Descripción del sitio de trabajo para el proyecto

Benchmark Site Description of the Los Tuxtlas, Veracruz, Mexico

J.A. García1*, T. Fuentes3, V. Sosa1, E. Meza1, S. Negrete-Yankelevich1, I. Barois1, D. Bennack1 and P. Okoth2

1 Instituto de Ecología, A.C., Xalapa, Veracruz, México

2 TSBF Institute of CIAT, Nairobi, Kenia

3 Red A. C.

 

1. Introduction

1.1 Site location in México

The Los Tuxtlas Biosphere Reserve is located in the state of Veracruz and the coastal plains of the Gulf of Mexico between 18° 10´ to 18° 45´ north of the Equator and 94° 42´ to 95° 27´ west of the Greenwich (figure 1). It lies within the municipalities of Angel R. Cabada, Santiago Tuxtla, San Andrés Tuxtla, Catemaco, Soteapan, Mecayapan, Tathuicapan de Juárez and Pajapan. The Gulf of Mexico at Punta Puntillas marks the eastern boundary of the protected area. The northern border is Lake Catemaco, the southeastern border is the Federal Terrestrial Maritime Zone on the Gulf of Mexico coast and the western border, the hill of Vigía.

 

1.2 Altitude of the Area

The altitudinal range is from sea level to higher altitudes above the mean sea level (msl) (figure 2). The San Martín Tuxtla volcano at 1780 metres above (msl) is the highest. Other high volcanoes are the Santa Marta at 1660 metres above (msl) and San Martín Pajapan at 1245 metres above (msl).

1.3 Climate of the Area

The climate of the region is hot and subhumid on the coastal plains, and temperate and humid in the highlands (Garcia 1981). The climate distribution in the Los Tuxtlas benchmark is showed in figure 3. The highest temperatures range from 27ºC to 36ºC, and the lowest range from 8ºC to 18ºC. Precipitation is seasonal, and during the dry season between March and May, monthly precipitation averages 111.7 mm. The rainy season is between June and February. During the rainy season, average monthly precipitation increases to 486.2 mm. From September to February, the region is affected by the displacement of cold, humid air masses from the north. This phenomenon results in humid wet winds locally known as "nortes," which reach speeds of 80 km/hour. These winds provide approximately 15% of the average annual precipitation and result in gradual reductions of mean temperatures (Coates-Estrada & Estrada 1986). The rainfall ranges from 1700 mm to 4700 mm per year. According to Koppen´s Classification, the area falls in the Cool Tropical Highlands climatic classification.

1.4 Why was the area selected?

The Los Tuxtlas Biosphere Reserve is characterized by the physical, biological, and social diversity that it covers. The Los Tuxtlas reserve is one of the most threatened protected areas in Mexico. It suffers pressure, resulting human demands on nature in the region. This has led to continuous and rapid disappearance of habitat and natural vegetation (figure 4). The principal causes are the expansion of agricultural activities, expanded livestock production, and population growth that places demands on the areas natural resources. The Los Tuxtlas Biosphere Reserve is considered to be critically under threat due to the before mentioned activities. It is therefore necessary and of great importance that the management of the Biosphere be investigated, documented and an action plan drawn to combat the threats that put the integrity of the protected area at risk.

Despite the fact that the reserve has lost more than 85% of its original area, there are still remaining regions of great biological importance such as the three core areas, which have close to 3,000 ha of protected forest, as well as a great number of forest fragments. This region represents one of the areas with the highest levels of annual precipitation in the country, between 1,700 mm in the dry season (March to May) and 4,700 mm in the rainy season (June to February). The forests of Sierra de Los Tuxtlas are therefore important in the capture of rainwater, control of soil erosion, climate regulation, maintenance of stable temperatures, and filtration and purification of water. Los Tuxtlas also contributes 30% of the water utilized by the urban areas around the cities of Catemaco, Minatitlán, Acayucan, San Andrés Tuxtla, and Catemaco.

The enormous biological importance and environmental services provided by the reserve to the human populations of the region have not been sufficiently studied and managed to promote policies of sustainable development that contain an in-built mechanism for its preservation and or conservation. Continued destruction of the forests has been documented over the last 35 years. From 1967 to 1990 in the Sierra Santa Marta alone, 6,100 ha of forests disappeared. It has only been possible to enforce conservation rights to property owned by UNAM and only in places such as the Los Tuxtlas Tropical Biological Station, which is under a system of private management. Illegal hunting and the extraction of wildlife is a current threat to the area around the Station because they do not have the necessary personnel to conduct permanent monitoring activities.

In 1998 a series of advances were made in the conservation of the Biosphere due to designation of the area as a biosphere reserve including implementing programs for ecological inventory, soil management, and alternative production projects, which should be continuously supported. The Mexican people have the responsibility to comply with their commitment made for conservate the biosphere reserve of the Los Tuxtlas.

