Ezcurra E.,University of California at Riverside |
Kolb M.,Comision Nacional para el Conocimiento Y Uso de la Biodiversidad |
Creel J.E.B.,Nature Conservancy
PLoS ONE | Year: 2015
Using publicly available data on land use and transportation corridors we calculated the human footprint index for the whole of Mexico to identify large-scale spatial patterns in the anthropogenic transformation of the land surface.We developed a map of the human footprint for the whole country and identified the ecological regions that have most transformed by human action. Additionally, we analyzed the extent to which (a) physical geography, expressed spatially in the form of biomes and ecoregions, compared to (b) historical geography, expressed as the spatial distribution of past human settlements, have driven the patterns of human modification of the land. Overall Mexico still has 56% of its land surface with low impact from human activities, but these areas are not evenly distributed. The lowest values are on the arid north and northwest, and the tropical southeast, while the highest values run along the coast of the Gulf of Mexico and from there inland along an east-to-west corridor that follows the Mexican transversal volcanic ranges and the associated upland plateau. The distribution of low- and high footprint areas within ecoregions forms a complex mosaic: the generally well-conserved Mexican deserts have some highly transformed agroindustrial areas, while many well-conserved, low footprint areas still persist in the highlytransformed ecoregions of central Mexico. We conclude that the spatial spread of the human footprint in Mexico is both the result of the limitations imposed by physical geography to human development at the biome level, and, within different biomes, of a complex history of past civilizations and technologies, including the 20 th Century demographic explosion but also the spatial pattern of ancient settlements that were occupied by the Spanish Colony. © 2015 González-Abraham et al.
PubMed | University of California at Riverside, The Nature Conservancy and Comision Nacional para el Conocimiento y Uso de la Biodiversidad
Type: Journal Article | Journal: PloS one | Year: 2015
Using publicly available data on land use and transportation corridors we calculated the human footprint index for the whole of Mexico to identify large-scale spatial patterns in the anthropogenic transformation of the land surface. We developed a map of the human footprint for the whole country and identified the ecological regions that have most transformed by human action. Additionally, we analyzed the extent to which (a) physical geography, expressed spatially in the form of biomes and ecoregions, compared to (b) historical geography, expressed as the spatial distribution of past human settlements, have driven the patterns of human modification of the land. Overall Mexico still has 56% of its land surface with low impact from human activities, but these areas are not evenly distributed. The lowest values are on the arid north and northwest, and the tropical southeast, while the highest values run along the coast of the Gulf of Mexico and from there inland along an east-to-west corridor that follows the Mexican transversal volcanic ranges and the associated upland plateau. The distribution of low- and high footprint areas within ecoregions forms a complex mosaic: the generally well-conserved Mexican deserts have some highly transformed agro-industrial areas, while many well-conserved, low footprint areas still persist in the highly-transformed ecoregions of central Mexico. We conclude that the spatial spread of the human footprint in Mexico is both the result of the limitations imposed by physical geography to human development at the biome level, and, within different biomes, of a complex history of past civilizations and technologies, including the 20th Century demographic explosion but also the spatial pattern of ancient settlements that were occupied by the Spanish Colony.
Alvarez-Romero J.G.,James Cook University |
Devlin M.,James Cook University |
Teixeira da Silva E.,James Cook University |
Petus C.,James Cook University |
And 8 more authors.
