Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 27
Filter
Add more filters











Publication year range
1.
Zookeys ; 1200: 199-213, 2024.
Article in English | MEDLINE | ID: mdl-38756345

ABSTRACT

Pooleagen. nov. is described for two noctuid species from southwestern United States: Pooleagrandimacula Barnes & McDunnough, comb. nov., previously in Oxycnemis Grote, and Pooleapsaphidoidessp. nov.Poolea is compared to Oxycnemis (Amphipyrinae, Psaphidini, Triocnemidina) and is retained in the same subtribe. Adult moths and male and female genitalia of Poolea species are illustrated along with those of Oxycnemisadvena Grote, the genus type species. Pertinent recent taxonomic changes to Amphipyrinae classification are reviewed.

2.
J Parasitol ; 109(5): 486-494, 2023 10 01.
Article in English | MEDLINE | ID: mdl-37722695

ABSTRACT

Bot flies (Oestridae: Cuterebrinae) are obligate mammalian parasites that complete the larval stage of their life cycle under the skin of their host. Most detailed studies of bot fly larval disease ecology have been conducted in temperate deciduous zone rodent systems. To understand the relative importance of seasonal and spatial factors, as well as factors intrinsic to the host, in underpinning the likelihood and extent of parasitism by bot flies in non-rodent hosts as well as in arid-land ecosystems, we examined the dynamic for black-tailed jackrabbit (Lepus californicus) and desert cottontail (Sylvilagus audubonii) parasitism by bot fly larvae (Cuterebra spp.) across 7 repeatedly sampled sites spread across approximately 500 km of the Chihuahuan Desert ecoregion of southern New Mexico. This environment is characterized by a climate that includes hot dry summers and cool to cold dry winters, as well as strongly seasonal summer monsoonal rains. Lagomorphs are a common mid-sized mammal in these landscapes. Bot fly parasitism was strongly seasonal, with peak prevalence and abundance in the spring, and there was spatial variation in the extent of parasitism between collection sites. Additionally, jackrabbits in better body condition were less likely to be parasitized (as indicated by kidney fat index). We did not find sex-based differences in bot fly parasitism between male and female jackrabbits. Thus, in arid-land ecoregions, abiotic factors are likely the primary driver of the bot fly-host interaction, whereas factors intrinsic to the host were of secondary importance for characterizing the interactions of bot flies and lagomorphs.


Subject(s)
Diptera , Hares , Lagomorpha , Female , Male , Animals , Ecosystem , New Mexico/epidemiology , Seasons , Larva
3.
CienciaUAT ; 17(2): 37-51, ene.-jun. 2023. tab, graf
Article in Spanish | LILACS-Express | LILACS | ID: biblio-1447822

ABSTRACT

RESUMEN El Área de Protección de Flora y Fauna (APFF) Maderas del Carmen, ubicada en el estado de Coahuila, se considera un reservorio natural para el matorral rosetófilo, el cual ha sido afectado por el cambio de uso de suelo en el norte de México. El objetivo del presente trabajo fue describir el estado actual del matorral desértico rosetófilo del Área Protegida de Flora y Fauna Maderas del Carmen, con base en su estructura, composición florística y diversidad. Se evaluó la vegetación mediante 35 parcelas de 5 m x 5 m en 7 transectos lineales. Se midió altura (m), diámetro (cm) y área de copa (m2). Se determinó abundancia, dominancia y frecuencia de cada especie para obtener el índice de valor de importancia (IVI), además del índice de entropía de Shannon (H´) para conocer la diversidad, y la diversidad verdadera de Shannon (1D). Se registraron 31 familias, 61 géneros y 70 especies de plantas vasculares, incluyendo una endémica de México (Galactia brachystachys) y a 20 bajo estatus de protección, como Agave havardiana, que además, es especie vulnerable. Las familias con mayor riqueza fueron Fabaceae, Asteraceae, Asparagaceae y Cactaceae. Las formas biológicas y de vida fueron árboles y arbustos (48 %), hierbas (36 %), suculentas (13 %) y trepadoras (3 %). El H´ fue de 3.13 y la 1D de 22.87. El matorral rosetófilo del APFF Maderas del Carmen tiene una diversidad media-alta, está dominado por Agave lechuguilla Torr., con mayor abundancia e IVI. La composición florística y la diversidad encontrada permite una línea base para estudios posteriores que determinen el estatus ecológico de la zona. Especialmente para conocer con mayor detalle la dinámica poblacional de las especies endémicas y bajo estatus de protección, además del hábitat para la fauna silvestre presente en el APFF Maderas del Carmen.


