Influence of the subterranean herbivorous rodent Ctenomys talarum on vegetation and soil

The influence of the subterranean herbivorous rodent Ctenomys talarum (tuco -tuco) on vegetation and soil was evaluated in a coastal grassland. Plant s pecies composition, dry plant biomass, soil pH, moisture, and nutrient cont ent (N, P, Na, K, Mg, and Ca) were compared between areas with and without the influence of tuco-tucos. C. talarum apparently does not affect either p lant species diversity or plant species richness. but modifies plant specie s composition at sites contiguous to burrows, where forbs occur more freque ntly than at sites without burrows. Abundance of most common grass and forb species, soil nutrient content, pH, and moisture were modified by C. talar um. Nitrogen, phosphorous, sodium, potassium, and magnesium had higher conc entrations in areas with C. talarum, whereas calcium showed the converse. S oil pH and percent moisture were lower in areas with burrows of C. talarum.