. Agaves-magueyes, lechuguillas y noas- del Estado de Durango y sus alrededores. C.I.I.D.I.R. – UPN - Unidad Durango y CONABIO. Durango, México. 163 p.

González-Elizondo S, González-Elizondo M, Ruacho L, Molina M. 2011. Pinus maximartinezii Rzed., primer registro para Durango, segunda localidad para la especie. Acta Bot. Mex. 96: 33-48.

González-Elizondo S, González-Elizondo M, Tena JA, Ruacho L, López-Enríquez IL. 2012. Vegetación de La Sierra Madre Occidental, México: Una Síntesis. Acta Bot. Mex. 100: 351-403.

González-Medrano F, 2003. Las Comunidades Vegetales de México. Instituto Nacional de Ecología y Secretaría de Medio Ambiente y Recursos Naturales. México D.F. 7 p.

González-Quintero L. 1974. Tipos de vegetación de México.In: Flores DA, González Quintero L, Álvarez T, de Lachica F, editors. El escenario geográfico: Recursos naturales. Instituto Nacional de Antropología e Historia, México DF, pp: 109-218.

González-Villareal LM. 1986. Contribución al conocimiento del género Quercus en el Estado de Jalisco, México. Colec-ción Flora de Jalisco. Universidad de Guadalajara. 1:1-240

González-Villareal LM. 1990. Las Ericáceas de Jalisco, Méxi-co. Colección Flora de Jalisco. Universidad de Guadalajara. 2:1-140.


34

Gordon AG. 1968. Ecology of Picea chihuahuana Martínez. Ecology 49: 880 896.

Hastings JR, Turner RM. 1965. Seasonal precipitation regimes in Baja California, México. Geografiska Annaler. Series A, Physical Geography 47(4):204-223.

Herrera A, Cortés A. 2009. Diversidad de las gramíneas de Durango, México. Polibotánica 28: 49-68.

Hijmans RJ, Cameron SE, Parra JL, Jones PG, Jarvis A. 2005. Very high resolution interpolated climate surfaces for global land areas. Int. J. Climatol. 25: 1965-1978.

Koleff P, Soberon J, Smith A. 2004. Madrean Pine-Oak Woodlands. In: Mittermeier, RA, Gil PR, Hoffman M, Pilgrim J, Brooks T, Mittermeier CG, Lamoreux J, da Fonseca GAB, editors. Hotspots revisited: Earth’s biologically richest and most threatened terrestrial ecoregions. CEMEX - Agrupación Sierra Madre, Mexico DF, pp. 205-217.

Laferriére JE. 1994. Vegetation and flora of the Mountain Pima Village of Nabogame, Chihuahua, México. Phytologia 77: 102-140.

Larcher W. 2003. Physiological plant ecology. 4th ed. Springer. Berlin. 513 p.

Lebgue Keleng T. 2002. Flora de las Barrancas del Cobre (Región Prioritaria 45).Sistema Nacional de Información sobre Biodiversidad-Comisión Nacional para el Conoci-miento y Uso de la Biodiversidad. Informe final del proyecto R102. México, DF, México.

Lebgue Keleng T. 2005. Análisis de las comunidades vegetales de las Barrancas del Cobre, municipios de Batopilas y Urique, Chihuahua, usando un Sistema de Información Geográfica. PhD Thesis. Universidad Autónoma de Chihuahua. Chihua-hua, México. 109 p.

LeSueur H. 1945. The ecology of the vegetation of Chihuahua, Mexico, north of parallel twenty-eight. University of Texas Publication 4521: 1-92.

Lieth H, Berlekamp J, Fuest S, Riediger S. 1999. Climate diagrams of the world. Backhuys Publishers. Leiden.

Lumholtz C. 1902. Unknown Mexico. Explorations in the Sierra Madre and other 271 regions, 1890-1898. Vol. 1. Dover Publications. New York, USA. 316 p.

Macías MA. 2009. Estudio de las relaciones entre zonobiomas, bioclimas y vegetación en la costa del Pacífico norteamerica-no. Phd Thesis, Departamento de Ecología, Universidad de Alcalá, Alcalá de Henares, España.

Martin PS, Yetman D, Fishbein M, Jenkins P,Van Devender TR, Wilson RK. 1998. Gentry´s Río Mayo plants: The tropical deciduous forest and environs of Northwest Mexico. The University of Arizona Press. Tucson, Arizona, USA. 558 p.

