Herbivory by tuco-tucos (Ctenomys mendocinus) on shrubs in the upper limit of the Monte desert (Argentina)

Ctenomys (tuco-tuco) is a small fossorial herbivorous rodent of the Monte desert, and is probably the most abundant and widely distributed rodent in these arid lands. The aim of this study is to describe the impact of C mendocinus herbivory on shrubs in two plant communities (Reserve of Divisadero Largo and Villavicencio) in the upper limit of the Monte desert, and to assess the association between environmental variables and level of damage caused by tuco-tucos. Herbivory by tuco-tucos affected 39% of the total shrubs in Villavicencio, and 9.37% of the total plants sampled in Divisadero Largo. In Villavicencio, the most highly damaged species were Larrea divaricata (65%), Lycium aff. chilensis (41%), Junellia seriphioides (38%) and Menodora decemfida (33%). In Divisadero Largo, damage was lower: I seriphioides (14%), Lycium chilensis (9%), and M. decemfida (6%). With respect to the association between level of damage caused by tuco-tucos and environmental variables, in Divisadero Largo the level of damage was negatively associated with both maximum and mean soil depth, while in Villavicencio it was negatively associated with plant cover, and positively associated with maximum and mean soil depth. There was no association between level of damage caused by tuco-tucos and mean stone diameter.