 

1.5 Why Los Tuxtlas is a Biodiversity Hotspot?

Los Tuxtlas has enormous biodiversity that is rivaled by few other areas in Mexico. Nine forest vegetation types have been identified according to Sousa (1968). These include deciduous forests, oak forests, mangroves, savannah vegetation, high evergreen forests, evergreen lowland forests, mid-elevation semi-deciduous forests, pine forests and coastal vegetation (figure 5). The mountainous topography rises from an extensive plain producing a large variety of climates, altitudinal ranges, and typical land uses. Biogeographically, the region is represented by aquatic, boreal, and endemic taxa encompassing a significant percentage of the original flora of Central and South America. Los Tuxtlas is registered as one of the five top regions for the greatest quantity of endemic trees in Mexico, with 26 of the 41 species of trees found exclusively in moist forests. The forests have a great variety of fauna including species endemic to tropical and boreal forests. Due to its immense ranges in elevation (from the coast to the tops of the volcanoes), the reserve is an example in Mexico where multiple forest types are contained in one region. In general, the Neotropical flora of Las Tuxlas is specific to the Caribbean region and the Gulf of Mexico Coastal Province (Rzedowski 1986, Estrada & Coates-Estrada 1999).

The region is considered a ´hostpot´ (figure 6), with approximately 2,695 species of vascular plants, including 42 subspecies and 102 varieties, represented in 214 families and 6 classes of plants. Dicots represent the majority of families and species (69% and 68% respectively). Both monocots and ferns represent 29% of the families, and comprise 21% and 10% of park species, respectively. The lycopodes and selaginella, woody gymnosperms, and cycads are characterized by five families, representing only 2% of the families and 1% of the total species (Ibarra et al 1997, Ramirez 1999).

Los Tuxtlas is one of the five areas in Mexico with the highest rates of endemism, with about 10% of the trees being endemic to the region's hot humid zone (Wendt 1993, Rzendowski 1991). Although further research is necessary to determine the full extent of their range, current data suggests several species could be considered endemic to the reserve: Thelypteris rachyflexuosa, Solenophora tuxtlensis, Iiinga sinacae, Begonia sousae, Pouteria rhynchocarpa, Mormodes tuxtlensis, Ruellia tuxtlensis, Tridineris tuxtlensis, Aristolochia veracruzana, Inga lacustris, Parathesis calzadae, Parathesis neei, Parathesis tuxtlensis, and Rondeletia tuxtlensis (Ibarra et al. 1997, Ramirez 1999).

Other species considered endemic to the Sierra Santa Marta region are Aristolochia impudica, Dichapetalum mexicanum, Salivia tuxtlensis, Parthesis pajapensis, and Chamaedora hooperiana (Ramirez 1999).

The Cycada family (Zamiaceae) is the only one in the region with four species receiving some degree of international protection. Three of the species are considered threatened, Certozamia mexicana var. robusta, Zamia furfuraceae, and Zamia loddigesii, while Certozamia miqueliana is critically endangered. Additionally, C. mexicana, C. miqueliana, and Z. furfuraceae are considered endemic species. Six species from other families are also considered endemic and five are critically endangered: Chamaedora tuerckheimii, Chamaedoreae tenella, Aporocactus leptophis, Olmeca recta and Olmeca reflexa. Chamaedorea alternans is also listed as threatened.

The fauna of the region is as rich as the flora. The ichthyofauna of Los Tuxtlas includes species distributed between freshwaters and estuaries. 109 species, with 78 genera in 36 families have been recorded in the park. The family of fish Characidae includes is locally known as "pepescas." Within this family, Bramochrarax caballeroi is endemic to Lake Catemaco. Astyanax fasciatus is an exotic species from South American. Of the family Atherinidae, locally known as "charales," Atherinella ammophila is endemic to the region near the La Palma River.

The marine fauna in the continental waters represent 72 % of the total ichthyofauna of the region. It comprises 63 genus and 33 families (Espinosa 1997, Fuentes & Espinosa 1997). Four species of marine origin are recognized as accidentals, seven species are endemic, two species are exotic, and five species are threatened. However, according to the Official Mexican Standard for Ecology number 059 of 1994, which lists species according to their threat categories (NOM-ECOL-059-1994), only Rhamdia guatemalensis and Priapella olmeca are considered threatened species, while Xiphophorus milleri is critically endangered. P. olmececae and X. milleri are considered endemic species.

The herpetofauna in the region represents an important percentage of the total number of species in Mexico (14.8% of the amphibians and 16.5% of the reptiles) (Flores-Villela 1993). Literature lists 166 species, represented in six orders and 33 families. Of these species, 24 are endemic to Mexico. Of these 24, 19 are exclusively found in Los Tuxtlas. Only Hemidactylus frenatus introduced from the Philippines, is considered exotic (Morales-Mavil et al 1995, Gonzalez et al. 1997). Of the 46 species of amphibians, 19 are protected under (NOM-ECOL-059-1994), one is under special protection, and 18 are considered rare. Twenty-six species of reptiles are classified as rare, 11 are threatened, 18 are subject to special protection, and seven are critically endangered.

The 561 species of birds in the region include both terrestrial and marine species. These species include 21 orders, one suborder, 72 families, and eight subfamilies. Two endemic species have been reported: the long tailed sabrewing (Campylopterus excellens) and the Tuxtla quail-dove (Geotrygon carrikeri). Five endemic subspecies have also been reported: Empidonax flavescens imperturbatus, Myioborus miniatus molochinus, Atlapetesbrunneinucha apertus, Cholorospingis opthalmicus wetmorei and Vireolanius pulchellus ramosi (Lowery & Newman 1949, Coates-Estrada & Estrada 1985, Estrada et al 2000). In 1997, the World Conservation Union (IUCN) reported 30 species of birds classified as critically endangered and 55 as threatened. However, the Mexican system, (NOM-ECOL-059-1994), protects 164 species: 55 are classified as rare, 46 are threatened, 12 are subject to special protection, and 11 are critically endangered (Winker 1997, Estrada & Coates-Estrada 1997). The king vulture (Saarcoramphus papa), the harpy eagle (Harpia harpyja), and the red macaw (Ara macao) are locally extinct.

