Effects of a Major Tree Invader on Urban Woodland Arthropods Sascha Buchholz Hedwig Tietze Ingo Kowarik Jens Schirmel 10.1371/journal.pone.0137723 https://plos.figshare.com/articles/dataset/_Effects_of_a_Major_Tree_Invader_on_Urban_Woodland_Arthropods_/1540560 <div><p>Biological invasions are a major threat to biodiversity; however, the degree of impact can vary depending on the ecosystem and taxa. Here, we test whether a top invader at a global scale, the tree <i>Robinia pseudoacacia</i> (black locust or false acacia), which is known to profoundly change site conditions, significantly affects urban animal diversity. As a first multi-taxon study of this kind, we analyzed the effects of <i>Robinia</i> dominance on 18 arthropod taxa by pairwise comparisons of woodlands in Berlin, Germany, that were dominated by <i>R</i>. <i>pseudoacacia</i> or the native pioneer tree <i>Betula pendula</i>. As a negative effect, abundances of five arthropod taxa decreased (Chilopoda, Formicidae, Diptera, Heteroptera, Hymenoptera); 13 others were not affected. Woodland type affected species composition of carabids and functional groups in spiders, but surprisingly did not decrease alpha and beta diversity of carabid and spider assemblages or the number of endangered species. Tree invasion thus did not induce biotic homogenization at the habitat scale. We detected no positive effects of alien dominance. Our results illustrate that invasions by a major tree invader can induce species turnover in ground-dwelling arthropods, but do not necessarily reduce arthropod species abundances or diversity and might thus contribute to the conservation of epigeal invertebrates in urban settings. Considering the context of invasion impacts thus helps to set priorities in managing biological invasions and can illustrate the potential of novel ecosystems to maintain urban biodiversity.</p></div> 2015-09-11 03:59:12 pairwise comparisons biotic homogenization arthropod taxa epigeal invertebrates tree Robinia pseudoacacia 18 arthropod taxa tree invader biodiversity species turnover animal diversity Major Tree Invader arthropod species abundances habitat scale beta diversity pioneer tree Betula pendula carabid Novel Ecosystems invasion impacts species composition Robinia dominance spider assemblages Woodland type change site conditions tree invasion Urban Woodland Arthropods