植物残体去除对帽儿山温带落叶林土壤碳、氮、磷化学计量特征及其相关因子的影响

Effects of detritus removal on soil carbon,nitrogen and phosphorus stoichiometry and related factors in a temperate deciduous forest in the Maoershan Mountain,China

2007年在帽儿山温带落叶阔叶林中设置了地上凋落物去除(NL)、根系去除(NR)2个处理,9年后(2016年)测定土壤碳(C)、氮(N)、磷(P)浓度,以及土壤含水率和容重.结果表明:NL和NR处理表层(0~10 cm)土壤C浓度分别降低15.6%和10.7%,0~30 cm土层加权平均C浓度分别降低7.9%和4.6%;NL处理表层土壤N浓度降低10.2%,而NR处理表层土壤P浓度增加6.6%,两种处理均降低了表层土壤的C∶P和N∶P.标准主轴回归分析表明,不同处理间0~30 cm各土层C、N、P浓度的回归斜率均差异显著,土壤C浓度与土壤含水率、容重的回归截距也差异显著,这表明处理使土壤C、N、P化学计量与土壤物理性质发生了协同变化.建议今后植物残体去除处理试验考虑生态化学计量的调控作用.

A detritus-removal experiment was conducted in a temperate deciduous broad-leaved forest in 2007 at the Maoershan Ecological Station in Northeast China,including two treatments：Litterfall removal（ NL）,root removal（ NR）. Soil water content,bulk density and the concentrations of soil C,N and P were measured in 2016. The results showed that the C concentration at the surface soil layer（ 0-10 cm） was reduced by 15. 6% and 10. 7% for the NL and NR treatments,respectively,while the weighted-mean soil C concentration in 0-30 cm depth was reduced by 7.9% and 4.6%,respectively. The N concentration of the surface layer in the NL treatment decreased by 10.2%,whereas the surface-soil P concentration in the NR treatment increased by 6.6%,resulting in reduced C： P and N： P for both treatments. The standardized major axis regressions showed that the regression slopes between the C,N and P at each layer of 0-30 cm soil depth differed significantly among the treatments. The intercepts of the regressions between soil C concentration and bulk density or soil water content had significant differences among the treatments. The results suggested that detritus-removal caused a coordinated variation in soil C,N and P stoichiometry and physical properties. Therefore,we recommend taking the effect on soil ecological stoichiometry into account in future detritus-removal experiments.