Distributión y diversidad de la familia poaceae en chihuahua, durango y zacatecas, México

We analyzed the geographic distribution and diversity of grasses in three stales of north central Mexico (Chihuahua, Durango, and Zacatecas), using spatial analysis techniques with GIS. The main objective was to document the distribution and diversity of the family Poaceae in the study area. Data were extracted from specimens in major herbaria in Mexico and the United States. Using the Diva-GIS program, we built a grid (0.5 × 0.5 degrees) in the three states, counted the number of herbarium specimens, and determined species richness; we looked at the intensity of collections from different sites and compared them to areas with little or no collections. Diversity was calculated using the Shannon and Margalef index The results indicate areas with greater diversity are located in temperate areas with forests and grasslands, and lower diversity was recorded in xerophytic regions. There is greater collecting in and around the capital cities of the three states, as well as along the main highways. In spite of the intensity of collecting near population centers and principal highways, we conclude that our analysis provides useful information in determining the location of grass diversity and where future collecting might be focused.