ABSTRACT The Maderas del Carmen Flora and Fauna Protection Area (APFF), located in the state of Coahuila, is considered a natural reservoir for rosetophyllous scrub, which has been affected by land use change in northern Mexico. The objective of this work was to describe the current state of the rosetophilous desert scrub in the Maderas del Carmen Flora and Fauna Protected Area, based on its structure, floristic composition, and diversity. Vegetation was evaluated using 35 plots of 5 m x 5 m in 7 linear transects. Height (m), diameter (cm) and crown area (m2) were measured. Abundance, dominance and frequency of each species were determined to obtain the importance value index (IVI), in addition to the Shannon entropy index (H´) to know the diversity, and the true diversity of Shannon (1D). 31 families, 61 genera and 70 species of vascular plants were recorded, including one endemic to Mexico (Galactia brachystachys) and 20 under protection status, such as Agave havardiana, which is also a vulnerable species. The richest families were Fabaceae, Asteraceae, Asparagaceae and Cactaceae. Biological and life forms were trees and shrubs (48 %), herbs (36 %), succulents (13 %), and climbers (3 %). The H' was 3.13 and the 1D was 22.87. The rosetophilous scrub of the APFF Maderas del Carmen has a medium-high diversity, it is dominated by Agave lechuguilla Torr., with greater abundance and IVI. The floristic composition and the diversity found allow a baseline for subsequent studies that determine the ecological status of the area. Especially, they allow us to know in greater detail the population dynamics of endemic species and under protection status, in addition to the habitat for wildlife present in the APFF Maderas del Carmen.

4.
Ecol Evol ; 13(5): e10050, 2023 May.
Article in English | MEDLINE | ID: mdl-37143992

ABSTRACT

Mexican territory is one of the centers of origin and dispersion of the genus Opuntia, where several of its species have been an important plant resource for people in arid and semiarid zones. Opuntia streptacantha is widely distributed in Mexico; however, precise aspects of its geographic distribution and ecological status are still unknown. Here, we modeled its potential distribution under paleoclimatic, current, and future conditions through maximum entropy and predictions from 824 records and seven environmental variables. Potential distribution of O. streptacantha in the interglacial period was contracted and slightly north than current distribution, with 44,773 km2 of optimal habitat. In other past periods, the central location of potential distribution coincides with the actual current distribution, but the period of the last glacial maximum was characterized by 201 km2 of very suitable habitat, absent in interglacial, current, and future periods. The future model suggests that potential distribution will move toward the south of the Mexican territory. Synthesis and applications. The potential distribution of O. streptacantha can be applied for the conservation and management of the species, and also in the selection of areas with crassicaule scrubs for protection, conservation, and reproduction of species resistant to the hostile conditions of arid and semiarid zones of Mexican territory, where the structure and composition of the vegetation will be affected in the next 100 years.

5.
PeerJ ; 10: e13324, 2022.
Article in English | MEDLINE | ID: mdl-35502207

ABSTRACT

The dietary niche breadth of the Burrowing Owl was determined (Athene cunicularia Molina, 1782) in Llano La Soledad, Galeana, Nuevo Leon in northern Mexico, by considering prey type, numerical percentage, weight, weight percentage, frequency of occurrence percentage, and IRI percentage. The study compared data from three winters (2002-2003, 2003-2004, 2004-2005) by analyzing 358 pellets, identifying 850 prey items. Invertebrates constituted 90% of prey items, which mostly included insects (85%); beetles were the most common insects found in pellets (70%). Vertebrates made up 84% of consumed weight, of which 83% were mammals. Most of the mammals were cricetid rodents (41%). Niche breadth based on the numerical and weight percentage confirmed the Burrowing Owl as a generalist species with mean values per year ranging between 0.65 and 0.82. Additionally, there was a strong association between the weight of rodent species in winter. This association was mainly driven by changes in composition and frequency of these prey species during the second winter, probably caused by high annual rainfall. The second season also showed a statistically significant narrower niche (Ro = 0.96) and the smallest overlap (0.45 vs. 0.76) among the three winters.


