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A neotype for the name Echinocactus fossulatus is here designated and the first record of Thelocactus hexaedrophorus, an endemic species to Mexico, for Aguascalientes is reported. [ABSTRACT FROM AUTHOR]

Copyright of Revista Mexicana de Biodiversidad is the property of Universidad Nacional Autonoma de Mexico, Instituto de Biologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The flat-headed myotis (Myotis planiceps) was declared extinct in 1996 but rediscovered in 2004, thus the reference to a revenant, one who came back from the dead, as it was declared extinct in 1996 but rediscovered in 2004. However, the species still faces serious extinction risk. To aid in the strategic planning and priorities for conservation, we studied roosting ecology. These bats inhabit the Chihuahuan Desert in one of the smallest distributional ranges of any mammal. Using radiotelemetry, we located 25 summer roosts, all in the skirts of dry leaves of yucca trees (Yucca carnerosana). We conclude that to roost, these bats search for clumps of tall yucca trees with a mean height of 3.93 m and mean width of skirts of 1.35 m. [ABSTRACT FROM AUTHOR]

Understanding home range size and habitat preferences is an important component of monitoring species in steep decline. Sprague's Pipit (Anthus spragueii) is a declining grassland specialist with a substantial portion of its population wintering in the highly threatened grasslands of the Chihuahuan Desert. We radio-tagged and tracked 10 wintering pipits between 2014 and 2017 at 3 sites across northern Mexico to generate baseline home range estimates and habitat preferences on their wintering grounds. We found that mean home range and core-use area size with 95% and 50% kernel density estimators were 11.4 ha and 2.4 ha, respectively, almost twice as large as some other grassland specialist passerines. Two birds left the study area and one individual shifted its home range 1.3 km after 20 d of monitoring, indicating that some individuals are flexible in their space use strategies. Within their home ranges, pipits selected grasslands with more bare ground and less "other cover" (litter, duff, animal excrement, and rocks) than what was available on the landscape. We found no relationship at the microhabitat scale between pipits and grass height nor shrub cover and heights, which in previous studies have been shown to influence habitat selection at larger scales. These findings may reflect different habitat use, diet, and predator avoidance strategies than other grassland passerines that select for denser grass cover during winter in the Chihuahuan Desert and highlight the importance of structurally heterogeneous grasslands. For this reason, strategies to manage and conserve Chihuahuan Desert grasslands and its avifauna must consider the diverse habitat and area needs of grassland birds to be effective. [ABSTRACT FROM AUTHOR]

Copyright of Revista Mexicana de Biodiversidad is the property of Universidad Nacional Autonoma de Mexico, Instituto de Biologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As a megadiverse country, Mexico harbors 4 to 8% of the flora of the world and of this, 51% is endemic. There is concern because several factors are impeding its conservation. In this paper, areas of endemism for the flowering plants of Mexico are identified to prioritize regions for conservation. To categorize zones for preservation, the approach followed takes biodiversity, weighted endemism and evolutionary history into account. Lineages of angiosperms, families, genera, and formal or informal groups within genera previously retrieved as monophyletic are selected to represent evolutionary history in equivalent spatial units. A database with 9416 entries based on specimens of species belonging to 259 monophyletic groups of angiosperms from Mexico was compiled, and their presence-absence recorded for every unit area. Species richness and weighted endemism index was calculated for each of these units. The results indicate that the majority of the regions with the highest indices of endemism have a dry climate with xeric vegetation, with the exception of two areas of tropical and temperate forests. They are: the northeastern rosette scrub in Nuevo León and Coahuila, gypsum grasslands in San Luis Potosí, the Sierra Gorda in Queréraro, Tolantongo in Hidalgo, the Tehuacán-Cuicatlán Valley in Puebla and Oaxaca, El Salto in Durango, Sierra de Quila in Jalisco, a western portion of the Balsas River Basin in Michoacán, Guerrero, Morelos and State of Mexico, the Tehuantepec area in Oaxaca, the Central Depression of Chiapas and El Triunfo in Chiapas. Some of the areas of endemism in the Chihuahuan Desert, Balsas River Basin, the Central Depression of Chiapas and the southern area of Oaxaca are not sufficiently protected. Approximately 340 species were microendemic, i.e. restricted to a single quadrat, and the Cactaceae account for the majority of the species on the Mexican Red List. [ABSTRACT FROM AUTHOR]