The Los Tuxtlas Biosphere Reserve reported a total of 139 species of mammals, representing 30 % of Mexico's total. These are divided into 11 orders, 31 families, and 17 sub families (Martinez & Sanchez 1997, Coates Estrada & Estrada 1986). The NOM-ECOL-059-1994 considers 31 species located in Los Tuxtlas to be under some form of conservation. Furthermore, it ranks the howler monkey (Alouatta palliata mexicana) as an endemic species. Seven mammal species are classified as threatened: porcupine (Sphiggurus mexicanus), nutria (Lutra longicaudis), jaguarondi (Herpailurus yaguarondi), and little grison (Galictis vittata). Eleven species are critically endangered, including the spider monkey (Ateles geoffroy), the howler monkey (Alouatta palliata mexicana), the banded anteater (Tamandua mexicana), and the tayra (Eira barbara); 13 species are considered rare, including the woolly opossum (Caluromis derbianus) the false vampire bat (Vampirum spectrum), the cacomiztle raccoon (Baassarscus sumichrasti), and the kinkajou (Potos flavus).

International organizations, including IUCN, report 17 species at risk. The puma (Puma concolor) is Critically Endangered, the rice rat (Orizomys melanotis) is classified as Data Deficient, the Mexican long-nosed bat (Leptonycteris nivalis) is considered Critically Endangered, the Mexican agouti (Dasyprocta mexicana) and the bat (Lonchorhina aurita) are considered Threatened, and the bat (Bauerus dubiaquercus) and the howler monkey (Alouatta palliaata mexicana) are considered Vulnerable.

Some of the larger mammals, including the jaguar (Panthera onca), the puma (Puma concolor), the tapir (Tapirus bairdii), the red brocket deer (Mazama amaericana), the white-lipped peccary (Tayassu pecari), and the west Indian manatee (Trichechus manatus) in the Sontecomapan Lake, have been locally exterminated due to illegal deforestation, uncontrolled hunting, and the illegal commerce of wild animals (Coates-Estrada & Estrada 1986).

The insects reported in the region fall within 72 families, 46 subfamilies, 88 tribes, 707 genera, and 1,117 species. Additionally, 172 species of butterflies have been reported (Moron 1992, Raguso &Lorente 1997). These included 24 newly reported species for Mexico in the case of the family Syrphidae and four new species described within the group of the fireflies, in the genera Phaenolis, Aspisoma, Photinus, and Photuris (Navarrete-Heredia 1997, Zaragoza 1997, Navarrete-Heredia 1997, Estrada & Coates-Estrada 1998).

 

 

1.6 General Geology

The region of Los Tuxtlas is a volcanic massif dating back to the Tertiary period, whose still active volcanism has produced principally basalts and basaltic clays. Lava flows, volcanic ash, and other pyroclastics cover almost the entire area. Very few sedimentary, marine outcrops from the Tertiary exist in the area, and most of these are found toward the south.

The most recent lava flows filled riverbeds, forming falls and cascades, and ash deposits were distributed over the majority of the area. The volcanoes are divided into three groups: large, partially eroded stratum volcanoes; small, partially eroded cones with a shallow slope; and very recent cones, generally with steep and abrupt slopes.

 

1.7 General Geomorphology

Geomorphology of the region: A volcanic massif, whose principal longitudinal axis measures 80 km. Seven large and partially eroded volcanoes and 300 small volcanic cones can be distinguished (figure 7). To a large extent, it is primarily volcanic byproducts that condition the local relief, as lava flows define the structure of buildings, river networks, and cliffs; whereas ash and other pyroclastic products form the hilly areas.

Ecological region. - The ecological province is 77, and is called the Sierra de los Tuxtlas. It is located on a coastal plain to which three terrestrial systems are assigned: 77-01, San Martín and San Andrés, Tuxtla; 77-02, San Martín Pajapan; and 77-03, Catemaco.

These three terrestrial systems are further subdivided into terrestrial landscapes, which are defined by the homogeneity of their topographic forms. The San Martín Pajapan system (77-02), to which the three ejidos in this soil biodiversity project are assigned, is composed of 26 terrestrial landscapes. Included among these landscapes are both the mountainous and hilly landforms (the latter being predominant in the area).

 

2. Sites of Study

2.1 Details of the windows in the Benchmark Area

Three windows were selected for in-depth study of soil organisms for their diversity and functional attributes (a description of sampling design and the sampling methodology is presented in appendix II). The three windows in Los Tuxtlas region are associated with three communities or ´ejidos´. They were the Adolfo López Mateos Community, the Venustiano Carranza Community and the San Fernando Community (Figure 8). A full description of the windows is presented in the following sub-sections.

 

2.1.1 Adolfo López Mateos

Geographic Location.- The Adolfo López Mateos window is located between 18° 24’ 56’’ to 18° 26’ 33’’ North Latitude and 94° 56’ 53’’ to 94° 58’ 18’’ West Longitude (Figure 9). It lies within the municipality of Catemaco. The Gulf of Mexico marks the North boundary of the window. The eastern and southern borders are the municipality of Soteapan and the western border is the Catemaco Lake.