Subject(s)
Strigiformes , Animals , Mexico , Seasons , Diet , Mammals
6.
Ecology ; 102(12): e03530, 2021 12.
Article in English | MEDLINE | ID: mdl-34496064

ABSTRACT

The data set covers a 101-yr period (1915-2016) of quadrat-based plant sampling at the Jornada Experimental Range in southern New Mexico. At each sampling event, a pantograph was used to record the location and perimeter of living plants within permanent quadrats. Basal area was recorded for perennial grass species, canopy cover area was recorded for shrub species, and all other perennial species were recorded as point data. The data set includes 122 1 × 1 m permanent quadrats, although not all quadrats were sampled in each year of the study and there is a gap in monitoring from 1980 to 1995. These data provide a unique opportunity to investigate changes in the plant community over 100 yr of variation in precipitation and other environmental conditions. We provide the following data and data formats: (1) the digitized maps in shapefile format; (2) a data table containing coordinates (x, y) of perennial species within quadrats, including cover area for grasses and shrubs; (3) a data table of counts of annual plant individuals per quadrat; (4) a species list indicating growth form and habit of recorded species; (5) a table of dates when each quadrat was sampled; (6) a table of the pasture each quadrat was located within (note that pasture boundaries have changed over time); (7) a table of depth to petrocalcic layer measurements taken at quadrat locations; (8) a table of particle size analysis of soil samples taken at quadrat locations; (9) a table of topographic characteristics of quadrat locations (e.g., concave or convex topography). Pantograph sampling is currently conducted at 5-yr intervals by USDA-ARS staff, and new data will be added periodically to the EDI Data Portal Repository (see section V.E.2). This information is released under the Creative Commons license-Attribution-CC BY and the consumer of these data is required to cite it appropriately in any publication that results from its use.


Subject(s)
Desert Climate , Grassland , Ecosystem , Humans , New Mexico , Poaceae
7.
Am J Bot ; 107(9): 1296-1308, 2020 09.
Article in English | MEDLINE | ID: mdl-33001458

ABSTRACT

PREMISE: Recent phylogeographic work suggests the existence of latitudinal gradients in genetic diversity in northern Mexican plants, but very few studies have examined plants of the Chihuahuan Desert. Tidestromia lanuginosa is a morphologically variable annual species whose distribution includes the Chihuahuan Desert Region. Here we undertook phylogeographic analyses of chloroplast loci in this species to test whether genetic diversity and differentiation of Mexican populations of T. lanuginosa change along a latitudinal gradient and whether diversity is higher in Coahuila, consistent with ideas of lower plant community turnover during the Pleistocene. METHODS: Haplotype network, maximum likelihood tree, and Bayesian phylogenetic haplotype were reconstructed, and genetic diversity was assessed among 26 populations. Barrier analysis was used to explore barriers to gene flow. RESULTS: Four major population groups were identified, corresponding with physiographic provinces in Mexico. Each population group displayed high levels of genetic structure, haplotype, and nucleotide diversity. Diversity was highest in southern populations across the species as a whole and among the Chihuahuan Desert populations. CONCLUSIONS: Tidestromia lanuginosa provides an important example of high phylogeographic and genetic diversity in plants of northern Mexico. Barriers to gene flow among the major population groups have most likely been due to a combination of orographic, climatic, and edaphic variables. The high genetic diversity of T. lanuginosa in southern and central Coahuila is consistent with the hypothesis of full-glacial refugia for arid-adapted plants in this area, and highlights the importance of this region as a center of diversity for the Chihuahuan Desert flora.


Subject(s)
Genetic Variation , Refugium , Bayes Theorem , Mexico , Phylogeny
8.
Biodivers Data J ; 8: e54495, 2020.
Article in English | MEDLINE | ID: mdl-32754001

ABSTRACT

BACKGROUND: Cerambycidae is one the most diverse families in the order Coleoptera with more than 37,000 species described in all continents. Cerambicyd beetles have a worldwide distribution from sea level to montane sites. In Mexico, more than 1,600 species have been recorded. Nevertheless, the diversity and distribution of this family in the Mexican deserts is poorly known. NEW INFORMATION: A first checklist of Cerambycidae from seven localities of Cuatro Ciénegas Basin is presented. This study is the result of sampling carried out between 2009 to 2013. Some material from other collections is also included. The species list includes four subfamilies, 13 tribes, 32 genera and 37 species, from which 13 are new records for the state of Coahuila and three species represent new records for Mexico. These results highlight the paucity of knowledge of insects in the deserts of Mexico.

