Alejandro Velázquez

Remote sensing and GIS-based regional geomorphological mapping—a tool for land use planning in developing countries

Abstract Land use planning and necessary supporting data are crucial to developing countries that are usually under severe environmental and demographic strains. Approaches and methods to map the variability of natural resources are important tools to properly guide spatial planning. In this paper, we describe a method to quickly map terrain at reconnaissance (1:250,000) and semi-detailed (1:50,000) levels. This method can be utilized as a basis for further land evaluation and land use planning in large territories. The approach was tested in the state of Michoacan, central-western Mexico, currently undergoing rapid deforestation and subsequent land degradation. Results at the reconnaissance level describe the geographic distribution of major landforms and dominant land cover, and provide a synoptic inventory of natural resources. Results at the semi-detailed level indicate how to nest individual landforms to major units and how they can be used to run procedures for land evaluation. If combined with appropriate socioeconomic data, governmental guidelines for land use planning can be formulated on the basis of reconnaissance and semi-detailed terrain analysis.

Tropical Deforestation, Community Forests, and Protected Areas in the Maya Forest

Community forests and protected areas have each been proposed as strategies to stop deforestation. These management strategies should be regarded as hypotheses to be evaluated for their effectiveness in particular places. We evaluated the community-forestry hypothesis and the protected-area hypothesis in community forests with commercial timber production and strict protected areas in the Maya Forest of Guatemala and Mexico. From land-use and land cover change (LUCC) maps derived from satellite images, we compared deforestation in 19 community forests and 11 protected areas in both countries in varying periods from 1988 to 2005. Deforestation rates were higher in protected areas than in community forests, but the differences were not significant. An analysis of human presence showed similar deforestation rates in inhabited protected areas and recently inhabited community forests, but the differences were not significant. There was also no significant difference in deforestation between uninhabited protected areas, uninhabited community forests, and long-inhabited community forests. A logistic regression analysis indicated that the factors correlated with deforestation varied by country. Distance to human settlements, seasonal wetlands, and degree and length of human residence were significant in Guatemala, and distance to previous deforestation and tropical semideciduous forest were significant in Mexico. Varying contexts and especially colonization histories are highlighted as likely factors that influence different outcomes. Poorly governed protected areas perform no better as a conservation strategy than poorly governed community forests with recent colonists in active colonization fronts. Long-inhabited extractive communities perform as well as uninhabited strict protected areas under low colonization pressure. A review of costs and benefits suggests that community forests may generate more local income with lower costs. Small sample sizes may have limited the statistical power of our comparisons, but descriptive statistics on deforestation rates, logistic regression analyses, LUCC maps, data available on local economic impacts, and long-term ethnographic and action-research constitute a web of evidence supporting our conclusions. Long-inhabited community forest management for timber can be as effective as uninhabited parks at delivering long-term forest protection under certain circumstances and more effective at delivering local benefits.

Land use-cover change processes in highly biodiverse areas: the case of Oaxaca, Mexico

Abstract Land use-cover changes (LUCC) such as deforestation, have resulted as global warming and a reduction of environmental services, with large negative consequences for mankind. Effects based on statistics alone have not been sufficient enough to detect, stop and eventually revert negative LUCC processes that are strongly related to biodiversity loss. It is, therefore, of prime concern to assess and depict cartographically, major LUCC processes simultaneously. Mexico harbors a large pool of biodiversity, mostly restricted to a few locations among which, The State of Oaxaca plays a major role. In this state, nevertheless, drastic negative LUCC processes are taking place. Land cover types, mapped in previous surveys, overlaid on recent Landsat imagery and 300 ground truth sites, were used to detect current LUCC. Rates of conversion of the most important LUCC processes were computed and mapped simultaneously. Oaxaca has lost over half a million hectares of forested areas during the last 20 years. The core results may contribute to the understanding of how LUCC and GIS methods can provide better and more targeted information that may help to improve conservation policies and land use planning strategies.

