For all researches, please visit our "Peer-reviewed publications" page.
Correa Ayram C, Mendoza M, Etter A, Pérez Salicrup D (2017)
Anthropogenic impact on habitat connectivity: A multidimensional human footprint index evaluated in a highly biodiverse landscape of Mexico
Ecological Indicators 72 895-909.
Evaluating the cumulative effects of the human footprint on landscape connectivity is crucial for implementing policies for the appropriate management and conservation of landscapes. We present an adjusted multidimensional spatial human footprint index (SHFI) to analyze the effects of landscape transformation on the remnant habitat connectivity for 40 terrestrial mammal species representative of the Trans-Mexican Volcanic System in Michoacán (TMVSMich), in western central Mexico. We adjusted the SHFI by adding fragmentation and habitat loss to its original three components: land use intensity, time of human landscape intervention, and biophysical vulnerability. The adjusted SHFI was applied to four scenarios: one grouping all species and three grouping several species by habitat spatial requirements. Using the SHFI as a dispersal resistance surface and applying a circuit theory based approach, we analyzed the effects of cumulative human impact on habitat connectivity in the different scenarios. For evaluating the relationship between habitat loss and connectivity, we applied graph theory-based equivalent connected area (ECA) index. Results show over 60% of the TMVSMich has high SHFI values, considerably lowering current flow for all species. Nevertheless, the effect on connectivity of human impact is higher for species with limited dispersal capacity (100–500m). Our approach provides a new form of evaluating human impact on habitat connectivity that can be applied to different scales and landscapes. Furthermore, the approach is useful for guiding discussions and implementing future biodiversity conservation initiatives that promote landscape connectivity as an adaptive strategy for climate change.
Keywords: Cumulative human impact, Habitat connectivity, Mexico, Multi-species
Feldman R, Peers M, Pickles R, Thornton D, Murray D (2017)
Global Ecology and Conservation 9 1-10.
Species interactions like parasitism influence the outcome of climate-driven shifts in species ranges. For some host species, parasitism can only occur in that part of its range that overlaps with a second host species. Thus, predicting future parasitism may depend on how the ranges of the two hosts change in relation to each other. In this study, we tested whether the climate driven species range shift of Odocoileus virginianus (white-tailed deer) accounts for predicted changes in parasitism of two other species from the family Cervidae, Alces alces (moose) and Rangifer tarandus (caribou), in North America. We used MaxEnt models to predict the recent (2000) and future (2050) ranges (probabilities of occurrence) of the cervids and a parasite Parelaphostrongylus tenuis (brainworm) taking into account range shifts of the parasite’s intermediate gastropod hosts. Our models predicted that range overlap between A. alces/R. tarandus and P. tenuis will decrease between 2000 and 2050, an outcome that reflects decreased overlap between A. alces/R. tarandus and O. virginianus and not the parasites, themselves. Geographically, our models predicted increasing potential occurrence of P. tenuis where A. alces/R. tarandus are likely to decline, but minimal spatial overlap where A. alces/R. tarandus are likely to increase. Thus, parasitism may exacerbate climate-mediated southern contraction of A. alces and R. tarandus ranges but will have limited influence on northward range expansion. Our results suggest that the spatial dynamics of one host species may be the driving force behind future rates of parasitism for another host species.
Keywords: Boreal, Cervidae, Climate change, Evolution, Parasitism, Synergistic effects
Aguilar-Lopez J, Pineda E, Luria-Manzano R, Canseco-Marquez L (2016)
Species Diversity, Distribution, and Conservation Status in a Mesoamerican Region: Amphibians of the Uxpanapa-Chimalapas Region, Mexico
Tropical Conservation Science 9(4) 1940082916670003.