Copyright of Revista Mexicana de Biodiversidad is the property of Universidad Nacional Autonoma de Mexico, Instituto de Biologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The Mexican buckeye Ungnadia speciosa, is one of the plants used in forestation programs in Mexico due its adaptive features and its shrub or small tree form; however production in the greenhouse is affected by pathogens that cause leaf blight, dwarf and fork stalks, making it impossible to use in plantations. The objective of this work was to determine the causal agent and evaluation of in vitro and in situ of benzalkonium chloride to control it. Plant tissue was collected in field and greenhouse and put in nutrient agar and potato dextrose agar. LOPAT and relevant biochemical test were conducted for identification. For the incidence and severity, the model proposed by French (1982), was used. The poisoned plate flock was used for the in vitro evaluation with 13 treatments and five repetitions, assessing the colony forming units (CFU); seven in situ treatments with three replications were used evaluating damaged leaf area. It was found that for Pseudomonas syringae, according to the Koch's postulates involved in the symptoms of blight and deformities in the Mexican buckeye, field incidence was 12,9% and 36% in greenhouse; severity was 6,5% and 32%, respectively. Benzalkonium chloride satisfactorily controlled in vitro in dosages, and the best treatment in situ was 3 000 ppm (7 g/L), which showed a leaf damaged area of 17,33% and target treatment 73,09%. [ABSTRACT FROM AUTHOR]

Ecologists and conservationists have long assumed that large grazers, including bison (Bison bison ), did not occur in post-Pleistocene southwestern North America. This perception has been influential in framing the debate over conservation and land use in the northern Chihuahuan Desert. The lack of an evolutionary history of large grazers is being used to challenge the validity of ranching as a conservation strategy and to limit the protection and reintroduction of bison as a significant component of desert grassland ecosystems. Archeological records and historical accounts from Mexican archives from AD 700 to the 19th century document that the historic range of the bison included northern Mexico and adjoining areas in the United States. The Janos-Hidalgo bison herd, one of the few free-ranging bison herds in North America, has moved between Chihuahua, Mexico, and New Mexico, United States, since at least the 1920s. The persistence of this cross-border bison herd in Chihuahuan Desert grasslands and shrublands demonstrates that the species can persist in desert landscapes. Additional lines of evidence include the existence of grazing-adapted grasslands and the results of experimental studies that document declines in vegetation density and diversity following the removal of large grazers. The Janos-Hidalgo herd was formed with animals from various sources at the turn of the 19th century. Yet the future of the herd is compromised by differing perceptions of the ecological and evolutionary role of bison in the Desert Grasslands of North America. In Mexico they are considered native and are protected by federal law, whereas in New Mexico, they are considered non-native livestock and therefore lack conservation status or federal protection. Evidence written in Spanish of the presence of bison south of the accepted range and evidence from the disciplines of archaeology and history illustrate how differences in language and academic disciplines, in addition to international boundaries, have acted as barriers in shaping comprehensive approaches to conservation. Bison recovery in the region depends on binational cooperation. [ABSTRACT FROM AUTHOR]

The Sierra de Catorce located in the north of San Luis Potosí state, shelters some of the most important peaks within the Chihuahuan Desert, whose altitudes reach beyond 3000 meters. The fact that the Sierra is an important area for flora and plant community diversification in this ecoregion has been favoured by this situation. From a phytosociological study of the territory vegetation, carried out since 1999, we have extracted a preliminary checklist of the flora. Until now the vascular plants checklist is composed by 526 species and four infraespecific taxa, assembled in 293 genera and 88 families. The best represented families and genera are Asteraceae, Poaceae, Cactaceae, Fabaceae, Fagaceae, and Lamiaceae, and Quercus, Opuntia, Muhlenbergia, Salvia, Agave, Bouteloua and Dyssodia respectively. The vegetation types representative of the area which shelter the diferent taxa, are indicated. Finally, from different checklists of threatened flora, the species included in some of the recognised categories are identified. [ABSTRACT FROM AUTHOR]