Mathiasen RL, González-Elizondo S, González-Elizondo M, Howell BE, López Enriquez IL, Scott J, Tena JA. 2008. Distribution of dwarf mistletoes (Arceuthobium spp., Viscaceae) in Durango, México. Madroño 55(2): 161-169.

McVaugh R. 1987. Leguminosae. Flora Novo Galiciana 5:1-786. The University of Michigan Press. Ann Arbor, USA.

McVaugh R. 1989. Bromeliaceae to Dioscoreaceae. Flora Novo Galiciana 15:1-398. The University of Michigan Press. Ann Arbor, USA.

McVaugh R. 1992. Gymnosperms and Pteridophytes. Flora Novo Galiciana 17:1-119. The University of Michigan Press. Ann Arbor, USA.

McVaugh R. 2001. Ochnaceae to Loasaceae. Flora Novo Gali-ciana 3:1-751. The University of Michigan Press. Ann Arbor, USA.

Medina C, Gopar F, Giménez de Azcárate J, Velázquez A. 2012. Análisis bioclimático y estudio de la vegetación del transecto Pico del Tancítaro-Valle de Apatzingán, Michoacán, México. In Mas JF, Cuevas G, compilers. Memorias XIX Reunión Nacional SELPER. CIGA-UNAM. Morelia, México, pp 293-301.

Medina G, Díaz G, Berzoza M, Silva M, Chávez AH, Báez AD. 2006a. Estadísticas Climatológicas Básicas del estado de Chihuahua (Período 1961-2003). Libro Técnico No. 1. Centro de Investigación Regional Norte Centro. Dirección de Coor-dinación y Vinculación Estatal de Chihuahua. Chihuahua, México.

Medina G, Díaz G, López J, Ruiz JA, Marín M. 2005. Estadís-ticas Climatológicas Básicas del estado de Durango (Período 1961-2003). Libro Técnico No. 1. Centro de Investigación Regional Norte Centro. Campo Experimental Valle del Gua-diana. Durango, México.

Medina G, Maciel L, Ruiz JA, Serrano V, Silva M. 2006b. Estadísticas Climatológicas Básicas del estado de Aguasca-lientes (Período 1961-2003). Libro Técnico No. 2. Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecua-rias. Centro de Investigación Regional Norte Centro. Pabellón de Artega, Aguascalientes, México.

Medina G, Ruiz JA. 2004. Estadísticas Climatológicas Básicas del estado de Zacatecas (Período 1961-2003). Libro Técnico No. 3. Centro de Investigación Regional Norte Centro. Campo Experimental Zacatecas. Calera. Zacatecas, México.

Miranda F, Hernández-X E. 1963. Los tipos de vegetación de México y su clasificación. Bol. Soc. Bot. México 28:29-179.

Mittermeier RA, Goettsch C. 1992. La importancia de la diversidad biológica de México. In Sarukhán J, Dirzo R, editors. México ante los retos de la biodiversidad. Comisión Nacional para el Conocimiento y Uso de la Biodiversidad, México DF, pp. 63-73.

Mosiño PA, García E. 1974. The climate of México. In Bryson RA, Hare FK, editors. Climates of North America. Amster-dam and New York, pp. 345-404.

Müller MJ. 1982. Selected climatic data for a global set of standard stations for vegetation science. Dr. W. Junk Publi-shers, The Hague.

Olson DM, Diner Stein E, Wikramanayake ED, Burgess ND, Powell GV, Underwood EC, D’amico JA Itoua I, Strand HE, Morrison JC, Loucks CJ, Allnutt T, Ricketts TH, Kura Y, Lamoreux JF, Wettengel WW, Hedao P, Kassem KR. 2001. Terrestrial Ecoregions of The World: A New Map of Life on Earth. Bioscience 51(11): 933-938.

Peinado M, Alcaraz F, Aguirre JL, Alvarez J. 1994a. Vegeta-tion formations and associations of the zonobiomes along the North American Pacific coast. Vegetatio 114:123-135.

Peinado M, Bartolomé C, Delgadillo J, Aguado I. 1994b. Pisos de Vegetación de la Sierra San Pedro Mártir, Baja California, México. Acta Bot. Mexicana 29:1-30.

Peinado M, Alcaraz F, Aguirre JL, Delgadillo J. 1995. Major plant associations of warm North American Deserts. J. Veg. Sci. 6:79-94.

