Invasive effects of Ageratina adenophora Sprengel(Asteraceae)on Soil microbial community and physical and chemical properties
紫茎泽兰(Ageratina adenophora)入侵对土壤微生物群落和理化性质的影响

Interaction between invasive plant and soil microbial community is an important aspect to understand the plant invasivibility and susceptibility of receptive communities, as a result, studies on effects of plant invasion on soil microbial community and physical and chemical properties are becoming increasingly important to explore the effects of plant invasion on ecosystem and the underground soil biota related invasion mechanism. In present study, soil microbial communities were analyzed using PLFAs (phospholipids fatty acids) method, and 11 different soil physical and chemical factors were measured following Ageratina adenophora invasion. Compared to non-invaded site and native plant site, invasion of A. adenophora modified soil microbial community composition. It was most noticeable that A. adenophora increased soil fungi, azotobacteria and ammonia oxidizing bacteria, but significantly decreased actinomycetes and denitrifying bacteria. Soil organic carbon, NO-3-N, NH 4-N, available P and available K content were most abundant in heavily invaded site, while soil total K and pH value were lower than non-invaded site. Soil fungi, azotobacteria and ammonia oxidizing bacteria were significantly associated with most of the measured soil physical and chemical properties. The results indicate that A. adenophora changed soil microbial communities, especially the soil nutrition transition related soil microbe groups, probably creating favorable soil environment to benefit itself. Modification of soil biota is an important part of A. adenophora invasion process, and the invasion-induced changes of soil microbial community may lead to high soil available nutrition abundance, through which A. adenophora gains its superority in competition.