Forage production and summer use by ungulates on game fields and surrounding areas

Abstract: Ungulates are causing conflicts between stakeholders due to browsing damage on forests and agricultural crops. At the same time there is a big demand of keeping high ungulate densities for sports hunting and recreational purposes. Movement patterns of ungulates are strongly correlated with forage availability. Therefore, measures affecting forage quantity and distribution might be a tool to reduce the economical losses in forestry without decreasing the ungulate densities and thereby decrease the conflict between different interest groups.This study investigated the potential biomass production and utilisation of marrow-stem kale (Brassica oleracea var. medullosa), at game fields in Misterhult, Sweden, as well as browsing effects on adjacent forests. The study included nine game fields and a total of 30 large herbivore exclosures. The biomass was cut and weight within the exclosures and paired controls in September and November. Transects of 500 m were distributed at four different directions from the fields with sample plots at seven different distances 0 (edge zone), 50, 100, 200, 300, 400 and 500 m from the game fields. In these plots browsing pressure was surveyed to investigate the browsing intensity in surrounding forests.A great biomass production was found, with mean dry biomass of marrow-stem kale of 1900 kg/0.01 km² in September significantly (p<0.05) increasing with 74 % to 3320 kg/0.01 km² in November. The utilisation was intensive, with highly significant differences between exclosure and control plots at the marrow-stem kale fields in both September and November. The observations of large herbivore species utilising the fields were too few to make any firm conclusions, but roe deer was the species most frequently utilising the marrow-stem kale fields.A general trend with higher browsing intensity in the edge zone (0 m) compared to zones further away from the fields was found. However, this pattern could not be significantly proven in all cases, probably due to the large variation in the landscape in a combination with too few plots.The biomass production on the game fields and the increased browsing intensity in the edge zone also indicate that game fields may have the potential to redistribute ungulates and decrease browsing intensity at a landscape scale as also found in other studies of supplemental forage.