Peinado M, Alcaraz F, Aguirre JL, Delgadillo J. 1997a. Phyto-sociological, bioclimatic and biogeographical classification of woody climax communities of western North America. J. Veg. Sci. 8:505-528.

Peinado M, Alcaraz F, Aguirre JL, Martínez-Parras JM. 1997b. Vegetation formations and associations of the zonobiomes along the North American Pacific coast: from Northern Cali-fornia to Alaska. Plant Ecol. 129:29-47.

Peinado M, Aguirre JL, de la Cruz M. 1998. A phytosociologi-cal survey of the boreal forest Vaccinio-Picetea in North America. Plant Ecol. 137:151-202.

Peinado M, Macías MA, Delgadillo J, Aguirre JL. 2006. Major plant communities of North America´s most arid region: The San Felipe Desert, Baja California, Mexico. Plant Biosystems 140(3):280-296.

Peinado M, Aguirre JL, Delgadillo J, Macías MA. 2007. Zono-biomes, zonoetonotes and azonal vegetation along the Pacific coast of North America. Plant Ecol. 191(2):221-252.


35

Peinado M, Aguirre JL, Delgadillo J, Macías MA. 2008. A phytosociological and phytogeographical survey of the coastal vegetation of western North America. Part 1: plant communities of Baja California, Mexico. Plant Ecol. 196:27-60.

Peinado M, Macías MA, Aguirre JL, Delgadillo J. 2010. Bio-climate-vegetation interrelations in Northwestern Mexico. Southwest. Nat. 55(3):311-322.

Peinado M, Macías MA, Ocaña FM, Aguirre JL, Delgadillo J, 2011. Bioclimates and vegetation along the Pacific basin of Northwestern Mexico. Plant Ecol. 212:263-281.

Penington TD, Sarukhán J. 2005. Árboles tropicales de Méxi-co. Manual para la identificación de las principales especies. 3ª ed. Universidad Nacional Autónoma de México y Fondo de Cultura Económica. México, D.F.

Reina AL, Van Devender TR, Trauba W, Búrquez A. 1999. Caminos de Yécora. Notes on the vegetation and flora of Yécora, Sonora. In: Vásquez del Castillo BD, Ortega M, Yocupicio CA, editors. Memorias del Simposium Inter-nacional Sobre la Utilización y Aprovechamiento de la Flora Silvestre de Zonas Áridas. Hermosillo, Sonora, México, pp. 137-144.

Reina AL, Van Devender TR. 2005. Floristic comparison of an Arizona Sky Island and the Sierra Madre Occidental in eastern Sonora: the Huachuca Mountains and the Yécora Area. In: Gottfried GJ, Gebow BS, Eskew LG, Edminster CB, coordinators. Biodiversity and management of the Madrean Archipelago II: Connecting mountain islands and desert seas. United States Department of Agriculture Forest Service, General Technical Report RMRS-P-36, pp: 154-157.

Rivas-Martínez S, 1997. Syntaxonomical synopsis of the North America natural potential vegetation communities, I (Com-pendio sintaxonómico de la vegetación natural potencial de Norteamérica, I). Itinera Geobot. 10:5-148.

Rivas-Martínez S, 2004. Sinopsis biogeográfica, bioclimática y vegetacional de América del Norte. Fitosociología 41(1) suppl. 2:19-52.

Rivas-Martínez S, 2005. Notions on dynamic-catenal phytoso-ciology as basis of landscape science. Plant Biosystems 139 (2): 135-144.

Rivas-Martínez S, 2007. Mapa de series, geoseries y geoperma-series de vegetación de España. Memoria del Mapa de Vege-tación Potencial de España, Parte I. Itinera Geobot. 17:5-436.

Rivas Martínez S, 2008. Global Bioclimatics (Clasificación Bioclimática de la Tierra). Available from http://www.globalbioclimatics.org/book/publications.htm.

Rivas-Martínez S, Sánchez-Mata D, Costa M. 1999. North America boreal and western temperate forest vegetation (Syntaxonomical synopsis of the potential natural plant com-munities of North America, II). Itinera Geobot. 12:5-316.

Rivas-Martínez S, Rivas-Sáenz, S, Penas A. 2011a. Worldwide bioclimatic classification system. Global Geobot. 1: 1-634.

