Assessment of weed invasion at bait sites in a Central European lower montane zone

Abstract

The effects of wild game feeding on the local environment have been widely investigated in northern European countries but have received little consideration in Central Europe. Bait sites, that is, places where food is set out to entice wild boar for hunting are becoming ever more widespread, and they are having an increasing impact on surrounding vegetation. The aim of the present study was to assess the extent of weed invasion at different bait types. 3 bait sites located in forests, 3 baits in clearings and 3 baits on unpaved forest roads in the Central European lower montane zone, in Hungary. The field work was conducted in May and August. Four transects were laid out (at right angles to each other) from the centre of each bait, and consisted of 22 one meter square quadrats, in which vegetation survey were conducted. The application of multivariate statistical methods (PCA) and UPGMA analysis to the data collected revealed substantial differences between the bait types. The baits in the forest were the least degraded, with a sparse understory cover in both surveys. Road baits displayed a notable difference, as they varied depending on canopy closure, accessibility and exposure. Sites in clearings proved to be the most infected. Furthermore, there was a significant difference between the vegetation of the periods examined, arable weeds dominated in August. A stress gradient was detected along the transects, with the proportion of weeds decreasing from the centre, while the natural components of the vegetation increased. The effect was more noticeable in clearings, probably due to their greater openness. Invasion is typically limited to the immediate environment of the bait sites, but valuable patches of habitat can also be destroyed, and bait sites may serve as bridgeheads for biological invasions.