Effect of <I>Solidago canadensis</I> invasions on soil nematode communities in Hangzhou Bay

Abstract

Ecologists are increasingly focusing on the effects of biological invasions on soil biodiversity and ecosystem functioning. We compared soil nematodes under plant communities dominated by invasive Solidago canadensis and native plant Phragmites australis at 6 sites (Zhenhai, Fengxian, Pinghu, Haiyan, Cixi and Hangzhou) in Hangzhou Bay to assess the effects of S. canadensis invasions on soil nematode communities. The total number of genera and diversity of soil nematode did not differ between S. canadensis and P. australis communities. Trophic diversity, most of the proportions of trophic groups and nematode community structure varied between the two plant communities. These results suggested that the invasion of S. canadensis changed soil community structure and functioning in Hangzhou Bay. Compared to P. australis communities, the proportion of fungivores tended to increase in soil under S. canadensis communities, suggesting that the invasion might modify soil nutrient cycling. The proportion of herbivores decreased in soil dominated by S. canadensis, suggesting that the exotic S. canadensis is less vulnerable to parasitic nematodes than the native P. australis. Interactions between plant community type and site were significant for nematode diversity and community structure, which indicated that site was an important factor in determining the impact of the invasive plant on soil fauna. Soil grain composition, soil carbon and soil nitrogen were identified as the most important factors in shaping nematode communities.