目标树经营对马尾松人工林不同土层深度土壤线虫群落结构的影响

Effects of target tree management of Pinus massoniana plantation on soil nematode community structure at different soil depths

为研究不同土层深度土壤线虫群落结构及其对目标树经营的响应机制,以马尾松人工林目标树经营样地和对照样地为研究对象,采集了土壤样品(0~10、10~20和20~50 cm)和凋落物样品,分析了土壤线虫群落结构、土壤环境因子及其相互关系。结果表明:目标树经营提高了土壤线虫数量,其中对0~10 cm土层中线虫数量的影响最显著;采用目标树经营的处理以植食性线虫数量最多,对照以食细菌线虫数量最多。与对照相比,目标树10~20 cm土层的土壤线虫Shannon多样性指数、丰富度指数、成熟度指数和20~50 cm土层Shannon多样性指数显著提高。Pearson相关性分析和冗余分析显示,土壤pH、全磷、有效磷、全钾和速效钾是影响土壤线虫群落结构和群落组成的主要环境因子。目标树经营改善了土壤微环境,有利于土壤线虫生存和发展,推动了马尾松人工林的可持续发展。

To understand soil nematode community structure at different soil depths and its responses to target tree management,we collected soil samples(0-10,10-20,and 20-50 cm)and litter samples from the target tree management plots and control plots of Pinus massoniana plantation and analyzed community structure,soil environmental factors,and their relationship.The results showed that target tree management increased the abundance of soil nematodes,with the most significant effect at a depth of 0-10 cm.The highest abundance of herbivores was found in the target tree management treatment,while that of bacterivores was found in the control.Compared with the control,Shannon diversity index,richness index,maturity index of nematodes at 10-20 cm soil layer and Shannon diversity index at 20-50 cm soil layer of target trees were significantly improved.According to the results of Pearson correlation and redundancy analysis,soil pH,total phosphorus,available phosphorus,total potassium,and available potassium were the main environmental factors affecting community structure and composition of soil nematodes.In general,target tree management was conducive to the survival and development of soil nematodes and promoted the sustainable development of P.massoniana plantations.