Journal of Environmental Management | Year: 2013
Increased loads of land-based pollutants are a major threat to coastal-marine ecosystems. Identifying the affected marine areas and the scale of influence on ecosystems is critical to assess the impacts of degraded water quality and to inform planning for catchment management and marine conservation. Studies using remotely-sensed data have contributed to our understanding of the occurrence and influence of river plumes, and to our ability to assess exposure of marine ecosystems to land-based pollutants. However, refinement of plume modeling techniques is required to improve risk assessments. We developed a novel, complementary, approach to model exposure of coastal-marine ecosystems to land-based pollutants. We used supervised classification of MODIS-Aqua true-color satellite imagery to map the extent of plumes and to qualitatively assess the dispersal of pollutants in plumes. We used the Great Barrier Reef (GBR), the world's largest coral reef system, to test our approach. We combined frequency of plume occurrence with spatially distributed loads (based on a cost-distance function) to create maps of exposure to suspended sediment and dissolved inorganic nitrogen. We then compared annual exposure maps (2007-2011) to assess inter-annual variability in the exposure of coral reefs and seagrass beds to these pollutants. We found this method useful to map plumes and qualitatively assess exposure to land-based pollutants. We observed inter-annual variation in exposure of ecosystems to pollutants in the GBR, stressing the need to incorporate a temporal component into plume exposure/risk models. Our study contributes to our understanding of plume spatial-temporal dynamics of the GBR and offers a method that can also be applied to monitor exposure of coastal-marine ecosystems to plumes and explore their ecological influences. © 2013 Elsevier Ltd.
Penner J.,Humboldt University of Berlin |
Wegmann M.,University of Würzburg |
Hillers A.,Royal Society for the Protection of Birds |
Schmidt M.,Comision Nacional para el Conocimiento y Uso de la Biodiversidad |
Rodel M.-O.,Humboldt University of Berlin
Diversity and Distributions | Year: 2011
Aim The study was aimed at testing whether West Africa can be regarded as a distinct biogeographic region based on amphibian assemblages. If so, we asked what were the relationships of these assemblages with those in Central Africa, and whether West African amphibian distributions showed biogeographic substructure. We further investigated what events or processes may explain the observed patterns. Location Sub-Saharan Africa. Methods Presence-absence data of amphibian assemblages derived from field surveys and the literature were statistically analysed using three different multivariate techniques (consensus clustering, Monmonier analysis and nonmetric multidimensional scaling) to emphasize consistent results. Results We showed that West Africa has unique amphibian assemblages, which could be clearly demarcated from Central African assemblages, particularly by the geographic barrier of the Cross River. Further biogeographic subdivisions were detected to the west of this barrier. Habitat, mainly forest, was the best factor explaining our observed pattern. Overall, intra-regional similarity (e.g. within West Africa) was higher than intra-habitat similarity (e.g. within forest) across regions. Main conclusions Our results are compared with previous works and interpreted in the light of the known evolutionary history of West and Central Africa. The observed pattern may be explained by postulated differences in river continuity through time, with West African rivers serving as more or less constant barriers in contrast to those in Central Africa. Our results demonstrate the uniqueness of West African amphibian assemblages, highlighting the need for their conservation as many are under acute anthropogenic pressure. © 2011 Blackwell Publishing Ltd.
Arita H.T.,National Autonomous University of Mexico |
Christen A.,Research Center en Matematicas |
Rodriguez P.,Comision Nacional para el Conocimiento y Uso de la Biodiversidad |
Soberon J.,University of Kansas
Global Ecology and Biogeography | Year: 2012
Aim A great deal of information on distribution and diversity can be extracted from presence-absence matrices (PAMs), the basic analytical tool of many biogeographic studies. This paper presents numerical procedures that allow the analysis of such information by taking advantage of mathematical relationships within PAMs. In particular, we show how range-diversity (RD) plots summarize much of the information contained in the matrices by the simultaneous depiction of data on distribution and diversity. Innovation We use matrix algebra to extract and process data from PAMs. Information on the distribution of species and on species richness of sites is computed using the traditional R (by rows) and Q (by columns) procedures, as well as the new Rq (by rows, considering the structure of columns) and Qr (by columns, considering the structure by rows) methods. Matrix notation is particularly suitable for summarizing complex calculations using PAMs, and the associated algebra allows the implementation of efficient computational programs. We show how information on distribution and species richness can be depicted simultaneously in RD plots, allowing a direct examination of the relationship between those two aspects of diversity. We explore the properties of RD plots with a simple example, and use null models to show that while parameters of central tendency are not affected by randomization, the dispersion of points in RD plots does change, showing the significance of patterns of co-occurrence of species and of similarity among sites. Main conclusion Species richness and range size are both valid measures of diversity that can be analysed simultaneously with RD plots. A full analysis of a system requires measures of central tendency and dispersion for both distribution and species richness. © 2011 Blackwell Publishing Ltd.
