Livestock Grazing Impact on Species Composition and Richness Understory of the Pinus cembroides Zucc. Forest in Northeastern Mexico

In the pine forests of Mexico, disturbances are primarily due to cattle, horses, goat, and sheep grazing, particularly in communal grazing lands. The most evident low tree recruitment, invasive shrubs establishment, species composition changes, invasion weeds dispersed mainly by livestock. Sierra de Zapalinamé is a mountain range natural protected area northeast Mexico. We conducted current study this forest stand Pinus cembroides excluded from last 25 years (1200 ha with vegetation chaparral) another nearby subjected livestock grazing. Forest structure (basal density), richness, total understory were analyzed at control grazed sites. Our results revealed that has modified reduced evenness plots. Therefore, maintain diversity structure, we concluded extensive should be restricted for some areas or number animals zones high ecological value.