9.
PeerJ ; 7: e6572, 2019.
Article in English | MEDLINE | ID: mdl-30867993

ABSTRACT

BACKGROUND: Deserts are biologically rich habitats with a vast array of animals and plants adapted to xeric conditions, and most deserts are among the planet's last remaining areas of total wilderness. Among North American deserts, the Chihuahuan Desert has the highest levels of diversity and endemism. To understand the effect of future climate change on plants distributed in this arid land and propose effective conservation planning, we focused on five endemic shrubby species that characterize the Chihuahuan Desert and used an integrative approach. METHODS: Ecological niche-based modeling, spatial genetics and ecological resistance analyses were carried out to identify the effect of global warming on the studied five shrubby species. Key areas that need to be preserved were identified taking into account the existing protected areas within the Chihuahuan Desert. RESULTS: The extent of future distribution will vary among these species, and on average expansion will occur in the western part of the Chihuahuan Desert. For most species low environmental resistance to gene flow was predicted, while higher future resistance was predicted for one species that would lead to increased population isolation. The highest haplotype diversity was identified in three hotspots. Based on future suitability of habitat and in the haplotype diversity we suggest preserving two hotspots of genetic diversity in the Sierra Madre Oriental, located in areas without protection. The third hotspot was detected in the well preserved Tehuacán-Cuicatlán Man and Biosphere Reserve. CONCLUSION: Global climate change will have an effect in arid adapted plants, favoring expansion in the western of the Chihuahuan Desert however negatively affecting others with high ecological resistance disrupting gene flow. Two hotspots of genetic diversity in the Sierra Madre Oriental should be protected.

10.
Rev. argent. microbiol ; Rev. argent. microbiol;50(3): 301-310, set. 2018. ilus, tab
Article in Spanish | LILACS | ID: biblio-977248

ABSTRACT

Los hongos micorrícicos arbusculares (HMA) de los ambientes áridos y semiáridos son importantes para el desarrollo de las plantas que crecen bajo estrés biótico y abiótico en áreas naturales o en agroecosistemas. Existe poca información sobre la diversidad temporal de los HMA en plantas perennes de ecosistemas áridos en el norte de México. En este estudiose evaluaron la colonización micorrícica y la diversidad temporal de los HMA en la rizosfera de Larrea tridentata, planta perenne de amplia distribución en el Desierto Chihuahuense. Se obtuvieron muestras de la rizosfera y de raíces de 15 plantas, en 3 fechas de muestreo del año 2015. Se encontró un total de 17 especies de HMA, distribuidas en 12 géneros y 7 familias dentro del phylum Glomeromycota. La especie más abundante fue Funneliformis geosporum. Esta especie pertenece a la familia Glomeraceae, la única que estuvo representada con varios géneros en L. tridentata. El mayor porcentaje de micorrización se presentó en febrero, con un 83,22%, en septiembre fue del 75,27% y en mayo del 65,27%. El muestreo realizado en febrero presentó el mayor número de especies (16), seguido por el de mayo (15) y el de septiembre (12). El análisis estadístico mostró diferencias significativas en el número de esporas entre los muestreos de febrero y los de mayo y septiembre.


Arbuscular mycorrhizal fungi (AMF) of arid and semiarid ecosystems are important for the development of plants that grow under biotic stress in wild or in agro-ecosystems. There is little information on the temporal diversity of these organisms in perennial plants from arid ecosystems in northern Mexico. On this study, the mycorrhizal colonization and the temporal diversity of AMF in the rhizosphere of Larrea tridentata, perennial plant abundant in the Chihuahuan Desert region were explored. Samples of the rhizosphere and roots of fifteen plants in each of the three sampling dates during the 2015 year were obtained. A total of 17 species of HMA belonging to 12 genera and 7 families within the phylum Glomeromycota in all three sampling dates were found. Funneliformis geosporum was the dominant species belonging to the family Glomeraceae which possess the highest genera number on L. tridentata.The highest mycorrhization percentage was in February with 83.22, followed by September and May with 75.27 and 65.27%, respectively. A maximum of 16 AM fungal species were isolated and identified from L. tridentata rhizosphere in February, 15 species in May and 12 species in September. Statistical analysis showed significant differences between sampling dates in the spores number.


