Epsilon Archive for Student Projects

Abstract

Wildlife is a valuable and renewable resource that promotes economical, ecological and social values. These values are important for developing and maintaining many rural societies. However, growing ungulate populations have led to increased browsing pressure on valuable forest trees and crops. Previous studies have proposed supplementary feeding and gamefields as potential methods for controlling the ungulate foraging and reducing browsing damage by providing other attractive food resources. However, quantitative estimates of potential biomass production of various gamefield crops and browsing pressure on the surrounding forest have been lacking. Within the thematic research program “Wildlife and Forestry” a three-year project was therefore initiated to evaluate marrow-stem kale, clover and rapeseed as gamefield crops together with browsing pressure in forests adjacent to the gamefields.
In this study, the biomass production of clover (Trifolium spp) in a gamefield mixture has been evaluated on 8 gamefields sown in 2008 and 2009 in the study area Misterhult in southern Sweden. This was done with fenced plots and with associated control plots randomly distributed across the gamefields. Since clover leys are trimmed down during the season, the biomass assessments had to be conducted immediately before each of the trimmings, and one last time before the end of the vegetation period. Browsing pressure on the adjacent forests was investigated using four 500-meter transects from each gamefield, one in each cardinal direction. Plots were laid out on the transects at distances of 0, 50, 100, 200, 300, 400 and 500 meters from the game field.
The study showed a high biomass production on gamefields. However, there were large variations in production between the gamefields, but also during the growing season. The study also showed large differences in biomass production between the gamefields sown 2008 and 2009. Gamefields sown in 2008 were able to produce between 100 grams and 656 grams and with a mean production of 304 grams dry weight of clover per m² with the current gamefield mixture during the growing season. This is equivalent to 3040 kg dry weight of clover per hectare. The corresponding clover biomass at the control plots was 48 grams and 331 grams dry weight per m². There were significant differences in available and grazed biomass. Game observations conducted during the fieldwork in the study area showed that the gamefields were frequented mostly by roe deer and hares, but also moose, fallow deer, red deer and wild boar.
The study also showed that different deciduous trees and shrubs were present in varying degrees relative to the gamefields with higher prevalence in the border zones next to the gamefield. Browsing pressure in the edge-zones was high on most deciduous trees and shrubs but decreased with increasing distance from the game field with some exceptions.
Maintaining an open landscape with browsed edges along with perennial and highly palatable crops on gamefields can provide opportunities to manage wildlife and browsing pressure in the landscape. In due course, this provides the necessary tools needed in an ecosystem-based wildlife management.