Dietary flexibility aids Asian earthworm invasion in North American forests

作者：Weixin Zhang, Paul F. Hendrix, Bruce A. Snyder, Marirosa Molina, Jianxiong Li, Xingquan Rao, Evan Siemann, Shenglei Fu · 发表于：Ecology · 年份：2009 · DOI：10.1890/09-0979 · 被引用次数：1 · 研究领域：Invertebrate Taxonomy and Ecology、Botany and Plant Ecology Studies、Collembola Taxonomy and Ecology Studies

On a local scale, invasiveness of introduced species and invasibility of habitats together determine invasion success. A key issue in invasion ecology has been how to quantify the contribution of species invasiveness and habitat invasibility separately. Conventional approaches, such as comparing the differences in traits and/or impacts of species between native and/or invaded ranges, do not determine the extent to which the performance of invaders is due to either the effects of species traits or habitat characteristics. Here we explore the interaction between two of the most widespread earthworm invaders in the world (Asian Amynthas agrestis and European Lumbricus rubellus) and study the effects of species invasiveness and habitat invasibility separately through an alternative approach of “third habitat” in Tennessee, USA. We propose that feeding behaviors of earthworms will be critical to invasion success because trophic ecology of invasive animals plays a key role in the invasion process. We found that (1) the biomass and isotopic abundances (δ13C and δ15N) of A. agrestis were not impacted by either direct effects of L. rubellus competition or indirect effects of L. rubellus-preconditioned habitat; (2) A. agrestis disrupted the relationship between L. rubellus and soil microorganisms and consequently hindered litter consumption by L. rubellus; and (3) compared to L. rubellus, A. agrestis shifted its diet more readily to consume more litter, more soil gram-positive (G+) bac...