Effect of wild boar disturbances on the soil seed bank in alpine plant communities

Abstract

AbstractSoil seed bank (SSB) determines essential ecological processes by maintaining species diversity and recovering damaged plant communities, and supports conservation of lost plant species. Nevertheless, the variation of SSBs, their densities, and composition changes when accompanied by wild boar disturbances are scarcely studied in sensitive habitats such as alpine grasslands. The aim of this study is to assess the effect of wild boar rooting on SSB characteristics. Five plant communities were selected and four disturbed patches in each community were recognized in alpine grassland, Albors Mountain Chain, Iran. SSB density, richness, diversity, evenness and similarity with aboveground vegetation were compared between disturbed and adjacent undisturbed patches. In total 80 soil cores in each community, 40 disturbed and 40 undisturbed were collected and transported to the greenhouse. The seedling emergence method was used to identify and quantify seeds from the germinable seed bank. The results showed that, totally, the SSB within disturbed patches was smaller than in undisturbed patches. Wild boar (Sus scrofa) rooting decreased SSB density, richness and diversity in all plant communities. We found that rooting homogenized SSBs in disturbed patches as indicated by the Pielou evenness index. The results suggested a deep alteration of the structure of seed banks by wild boar rooting, which in turn, vegetation recovery did not rely on SSBs after disturbances. In order to reduce wild boar rooting damage, a large reduction in wild boar abundance is suggested.