THE USE OF ECOLOGICAL SCIENCE BY RURAL PRODUCERS: A CASE STUDY IN MEXICO

The role of ecological science in promoting sound environmental decisions has concerned ecologists worldwide and it has been stressed that the application of eco- logical knowledge requires new interactive and participatory forms of research, as well as sound partnerships between ecologists and land managers. However, concrete examples of ecological science as part of rural decision making have rarely been examined, especially in intertropical countries. We analyzed interactions between ecological scientists from the National Autonomous University of Mexico (UNAM) and a rural indigenous community involved in forest management in Central-Western Mexico. Using qualitative research meth- ods (such as observing participants, conducting interviews; generally focusing on the mean- ings that social actors give to phenomena), we compared the perspectives of the academic and community sectors in relation to benefits, products, problems, and obstacles faced when conducting integrative forest management. The research showed the relevance of rural communities demanding scientific information for ecosystem management and of academic institutions accepting to respond to these demands. Participatory approaches and continuous communication between sectors were essential for establishing trust and commitment for everyone involved. The obstacles found were related to an academic institutions inability to support such an experience and to accept capacity building of rural managers as part of its scientific mission. We concluded that applied ecological science in developing countries, such as Mexico, should regard rural communities as key ecosystem managers and should respond to their needs and demands in order to convert pure scientific findings into wise environmental decisions.

Altitudinal distribution patterns of Mexican cloud forests based upon preferential characteristic genera

Mexican cloud forest vegetation has been recorded in temperate humidconditions at rather different elevations ranging from 600 to 3000m. They are characterised by high biodiversity under continuousfoggy situations. Some authors state that many genera are quantitativelyimportant to depict cloud forest conditions. Detailed quantitative studiescomprising most of the localities of Mexican cloud forests to depict altidudinaldistribution ranges on basis of preferential genera have not been previouslyconducted. The aim of this study is (1) to recognise characteristic preferentialgenera of Mexican cloud forest conditions, and (2) to determine quantitativelythe current altitudinal distribution pattern of this vegetation type. From adatabase composed by 995 genera inhabiting in the Mexican cloud forests, sixgenera were chosen preliminary as preferential characteristics. These wereClethra, Magnolia, Meliosma, Styrax, Symplocos, andTernstroemia. These genera include 70 species that occur atover 70% of the current Mexican cloud forest fragments. The mean elevation ofthese genera records were 1853 m (±600 at 95% confidenceinterval). The results showed that Mexican cloud forests occur optimally between1250 and 2450 m. Additionally, Mexican cloud forest is the bestdistributed within some provinces of the “Región Mesoamericana deMontaña”, chiefly at “Serranías Meridionales”,“Sierra Madre Oriental”, and “SerraníasTransístmicas”. The results are discussed in light of theimportance of these regions as diversification centres.

From Displacement-based Conservation to Place-based Conservation

The viability of biodiversity conservation based uniquely upon a model of protected areas is being questioned in the developing world, and new evidence is emerging on the social and ecological costs of displacing people in order to ‚impose wilderness™ (Neumann 2002; Igoe 2004; Rodrigues 2006). This re-evaluation of the strict protected areas model is driven in part by new data showing that some human-dominated regimes of land use and tenure are effective complementary conservation strategies that can achieve both sustainable livelihoods and biodiversity conservation, although there are tradeoffs in all forms of conservation land use (VelAEzquez

A Landscape Perspective on Biodiversity Conservation The Case of Central Mexico

Abstract The aim of this article is two fold: first, to depict key species and relate them to landscape units (LUs) to define habitats; second, to generate a sound network of protected areas to ensure the functional integrity of the ecosystem. In the present study, 6500 vertebrate and vascular plant species records were gathered into a database. A total of 137 sampling units were surveyed to verify key species and depict discrete LUs (scale 1:25,000). Using multivariate statistics (detrended correspondence analysis and canonical correspondence analysis), key species were selected and associated with LUs in a geographical information system. From the 1162 species recorded, 122 were identified as key species based on their endemicity and conservation status (12 amphibians, 42 reptiles, 37 birds, 11 mammals, and 20 vascular plants). Volcanic bodies and Holocene lava flows contain most key species but harbor less species overall, whereas mixed forest, meadows and crops, foot slopes, and accumulation plains harbor fewer key species but a greater number overall. These patterns were spatially displayed and discussed in light of their role in conservation and participatory management after over 15 years of research.

