To reveal the dynamic characteristics of root-associated fungal communities of P. sylvestris plantation, the co-occurrence network of root-associated fungi in P. sylvestris plantation were analyzed by using molecular ecological network analysis in the Mu Us Desert and its response to climate factors in different stand ages (27 a, 33 a and 44 a) and their annual growth stages (early growth season, vigorous growth season and end-of-growth season). The following conclusions are obtained. 1) Different growing seasons rather than different stand ages had significant differences in the co-occurrence network of fungi in roots of P. sylvestris plantation, and the co-occurrence network of fungi in roots was more complex in the vigorous growing season. 2) The keystone species of root-associated fungi of P. sylvestris plantation were significant in different growing seasons and stand ages. The keystone genera mainly included Geopora, Tomentella, Phaeosphaeria, Neocucurbitaria, Mortierella, etc. Ectomycorrhizal and saprophytic fungi were the keystone taxa in the early and end of the growth season, and saprophytic fungi and pathogens were the keystone taxa in the vigorous growth season. Meanwhile, the keystone taxa of middle-aged forest were saprophytic fungi and pathogens, while the mature forest were ectomycorrhizal and saprophytic fungi. 3) Relative humidity was the main influencing factor for ectomycorrhizal fungi network, and average precipitation and relative humidity were the main influencing factors for saprophytic fungi network and pathogens network (P<0.05). Therefore, the network dynamic of root-associated fungi of P. sylvestris plantation in different growing seasons was stronger than that of stand age in Mu Us Desert, and the co-occurrence network structure was more complex in the vigorous growth season. The root-associated fungal network was mainly affected by average precipitation and relative humidity. Saprophytic fungi played an important role in maintaining the stability of the fungal network in different stand ages and growing seasons. Saprophytic fungi and pathogens in the vigorous growth season with high precipitation and relative humidity, which potentially contributed to the growth and health of P. sylvestris plantation. 

为揭示樟子松人工林根内真菌群落相互关系的动态特征, 以毛乌素沙地樟子松人工林为研究对象, 采用生态网络分析法, 分析不同林龄(中龄、近熟和成熟)及其年内生长阶段(生长季初期、旺盛期和末期)樟子松根内真菌群落共现网络动态特征及其对气候因子的响应, 得到如下结果。1) 在不同林龄阶段, 樟子松人工林根内真菌共现网络差异不明显; 在不同生长季阶段, 根内真菌共现网络差异明显, 生长季旺盛期, 根内真菌共现网络较为复杂。2) 在不同林龄和不同生长季阶段, 樟子松人工林根内真菌关键类群差异明显, 主要包括地孔菌 属(Geopora)、 棉革菌属(Tomentella)、 暗球腔菌属(Phaeosphaeria)、Neocucurbitaria和被孢霉属(Mortierella)等。生长季初期和末期关键类群为外生菌根真菌和腐生真菌, 旺盛期为腐生真菌和病原真菌。中龄林关键类群为腐生真菌和病原真菌, 成熟林为外生菌根真菌和腐生真菌。3) 外生菌根真菌网络的主要影响因子为相对湿度(P<0.05), 腐生真菌和病原真菌网络的主要影响因子为平均降水量和相对湿度。因此, 毛乌素沙地樟子松人工林根内真菌网络在不同生长季阶段的动态变化强于不同林龄阶段, 且生长季旺盛期共现网络的结构较复杂; 根内真菌网络主要受平均降水量和相对湿度影响。腐生真菌对维持不同林龄和不同生长季阶段真菌网络的稳定性均有重要作用, 在较大降水量和湿度的生长季旺盛期, 关键类群为腐生真菌和病原真菌, 对樟子松的生长和健康状况有着潜在的影响。