Are Wild boars a future threat to the Swedish flora?

Abstract

The degradation of natural communities as a result of pig rooting, trampling and damage to different agricultural crops has been noted in numerous publications, but there is seldom mention of the animals’ positive effect on flora and fauna. Exceptions are mainly collected from silviculture, where wild boars effectively locate areas with large numbers of pest species for consumption and with increased growth of different tree species, presumably caused by enhanced nutrient mobilization as a result of the animals rooting activity. The purpose of this study was to document the rooting effect of Wild boar and compare the vascular flora of different rooted and undisturbed vege-tational types in the part of Sweden with the densest population of wild boars. The result was an increase in species number in all six vegetational types studied. The average number of total species found in rooted areas was 61.6 ±36.5, to be compared with 39.2 ± 25.8 species (n for rooted sites is 288, n for control sites is 232). The largest difference was found in alder marshes with a total of 115 species to be compared with 66. Species found in rooted areas were not always found in control areas but species found in control areas were most often found in the rooted areas. Species found in rooted sites and not otherwise were mainly species with low competition ability and field weeds.