Lira-Noriega A.,Comision Nacional para el Conocimiento y Uso de la Biodiversidad |
Lira-Noriega A.,Investigador Catedras Conacyt En El Institute Ecologia A C |
Aguilar V.,Comision Nacional para el Conocimiento y Uso de la Biodiversidad |
Alarcon J.,Comision Nacional para el Conocimiento y Uso de la Biodiversidad |
And 5 more authors.
Biological Conservation | Year: 2015
Freshwater ecosystems are key to maintaining biological diversity and for human well-being. Despite their importance, these ecosystems have suffered severe transformations due to anthropogenic activity. Here we present the first priority assessment of freshwater ecosystems in Mexico at the national scale. Because species' compositional and hydrological conditions vary widely across Mexico we divided the territory into seven distinct regions in order to assign different conservation targets for biodiversity surrogates and to consider specific threats according to their impact in each region. The total conservation area network identified is equal to 30% of the country's continental surface, in which more than 94% of the biodiversity surrogates meet their established conservation targets. The regions of the Tropical Pacific and Gulf of Mexico have the largest proportions of priority sites, followed by the Central Highlands, which contains the largest number of irreplaceable sites. Tropical Pacific and the Baja California Peninsula possess the largest proportion of sites with extreme importance for conservation. Nationally, the percentage of priority sites under protection is 15.8%, of which 5.6% are sites of extreme importance, 4.2% are sites of high importance, and 6% are sites of medium importance for conservation. Our study highlights the importance of conducting conservation prioritization assessments at higher spatial resolution using information that is up to date and doing so in a collaborative way to strengthen decision making. This analysis helps to bridge the research-implementation gap in conservation planning to improve the representation of Mexico's freshwater biodiversity in conservation areas. © 2015 Elsevier B.V.
Wegier A.,National Autonomous University of Mexico |
Wegier A.,Instituto Nacional de Investigaciones Nucleares |
Pineyro-Nelson A.,National Autonomous University of Mexico |
Pineyro-Nelson A.,Instituto Nacional de Investigaciones Nucleares |
And 8 more authors.
Molecular Ecology | Year: 2011
Over 95% of the currently cultivated cotton was domesticated from Gossypium hirsutum, which originated and diversified in Mexico. Demographic and genetic studies of this species at its centre of origin and diversification are lacking, although they are critical for cotton conservation and breeding. We investigated the actual and potential distribution of wild cotton populations, as well as the contribution of historical and recent gene flow in shaping cotton genetic diversity and structure. We evaluated historical gene flow using chloroplast microsatellites and recent gene flow through the assessment of transgene presence in wild cotton populations, exploiting the fact that genetically modified cotton has been planted in the North of Mexico since 1996. Assessment of geographic structure through Bayesian spatial analysis, BAPS and Genetic Algorithm for Rule-set Production (GARP), suggests that G. hirsutum seems to conform to a metapopulation scheme, with eight distinct metapopulations. Despite evidence for long-distance gene flow, genetic variation among the metapopulations of G. hirsutum is high (He = 0.894 ± 0.01). We identified 46 different haplotypes, 78% of which are unique to a particular metapopulation, in contrast to a single haplotype detected in cotton cultivars. Recent gene flow was also detected (m = 66/270 = 0.24), with four out of eight metapopulations having transgenes. We discuss the implications of the data presented here with respect to the conservation and future breeding of cotton populations and genetic diversity at its centre of crop origin. © 2011 Blackwell Publishing Ltd.
