Extracted from the Mendeley GBIF Public Library.
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
Monroy-Vilchis O, Castillo-Huitrón N, Zarco-González M, Rodríguez-Soto C (2016)
Potential distribution of Ursus americanus in Mexico and its persistence: Implications for conservation
Journal for Nature Conservation 29 62-68.
The black bear Ursus americanus is an endangered species in Mexico. Its historical distribution has decreased by approximately 80% although its current distribution is not known with precision; it is only reported to be present in the mountains of Northern Mexico. This study proposes two ensemble models: Mexicós black bear (a) potential distribution compared with Natural Protected Areas (NPAs); and, (b) persistence areas for 2024. The current distribution variables are coniferous forest, elevation and dry forest. Suitable habitat for black bear (354,047km2, 18.07% of the country) was found mainly in the north of the Sonoran biogeographical zone, along the Sierra Madre Occidental, the center and south of the Sierra Madre Oriental and some northern regions of the Altiplano Norte. Comparing these areas with NPAs documented that only 12.41% of potential distribution coincided with current suitable habitat. There are unprotected areas in Sierra Madre Occidental center and central and southern of Sierra Madre Oriental. The model for 2024 indicates a reduction of suitable habitat of 64.5%, mainly in the northern Sonoran zone and the center Sierra Madre Occidental. On the other hand, areas that will persist (125,673km2) are located along the two main mountain ranges of Mexico. Identification of these sites will allow strengthening of long-term conservation strategies.
Keywords: Black bear, Conservation, Ensemble model, Future model, Habitat suitability, Mexico, Ursus americanus
Morales A, Villalobos F, Velazco P, Simmons N, Piñero D (2016)
Journal of Biogeography.
Aim To explore whether environmental factors are correlated with genetic and morphometric differences in the widely distributed bat species Tadarida brasiliensis. Location North America and Central America. Methods We used an extensive sampling comprising 131 localities that represent heterogeneous environments across the Nearctic and Neotropical regions. Museum specimens were examined and 25 craniodental characters were recorded. Individuals were genotyped at one mitochondrial locus (mtDNA) and nine nuclear loci (nDNA). Clustering and phylogenetic analyses were used to identify differentiated groups. Environmental variables and PCA-env approaches were used to determine the climatic niche and to measure the niche overlap, equivalence and similarity between groups. Mantel tests between genetic groupings and environmental variables, dispersal costs, Euclidean geographical distances and niche overlap were performed. Results We identified six genetic groups within Central and North American T. brasiliensis based on nDNA. The most strongly differentiated group, in both nDNA and mtDNA, was located in central Mexico. Morphometric data showed that individuals from populations in Florida are slightly larger than the others. Niche overlap was detected among Neotropical groups but not among Nearctic groups. The currently recognized subspecies were not recovered as distinct groups with either genetic or morphometric data. Main conclusions Our approaches suggest that environmental niche variation may help shape the distribution of genetic variation across heterogeneous landscapes, particularly in widely distributed species. Environmental niche analyses suggest that genetic differences between migratory and non-migratory groups of T. brasiliensis may be promoted by climatic variation throughout the Nearctic and Neotropical regions. In addition, genetic and morphometric analyses do not support the current subspecies classification of T. brasiliensis in North and Central America, which should be abandoned.
Keywords: Tadarida brasiliensis, ecological niche, genetic structure, morphometric, phylogeography, subspecies
Ornelas J, González C, Hernández-Baños B, García-Moreno J (2016)
Molecular and iridescent feather reflectance data reveal recent genetic diversification and phenotypic differentiation in a cloud forest hummingbird
Ecology and Evolution.
The present day distribution and spatial genetic diversity of Mesoamerican biota reflects a long history of responses to habitat change. The hummingbird Lampornis amethystinus is distributed in northern Mesoamerica, with geographically disjunct populations. Based on sampling across the species range using mitochondrial DNA (mtDNA) sequences and nuclear microsatellites jointly analysed with phenotypic and climatic data, we (1) test whether the fragmented distribution is correlated with main evolutionary lineages, (2) assess body size and plumage color differentiation of populations in geographic isolation, and (3) evaluate a set of divergence scenarios and demographic patterns of the hummingbird populations. Analysis of genetic variation revealed four main groups: blue-throated populations (Sierra Madre del Sur); two groups of amethyst-throated populations (Trans-Mexican Volcanic Belt and Sierra Madre Oriental); and populations east of the Isthmus of Tehuantepec (IT) with males showing an amethyst throat. The most basal split is estimated to have originated in the Pleistocene, 2.39–0.57 million years ago (MYA), and corresponded to groups of populations separated by the IT. However, the estimated recent divergence time between blue- and amethyst-throated populations does not correspond to the 2-MY needed to be in isolation for substantial plumage divergence, likely because structurally iridescent colors are more malleable than others. Results of species distribution modeling and Approximate Bayesian Computation analysis fit a model of lineage divergence west of the Isthmus after the Last Glacial Maximum (LGM), and that the species’ suitable habitat was disjunct during past and current conditions. These results challenge the generality of the contraction/expansion glacial model to cloud forest-interior species and urges management of cloud forest, a highly vulnerable ecosystem to climate change and currently facing destruction, to prevent further loss of genetic diversity or extinction.