Subject(s)
Soil Microbiology , Mycorrhizae , Larrea , Biodiversity , Spores, Fungal , Ecosystem , Plant Roots , Mexico
11.
Ecology ; 99(7): 1552-1561, 2018 07.
Article in English | MEDLINE | ID: mdl-29882955

ABSTRACT

Consumer-driven nutrient recycling can have substantial effects on primary production and patterns of nutrient limitation in aquatic ecosystems by altering the rates as well as the relative supplies of the key nutrients nitrogen (N) and phosphorus (P). While variation in nutrient recycling stoichiometry has been well-studied among species, the mechanisms that explain intraspecific variation in recycling N:P are not well-understood. We examined the relative importance of potential drivers of variation in nutrient recycling by the fish Gambusia marshi among aquatic habitats in the Cuatro Ciénegas basin of Coahuila, Mexico. There, G. marshi inhabits warm thermal springs with high predation pressure as well as cooler, surface runoff-fed systems with low predation pressure. We hypothesized that variation in food consumption among these habitats would drive intraspecific differences in excretion rates and N:P ratios. Stoichiometric models predicted that temperature alone should not cause substantial variation in excretion N:P, but that further reducing consumption rates should substantially increase excretion N:P. We performed temperature and diet ration manipulation experiments in the laboratory and found strong support for model predictions. We then tested these predictions in the field by measuring nutrient recycling rates and ratios as well as body stoichiometry of fish from nine sites that vary in temperature and predation pressure. Fish from warm, high-predation sites excreted nutrients at a lower N:P ratio than fish from cool, low-predation sites, consistent with the hypothesis that reduced consumption under reduced predation pressure had stronger consequences for P retention and excretion among populations than did variation in body stoichiometry. These results highlight the utility of stoichiometric models for predicting variation in consumer-driven nutrient recycling within a phenotypically variable species.


Subject(s)
Ecosystem , Nutrients , Animals , Fishes , Mexico , Nitrogen , Phosphorus
12.
Zookeys ; (753): 83-106, 2018.
Article in English | MEDLINE | ID: mdl-29731682

ABSTRACT

A summary of the species of amphibians and reptiles of the state has been compiled, including their geographic distributions, habitats, and conservation statuses. The herpetofauna of San Luis Potosí consists of 41 species of amphibians and 141 species of reptiles. San Luis Potosí shares the highest number of species with Hidalgo and Tamaulipas, and the least number of species with Nuevo León. In San Luis Potosí, there are several taxa of particular conservation concern including salamanders, emydid and trionychid turtles, anguid and xenosaurid lizards, and natricid and colubrid snakes.

13.
Zookeys ; (748): 65-87, 2018.
Article in English | MEDLINE | ID: mdl-29674915

ABSTRACT

A summary of the species of amphibians and reptiles of Durango, as well as their geographic distributions, habitat, and conservation status have been compiled. The herpetofauna of Durango consists of 36 species of amphibians and 120 species of reptiles. Durango shares the most species with Chihuahua (74.0%), and shares fewer species with Sinaloa (48.0%), Nayarit (48.7%), and Coahuila (48.0%). Arid-semiarid and Sierras habitat types have the most species, with valleys and Quebradas habitat types having fewer species. In Durango, there are several taxa of particular conservation concern including eleutherodactylid frogs, eublepharid, iguanid, phrynosomatid, and xantusid lizards, boid, colubrid, and natricid snakes, and emydid and testudinid turtles.

14.
Rev Argent Microbiol ; 50(3): 301-310, 2018.
Article in Spanish | MEDLINE | ID: mdl-29223919

ABSTRACT

Arbuscular mycorrhizal fungi (AMF) of arid and semiarid ecosystems are important for the development of plants that grow under biotic stress in wild or in agro-ecosystems. There is little information on the temporal diversity of these organisms in perennial plants from arid ecosystems in northern Mexico. On this study, the mycorrhizal colonization and the temporal diversity of AMF in the rhizosphere of Larrea tridentata, perennial plant abundant in the Chihuahuan Desert region were explored. Samples of the rhizosphere and roots of fifteen plants in each of the three sampling dates during the 2015 year were obtained. A total of 17 species of HMA belonging to 12 genera and 7 families within the phylum Glomeromycota in all three sampling dates were found. Funneliformis geosporum was the dominant species belonging to the family Glomeraceae which possess the highest genera number on L. tridentata. The highest mycorrhization percentage was in February with 83.22, followed by September and May with 75.27 and 65.27%, respectively. A maximum of 16 AM fungal species were isolated and identified from L. tridentata rhizosphere in February, 15 species in May and 12 species in September. Statistical analysis showed significant differences between sampling dates in the spores number.


