外来植物紫茎泽兰入侵对根际土壤有益功能细菌群、酶活性和肥力的影响

通过对紫茎泽兰不同入侵阶段下的实地采样,分析了外来入侵植物紫茎泽兰对入侵地根际土壤有益微生物菌群和土壤酶活性以及肥力的影响。发现除了全磷、全钾以外,重度入侵土壤的功能菌数量、酶活性、土壤肥力都要显著高于其它土壤区系。根际土中有机磷细菌差异最显著,其重度入侵土中的含量是轻度入侵土中含量的3.0倍,是当地植物土中含量的1.8倍,是空白地区含量的22.2倍。同时,土壤微生物类群、土壤酶活与土壤肥力的相关分析表明,它们之间存在显著相关关系,自生固氮菌与全氮相关性最明显,为0.922。外来植物对入侵地的影响是其入侵力和生态系统可入侵性的重要组成部分,紫茎泽兰入侵提高了土壤功能菌种群和土壤酶活,从而使土壤肥力也发生了相应的变化,这可能促进其养分转化吸收,提高种群竞争力。本文为紫茎泽兰成功入侵的土壤微生物学机制提供理论依据。

Invasive effects of Ageratina adenophora (Asteraceae) on the changes of effective functional bacteria, enzyme activity and fertility in rhizosphere soil ecosystem.

In the study,the soil functional bacterial communities were studied and compared using plate cultivation method with selective media,at the same time we compared the activity of the soil enzyme and the soil physical and chemical properties in five different type of soil area（divided following the invasion of Ageratina adenophora）.It was found that the number of the soil functional bacteria,the activity of the soil enzyme,and the soil nutrient level（except for the soil N and the soil K） of the rhizosphere soi1 in heavily invaded area were extreme higher than the other area.The content of the Organic-phosphorus-dissolving bacteria is 3.0 times in heavily area more than the content in the newly invaded area,is 1.8 times more than the content in the native plants area,and is 22.2 times more than the content in the bare soil area.At the same time,after analyzing the correlations coefficient among soil microbe groups,soil enzyme and soil nutrient we found that there were significant positive correlations between soil enzymatic activities and soil nutrient level（except that the soil N and soil K）,also there were significant positive correlations between soil functional bacterial and soil nutrient level（except that the soil N and soil K）.The correlations coefficient between the azotobacter and the soil N is 0.922.The effects of invasive plants on the soil is an important part of the invasive mechanism,the invasive of the Ageratina adenophora increase the number of the soil functional bacterial and the activity of the soil enzyme,which made the soil nutrient level changed at the same time,these changes may raise its competent ability compared to the native plants.This study provided a basical theory for further exploring the microorganism mechanism of its invasion.