Ants are considered an important aspect of arid zones mainly due to their role in structuring plant communities and for the diverse interactions they establish with other organisms. However in Mexican arid zones a basic understanding of ant species diversity is lacking. In this study we examined the ant fauna of a locality situated in the semi-desert Tehuacán Valley (San Rafael Coxcatlán). Our objectives were to estimate ant species richness within this region and to obtain a more extensive survey of the Tehuacán Valley by combining our data with another study. Finally we compared the species richness of this Valley to that of other Mexican arid zones (Mapimí, Durango, Chihuahuan Desert and Los Horcones, Sonora, Sonoran Desert). Ants of San Rafael Coxcatlán were collected between November 1999 and January 2001 using pitfall traps. 28 ant species were captured from 14 genera within five subfamilies, which is a high species richness for a small area (5 km²). Based on a cluster analysis, the mirmecofauna of Los Horcones and the Tehuacán Valley were the most similar; both areas have ant species with broad distribution as well as some of tropical affinity such as Pseudomyrmex major and Camponotus atriceps. Similar patterns have been reported for the vegetation, birds and mammals in both areas; several genera are shared, most of them of tropical affinity. This work represents one of the first efforts to understand ant diversity in an arid zone of central Mexico. [ABSTRACT FROM AUTHOR]

Uma paraphygas is an endemic lizard which is in danger of extinction because of its very restricted distribution, low genetic variability, and the high environmental pressure to which it is exposed. Two populations of U. paraphygas were observed in two areas of 2 ha each in the Mapimi Biosphere Reserve, Durango. The field work was carried out from autumn of 1997 to the summer of 1999. The survey was made by the capture-recapture method, using the noose technique. The animals captured were marked permanently. This survey provides information about the structure and dynamics of two populations of this lizard in order to determine its current status. Density, biomass, age structure, growth rates, survival, population replacement rate and generational time of this lizard were determined. Density and biomass changed in relation to acumulated rainfall. There were no significant differences for density and biomass factors between the two populations. The higest percentage of the population was represented by adult females followed by adult males. The highest daily growth rate was for offspring of both sexes which gradually decreased as they grow older. Offspring annual survival was 0.20. However, the lowest survival rate was for subadult females, while the highest one was for subadult males. We suggest that the survival for different age classes is related to intraspecific competition factors. The population replacement rate indicated an apparent stability for the two populations, and the generational time was 1.26 years. [ABSTRACT FROM AUTHOR]

The vegetation and the vascular plants of an ecotonal zone between the floristic provinces of the Desert Plateau (Chihuahuan Desert) and Gulf Coastal Plain in northeastern México were studied. The study zone has a surface of 2,526.25 km² and it is located in the northern part of the state of Nuevo León. On the basis of physiognomy, ecological characteristics and dominant species, seven types of vegetation were recognized. With the aid of 50 sampling plots, aerial photographs and floristic composition, the units of vegetation were delimited and mapped. 405 species (varieties and subspecies included) were identified. The study zone showed geographical affinity with the vegetation of the Chihuahuan Desert in the Desert Plateau of México (Hilaria mutica grassland, low thornless scrub of Flourensia cernua and medium size mixed scrub of Acacia-Prosopis-Flourensia-Larrea) and with the Gulf Coastal Plain (medium size mixed scrub of Leucophyllum frutescens and Acacia rigidula and high mixed scrub of Helietta parvifolia). The medium size and high thorny scrubs of Prosopis-Acacia showed no clear relationships with any of the floristic provinces. The coexistence of shrubby vegetation characteristic of the lowlands in the Gulf Coastal Plain and the vegetation usually present in the Chihuahuan Desert, can be explained in view of the increment of aridity and gentle raising of the continental surface in east-west direction, and of the absence of notable topographic accidents in the northeastern region of México. [ABSTRACT FROM AUTHOR]

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., (Copyright © 2017 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.)