The altitude of the López Mateos window is 238.39 ± 37.45 msl (mean ± Standar deviation). This window have an annual precipitation between 2000 y 2500 mm and the climate is hot and humid, Am (f). Annual temperature is > 22°C and the precipitation in drier month is < 60mm.

Number of selected observation points: initially, eight points for each soil use were selected for a total of 32 points (figure 10). Recently, new sampling points were added in order to obtain a better picture of the patterns observed in the results. Points in some places were difficult to georeference due to dense vegetation.

Adolfo López Mateos is an ejido that corresponds to the “San Juan Volador” terrestrial landscape. Hilly area Low, undulating to slightly undulating, (figure 11). Hilly area corresponds to the eastern foothills of the volcano, San Martín Pajapan. Low, undulating to slightly undulating, its basaltic constitution has taken the form of very shallow gullies, elongated summits, and extensive plains. In addition, coastal alluvial plains with sandy beaches and rock outcrops can be found.

Morpho-edaphological landscapes.- LoM1 Gentle hilly areas composed of ash and volcanic breccia, with deep, umbric andisols. LaM2 Moderately to strongly inclined slopes, with moderately deep, umbric andisols. Va3 Narrow to wide valleys composed of basalt, with very thin leptosols, lithosols, and alluvion.

 

A complete soil type description of each window or ejido, is showed in appendix I and data for chemical variables of the sampling points are presented in the appendix III.

 

2.1.2 Venustiano Carranza

Geographic Location.- The Venustiano Carranza window is located between 18° 19’ 09’’ to 18° 21´ 50’’ North Latitude and 94° 44´ 41’’ to 94° 46´ 44’’ West Longitude (Figure 12). It lies within the municipality of Tatahuicapan. The Gulf of Mexico marks the North boundary of the window. The eastern border is the Pajapan municipality, the south border is the Tatahuicapan municipality and the western border is the Soteapan municipality.

 

The altitude of Venustiano Carranza window is 225.7 ± 44.89 msl (mean ± Standar deviation). This window have an annual precipitation of 2900 mm and the climate is hot and humid, Af (m). Annual temperature is > 22°C and the precipitation in drier month is > 60mm.

Number of selected observation points: Initially, eight points for each soil use were selected for a total of 32 points (figure 13). In same way that López Mateos, new sampling points were added. Some points are absent due they are difficult to georreference.

Landscape.- Venustiano Carranza is an ejido that corresponds to the “Mirador Pilapa” terrestrial landscape (occupies 90% of the total area and is found in the western part of the ejido) and the “San Martín” landscape (occupies 10% of the total area and occurs to the east).

The Mirador Pilapa: Intermediate to low, undulating hilly area, that corresponds to the broad, mountain pass between the Sierra de Santa Martha and the volcano, San Martín Pajapan, and that includes its contact with the coastal, alluvial plain. It is a hilly area characterized by very shallow ravines and broad summits carved out of extensive basalts (Figure 14); in addition, there are a few interfluvial and fluvial plains. Drainage is sub-dendritic, radial centrifugal (for the moment), and with moderate to strong vertical dissection.

San Martín: Low, mountainous area with steep slopes. Upper slopes are steep. Undulating slopes are found at the foot of the mountain. Inscribed and adjacent, brechoid volcanic cones are found in the main crater. The basalt-and-slag slopes are dissected by deep ravines that alternate with sharp, elongated peaks. In general, these present a very strong, dissection density and show a radial centrifugal type of drainage system.

Morpho-edaphological landscapes.- Vc1 Strongly dissected, hilly areas comprised of basalt, with moderately deep soils. Vc2 Moderately dissected, hilly areas with deep soils.

 

2.1.3 San Fernando

Geographic Location.- The Adolfo López Mateos window is located between 18° 15´ 08’’to 18° 19´ 55’’ North Latitude and 94° 52´ 00’’ to 94° 54´ 06’’ West Longitude (Figure 15). It lies within the municipality of Soteapan. The Santa Marta volcano marks the North boundary of the window. The eastern border is the Tatahuicapan municipality, the south border is the Tatahuicapan municipality and the western border is the Soteapan municipality.

 

The altitude of San Fernando window is 994.86 ± 144.37 msl (mean ± Standar deviation). This window have an annual precipitation of 1182.7 mm and the climate is hot and humid, Am. Annual temperature is > 22°C and % of winter precipitation respect to annual total is between 5% to 10.2%.

Number of selected observation points: Initially eight points for each soil use were selected for a total of 32 points but same way that other two windows, new sampling points were added (figure 16).

 

Lanscape.- San Fernando is an ejido that corresponds to the “Buena Vista” terrestrial landscape (occupies 60% of the total area and is found in the northern part of the ejido) and the “El Tulin” landscape (occupies 40% of the total area and occurs to the south).

 

Buena Vista: Elevated, highly undulating, hilly area, located in the south of the Sierra de Santa Martha. A dissected hilly area characterized by straight and deeply cut ravines, and broad, elongated summits (figure 17). This landscape is composed of basalt and slag that has been submitted to a moderately strong density of dissection that models a sub-parallel drainage network.

