Movement of seeds by the burrowing activity of mole-voles on disturbed soil mounds in the Spanish pyrenees

Three species of Microtus (voles) living in Pyrenean subalpine pastures bro ught seeds to the surface on vole mounds. This activity was studied to lear n about the voles' influence on seed composition and vegetation gap coloniz ation. Twenty-two plant species germinated from seed in the soil mounds. Th e plant composition of pastures was dominated by graminoids-hemicryptophyte s. Nearly half of the seeds that occurred in mounds are of annual dicots ab le to quickly colonize the gaps and complete their vegetative cycle before the entry of perennial plants. Mound revegetation occurs chiefly by means o f vegetative reproduction strategies. Nevertheless germination of seed brou ght to the surface can be important at the early stages of colonization aft er soil disturbance. Thus, such disturbances increase short-term plant dive rsity and patch heterogeneity.