Keywords: Feather iridescence, Lampornis amethystinus, Mesoamerican highlands, glacial cycles
Ramirez-Cabral N, Kumar L, Taylor S (2016)
Agricultural and Forest Meteorology 218-219 102-113.
Crops experience different climate stresses during development. The magnitude of damage will depend on the phenological stage of the crop and the stress duration. Climate change could intensify some or all of these stresses, thus negatively impacting agriculture. An assessment of staple crop productivity, quality and climatically suitable areas under climate change conditions is necessary to undertake any global initiatives to tackle food security issues. The common bean (Phaseolus vulgaris L.) is a staple crop and the main source of proteins and nutrients in Africa and Latin America. The purpose of this study is to develop a process-oriented niche model to assess the impacts of climate change on the current and future potential distribution of common bean and to use this model to investigate the changes in heat, cold, dry and wet stresses under climate change. We used A2 and A1B emission scenarios and two different global climate models, CSIRO-Mk3.0 and MIROC-H, for the years 2050 and 2100. Our results indicate future climate conditions are more favorable for common bean cultivation in the Northern Hemisphere, but are less favorable in the Southern Hemisphere. Heat and dry stresses are the main factors limiting and reducing common bean distribution under current and future projected conditions. Africa and Latin America are projected to decrease with respect to suitability for common bean cultivation. The model projections indicate that a shift in the common bean productive areas is highly likely with a loss of suitability of the current common bean cultivation areas and an increase in cold regions such as Canada, the Nordic countries and Russia. The results indicate the likelihood of changes in climatic suitability and the distribution of common bean at a global scale under a future climate, which will affect regions where this legume is a staple crop and an important source of household income. Regions in the Northern Hemisphere could take advantage of the increase in suitability by increasing the production and exportation of this grain.
Keywords: Abiotic stresses, Agriculture suitability, CLIMEX, Climate change, Phaseolus vulgaris L.
Botello F, Sarkar S, Sánchez-Cordero V (2015)
Impact of habitat loss on distributions of terrestrial vertebrates in a high-biodiversity region in Mexico
Biological Conservation 184 59-65.
Mexico is considered a country of biological megadiversity because of its exceptional species richness and endemism. However, much of Mexico’s biodiversity is under threat due to a variety of factors, in particular, habitat loss. The Mexican legal standard (Norma Oficial Mexicana; NOM-ECOL-059-2010) uses four criteria to analyze specieś extinction risk at a national scale. However, when prioritizing areas for biodiversity conservation it is also important to incorporate knowledge of the conservation status of species at a more localized scale (regional, state, or municipal levels) for identifying possible risks associated with population declines. This paper focuses on Guerrero, which is the fourth most biologically diverse state in Mexico. The total extent of the conservation areas in Guerrero is low, amounting to 0.09% of its total area. We analyzed data for 582 terrestrial vertebrate species in Guerrero (53 amphibians, 115 reptiles, 334 birds and 80 mammals), modeling their potential distribution using a maximum entropy algorithm, and 114,555 occurrence records, and 23 predictive environmental (19 climatic and four topographical) variables. The portion of the potential distribution for each species including only remnant natural habitat was designated as its predicted distribution. The area of the predicted distribution was used to compute the fraction of natural habitat remaining for each species overlapping within decreed protected areas at the state and national levels, that is, for Guerrero and all of Mexico. Results show significant differences in the fraction of species’ predicted distribution and species’ potential distribution at different scales (state and national) and differences between the vertebrate groups analyzed. Because quantitative conservation targets are typically set for individual species, this exercise enables an analysis of the impact of the habitat lost on each species’ distribution by assessing the fraction of its predicted distribution that coincides with protected areas. We conclude that this must be part of systematic conservation planning to prioritize areas for potential conservation in Guerrero.