Rivas-Martínez S, Navarro G, Penas A, Costa M. 2011b. Biogeographic map of South America. A preliminary survey. Inter. J. Geobot. Research. 1: 21-40.

Ruiz JA, González IJ, Anguiano J, Vizcaíno I, Ibarra D, Alcalá J, Espinoza S, Flores HE. 2003. Estadísticas Climatológicas Básicas para el Estado de Jalisco (Período 1961-2000). Libro Técnico Núm. 1. INIFAP-CIRPAC. Campo Experimental Centro de Jalisco, Guadalajara, Jalisco, México.

Ruiz JA, Medina G, Macías J, Silva MM, Diaz G. 2005. Estadísticas Climatológicas Básicas del estado de Sinaloa (Período 1961-2003). Libro Técnico Núm. 2. INIFAP-CIRNO. Ciudad Obregón, Sonora. México.

Rzedowski, J. 1978. Vegetación de México. Ed. Limusa. Méxi-co, DF. 432 p.

Rzedowski J. 1991. Diversidad y orígenes de la Flora Fanerogámica de México. Acta Bot. Mex. 14:3-21.

Rzedowski J. 1996. Análisis preliminar de la flora vascular de los bosques mesófilos de montaña de México. Acta Bot. Mex. 35: 25-44.

Rzedowski, J & Reina AL1990. Provincias florísticas. Mapa IV.8.3. Atlas Nacional de México. Vol. III. Instituto de Geo-grafía, Universidad Nacional Autónoma de México. México DF, México.

Sayre RA, Yanosky, Muchoney D. 2007. Mapping global ecosystems - the GEOSS approach: Group on Earth Obser-vations, editors. The Full Picture. Tudor Rose, London, UK.

Sayre RA, Bow J, Josse C, Sotomayor L, Touval. 2008. Ter-restrial ecosystems of South America, chap. 9 . En Campbell JC, Jones KB, Smith, JH, Koeppe MT, editors. North Ameri-ca Land Cover Summit. Association of American Geogra-phers Washington DC, pp. 131 -152.

Sayre, Roger, Comer, Patrick, Warner, Harumi, and Cress, Jill, 2009, A new map of standardized terrestrial ecosystems of the conterminous United States: U.S. Geological Survey Profes-sional Paper 1768, 17 p. Available from http://pubs.usgs.gov/sim/3084/downloads/SIM3084.pdf

Schultz J, 2005. The Ecozones of the World. The Ecological Divisions of the Geosphere. 2nd ed. Springer. The Hague.

Tropicos. 2013. The botanical Garden Information System. Missouri Botanical Garden. Available from: http://www.Tropicos.org.

Tuhkanen S. 1980. Climatic parameters and indices in Plant Geography. Acta Phytogeographical Sueca 67: 9-109.

Van Devender TR, Felger RS, Fishbein M, Molina-Freaner FE, Sánchez-Escalante JJ, Reina AL. 2010. Biodiversidad de las plantas vasculares. In: Molina-Freaner, FE, Van Devender TR, editors. Diversidad biológica de Sonora. Universidad Nacio-nal Autónoma de México. México, D.F.,México. pp. 229-261.

Vázquez-García JA, Nieves G, Cházaro M, Vargas-Rodríguez Y, Flores A, Luquín H. 2004. Listado preliminar de plantas vasculares del norte de Jalisco y zonas adyacentes. Serie Fronteras de Biodiversidad 1. In Vázquez-García JA, Cházaro M, Nieves G, Vargas-Rodríguez Y,Vázquez-García M, Flores A, editors. Flora del Norte de Jalisco y Etnobotánica Huichola. Universidad de Guadalajara, pp. 115-168.

Villaseñor JL. 2004. Los géneros de plantas vasculares de la flora de México. Bol. Soc. Bot. México 75: 105-135.

Walter H, Lieth H. 1960-1967. Klimadiagramm-Weltatlas. Stuttgar, Germany: Gustav Fischer Verlag.

Westthoff V, van der Maarel E. 1980. The Braun-Blanquet approach. In: Whittaker RH, editor. Classification of plant communities. Dr. W. Junk by Publishers. La Haya, pp. 287-399.

White SS, 1948. The vegetation and flora of the region of the Río Bavispe in northeastern Sonora, Mexico. Lloydia 11: 229-302.

bioclimatic belts of sierra madre occidental (mexico):a preliminary approach

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