2种入侵植物对根际土壤微生物种群及代谢的影响

选取2种入侵植物（一年蓬Annual Fleabane及加拿大蓬Erigeron Canadensis）及本土植物（艾蒿Artemisia argyi）的根际土壤微生物种群为研究对象,以分析不同根际土壤微生物种群的数量及测定根际土壤微生物酶活的活性为切入点来探析入侵植物对土壤微生物的影响及其响应机制。结果显示：2种入侵植物显著增加了其根际土壤中的细菌的数量,而显著抑制了真菌与放线菌的数量。另外,入侵植物一年蓬显著抑制其根际土壤中纤维素酶的活性,而3种植物的根际土壤硝酸还原酶活性无显著差异。入侵植物对其他3种土壤酶（即转化酶、脲酶及酸性磷酸酶）活性的影响却呈现出截然相反的影响,即一年蓬显著增加了3种根际土壤酶的活性,而加拿大蓬却显著减少了3种根际土壤酶的活性。导致这种现象的原因可能是不同入侵植物的根系释放不同的化学物质进而对土壤微生物的数量和活性造成不同的影响。

The eological effects of two invasive plants on soil microorganism community in rhizosphere

This study was carried out with two invasive species（Annual Fleabane and Erigeron Canadensis） and native plant species（Artemisia argyi） seleseted as research target in order to assess（1） the effects of invasive plants on the population amount of soil microorganisms in rhizosphere revealed by dilution plate method with spread plates;and（2） the effects of invasive plants on the metabolic activities of soil microorganisms in rhizosphere through determine soil enzyme activities（i.e.,cellulase,invertase,urease,nitrate reductase,and acid phosphatase） to insights into the invasive process of invasive plants.The results of this study suggested that invasive plants increase the bacterial amount significantly,and significantly decrease the fungal and actinomycetic amount contrarily.Meanwhile,invasive plants of Annual Fleabane restrained cellulase activities significantly,and the activities of nitrate reductase of the three plants were equivalent basically.While,the ecological effects of invasive plants on the activities of invertase,urease,and acid phosphatase shows the opposite results between the two invasive species,in other words,one invasive species（Annual Fleabane） enhanced enzymatic activities significantly,while other invasive species（Erigeron Canadensis） restrained enzymatic activities significantly.The interesting phenomenon may be attributed to that chemical substances released by different invasive species can induce different effects on the population amount and metabolic activities of soil microorganisms in rhizosphere.