Keywords: Biodiversity, Deforestation, Distribution, Guerrero, Maximum entropy modeling, Protected areas
Castellanos-Morales G, Gámez N, Castillo-Gámez R, Eguiarte L (2015)
Peripatric speciation of an endemic species driven by Pleistocene climate change: the case of the Mexican prairie dog (Cynomys mexicanus).
Molecular phylogenetics and evolution 94 171-181.
The hypothesis that endemic species could have originated by the isolation and divergence of peripheral populations of widespread species can be tested through the use of ecological niche models (ENMs) and statistical phylogeography. The joint use of these tools provides complementary perspectives on historical dynamics and allows testing hypotheses regarding the origin of endemic taxa. We used this approach to infer the historical processes that have influenced the origin of a species endemic to the Mexican Plateau (Cynomys mexicanus) and its divergence from a widespread ancestor (Cynomys ludovicianus), and to test whether this endemic species originated through peripatric speciation. We obtained genetic data for 295 individuals for two species of black-tailed prairie dogs (C. ludovicianus and C. mexicanus). Genetic data consisted of mitochondrial DNA sequences (cytochrome b and control region), and 10 nuclear microsatellite loci. We estimated dates of divergence between species and between lineages within each species and performed ecological niche modelling (Present, Last Glacial Maximum and Last Interglacial) to determine changes in the distribution range of both species during the Pleistocene. Finally, we used Bayesian inference methods (DIYABC) to test different hypotheses regarding the divergence and demographic history of these species. Data supported the hypothesis of the origin of C. mexicanus from a peripheral population isolated during the Pleistocene [∼230,000 years ago (0.1 - 0.43 Ma 95% HPD)], with a Pleistocene-Holocene (∼9,000 - 11,000 years ago) population expansion (∼10-fold increase in population size). We identified the presence of two possible refugia in the southern area of the distribution range of C. ludovicianus and another, consistent with the distribution range of C. mexicanus. Our analyses suggest that Pleistocene climate change had a strong impact in the distribution of these species, promoting peripatric speciation for the origin of C. mexicanus and lineage divergence within C. ludovicianus.
Keywords: Bayesian inference, Chihuahuan Desert, Cynomys, Ecological niche modelling, Speciation
Cavender-Bares J, Gonzalez-Rodriguez A, Eaton D, Hipp A, Beulke A, Manos P (2015)
Phylogeny and biogeography of the American live oaks (Quercus subsection Virentes): A genomic and population genetics approach.
Molecular ecology 24(14) 3668-87.
The nature and timing of evolution of niche differentiation among closely related species remains an important question in ecology and evolution. The American live oak clade, Virentes, which spans the unglaciated temperate and tropical regions of North America and Mesoamerica, provides an instructive system in which to examine speciation and niche evolution. We generated a fossil-calibrated phylogeny of Virentes using RADseq data to estimate divergence times and used nuclear microsatellites, chloroplast sequences and an intron region of nitrate reductase (NIA-i3) to examine genetic diversity within species, rates of gene flow among species, and ancestral population size of disjunct sister species. Transitions in functional and morphological traits associated with ecological and climatic niche axes were examined across the phylogeny. We found the Virentes to be monophyletic with three subclades, including a southwest clade, a southeastern US clade and a central American/Cuban clade. Despite high leaf morphological variation within species and transpecific chloroplast haplotypes, RADseq and nuclear SSR data show genetic coherence of species. We estimate a crown date for Virentes of 11 Ma and implicate the formation of the Sea of Cortés in a speciation event ~5 Ma. Tree height at maturity, associated with fire tolerance, differs among the sympatric species while freezing tolerance appears to have diverged repeatedly across the tropical-temperate divide. Sympatric species thus show evidence of ecological niche differentiation but share climatic niches, while allopatric and parapatric species conserve ecological niches, but diverge in climatic niches. The mode of speciation and/or degree of co-occurrence may thus influence which niche axis plants diverge along. This article is protected by copyright. All rights reserved.
Keywords: RADseq, Sea of Cortés, Virentes, conservation, ecological and climatic niches, fossil calibration, genomic data, introgression, phylogeography
Esperón-Rodríguez M, Barradas V (2015)
Comparing environmental vulnerability in the montane cloud forest of eastern Mexico: A vulnerability index
Ecological Indicators 52 300-310.
