不同林下植被管理措施对杉木大径材林分土壤真菌群落结构的影响

Differential influence of undergrowth vegetation management measures on the soil fungal community structure of a large-diameter timber plantation of Cunninghamia lanceolata

林下植被是人工林生态系统重要组成部分.使用高通量技术分析,研究林下植被保留(UP)、林下植被去除(UR)、林下套种楠木(IP)3种处理措施对杉木大径材人工林土壤真菌群落结构与多样性的影响,并进一步分析土壤理化性质与真菌群落结构的相关关系.结果显示:相比于UR模式,IP模式与UP模式土壤真菌群落Chao l指数、Shannon指数和Ace指数较高;本研究区域杉木人工林土壤主要优势真菌为座囊菌纲与木霉属;在纲分类水平下,与其他两种模式相比,IP模式土壤中座囊菌纲相对丰度较高(23.2%),粪壳菌纲相对丰度较低(8.78%);在属分类水平下,与其他2种模式相比,UP模式土壤中木霉属真菌相对丰度较高(9.97%),Apiotrichum属相对丰度较低(0.56%);3种林下植被管理措施下,格孢菌目、Paraboeremia、Paraboeremiaselaginellea等真菌类群相对丰度差异显著(P<0.05);土壤真菌多样性指数与土壤全氮、全磷、水解氮和速效钾含量呈显著正相关(P<0.05);土壤速效钾含量、速效磷含量、自然含水率与非毛管孔隙度为不同管理模式下土壤真菌群落结构变化的主要因素.本研究表明IP模式下真菌群落结构所发生的变化可能更利于土壤养分的维持与土壤质量的提高,结果可为探究科学合理的林下植被管理措施及杉木人工林长期生产力维护提供技术参考.

Understory vegetation is an important component of plantation ecosystems.In this study,a highthroughput technique was used to analyze the effects of three treatment measures,undergrowth vegetation preservation(UP),undergrowth vegetation removal(UR),and interplanting with Phoebe zhennan(IP),on the soil fungal diversity and community structure of Cunninghamia lanceolata plantations;the correlation between soil physical and chemical properties and fungal community structure was further analyzed.The results showed that compared with the UP treatment,in the IP and UR treatments the Chao l,Shannon,and Ace indexes of the soil fungal community were high.The dominant fungi in the soil of this C.lanceolata plantation were Dothideomycetes and Trichoderma.At the class level,the relative abundance of Dothideomycetes(23.2%)was high and that of Sordariomycetes(8.78%)was low in the soil under IP treatment compared with soil under the other two treatments.At the genus level,the relative abundance of Trichoderma(9.97%)was high and that of Apiotrichum(0.56%)was low in the soil under the UP treatment compared to that under the other two treatments.Among the three types of understory vegetation management measures,the relative abundance of fungi,such as Pleosporales,Paraboeremia sp.,and Paraboeremia selaginellea were significantly different(P<0.05).Soil fungal diversity index was positively correlated with the levels of soil total nitrogen,total phosphorus,hydrolytic nitrogen,and available potassium(P<0.05).The total potassium,available phosphorus,natural water content,and non-capillary porosity were the main factors affecting the changes in the soil fungal community under different management measures.The present study indicates that the fungal community structure with the IP measure may be the most beneficial for soil nutrient maintenance and soil quality improvement.The above results provide a technical reference for exploring scientific and appropriate measures of understory vegetation management and the maintenance of long-term productivity of C.lanceolata large-diameter timber.