 

El Tulin: Intermediate hilly area, undulating to highly undulating, corresponding to the southern, lower slopes of the Sierra de Santa Martha. This relief is due to the dissection of basalts dating from the upper Tertiary period. This type of erosion formed very deep and sinuous gullies, small and shallow ravines, and broad, flat summits. The drainage pattern is sub-parallel and moderately dense.

Ravines.- B1 Strongly dissected basalt ravines, with lithosols; B2 Moderately dissected ravines comprised of basalt and volcanic breccia, with leptosols

 

Morpho-edaphological landscapes.- Hilly areas, Lo1f Strongly dissected hilly areas, comprised of breccia and ash, with compacted clay soils and andic alfisols. Lo2f Moderately dissected hilly areas, with deep, andic alfisols.

 

2.2 Sampling Sites Socioeconomic Context the Los Tuxtlas Region and the Biosphere Reserve in Veracruz State, México

 

2.2.1 Summary

BGDB project sampling sites in Mexico are located in the territory of three communities within the buffer zone of the Biosphere Reserva of Los Tuxtlas, in the southern part of Veracruz State, Mexico. Efforts to preserve the environment in this mega diverse area started in the decade of 1930´s, since then the region has been object of several protection decrees. Government institutions, NGO´s, academic centers and Foundations (national and international) had promoted conservation-development projects in the last two decades. Despite these efforts this Reserve is considered critically threatened. The environmental deterioration of Los Tuxtlas region as part of the destruction of tropical forest in México, among the main causes is:

• Colonization of the tropical forest (1950-1980) as response of land demand from rural sectors after the post revolutionary agrarian reform.

• Government supported land use change from forest to grass and agriculture during this period.

• Population increase in the region.

• Immigration from other parts of Mexico.

• Lack of environmental perspective in public polices.

 

 

2.2.2 Economic activities in the region

Livestock

• Livestock is the main economic activity in the region, is practiced under an extensive model that supports an average of less than 1 head per hectare.

• Continuous replacement of subsistence agriculture for livestock has produced the loss of self-sufficiency in basic products as well as the substitution of traditional technologies and diversified strategies.

• In the region an estimated area of 86,739 ha is under pasture and livestock (more than 65 %).

 

Agriculture

• The population primarily cultivates corn practicing slash and burn agriculture.

• Corn is cultivated as part of a traditional agriculture system, the MILPA, an association of several crops; beans, squash, yucca, and others

• Agriculture in the region produces poor yields (ranging from 300-1500 kg/hectare) due to the low fertility of the soil. Erosion and the loss of soil are common threats for the land.

• Approximately 53% of the wage-earning population works in corn production for family feeding. Most of the farmers own an average of 1.5 ha

Population

• This region hosted the first civilization of Mexico and maybe in the Americas; the Olmec culture.

• Cultural diversity is present with populca and nahua population which holds a deep and acute knowledge of the agroforestal systems.

• Cultural erosion due to extreme poverty and margination is linked to adoption of external productive models and acculturation related to migratory process.

 

Farmer’s economy is in the worst crisis of its long history of poverty, besides natural resources degradation decreases yields and productivity, these factors presses the population to migrate in search of complementary income. Actually migration to cities and USA has blunt social impacts, such as rural population aging and feminization.

Public investment used for decades to promote Party agendas created a clientelary culture based on subsidy and free delivery of technologic packages of the green revolution. Thus, any attempt to mobilize or engage local population to any communitarian problem or issue, has to deal with the expectative of receive immediate material benefit (in cash, or kind)

 

2.2.3 The three Communities

Land tenure at the three sites is ejidal, a form of collective property, were use of land was individual, but not the property. This form of land tenure changed in 1992, allowing private property, this weakened the ejidal structure and its capacity to take effective decisions to regulate communitarian life, such as access and regulation to natural resources use. As result communitarian life at regional level is highly disorganize dew to the weakening of the internal government structures, and the lack of new forms for public matters regulation.

This is the case of Venustiano Carranza and San Fernando, large communities were diverse conservation-development programs and projects had operated in the last 10 years, achieving low impacts and permanence. In both ejidos the last communitarian forest reserves were distributed and deforested after 1992 reforms to land tenure. López Mateos is a small ejido highly organized around a communitarian conservation project; ecotourism.

A common trait in the three “Ejidos” is that the young man migrates to the north of Mexico or the USA to get cash and sent it to their family.

 

Adolfo López Mateos

 

Migrant families from various parts of Mexico occupied the area now known as López Mateos from approximately 1971 to 1984. Their intention was to claim and settle in the rainforest lands for agricultural purposes, as permitted under the agrarian reform act. During these early years conflicts with local ranchers arose over land claims, and the disputes eventually lead to the burning of settlers’ homes and a general scattering of families for several years. Nevertheless, with considerable persistence homesteaders were able to return to the area and obtain legal land tenure, eventually incorporating as the Ejido “López Mateos” in 1984.

After practicing slash and burn milpa for several years the ejidal general assembly of this Mestizo (i.e., a mixed Spanish and indigenous inheritance), community decided ban deforestation and adopted communitarian ecotourism as they key project. This decision made of López Mateos a referent to communitarian ecotourism at regional and national level, diverse foundations, NGO´s Government institutions and academic centers have collaborated with the ejido in this project.

