<正>采用连续钻取土芯法对苏北两种模式（网格模式P。、网格台田模式PT）下4年生杨树（Populusdeltoides cn. 35?）人5-林细根（≤5mm）进行研究，并采用不同估算方法对细根年净生产量、死亡量、分解量和周转率进行比较。结果表明，细根现存生物量为1.26～1.86t/hm2.PW和PT两种模式下，细根年净生产量、死亡量、分解量和周转率分别为2.24t/hm2、2.34t/hm2、1.88t/hm2、1.43次/a和1.43t/hm2、1.29t/hm2、1.37t/hm2、1.31次/a，与决策矩阵法相比，采用最大最小值法平均低估了19%的细根年净生产量、68%的年死亡量、89%的年分解量和23%的周转率；土壤养分和季节水分动态是PW和PT模式细根生产量和周转率存在差异的主要原因。

This paper deals with study the spatial variation characteristics of soil fertility index (index as follows) in different Phyllostachys edulis (Moso bamboo) stands by means of collecting soils sampling in July at fixed monitoring station in the hilly of forest region at Jian-shan mountainous area,Fuyang county,Zhejiang province,In the meantime the mixed coniferous with broadleaf stands (Pinus massoniana+Liquidambar formosana evergreen broadleaved forest) and" aiphyllium forest (Cinnamomum camphora+Castanopsis sclerophylla) were sellected as comparison. The subjection values and index were calculated for evaluating soil fertility condition in term of fuzzy mathematics principles. Resuhs showed that the index of layer I (0--10 cm) is larger than that in layer I1 (10--30 cm) or layer Ⅲ (30--50 cm)among various stands in general, The index of layer I of mixed Moso bamboo with Schima superba stands was larger than that of pure Moso bamboo stands. The index of layer Ⅰ in reclamation pure Moso bamboo stands was lower than that mixed coniferous with broadleaf stands or aiphyllium stands respectively, whereas the index of layer Ⅱ or layer Ⅲ was larger than that in the other stands. The index above three layers was the lowest in no reclamation Moso bamboo stands. While the index in stands mixed Moso bamboo with Schima superba was similar to that mixed coniferous with broadleaf stands above three layers.