The Uxpanapa-Chimalapas region, with one of the most extensive and best preserved tropical forest areas in Mexico, is undergoing major anthropogenic changes, and only some portions of the territory are under the protection of local communities. Although the biodiversity of the region is known to be high, no study has yet analyzed the diversity of amphibian species in the region or contributed to valuing the region in a context of amphibian conservation. Based on a review of databases and the existing scientific literature, as well as our own fieldwork, in this study, we analyze the amphibian species richness, species composition, their spatial distribution, and their conservation status in the Uxpanapa-Chimalapas region. Additionally, we compare this information with the available data for seven other tropical regions in central-northern Mesoamerica. The amphibian fauna recorded at the study region comprises 51 species, which makes it the richest tropical region in amphibian species in central-northern Mesoamerica and Mexico. Among the regions compared, this one stands out as the one with the most distinctive composition of amphibian species, sharing on average only 35% of its species with the other regions. However, it is also the region with the highest number of threatened species since one third of its species are in higher extinction risk categories. These characteristics turn the Uxpanapa-Chimalapas into a high-priority region for both Mexico and Mesoamerica, and a regional conservation plan is necessary for the immediate protection of areas where the forest is being replaced and to promote or to support community protected areas.
Keywords: amphibian fauna, conservation value, species composition, species richness
Arias-Alzate A, González-Maya J, Arroyo-Cabrales J, Martínez-Meyer E (2016)
Wild Felid Range Shift Due to Climatic Constraints in the Americas: a Bottleneck Explanation for Extinct Felids?
Journal of Mammalian Evolution 1-12.
Theoretical and empirical evidence suggests that the ecological niche of species tends to be conservative over evolutionary time in many taxonomic groups, thus representing long-term stable constraints on species geographic distributions. Using an ecological niche modeling approach, we assessed the impact of climatic change on wild felid species potential range shifts over the last 130 K years in the Americas and the potential of such shifts as an extinction driver. We found a significant range shift for most species (both living and extinct) across their distributions driven by large-scale environmental changes. Proportionally, the most drastic range increase for all species occurred in the Last Glacial Maximum (LGM: 18 K years)–Current transition, while for the Last Inter-Glacial (LIG: 130 K years)–LGM transition an important range reduction occurred, which was larger for extinct North American species. In conclusion, the reduction of climatically suitable areas for many species in the transition LIG–LGM may have produced population reductions, which, in turn, may have played an important role in species’ extinction throughout the continent.
Keywords: Bottlenecks, Ecological niche, Extinction, Felidae, Late Pleistocene, Range shift
Bush M, Correa-Metrio A, McMichael C, Sully S, Shadik C, Valencia B et al. (2016)
Quaternary Science Reviews 141 52-64.
A sedimentary record from the Peruvian Amazon provided evidence of climate and vegetation change for the last 6900 years. Piston cores collected from the center of Lake Sauce, a 20 m deep lake at 600 m elevation, were 19.7 m in length. The fossil pollen record showed a continuously forested catchment within the period of the record, although substantial changes in forest composition were apparent. Fossil charcoal, found throughout the record, was probably associated with humans setting fires. Two fires, at c. 6700 cal BP and 4270 cal BP, appear to have been stand-replacing events possibly associated with megadroughts. The fire event at 4270 cal BP followed a drought that caused lowered lake levels for several centuries. The successional trajectories of forest recovery following these large fires were prolonged by smaller fire events. Fossil pollen of Zea mays (cultivated maize) provided evidence of agricultural activity at the site since c. 6320 cal BP. About 5150 years ago, the lake deepened and started to deposit laminated sediments. Maize agriculture reached a peak of intensity between c. 3380 and 700 cal BP. Fossil diatom data provided a proxy for lake nutrient status and productivity, both of which peaked during the period of maize cultivation. A marked change in land use was evident after c. 700 cal BP when maize agriculture was apparently abandoned at this site. Iriartea, a hyperdominant of riparian settings in western Amazonia, increased in abundance within the last 1100 years, but declined markedly at c. 1070 cal BP and again between c. 80 and −10 cal BP.
