Authors: Rodriguez Barrera, Maria; Kühn, Ingolf;Estrada-Castillón, Eduardo;Cord, Anna ;

Prairie dogs (Cynomys sp.) are considered keystone species and ecosystem engineers due to their grazing and burrowing activities (summarized here as disturbances). As climate changes and its variability increases, the mechanisms underlying organisms’ interactions with their habitat will likely shift. Understanding the mediating role of prairie dog disturbance will increase knowledge on these mechanisms and the vulnerability of grasslands. Here, we studied how plant taxonomic diversity and functional structure respond to prairie dog disturbance across grassland types and seasons in a conservation priority, semiarid grassland of Northeast Mexico. We found grassland type and season explained most of the effects on plant taxonomic diversity and functional structure. Contrary to other studies, we further found weak evidence that prairie dog disturbance has a negative effect on vegetation structure, except for effects on C4 and graminoid cover, which however mainly depended on season. Our results provide evidence that environmental effects have a stronger role than grazing and animal disturbances on vegetation. We argue that a focus on disturbance and grazing effects is misleading, and instead attention is needed on the relationships between vegetation and environmental conditions which will be critical to understand semi-arid grassland dynamics in the region.