Subject(s)
Biodiversity , Larrea , Mycorrhizae , Soil Microbiology , Ecosystem , Mexico , Plant Roots , Spores, Fungal
15.
PeerJ ; 5: e4007, 2017.
Article in English | MEDLINE | ID: mdl-29134149

ABSTRACT

BACKGROUND: Soil microbial communities (SMC) play a central role in the structure and function of desert ecosystems. However, the high variability of annual precipitation could results in the alteration of SMC and related biological processes depending on soil water potential. The nature of the physiological adjustments made by SMC in order to obtain energy and nutrients remains unclear under different soil resource availabilities in desert ecosystems. In order to examine this dynamic, the present study examined the effects of variation in annual precipitation on physiological adjustments by the SMC across two vegetation-soil systems of different soil organic matter input in an oligotrophic desert ecosystem. METHODS: We collected soil samples in the Cuatro Ciénegas Basin (Mexico) under two vegetation covers: rosetophylous scrub (RS) and grassland (G), that differ in terms of quantity and quality of organic matter. Collections were conducted during the years 2011, 2012, 2013 and 2014, over which a noticeable variation in the annual precipitation occurred. The ecoenzymatic activity involved in the decomposition of organic matter, and the concentration of dissolved, available and microbial biomass nutrients, were determined and compared between sites and years. RESULTS: In 2011, we observed differences in bacterial taxonomic composition between the two vegetation covers. The lowest values of dissolved, available and microbial nutrients in both cover types were found in 2012. The G soil showed higher values of dissolved and available nutrients in the wet years. Significant positive correlations were detected between precipitation and the ratios Cmic:Nmic and Cmic:Pmic in the RS soil and Cmic:Pmic and Nmic:Pmic in the G soil. The slopes of the regression with Cmic and Nmic were higher in the G soil and lower in the RS soil. Moreover, the SMC under each vegetation cover were co-limited by different nutrients and responded to the sum of water stress and nutrient limitation. DISCUSSION: Soil community within both sites (RS and G) may be vulnerable to drought. However, the community of the site with lower resources (RS) is well adapted to acquire P resources by ecoenzyme upregulation during years with adequate precipitation, suggesting that this community is resilient after drought occurs. Under the Global Climate Change scenarios for desert ecosystems that predict reduced annual precipitation and an increased intensity and frequency of torrential rains and drought events, the soil microbial communities of both sites could be vulnerable to drought through C and P co-limitation and reallocation of resources to physiological acclimatization strategies in order to survive.

16.
Conserv Physiol ; 5(1): cox042, 2017.
Article in English | MEDLINE | ID: mdl-28729902

ABSTRACT

We determined the seasonal ecophysiological performance under perennial plants and under high solar radiation for adult individuals from the 'living rock' cactus Ariocarpus kotschoubeyanus, which occurs equally under nurse plants and in open spaces. We evaluated the effective quantum yield of photosystem II (ΦPSII) and the dissipation of thermal energy [non-photochemical quenching (NPQ)] thorough the year. The maximum apparent electron transport rate (ETRmax) and the saturating photosynthetically active photon flux density for PSII (PFDsat) were also determined from rapid light curves. We found that although the ΦPSII was higher in shaded sites under potential nurse plants than in exposed sites, all values were close to the optimal value of 0.83. The high ΦPSII found for A. kotschoubeyanus plants suggests that they use a great proportion of the absorbed light for photosynthesis, under nurse plants as well as in open spaces. We also found higher NPQ values in exposed sites than in shaded ones but only in Autumn, thus reducing the risk of photoinhibition. In addition, the PFDsat was higher in exposed sites than in shaded ones in Spring, Summer and Autumn, but in Winter there were no differences between treatments. We also found high saturating light levels for ETR (PFDsat higher than 1378 µmol m-2 s-1) in all seasons but in winter for shaded and non-shaded plants. Our findings indicate that A. kotschoubeyanus plants use a great proportion of the light that they absorb for photosynthesis. This high tolerance to high-light conditions could explain why A. kotschoubeyanus do not show preferences for protected sites under nurse plants.

