Movement of Seeds by the Burrowing Activity of Mole-Voles on Disturbed Soil Mounds in the Spanish Pyrenees

Abstract

Three species of Microtus (voles) living in Pyrenean subalpine pastures brought seeds to the surface on vole mounds. This activity was studied to learn about the voles' influence on seed composition and vegetation gap colonization. Twenty-two plant species germinated from seed in the soil mounds. The plant composition of pastures was dominated by graminoids-hemicryptophytes. Nearly half of the seeds that occurred in mounds are of annual dicots able to quickly colonize the gaps and complete their vegetative cycle before the entry of perennial plants. Mound revegetation occurs chiefly by means of vegetative reproduction strategies. Nevertheless germination of seed brought to the surface can be important at the early stages of colonization after soil disturbance. Thus, such disturbances increase short-term plant diversity and patch heterogeneity.