Candelilla (Euphorbia antisyphilitica Zucc.) is a shrub species distributed throughout the Chihuahuan Desert in northern Mexico and southern of the United States of America. Candelilla has an economic importance due to natural wax it produces. The economic importance and the intense harvest of the wax from candelilla seems to gradually reduce the natural populations of this species. The essence of this research was to project the potential distribution of candelilla populations under different climate change scenarios in its natural distribution area in North America. We created a spatial database with points of candelilla presence, according to the Global Biodiversity Information Facility (GBIF). A spatial analysis to predict the potential distribution of the species using Maxent software was performed. Thirteen of 19 variables from the WorldClim database were used for two scenarios of representative concentration pathways (RCPs) (4.5 as a conservative and 8.5 as extreme). We used climate projections from three global climate models (GCMs) (Max Planck institute, the Geophysical Fluid Dynamics Laboratory and the Met Office Hadley), each simulating the two scenarios. The final predicted distribution areas were classified in five on-site possible candelilla habitat suitability categories: none (< 19%), low (20–38%), medium (39–57%), high (58–76%) and very high (> 77%). According to the area under the curve (0.970), the models and scenarios used showed an adequate fit to project the current and future distribution of candelilla. The variable that contributed the most in the three GCMs and the two RCPs was the mean temperature of the coldest quarter with an influence of 45.7% (Jackknife test). The candelilla’s distribution area for North America was predicted as approximately 19.1 million hectares under the current conditions for the high habitat suitability; however, the projection for the next fifty years is not promising because the GCMs projected a reduction of more than 6.9 million hectares using either the conservative or extreme scenarios. The results are useful for conservation of the species in the area with vulnerable wild populations, as well as for the selection of new sites suitable for the species growth and cultivation while facing climate change.

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In Mexico, buffelgrass (Cenchrus ciliaris) was introduced in the middle of the 20th century. Currently, buffelgrass has become an invasive species and has colonized various ecosystems in the country. In addition to its invasive capacity, climate change is a factor that has to be taken into account when considering how to effectively manage and control this species. The climatic niche models (CNM) and their projections for climate change scenarios allow for estimating the extent of biological invasions. Our study aimed to calibrate a CNM for buffelgrass in Mexico under the current climatic conditions and to project the extent of its biological invasion under climate change scenarios. For that, we used MaxEnt to generate the current CNM and to detect if climate change could cause future changes, we then evaluated the distribution patterns over the periods of 2041–2060, 2061–2080, and 2081–2100 for all the shared socioeconomic pathways (SSPs). Linear regressions were used to compare the outputs between current and future scenarios. Under the current climate, the CNM estimated that 42.2% of the continental surface of Mexico is highly suitable for buffelgrass. The regression analyses indicated no effects from climate change on the distribution of buffelgrass. Moreover, when the projected period is further in the future, and when the SSPs intensify, the surface of suitable areas for the species increases. These analyses clearly suggest Mexico is facing a biological invasion from buffelgrass, which may represent a threat to native biodiversity.

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En los últimos años se han realizado diversos trabajos para seleccionar genotipos sobresalientes de pastos para restauración de pastizales. Estos trabajos se han enfocado principalmente en características agronómicas y poca importancia se ha dado a la estructura genética y adaptación ambiental de los genotipos. El objetivo fue evaluar la estructura genética y aptitud ambiental de poblaciones de pasto banderita en Chihuahua, México. Se evaluaron 51 poblaciones de pasto banderita (Bouteloua curtipendula) a través de marcadores AFLP y análisis de su estructura genética. La aptitud ambiental de los grupos genéticos que se conformaron se determinó mediante el diseño de modelos que utilizan el algoritmo de MaxEnt. Lo anterior, representa una manera novedosa de usar el algoritmo, ya que comúnmente solo se utilizada a nivel especie. El análisis STRUCTURE dividió las poblaciones de pasto banderita en dos grupos genéticos diferentes (AMOVA; P<0.0001). El 89 % de las poblaciones integradas al Grupo 1 habitan en la región semiárida y 90 % de las poblaciones del Grupo 2 se encuentran en la región árida. Los resultados del análisis de MaxEnt revelaron que los grupos genéticos tienen aptitud ambiental diferente. El nicho climático del Grupo 1 se encuentra en el centro y sur del estado, mientras que el del Grupo 2 se localiza en el centro, oeste y noreste. Por lo anterior, se concluye que los programas de restauración con pasto banderita deben realizarse con genotipos locales de cada ecorregión del Estado y en áreas con mayor aptitud ambiental.