细根生物量(Fine Root Biomass,FRB)是森林生态系统物质循环和能量流动的重要指示指标,但树种组成和多样性对其影响尚不清楚.为了探讨不同树种混交模式对细根生物量的影响,本研究采用土钻法比较不同树种混交模式林分在0-10、10-20和20-40 cm 土层中细根的生物量大小和分布情况,使用叶面积指数仪测量叶面积指数(Leaf Area Index,LAI).结果表明:(1)随着土层加深,不同树种混交模式林分的细根生物量均呈下降趋势.(2)0-10和20-40 cm 土层的细根生物量与树种多样性呈显著正相关,10-20 cm 土层的细根生物量对树种多样性的响应不如0-10 cm 土层明显,这可能归因于不同树种根系的养分吸收策略导致细根在不同土层上的分布产生差异.(3)细根生物量与叶面积指数呈显著正相关.(4)细根生物量随针叶、阔叶树种的混交模式变化呈极显著差异,大小顺序依次为阔阔混交＞针阔混交＞阔叶纯林＞针叶纯林.本研究表明树种多样性对细根生物量的大小和空间结构分布有明显影响,该结果为深入认识不同混交树种间的相互作用提供理论依据.
Effects of Different Mixed Tree Species Patterns on Fine Root Biomass in a Southern Subtropical Plantation
Fine Root Biomass(FRB)is an important indicator of material cycling and energy flow in forest e-cosystems,while the effects of tree species assembly and diversity on FRB remain unclear.The effects of dif-ferent mixed tree species patterns on FRB were studied.The soil drilling method was employed to compare the biomass and distribution patterns of fine roots in the soil layers of 0-10,10-20 and 20-40 cm in the stands with different mixed tree species patterns.The Leaf Area Index(LAI)was measured by a LAI meter.The results showed:(1)A decreasing trend in FRB with the deepening of soil layer was demonstrated in dif-ferent mixed tree species patterns.(2)In the soil layers of 0-10 and 20-40 cm,FRB had a significantly pos-itive correlation with species diversity.The response of FRB in the 10-20 cm soil layer to tree species diver-sity was not as pronounced as that in the 0-10 cm soil layer,which might be attributed to the differences in spatial distribution of fine roots in different soil layers due to different nutrient uptake strategies of diverse species.(3)FRB had a significantly positive correlation with LAI.(4)FRB showed highly significant differ-ences among different mixed patterns of coniferous and broad-leaved species,following the order of broad-leaved mixed forests＞coniferous and broad-leaved mixed forests＞broad-leaved forests＞coniferous forests.This study indicates that mixed tree species patterns have significant effects on FRB and the spatial structure of fine roots,providing a theoretical basis for deeply understanding the interactions between different mixed tree species.
tree species richnessmixed tree speciesfine root biomassleaf area indexdifferent soil layers
万方数据
维普
