Occurrence of Ctenomys mendocinusin a High-Altitude Cold Desert: Effect on Density, Biomass, and Fitness of Sagebrush Plants

ABSTRACTIn arid and semiarid ecosystems, subterranean herbivorous rodents play an important role in determining the composition, function, and structure of plant communities. We hypothesized that in a high-altitude cold desert in the southern Puna region of Argentina, Ctenomys mendocinus(mendocino tuco-tuco), a subterranean herbivorous rodent, may increase dominance of the shrub Artemisia mendozana(sagebrush). We performed an observational study to assess factors affecting the abundance and fitness of A. mendozanain southern Puna, on sites co-inhabited and undisturbed by C. mendocinus. Density, biomass, plant height, number of fruits per plant, number of seeds, and seed size of A. mendozanawere higher in mendocino tuco-tuco—disturbed areas.Because the abundance and reproductive ability of sagebrush increase in areas inhabited by mendocino tuco-tucos, C. mendocinusmay function as an ecosystem engineer in southern Puna. We suggest further manipulative experimental studies be conducted to clarify the role of this subterranean rodent in this ecosystem.