The montane cloud forest (MCF) is one of the most threatened ecosystems, in spite of its high strategic value for sustainable development, the role it plays in the hydrological cycle maintenance, and as reservoir of endemic biodiversity. For Mexico, this forest is considered the most threatened terrestrial ecosystem at national level because of land-use changes and the effects of global climate change. To compare and assess the environmental vulnerability in the MCF we measured two physiological traits (stomatal conductance and leaf water potential), four climate variables (air temperature, photosynthetically active radiation, vapor pressure deficit, water availability) and the potential geographic distribution of eleven tree species from this forest. We evaluated stomatal conductance responses using the envelope function method (EFM), and after analyzing these responses we developed a vulnerability index that allowed us to compare the environmental vulnerability among species. We proposed the EFM as a useful tool to assess regional environmental vulnerability by comparing species. Our results showed differential species responses to all the studied variables; however, the vulnerability index allowed us to conclude that the most vulnerable species was Liquidambar styraciflua, and the least vulnerable Persea longipes. We also found that temperatures above 34°C, and vapor pressure deficit above 2.9kPa with relative humidity below 30% jeopardized the stomatal conductance performance of all species. We also found leaf water potential as the most influential variable over the studied species followed by vapor pressure deficit, showing that even in the MCF water is a determinant factor for species’ development.
Keywords: Air temperature, Envelope function method, Environmental vulnerability, Leaf water potential, Montane cloud forest, PAR, Photosynthetically active radiation, Potential distribution, RH, Stomatal conductance, TA, VPD, Vapor pressure deficit, Vulnerability index, air temperature, gS, leaf water potential, photosynthetically active radiation, relative humidity, stomatal conductance, vapor pressure deficit, Ψ
Flores-Maldonado J, Ruvalcaba-Ortega I, Moreno-Talamantes A, García-Aranda M, Favela-Lara S, González-Rojas J (2015)
Representatividad geográfica y ambiental del inventario de especies arbustivas en el Área de Protección de Recursos Naturales “Cuenca Alimentadora del Distrito Nacional de Riego 004 Don Martín”, Coahuila, México
Revista Mexicana de Biodiversidad.
Se analizó la representatividad del inventario de plantas arbustivas de un área natural protegida de Coahuila, México, con los siguientes objetivos: describir los tipos de sesgos de muestreo; definir la heterogeneidad ambiental de la reserva captada en las recolectas botánicas, y determinar el nivel de resolución espacial que respalda la información recolectada. Los sesgos fueron significativos (por distancia a carreteras, χ2=199.01; p<0.01; por rango altitudinal, χ2=391.02; p<0.01, y por tipo de vegetación, χ2=518.13; p<0.01). La muestra del inventario exhibe diferencias significativas entre el grupo testigo y un diseño aleatorizado para 5 variables bioclimáticas (temperatura media anual [Bio1]: U=117,900; p<0.01; isotermalidad [Bio3]: U=189,650; p<0.01; precipitación del mes más húmedo [Bio13]: U=134,330; p<0.01; estacionalidad de la precipitación [Bio15]: U=175,720; p<0.01 y la precipitación del trimestre más frío [Bio19]: U=146,550; p<0.01). Respecto a las variables ambientales y distancias a carreteras, el cubrimiento de esta infraestructura dentro del área puede contribuir a una buena caracterización del área natural protegida. La información proveniente de las recolectas realizadas es adecuada para escalas pequeñas de análisis (1 y 0.5°). The representativeness of the inventory of shrub species of a natural protected area in Coahuila, Mexico was analyzed, with the following objectives: to describe the types of sampling bias; to define the environmental heterogeneity of the botanical records; to determine the level of spatial resolution that supports the information collected. Biases were significant (χ2=distance road 199.01; p<0.01, by altitudinal range χ2=391.02; p<0.01 and vegetation χ2=518.13; p<0.01). The inventory sample exhibits significant differences between the control group and a randomized design for 5 bioclimatic variables (mean annual temperature (Bio1): U=117,900; p<0.01; isothermality (Bio3): U=189.650, p<0.01; precipitation wettest month (Bio13): U=134.330, p<0.01; seasonality of precipitation (Bio15): U=175.720, p<0.01 and precipitation of the coldest quarter (Bio19): U=146.550, p<0.01). Environmental variables and road distances, on the coverage of this infrastructure in the area, can contribute to a good characterization of the ANP. The information from collected records is adequate for small scales of analysis (1 and 0.5°).
Keywords: Botanical records, Coahuila, Conservación, Conservation, Natural Protected Area, Registros botánicos, Río Sabinas, Área Natural Protegida