Antecedentes: Las características de germinación en gramíneas pueden ayudar a explicar la adaptación a cambios ambientales, así como comportamientos de invasión. Hipótesis: Cada especie tiene características de germinación que pueden explicar su éxito de establecimiento en pastizales naturales. Especies de estudio: Bouteloua curtipendula , B . dactyloides , B. eriopoda , B. gracilis , B. hirsuta , B. repens , B. rigidiseta , Chloris virgata , Digitaria californica , Eragrostis curvula , E. echinochloidea , E. lehmanniana , E. superba , Heteropogon contortus , Hilaria mutica , Leptochloa dubia , Melinis repens , Muhlenbergia emersleyi , M. macroura , M. rigida , Pappophorum bicolor y Pennisetum ciliare (16 especies nativas y seis exóticas). Sitio de estudio y fechas: Pastizales del Desierto Chihuahuense, 2019. Métodos: Pruebas de germinación a 28 °C, humedad constante y en obscuridad. Las variables cuantificadas fueron número de semillas germinadas, tiempo de germinación y longitud de raíz y tallo. Con base en esto se determinó: rango, tiempo, velocidad, índice de germinación y proporción raíz:tallo. Resultados: El rango de germinación fue ≤ 4 días en 18 especies. Los valores mas altos ( P < 0.05) fueron 7.8 semillas por día y 3.3 de índice de germinación. Once de las especies presentaron valores ≤ 1 en R:T a la semana de crecimiento. Conclusiones: Las especies E. curvula , B. curtipendula , L. dubia y D. californica presentan valores que las ubican con potencial para su rápido establecimiento en zonas áridas. Sin embargo, las exóticas invasoras E. lehmanniana y Melinis repens posiblemente tienen otras estrategias que facilitan su establecimiento.

During botanical explorations in the highlands of NW Mexico, two new Salvia L. species were discovered in the state of Chihuahua: S. reginae J. G. González & J. H. Vega and S. spellenbergii J. G. González. The first one is morphologically similar to S. concolor Lamb. ex Benth., from which it differs by having smaller floral bracts, a longer upper corolla lip, stamens parallel to the dorsal corolla line, longer filament and connective, the latter ornate with an antrorse tiny acute tooth, longer thecae, longer and exserted styles, and bigger mericarps. Salvia spellenbergii resembles S. fruticulosa Benth., S. goldmanii Fernald and S. pruinosa Fernald; however, it can be distinguished from these because of its shorter petioles, smaller leaf blades, usually fewer floral nodes, fewer flowers per floral node, and regularly shorter calyces. Both species are described and illustrated. Tables with morphological comparisons, illustrations, conservation assessment, and a distribution map are also presented.Citation: González-Gallegos J. G., Vega-Mares J. H. & Fernández J. A. 2019: Salvia reginae and S. spellenbergii (Lamiaceae), two new species from Chihuahua, Mexico. – Willdenowia 49: 319 – 328. doi: https://doi.org/10.3372/wi.49.49303Version of record first published online on 26 November 2019 ahead of inclusion in December 2019 issue.

Sotol (Dasylirion leiophyllum) is a shrubby species that grows in the Chihuahuan Desert. Sotol plants are commonly used to produce an alcoholic beverage, also known as “sotol”. A study was carried out to assess the composition and structure of shrubby communities where sotol inhabits in northern Mexico. The importance value index (IVI), diversity indexes, and structural attributes of the sotol community were estimated. Furthermore, a principal component and a cluster analysis were conducted in order to identify possible associations of species along the sotol distribution area. A total of 10,273 plants belonging to 17 families and 46 species were recorded, where the Agave lechuguilla and Tiquilia greggi were the most abundant species. Higher abundances of sotol and higher diversity indexes were observed in hillside areas and eastern aspects. The multivariate analyses revealed five shrubby groups in the distribution area of sotol, which grows in valleys, hillsides, and also on the top of mountains. The main communities found where sotol grows are rosetophyllous, microphyllous, and mesquite communities, and also, in higher altitudes, sotol is associated with oak species. This information is not only useful for a better species knowledge, but also for the protection of shrubby communities where Dasylirion leiophyllum inhabits.

The objective of this study was to implement a pilot system of treatment wetlands, using phytoremediation as an alternative technology to remove arsenic from the concentrate of a reverse osmosis system. The pilot system was composed of two subsurface flow constructed wetlands, planted with Eleocharis macrostachya and Shoenoplectus americanus. The wetlands were fed concentrate from a reverse osmosis system for seven months, with an average flow of 962 Ld-1 and an average arsenic concentration of 0.241 mgL-1. Removal rates between 43 % and 86 % were obtained for wetland 1 and between 35 % and 79 % for wetland 2 throughout the experiment. The two plant species developed normally despite the high levels of electrical conductivity in the range of 3584 to 5455 µscm-1 in wetland intake waters. The pilot wetland system removed significant levels of arsenic from the reverse osmosis concentrate, resulting in arsenic levels in the output waters that meet Mexican standard for using water in agricultural irrigation.

This study determined the influence of foraging distance, environmental factors, and native vegetation on honeybee (Apis mellifera) foraging in arid shrublands and grasslands in Northern Mexico. Apiary distance from inflorescence sites did not have a significant influence on the intensity of foraging. Apiary location and landscape were decisive factors in the response of honeybees to environmental factors. Air temperature, minimum temperature, wind velocity, and relative humidity explained foraging by 87, 80, 68, and 41% (R²), respectively, in shrubland sites in open landscapes but had no significant influence on foraging in the grassland sites in a valley surrounded by hills (1820–2020 amsl). Nights with a minimum temperature of <20 °C increased foraging activity during the day. Minimum temperature, which has the least correlative influence among climate elements, can be used to determine climate change’s impact on bees. The quantity of available inflorescence explained the foraging intensity by 78% in shrublands and 84% in grasslands. Moreover, when honeybees depended mainly on native vegetation in grasslands, the quantity of inflorescence explained the intensity of foraging by 95%. High intensity of honeybee foraging was observed in allthorn (Koeberlinia spinosa) and wait-a-minute bush (Mimosa aculeaticarpa) in shrublands and honey mesquite (Neltuma glandulosa) and wait-a-minute bush (Mimosa aculeaticarpa) in grasslands. The findings and baseline data contributed by this study may be used to identify suitable environments for increasing apiary productivity and other agricultural and ecological benefits.

Habitat fragmentation due to anthropogenic pressures threats functional connectivity across landscapes for flying mammals. Tadarida brasiliensis depends on nocturnal movement corridors linking refuge and foraging areas, yet these pathways are increasingly constrained in semi-arid regions of northern Mexico. This study developed and analyzed the potential ecological corridors connecting the main colony of T. brasiliensis located in Santa Eulalia with the Irrigation District 005 Delicias, in Chihuahua, Mexico. We integrated multi-source geospatial data within a geographic information system, including wind speed, terrain slope, normalized difference vegetation index, land surface temperature, distance to rivers, landscape aggregation, nighttime lighting, and distance to roads, power lines, and human settlements. Landscape resistance to movement was assessed using a combined framework based on the Analytic Hierarchy Process, the InVEST-Habitat Quality model, and Least Cost Path analysis, generating composite resistance. Five potential corridors were identified, with ranges of lengths and CWD:EucD ratios of 6.8–34.0 km and 20.4–51.3, respectively, reflecting variable cumulative resistance along pathways. Nighttime lighting and proximity to urban areas were major contributors to high resistance, particularly within urban and agricultural environments. The identified corridor network provides a spatial representation of potential routes and supports landscape-level conservation planning to mitigate anthropogenic pressures and maintain functional connectivity.