High canopy cover of invasive Acer negundo L. affects ground vegetation taxonomic richness
Д. В. Веселкин, D. I. Dubrovin, Aro L
Abstract
Abstract We assessed the link between canopy cover degree and ground vegetation taxonomic richness under alien ash-leaved maple ( Acer negundo ) and other (native or alien) tree species. We investigated urban and suburban forests in the large city of Yekaterinburg, Russia. Forests were evaluated on two spatial scales. Through an inter-habitat comparison we recorded canopy cover and plant taxonomic richness among 13 sample plots of 20 × 20 m where A . negundo dominated and 13 plots where other tree species dominated. In an intra-habitat comparison, we recorded canopy cover and ground vegetation taxonomic richness among 800 sample plots measuring 1 m 2 in the extended urbanised forest, which featured abundant alien (308 plots) and native trees (492 plots). We observed decreased taxonomic richness among vascular ground plant species by 40% (inter-habitat) and 20% (intra-habitat) in areas dominated by A. negundo compared to areas dominated by native tree and shrub species. An abundance of A . negundo was accompanied by increased canopy cover. We found a negative relationship between canopy cover and the number of understory herbaceous species. Thus, the interception of light and the restriction of its amount for other species is a main factor supporting the negative influence of A . negundo on native plant communities.