 

Typical land use trajectories in López Mateos have involved the initial clearing of rainforest during a period of three to five years. As rainforest was eliminated, maize polycultures were substituted. These polycultures, or milpas, included other annual crops such as beans and squash. Following approximately three to five years of continuous planting of milpas, the croplands were allowed to fallow. Since that time, fallowed plots have been permitted in many cases to revert to secondary forests of varying ages. The general consensus among local residents is that a secondary forest, upon attaining approximately 20 years of age, is now a fully restored rainforest. Examples of such “recovered” rainforest exist in López Mateos and are also included in the soil biodiversity inventory. Some lands on short fallow cycles have been replanted with maize; however, the more general trend in the López Mateos area has been to convert these cleared and briefly farmed plots to cattle pastures by relying especially upon exotic species of grass. In general, the cultivation of maize has been discontinued in López Mateos, as the strong, prevailing, winter winds from the Gulf of Mexico tend to blow over maize stalks that would otherwise grow well at this time of year. They also they mention that a pest “la plaga” disrupt the maize from growing and the beans are disrupted by too much water or humidity. Hunting and fishing in rainforest areas was initially an important economic activity in the early years of the ejido, but this quickly decreased as more and more land was cleared and the larger fish, shrimp, bird, and mammal species disappearing. Currently, local ordinances, restrictions and/or closed seasons on timber extraction, hunting and fishing have been passed and put in effect.

Some families in López Mateos have implemented agroforestry practices in their plots. These practices have principally included the production of coffee (low quality coffee) oranges and tangerines. The last two have an ant pest (leaf cutters) attacking them. Nevertheless, markets have been unfavorable in recent years, and local residents perceive these activities to have little current economic viability. They lack transport to take the products to better markets where they can fetch better prices. A small number of families are also engaged in the cultivation of ornamental palms (chamaedora spp) under rainforest canopies remaining on their properties. At some point in the near future these plants will be harvested and sold to local intermediaries who represent the floriculture industry. At present, the cultivation of native palms generates no income for local residents, as management activities are directed toward the establishing a standing crop.

In recent years the Mexican government has provided local residents with tree seedlings (primarily cedar, walnut and mahogany) for reforesting and eventual selective commercial extraction. The first harvest is still some years into the future such that the activity does not yet provide an income for local residents.

López Mateos is an ecologically minded community that has been developing conservation awareness and sustainable use activities since about 1980. In 1992, the community was favorably impressed with the possibility of developing ecotourism activities. Because López Mateos is located within the buffer zone of the “Los Tuxtlas” Biosphere Reserve (where rural communities are legally permitted to engage in low-to-no impact economic activities), ecotourism has been perceived as a desirable, alternative source of income. Interest in ecotourism was also spurred by this community’s realization that the local climate does not sustain an agriculturally based, local economy. Since 1996, López Mateos has been facilitating visits to the community and surrounding rainforest by providing food, lodging, and nature guide services. These activities provide an important, supplementary income for many local families. Although the cattle is not widespread in this Ejido, the family who have it are much better off than the rest.

 

Current land distribution

Current land uses are showed in figure 10 and rain forest cover about 75% of the total area (Figure 18).

López Mateos has a total area of 358 ha and part of the ejido is divided in 39 plots of 100 x 300 meters (117 ha.). The rest is a communitarian forest reserve (241 ha.). Forest area is stable, grass and milpa areas are decreasing.

In López Mateos, seven economic activities are the most practiced:

• Ecotourism
• Calmedor palm (Chamedora spp) recollection from the forest.
• Livestock
• Agroforestery (shade coffee, camedor palm, ixtle –Aechmea magdalenacea, citrus and banano)
• Fishing
• Pisciculture
• Milpa

 

Population changes and “ejidatarios” number are showed in table 1.

 

Table 1. Changes in population in the ejido López Mateos

López Mateos
Population 1995	Population 2000	Area	Ejidatarios
153	133	358 ha.	39

Venustiano Carranza

As was the case in López Mateos, peasant farmers seeking land under the agrarian reform act were also involved in the founding of Venustiano Carranza in 1967. In V. Carranza, a small portion of the community is descended from the Nahuatl indigenous group; however the majority of its members claim a Mestizo origin. V. Carranza has experienced greater levels of natural resource exploitation by the local settlers and ranchers than the ecologically minded community of López Mateos. In particular, the conversion of rainforests to cattle pastures has been more extensive and pervasive in V. Carranza than in López Mateos.

From 1967 to 1984, land holdings in Venustiano Carranza were communal (i.e., there was no individual ownership of land). But since 1985, communal property has been divided and individual Deeds provided to individual heads of households. The most common land use practice in V. Carranza following the clearing of rainforest in the early years was the planting maize polycultures (milpas). In addition to maize as the staple crop, plantings of yucca, squash, beans, bananas were common on farm plots. The milpa was intended to meet the food self-sufficiency needs of individual households. However, harvests were generally only adequate for the first few years following the initial felling of the forest (a condition attributed by local residents to cool soil temperatures and plant pests and pathogens - but also affected by the loss of topsoil and organic matter on rapidly eroding lands) such that the planting of diversified annual crops was largely abandoned.

In the case of V. Carranza, extensive cattle ranching was introduced quickly into the area and accelerated rapidly, resulting in the felling of more and more forested lands throughout the ejido. The introduction of exotic grass species into the community dates to the period from 1967 to 1975, although the extension of pasturelands continues to the present day. As the amount of land dedicated to cattle ranching in V. Carranza has continued to grow, forested tracts have become increasingly smaller, inaccessible and fragmented. In addition, subsistence-level hunting and fishing by local people have since disappeared.