Keywords: Agriculture, Forest enrichment, Fossil charcoal, Fossil diatoms, Fossil pollen, Human disturbance, Iriartea, Maize, Mauritia, Pre-Columbian
Bélgica Pérez-De la O, López-Martínez V, Jiménez-García D, Campos-Figueroa M (2016)
Model Simulation of Potential Distribution of Lobesia botrana (Denis & Schiffermüller) in Grape, Vitis vinifera (L.) Vineyard Regions of Mexico
Southwestern Entomologist 41(3) 693-704.
Abstract. Environmental suitability for the European grapevine moth, Lobesia botrana (Denis & Schiffermüller) was studied in Mexico. Nineteen weather variables were studied in grapevine, Vitis vinifera (L.), regions of the country. The model calculated areas with high and medium probability of environmental suitability in Baja California, medium probability in central and northern Chihuahua, and low probability in Coahuila, Durango, Puebla, Sonora, and Zacatecas. The environmental variables with most impact were average annual temperature (17.2%), rainfall amount during coldest month (16.4%), average temperature of most humid quartile (14.4%), and minimum temperature of coldest month (11.4%). Baja California State is most at risk for invasion by European grapevine moth.
Keywords: Agriculture, Forest enrichment, Fossil charcoal, Fossil diatoms, Fossil pollen, Human disturbance, Iriartea, Maize, Mauritia, Pre-Columbian
Carrillo-Angeles I, Suzán-Azpiri H, Mandujano M, Golubov J, Martínez-Ávalos J (2016)
Niche breadth and the implications of climate change in the conservation of the genus Astrophytum (Cactaceae)
Journal of Arid Environments 124 310-317.
The niche breadth of a species reflects its ability to inhabit different conditions, and to use different resources, hence, species with wider niche are expected to be more resilient to anthropogenic derived climate change. We estimated the niche breadth of all species of the genus Astrophytum from macro-environmental variables and measures of local habitat uses, in order to evaluate whether species having wider niche breadths are less prone to experience unsuitable conditions projected by the A1B and A2 scenarios of the IPCC for 2020 and 2050, and analyzed the implications of projections for the conservation of the genus Astrophytum. Our analysis suggests that most of populations of the four species will experience increasingly unsuitable conditions due to the increase of temperature and reduction in precipitation. The species less affected were those with wider niche breadth and situated in the middle of the latitudinal range and in the middle or lower extreme of the precipitation range for the genus (A. capricorne and A. myriostigma). Although the main threats for Astrophytum species come from the destruction of their habitats and activities as illegal extraction, climate change may reduce the chances for the regeneration of populations and the success of reintroduction programs.
Keywords: Bioclimatic variables, IPCC scenarios, MaxEnt, Threatened species
Castellanos-Morales G, Gutiérrez-Guerrero Y, Gámez N, Eguiarte L (2016)
Use of molecular and environmental analyses for integrated in situ and ex situ conservation: The case of the Mexican prairie dog
An important step in species conservation is to identify populations that significantly contribute to it. Considering both in situ and ex situ populations provides an integrated approach to the preservation of a species' evolutionary potential. The joint use of molecular and environmental analyses allows conservation schemes to be implemented when reintroducing captive populations, and wild populations to be prioritized for conservation purposes. We used genetic data and environmental analyses to select candidate areas for the reintroduction of a captive population of the Mexican prairie dog, Cynomys mexicanus, and prioritize wild populations for the conservation of this endangered endemic species. We estimated the levels of genetic diversity and differentiation of the captive population and compared them with those of six wild populations. We used species distribution modeling (SDM) to perform forecasts under future climate change scenarios and identify areas with suitable environmental conditions for the populations to persist in the medium to long term. The captive population showed high levels of genetic diversity (Hd=0.692, HE=0.52), but was genetically differentiated from the wild populations. The genetic structure of wild populations should therefore be considered when reintroducing captive Mexican prairie dogs. In the wild populations, we found a correlation between colony area and nuclear genetic diversity, suggesting that genetic drift and/or inbreeding have been stronger in smaller colonies. The occupied climate space was well differentiated among wild colonies. The impact of agriculture and roads was stronger in the northeastern area of the species range, where SDM forecasts suggest that environmental conditions may remain suitable in the future. Finally, we identified three colonies as conservation priorities based on both genetic and ecological criteria.
