黔中地区马尾松针阔混交林细根性状空间变异特征

Spatial variation of root functional traits of Pinus massoniana mixed forest in central Guizhou

【目的】细根在土壤养分、水分和碳循环中发挥着关键作用,其空间分布规律及变异特征对于表征不同生境中植物地下生长策略具有重要意义。【方法】以黔中地区马尾松纯林和马尾松-甜槠针阔混交林为研究对象,采用经典统计学和地统计学相结合的方法,分析不同林型细根性状的空间变异特征及其影响因子。【结果】1)马尾松纯林与马尾松-甜槠针阔混交林细根性状具有显著差异(P <0.01),其中根组织密度、根长密度、根体积密度、根生物量密度均表现为马尾松-甜槠针阔混交林显著高于马尾松纯林;2)两种森林类型中各细根性状主要表现为强烈的空间自相关,且细根性状的变程大小基本上表现为:马尾松纯林>马尾松-甜槠针阔混交林;3)普通Kriging插值细根性状的空间分布图表明,马尾松-甜槠针阔混交林细根空间分布较马尾松纯林空间异质性强,且高值区较多;4)不同土壤因子对细根性状各指标空间变异的影响存在差异;根长密度、根体积密度、根生物量密度的空间变异在马尾松纯林的主要解释因子为AK,而在马尾松-甜槠针阔混交林的主要解释因子则为TP和pH值。【结论】两种森林类型的细根性状指标及细根性状空间分布格局均存在显著性差异,这一差异反映了在混交林中根系获取资源的策略与竞争的优势,因此本研究结果可为该区域马尾松与阔叶树种的混交生态效益评估提供参考。

【Objective】Fine roots play a key role in soil nutrient,water and carbon cycles,and their spatial distribution and variation characteristics are of great significance to characterize the underground growth strategies of plants in different habitats.【Method】Taking Pinus massoniana forest and Pinus massoniana–Castanopsis eyrei mixed forest in central Guizhou as the research objects,the spatial variation characteristics and influencing factors of fine root functional traits of different forest types were analyzed by using the method of classical statistics and geostatistics.【Result】1)There were significant differences in root functional traits between P.massoniana forest and P.massoniana–C.eyrei mixed forest(P<0.01).The root tissue density,root length density,root volume density and root biomass density of P.massoniana–C.eyrei mixed forest was significantly higher than those of P.massoniana–C.eyrei mixed forest.2)Fine root traits showed strong spatial autocorrelation in the two forest types,and the range of fine root traits was as follows:P.massoniana forest>P.massoniana–C.eyrei mixed forest.3)The spatial distribution map of fine root traits by Kriging interpolation showed that the spatial distribution of fine roots in P.massoniana–C.eyrei mixed forest was more heterogeneous than that in P.massoniana forest,and there were more high-value areas.4)The effects of different soil factors on spatial variation of root functional traits were different;AK was the main explaining factor for the spatial variation of root length density,root volume density and root biomass density in P.massoniana forest,while TP and pH were the main explaining factors in P.massoniana–C.eyrei mixed forest.【Conclusion】There are significant differences between the two forest types in the indices of fine root traits and the spatial distribution pattern of each index,which reflects the resource acquisition strategy and competitive advantage of the root system in the mixed forest.Therefore,the results of this study can provide reference for the evaluation of mixed ecological benefits of P.massoniana and broadleaf trees in this area.