两种不同经营模式下杨树生物量及土壤碳储量的空间变异

Spatial variation of poplar (Populus deltoids cv.35) biomass and soil carbon storage at two different management patterns

在江苏北部地区选择宽窄行（K）和微型林网（w）2种杨农复合经营模式，研究各模式内杨树（Populus deltoids cv．35）地上部生物量、根系及土壤碳储量的空间变异，结果表明，6年生时K、W模式杨树地上部生物量分别为40．09和83．38kg，后者高出前者108％；地上部各器官生物量随高度上升而下降，其中树干组成比例最大；杨树根系空间变异表现为随土层加深而减少，主要分布在0～40cm土层，但W模式杨树根系分布比K模式相对更深、更均匀，更有利于进行杨农复合经营；不同经营模式土壤碳储量也存在较大差别，且表现出不同空间变异，K模式碳储量为58．74t·hm^-2随土层加深而下降；而w模式碳储量为46．35t·hm^-2，随土层加深先下降再回升。

The spatial variations of poplar （ Populus deltoids cv. 35 ） biomass and soil carbon storage were studied under two different agroforestry management patterns,wide-narrow row （K） and micro-web （W）, in the north of Jiangsu Province. The results showed that the poplar aboveground biomass at age 6 under K-pattern and W-pattern were 40. 09 kg and 83.38 kg,respectively,and the latter was 108% higher than the former. The aboveground organ biomass decreased with the increasing of tree height and the trunk was the largest component. The spatial variation of poplar root biomass decreased with the increasing of soil depth and root system distributed mainly in 0 - 40 cm soil. The root system under W-pattern distributed more deep and symmetrical than that of K-pattern. Significant differences also observed in soil carbon storage and its spatial variation under two patterns. The carbon storage under K-pattern decreased with increase of soil depth while that under W-pattern decreased at first then increased with the increase of soil depth.