四川盆地麻竹、巨桉人工林对土壤线虫群落结构的影响

Effect of Dendrocalamus latiflorus and Eucalyptus grandis plantations on soil nematode community in Sichuan Basin

了解四川盆地退耕造林对土壤线虫群落结构的影响，可为协调该区域退耕还林后土壤生态系统健康发展提供科学依据。本研究于2013年4月对四川成都周边山区造林11年的麻竹（Dendrocalamus latiflorus）人工林（DL）、巨桉（Eucalyptus grandis）人工林（EG）和邻近坡耕地（CK）3种样地土壤进行分层（0～10 cm、10～20 cm和20～40 cm）取样调查。共捕获线虫10103条，分别隶属于2纲6目22科37属，优势属为滑刃属和绕线属，常见属为丽突属、鹿角唇属、小杆属等16个属，其余为稀有属。结果显示，不同样地间土壤线虫数量差异明显，但在垂直分布上具有明显的表聚现象。土壤线虫多样性指数（H′、SR、J′）表现为DL〉CK〉EG，而优势度指数λ则相反；功能类群指数MI表现为DL〉EG〉CK，PPI和PPI/MI指数为CK〉DL〉EG。土壤线虫区系划分显示DL受干扰程度较小，食物网结构相对成熟，EG次之，而CK处于退化状态。以上表明，麻竹造林可丰富土壤线虫群落的种类组成和维持较高的多样性，使土壤生态系统结构和功能处于相对稳定的状态。

Soil nematode plays an important role in nutrient cycling and is often used as a good bioindicator of soil quality assessment. To understand the effect of implementing the Grain to Green Program on soil ecosystem health, we investigated the soil nematode communities from different soil depths （0-10, 10-20 and 20-40 cm） under three landuse types： 11-year-old Dendrocalamus latiflorus plantation （DL）, 11-year-old Eucalyptus grandis plantation （EG）, and the adjacent sloping cropland （CK） in a hilly area of the Chengdu plain, Sichuan Province, in April 2013. A total of 10103 nematodes were captured and fell into 2 classes, 6 orders, 22 families, and 37 genera. Aphelenchoides and Plectus were the dominant genera. Acrobeles, Cervidellus, Rhabditis were the common genera. There was a significant difference in the number of soil nematodes among different landuse types, and the vertical distribution of nematodes had an obvious surface aggregation phenomenon. The diversity index of soil nematodes, including Shannon index （H′）, Margalef index （SR） and Pielou index （J′）, followed the order of DL〉CK〉EG, except Simpson index （λ）. Maturity index （MI） followed the order of DL〉EG〉CK, and plant parasites index （PPI） CK〉DL〉EG. Based on nematode faunal analysis, the structure of soil food web in DL was relatively mature and lessdisturbed, compared with EG and CK. The results suggest that DL can enrich species composition of soil nematode community, achieve higher diversity and then maintain a steadystate structure and function of soil ecosystem.