Overseeding and rehabilitation of degraded upland grasslands after Arvicola terrestris outbreaks.
Abstract
Outbreaks of grassland rodent (water vole: Arvicola terrestris) populations can cause dramatic grasslanddamage, impacting grassland structure and function, as well as the provision of ecosystem services. There is a pressing need to identify effective management techniques which promote grassland recovery after rodent disturbance, and clear guidelines on soil preparation and species mixtures are currently lacking. We have set up a field-scale experiment to examine the interactive effects of mechanical soil treatments and seed mixtures on an upland permanent grassland experiencing an A. terrestris outbreak. The
ultimate objective is to determine which management practices satisfy two key criteria: (1) sufficient hay production to support a dairy herd during the winter; and (2) limited adverse effects on plant community recovery and longer-term grassland biodiversity. We test two types of soil preparation (with or without use of a disc cultivator) in combination with five overseeding treatments (no seed, annual species in monoculture, mixtures of annual species), and record biomass production, forage quantity and quality and soil properties over a two-year period. Aerial pictures and trapping are used to estimate rodent population density and dynamics. First results are presented and suggest effects of both seed mix and soil preparation treatments on hay quantity and quality.