Multivariate analysis of the vegetation of the volcanoes Tláloc and Pelado, Mexico

Multivariate analysis was used to describe the com- position and distribution of vegetation types on the slopes of the volcanoes Tlaloc and Pelado, Mexico. These volcanoes are situated in the transitional zone between the Holarctic and Neotropical floristic regions, which offers a partial explana- tion for the relatively high α and β diversities. Previous research argued that human activities, i.e. burning and graz- ing, rather than abiotic factors, play a major role in determin- ing the distribution and floristic composition of the vegetation. TWINSPAN, Detrended Correspondence Analysis and Ca- nonical Correspondence Analysis were used to test this hy- pothesis. Floristic and environmental data from 138 releves and seven explanatory environmental variables were included: elevation, soil depth, soil moisture, percentage litter cover, percentage cover of bare ground, burning and grazing were included in the analysis. Soil moisture and elevation accounted for ca. 63 % of the residual inertia and none of the remaining explanatory variables proved to be correlated significantly with the first two axes. The present results suggest that burn- ing and grazing operate on a finer scale. In conclusion, soil moisture and elevation are the most relevant variables to explain the distribution of the vegetation under study.

Distribution and population size of Romerolagus diazi on El Pelado volcano, Mexico

Distribution and population size of the volcano rabbit or zacatuche ( Romerolagus diazi ) were investigated at El Pelado volcano, one of the four remaining core distribution areas left in Mexico. Latrines or fecal pellets were counted at 342 randomly selected sampling sites between 1986 and 1989. Rabbits also were censused directly from horseback along 29 line transects in October 1988. There was a significant correlation between the mean number of latrines and mean number of rabbits sighted within each of four categories of abundance. Spatial distribution was mapped based on these categories of abundance. Mean size of populations of volcano rabbit was estimated at 6,488 individuals (range of 2,478–12,120). The lower value (2,478) should be used for conservation efforts. Most volcano rabbits occurred at 3,150–3,400 m elev., mainly in the upper and middle southern slopes.

Habitat suitability study for the conservation of the volcano rabbit (Romerolagus diazi)

The endangered Mexican volcano rabbit (Romerolagus diazi)-habitat relationship was investigated. Data, obtained from 137 sampling units in 14 patches of the geographical distribution areas of the rabbit, included information on floristic composition, vegetation structure, terrain characteristics and human activities. The abundance of the volcano rabbit was measured in 685 subsampling units by pellet-counts and estimations of pellet-coverage. Two questions have been addressed in this paper: what is a good indicator of habitat type and which are the habitat factors that explain best the distribution of the volcano rabbit? Thirteen plant communities were identified. Terrain and landscape units were distinguished through aerial photograph interpretation and were verified in the field. By means of classical (parametric and non-parametric) and multivariate (Canonical Correspondence Analysis) statistical analyses, the most suitable, suitable and unsuitable habitat classes were detected. The results indicated that plant communities (F = 4,14; P < 0.0001) and landscape units (F = 7,29; P < 0.001) were adequate levels to distinguish habitat types for the rabbit. Plant communities of Festuca tolucensis and Trisetum altijugum-Festuca tolucensis attained the largest abundance of rabbits, followed by the communities Muhlenbergia quadridentata-Pinus hartwegii, Festuca tolucensis-Pinus hartwegii and Pinus sp.-Alnus firmifolia. The abundances of the volcano rabbit in the remaining plant communities were significantly less than in the communities mentioned above. These results suggest that the volcano rabbit shows strong preferences for subalpine habitat types. Soil moisture (r = -0.840), altitude (r = -0.756), grazing (r = -0.423) and burning (r = 0.494) correlated significantly with the distribution and abundance of the volcano rabbit. These results are discussed in light of their role in the conservation of the volcano rabbit.