Keywords: Conservation genetics, Cynomys mexicanus, Distribution forecast, Microsatellites, Species distribution modeling, mtDNA
Cruz JA A (2016)
Reconstructing the paleoenvironment of Loltún Cave, Yucatán, Mexico, with Pleistocene amphibians and reptiles and their paleobiogeographic implications
Revista Mexicana de Ciencias Geologicas.
Loltún cave on the Ucatán peninsula is an important fossil site. The cave preserves Pleistocene fauna and lithic tools, and it's among teh few sites with amphibian and reptile fossila of the Mexican Pleistocene. We used teh fossil amphibians and reptiles community to reconstruct the paleoclimate and paleoenvironment of Loltún cave in the late Pleistocene. The Pleistocene amphibian and reptiles' community in Loltún cave consists of one frog, three lizards, five snakes and one turtle, Applying the Habitat Weighting method to teh fossil herpetofaunal assemblage, we inferred a vegetation mosaic non-analog with the present one, comprising evergreen seasonal forest, tropical deciduous forest found nowadays around Loltún cave. Using teh Mutual Climatic Range (MCR) method we inferred a mean annual temperature of 25.33 C and a mean annual precipitation of 1183.74 mm; teh temperature was 1.47 C lower and teh MAP was 85.14 mm higher than teh present climate condition. It is the first time that a paleoclimatic reconstruction using amphibians and reptiles in a tropical region is made using mCR method. Our result are in concordance with other paleoclimatic inferences using fossil pollen as a proxy. We found a range shift of the iguanid Ctenosaura subgenus Loganiosaura during teh Late Pleistocene, of 446.4 km north of teh present distribution surely given by the climatic and vegertation structure changes in the past.
Keywords: Paleoclimate, Pleistocene, Yucatán peninsula, amphibians and reptiles, paleoenvironment
Cuéllar-Martínez M, Sosa V (2016)
Botanical Sciences 94.
Background : Geophytes, plants with underground perennating organs that lose their aerial organs annually, are able to survive in harsh habitats. This life form is common in the monocots that inhabit Mediterranean climates around the world. In Mexico only the northern area of Baja California has this type of climate. Hypothesis : In this study, we recorded the species and distribution of Mexican geophyte monocots to pinpoint diversity hotspots. Our hypothesis is that the highest diversity of geophytes will be found in biogeographic areas with complex topography and seasonal climate such like Trans-Mexican Volcanic Belt and Sierra Madre del Sur, not only in the north of the Baja California Peninsula. Data description : Records of geophytes were taken from different sources, collections, taxonomic references and diversity databases. Geophyte locations were mapped in the context of biogeographic and protected areas. Results : The Mexican geophyte flora is composed of 476 species, approximately 10% of the total diversity of monocots. Echeandia and Tigridia were the two most diverse genera. This flora is dominated by the taxa of Orchidaceae, Asparagaceae and Iridaceae, and nine small endemic genera were recorded. Geophyte diversity was highest in two biogeographic provinces: the Trans-Mexican Volcanic Belt and the Sierra Madre del Sur, in dry forests such as oak-pine, seasonally dry tropical forests and semi-arid shrubby vegetation. Conclusions : Diversity of geophytes in Mexico is similar compared with certain regions with Mediterranean climate around the world. Areas sustaining a high diversity and endemism of geophytes are located in the Mesoamerican Biodiversity Hotspot, in unprotected and threatened areas.
Keywords: Balsas River Basin, Chiapas Depression, Echeandia, Tehuacán Valley, Tigridia, Trans-Mexican Volcanic Belt, endemism