Marin-Sanchez A.I.,Comision Nacional para el Conocimiento y Uso de la Biodiversidad |
Briones-Salas M.,National Polytechnic Institute of Mexico |
Lopez-Wilchis R.,Metropolitan Autonomous University |
Servin J.,Metropolitan Autonomous University
Revista Mexicana de Biodiversidad | Year: 2015
The size of the coyote's (Canis latrans) home range was estimated in a temperate forest in Sierra Madre, Oaxaca, Mexico. The periods of reproduction, gestation, breeding and pups independence and rain and dry seasons are compared. A collar with activity sensor was placed in 4 coyotes and monthly readings were registered in cycles of 24 h. To delimit the home range area minimum convex polygons at 95% in digital maps were employed. The average size of the home range for all coyotes was 3.45 km2 with a bigger size in the period of independence (4.74 km2), followed by gestation (4.58 km2), reproduction (2.44 km2) and breeding (2.04 km2); but significant differences between periods were not found per coyote, nor when doing a comparison between them. The average value in the home range for the seasons was 6.52 km2, higher for the dry one with 6.69 km2. The size of the female's home range was higher during the dry season, while for the young male was higher during the rainy season. It was concluded that there are significant differences among coyotes due to sex and age. All Rights Reserved © 2015 Universidad Nacional Autónoma de México, Instituto de Biología.
Lira-Torres I.,National Polytechnic Institute of Mexico |
Galindo-Leal C.,Comision Nacional para el Conocimiento y Uso de la Biodiversidad |
Briones-Salas M.,National Polytechnic Institute of Mexico
Revista de Biologia Tropical | Year: 2012
Zoque Forest is one of the richest and threatened regions in Southeastern Mexico, and for which few studies on mammal biology and use are available. Here we analyzed the conservation status of mammalian species according to Mexican and international laws, with an updated checklist of mammals in this forest, and some information on their use by some rural communities. Basic information was obtained from national and international collections and publications. A total of 42 fieldtrips, that followed conventional techniques, were conducted from 2003 through 2010, and some questionnaires to local hunters were applied. The mammalian fauna found in the area was composed of 149 species belonging to 99 genera and 30 families; these results support that the Zoque Forest is the richest in the number of mammalian species in Mexico. A total of 35 species were considered at risk by the Mexican National Law NOM-059-SEMARNAT-2010, and 21 species were found to be registered in the IUCN Red List or in CITES. Of the 40 species included in any of the lists, only the Baird's tapir, jaguar and white-lipped peccary were included in all three lists and 14 species were shared by the two of them. The main uses of mammals in order of importance are: 1) bushmeat, 2) pets, 3) skins, and 4) traditional medicine. Subsistence hunting and trade are unofficially allowed for farmers in this area. As for now, the region has healthy populations of a large number of mammals even though they have been used by local residents. However, since a considerable number of these species are listed under some criterion of threat, local authorities are called for more control.
Moreno C.E.,Autonomous University of the State of Hidalgo |
Rodriguez P.,Comision Nacional para el Conocimiento y Uso de la Biodiversidad
Oecologia | Year: 2011
After decades of misusing the term diversity in community ecology, over the last 5 years some papers have offered important advances toward developing a more rigorous mathematical background, which allows us to achieve more clarity in the terminology for the vast range of biological phenomena that have been placed under the umbrella of this term. Some points have been clearly stated in previous papers of this Views and Comments section, and new terms have even been proposed for specific cases, but other issues, such as the need for the prefix true have not been discussed. Our aim is to clarify some of the terms and concepts, the proper use of which appears still to remain unclear, and to provide biologists with a simplified version of the general framework resulting from recent contributions, with an emphasis on identifying points of consensus in the field. We also comment on the possibility of extending the basics of this general framework to other facets of the broad term biodiversity, such as functional or phylogenetic diversity. © 2011 Springer-Verlag.