The early 1980s in V. Carranza were marked by prolonged droughts and a number of high intensity fire events. In addition the commercial cultivation of lilies (“azucena”) was introduced into the community at this time. Many peasant families saw the production and sale of azucena bulbs to regional and out-of-state intermediaries as an economically viable activity, meaning that significant revenues could be generated from the cultivation of relatively small tracts of land. However, bulbs and foliage soon became infected with plant pests and pathogens, and the losses of potential yields were (and still are) substantial. As a consequence, most community members consider the cultivation of azucena to be risky compared to the unpredictable harvests and marginal profits.

In 1997, cedar and mahogany saplings were made available to community members by a government program dedicated to reforestation efforts. Small agroforestry plantations were started by many property owners throughout the ejido, with the understanding that mature trees would be selectively harvested and sold for timber at some future date. It is noteworthy to mention that these trees are not growing satisfactorily most probably due to poor soils (i.e., soils low in organic matter, are acid and with heavy clay sub-soils).

Since early 1990´s several projects were implemented by NGO´s and government, as result of a PRA diagnosis exercise, including training an funding, such project included pisciculture, reforestation with commercial species (cedar, mahogany), horticulture, vermicompost, camedor palm and ixtle growing, green manure and cover crops, etc. Nevertheless, in less of 5 years all most all this initiatives were abandoned.

 

Economy

Principal activity in V. Carranza is livestock; therefore, pastures cover an important area in this ejido (Figure 13 and 19).

• Livestock is oriented to meat and milk production, around 500 cows graze in the ejido, but less than 30% is owned by local farmers.
• Migration
• Milpa is cultivated by most of the families, production is oriented to self consume.
• Agroforestal systems are practiced under mature forest or fallow shade; 30 ha. of ixtle (aechmea magdalenae) y camedor palm (chamaedora spp)
• Forestall plantations with commercial spices.
• Ixtle and forestall plantations have not been harvested yet. Income in cash depends on milk and cattle, camedor palm, and shrimp River sell.
• Lily is economically relevant, but plagues affected severally this activity.

This community confirms the regional trend towards pasture extension and reduction of milpa area. Trends in population are showed in table 2.

 

Table 2. Changes in population in the ejido V. Carranza

Venustiano Carranza
Population 1995	Population 2000	Area	Ejidatarios
267	247	1020 ha.	74

 

San Fernando

Since early XX century populacas farmers practiced a productive system were shade coffee was a key component of a traditional agroforestery system which long contributed to the conservation of the ecosystem. (Milpa, rustic coffee, gathering, hunting, and fishing). Actually this system is threatened by the international crisis of coffee prices, thus a tendency to shade coffee conversion to other land uses (pasture mostly) or abandon is observed.

This ejido has a much longer history in the region of the Sierra de Santa Martha, in 1906, as well as during the years of the Mexican Revolution (a civil war undertaken by the poor and landless against the government of Porfirio Díaz), the region of San Fernando came to be settled by members of the Popoluca indigenous group who arrived from the lower elevation and nearby community of Soteapan. Important struggles for tenancy of the land by rural peasant farmers began in 1930 and continued for approximately the next 20 years, at which time issues of agrarian reform were apparently settled during the Cardenas presidency. During this time, and especially beginning in 1935, the cultivation of “criollo” coffee (i.e., locally adapted varieties of shade-grown coffee) was introduced into the San Fernando region.

In 1958, conflicts over tenancy of the land began again in earnest under the presidency of Adolfo López Mateos. In 1960, the Popoluca peasant farmers living in the area solicited legal tenancy of their lands from the federal government and in 1963 the ejido of San Fernando was officially recognized (figure 13).

In 1960, forested lands in the San Fernando area covered approximately 1500 hectares. By 1990 this had been reduced by more than half, as additional lands were cleared to meet the growing, self-sufficiency needs of rural families.

In 1974, the Instituto Mexicano de Café (INMECAFE) organized local coffee growers in order to plant improved varieties of coffee, including the “caturra”, “mundonovo”, “garnica”, “borbon”, “Costa Rica” and “Robusta” varieties. The use of fertilizers, pesticides and other technological “packages” was encouraged at this time. Many local coffee growers resisted this governmental pressure, preferring to continue the traditional practice of “rustic” coffee. Rustic coffee relies upon the use and selection of local forest trees (primarily of the genus Inga) to provide the necessary shade cover for the proper growth, maturation, and harvesting of the coffee plant. The activity is basically organic, requiring little-to-no external chemical inputs by peasant farmers. In 1989, INMECAFE was decommissioned and financial and technical support to coffee producers disappeared. As a consequence, plus the fall of the international coffee price, many farmers abandoned their coffee “fincas” (i.e., small holdings although this activity still their main economic income as a product of their land.

Apiculture was practiced for a brief time in San Fernando beginning in 1975. However, this activity was abandoned by 1982 due to a fall in honey prices and the crossing of local bee strains with the aggressive “African” variety.

Issues of land tenancy resurfaced in the community in 1993 with the appearance of the governmental program PROCEDE. PROCEDE was involved in establishing, with greater precision, the physical extent of the actual landholdings of peasant farmers in Mexico. By 1996, community members were satisfied that the traditional areas worked by individual families for many years would be respected by the government in the redrawing property lines.