17.
Zookeys ; (658): 105-130, 2017.
Article in English | MEDLINE | ID: mdl-28435388

ABSTRACT

Chihuahua is Mexico's largest state, and its physiographic complexity affects the distribution of its herpetofauna. We list amphibians and reptiles for the state of Chihuahua, with their conservation status. We also compare this list to those of six adjoining states in the United States and Mexico (New Mexico, Texas, Coahuila, Durango, Sinaloa, and Sonora). A total of 175 species of amphibians and reptiles is found in Chihuahua. Thirty-eight are amphibians, and 137 reptiles. Chihuahuan amphibians and reptiles represent just over 37% of such species from Chihuahua and neighboring states. Chihuahua shares the highest proportion of its herpetofauna with Sonora and Durango. Most of the herpetofauna of Chihuahua falls in IUCNs least concern category and is not listed by SEMARNAT. However, turtles in Chihuahua are a group of particular conservation concern.

18.
Mol Phylogenet Evol ; 111: 185-195, 2017 06.
Article in English | MEDLINE | ID: mdl-28392486

ABSTRACT

Species delimitation is a major topic in systematics. Species delimitation methods based on molecular data have become more common since this approach provides insights about species identification via levels of gene flow, the degree of hybridization and phylogenetic relationships. Also, combining multilocus mitochondrial and nuclear DNA leads to more reliable conclusions about species limits. Coalescent-based species delimitation methods explicitly reveal separately evolving lineages using probabilistic approaches and testing the delimitation hypotheses for several species. Within a multispecies, multilocus, coalescent framework, we were able to clarify taxonomic uncertainties within S. cyanostictus, an endangered lizard that inhabits a narrow strip of the Chihuahuan Desert in Mexico. We included, for the first time in a phylogenetic analysis, lizards from the three populations of S. cyanostictus recognized so far (East Coahuila, West Coahuila and Nuevo León). Phylogenetic analysis corroborates the hypothesis of two separately evolving lineages, i.e. the East and West Coahuila populations, as proposed in a previous study. We also found a distant phylogenetic relationship between the lizards from Nuevo León and those of East and West Coahuila. Finally, based on the species delimitation results, we propose and describe a new species of Sceloporus: S. gadsdeni sp. nov.


Subject(s)
Genetic Loci , Lizards/genetics , Phylogeny , Animals , Bayes Theorem , Genetic Variation , Male , Mexico , Nucleotides/genetics , Species Specificity
19.
BMC Ecol ; 16: 38, 2016 Aug 26.
Article in English | MEDLINE | ID: mdl-27566259

ABSTRACT

BACKGROUND: The western burrowing owl (Athene cunicularia hypugaea) occurs throughout western North America in various habitats such as desert, short-grass prairie and shrub-steppe, among others, where the main threat for this species is habitat loss. Range-wide declines have prompted a need for reliable estimates of its populations in Mexico, where the size of resident and migratory populations remain unknown. RESULTS: Our objective was to estimate the abundance and density of breeding western burrowing owl populations in Mexican prairie dog (Cynomys mexicanus) colonies in two sites located within the Chihuahuan Desert ecoregion in the states of Nuevo Leon and San Luis Potosi, Mexico. Line transect surveys were conducted from February to April of 2010 and 2011. Fifty 60 ha transects were analyzed using distance sampling to estimate owl and Mexican prairie dog populations. We estimated a population of 2026 owls (95 % CI 1756-2336) in 2010 and 2015 owls (95 % CI 1573-2317) in 2011 across 50 Mexican prairie dog colonies (20,529 ha). CONCLUSIONS: The results represent the first systematic attempt to provide reliable evidence related to the size of the adult owl populations, within the largest and best preserved Mexican prairie dog colonies in Mexico.


Subject(s)
Sciuridae/physiology , Strigiformes/physiology , Animals , Ecosystem , Mexico , Population Density , Population Dynamics
20.
Mol Phylogenet Evol ; 94(Pt A): 171-81, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26343460

ABSTRACT

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.


Subject(s)
Climate Change , Genetic Speciation , Phylogeny , Sciuridae/genetics , Animals , Bayes Theorem , Climate Change/history , Cytochromes b/genetics , DNA, Mitochondrial/genetics , Desert Climate , History, Ancient , Mexico , Microsatellite Repeats/genetics , Phylogeography , Population Density , Sciuridae/classification
SELECTION OF CITATIONS
SEARCH DETAIL