In the 1990´s decade several conservation and development initiatives were implemented by the PSSM, a long established in the region NGO. Impact and permanence of the projects is low, with some outstanding exceptions, like the Popolucas palm producers cooperative of San Fernando.

In 1994, the planting of “mucuna” (mucuna derengianna, a type of leguminous, “green manure”) was introduced into the traditional “milpa” (maize polyculture). Initially, some 25 peasant farmer families adopted this practice, but currently only about 10 are actively engaged in this form of maize cultivation. Additional government-sponsored programs of special note in San Fernando began in 1997 and 1997. These included the planting of ornamental palms (mostly “Palma Camedor”) under remaining forest canopy (and for eventual sale to outside markets) and the reforestation of agricultural lands with precious wood species such as red cedar (Cedrella odorata) and mahogany (Swietenia macrophylla). In 2000, the first harvest of Palma Camedor took place, which resulted in both local and out-of-state sales. To date, this alternative economic activity continues to grow in strength and participation in San Fernando. Trees planted for reforestation purposes have yet to reach harvestable maturity.

Economic activities

 

Principal economic activity in San Fernando is coffee (figure 16), the proportional distribution of land use is showed in figure 20.

• Agroforestal systems are practiced under forest or fallow shade; coffee, Camedor palm, Ixtle.

• Milpa is cultivated by most of the families, production is oriented to self consume.

• Migration.

• Livestock.

• Few farmers still cultivate mucuna spp as part of a complex milpa system with out use of fire.

 

Trends in population number is showed in table 3, it can be see that changes in population number are low in a 5 years period. Migration to the north of México can be the cause.

 

Table 3. Changes in population number in the ejido San Fernando

San Fernando
Population 1995	Population 2000	Area	Ejidatarios
1214	1300	2130 ha.

 

2.3 Comparison between Windows

On table 4 it is showed the differences between windows. The windows have different kind of soil, precipitation, % of Carbon and C:N relationship. On same way, the principal land use is different in each “ejido” and the rain forest cover also is different. The differences are important because we would expect variations in the diversity patterns in accordance with the differences between windows.

 

Table 4. Similarities and or differences between windows

	López Mateos	San Fernando	Venustiano Carranza
Localization	18° 24’ 56’’ to 18° 26’ 33’’ North Latitude and 94° 56’ 53’’ to 94° 58’ 18’’ West Longitude	18° 15´ 08’’to 18° 19´ 55’’ North Latitude and 94° 52´ 00’’ to 94° 54´ 06’’ West Longitude	18° 19’ 09’’ to 18° 21´ 50’’ North Latitude and 94° 44´ 41’’ to 94° 46´ 44’’ West Longitude
Altitude msnm	238.39 ± 37.45 msnm	994.86 ± 144.37 msnm	225.7 ± 44.89 msnm
Rainfall mm	2000 y 2500 mm	1182.7 mm	2900 mm
Soil:	Humic Andisol	Cromic Acrisol and Mollic Acrisol	Cromic Luvisol and Ocric Luvisol
Organic carbon (%) A1	6	9	4
Total Nitrogen (%) A1	1	0.6	0.6
C:N A1	9	15	7
Textura (Boyoucos)	Crumb-clay-sandy and clayed	Crumb-clay-sandy and clayed	Crumb-clay-sandy and clayed
pH (water)	5-6	5-6	4-5
Geomorphology	Mountain with convex hillsides of 40° of slope, with ondulated relief	Hilly in middle part of the mountains and crest plane of hills. Fluvial valley in low part	Fluvial Valley and llanures sloping gentle dissecction
Geology	Volcanic rock high modified and mixed with volcanic ashes	Basalt of de riolit with form of layers (lajas) and volcanic molasse imtemperizate	Basalts with volcanics very intermediate in composition
Principal land use	Rain forest conservation	Shaded Coffee plantations	Grassland for cattle raising
Rain Forest cover	76.85%	49.55%	27.23%
Ejido Size Ha.	571.99 Ha	2192.32Ha	970.73Ha

3. Conclusion

 

In spite the three communities in the benchmark site are near on each other, they have different characteristics. This situation would result in differences in both, between land uses and between landscapes, and the diversity in the functional groups could be explained by those two levels. For example, there are differences in the C and C:N concentration between “ejidos”, the values in these variables are lower in V. Carranza while the higher values are in San Fernando (table ). Likewise, the soils in V. Carranza are more acid than those in López Mateos and San Fernando. Differently, the mean precipitation have the highest value in V. Carranza, while the lowest value is in San Fernando.

Preliminary results in some functional groups, e.g. Macrofaune, Nematodes, showed that diversity is lower in the “ejido” V. Carranza while the higher diversity values are present in the “ejido” San Fernando.

Other factor to landscape level is the altitude over sea level, the mean altitude for San Fernando is about 900 m while for the other two communities is about the 230 m. Los Tuxtlas has enormous biodiversity that is rivaled by few other areas in Mexico.

Acknowledges:

 

We are grateful with CONAFOR (Comisión Nacional Forestal) because they provided us with satellite image and land use maps of the Los Tuxtlas; similarly, we are in indebted with Benito Hernández for his help in the chemical analysis of soil profiles and the sampling points.

 

 

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