摘要
【目的】分析暖温带针阔混交林内木材密度的变化程度;探讨多元生境因子对不同群落木材密度空间分布的影响,揭示木材密度的种间和种内差异及其影响因素,为研究暖温带针阔混交林的物种共存与群落构建机制奠定基础。【方法】在甘肃小陇山地区的暖温带针阔混交林内布设大样地,依据样地内所有胸径≥10 cm独立个体的木材密度实测数据,利用方差分解分析种内、种间以及群落水平上木材密度的变化程度;利用多元回归分析探讨多元生境因子对群落水平木材密度空间分布的影响。【结果】样地内木材密度的差异主要来源于不同群落里树种间的差异,种间差异(71.70%)大于种内差异(28.30%)。在影响群落水平木材密度空间分布的因素中,非生物因子的影响大于生物因子。土壤因子中的pH值和地形因子中的海拔是影响木材密度的主要因子。在土壤pH值较低、海拔较高的群落中,木材密度的加权平均值较高。木材密度方差主要受土壤pH值影响,并随pH值的增大而增大。种内差异对木材密度加权平均值无显著影响,但对木材密度方差影响显著。【结论】甘肃小陇山针阔混交林木材密度空间异质性较强,非生物因子通过影响功能性状的总体分布来影响植物适应性,木材密度较高、种内差异较低的树种倾向于分布在海拔较高、土壤pH值较低的区域;相反,木材密度较低、种内差异较高的树种倾向于分布在海拔较低、土壤pH值较高的区域。在局域尺度下,忽视种内差异会导致木材密度方差被低估,影响对真实群落构建机制的理解。
【Objective】This project was conducted to determine the variation of wood density within coniferous-broadleaved mixed forest dynamics plot in Xiaolong Mountains.We also investigated the relative significance of multiple habitat factors on the spatial distribution of wood density.Finally,it was revealed that inter-and intraspecific differences in wood density and their driving factors.This research would provide the basis for studying species coexistence and community assembly mechanism in coniferous-broadleaved mixed forests in warm temperate regions.【Method】The wood density of all living stems DBH≥10 cm in the plot were sampled and measured.The variance decomposition was applied to differentiate the variance of wood density among individu-als,species,and quadrat levels.The relative significance of various habitat factors on the wood density spatial distribution was in-vestigated by multiple regression analysis,specifically community weighted mean(CWM)and community weighted variance(CWV).【Result】The variation of wood density was mainly contributed by the interspecies differences in the Xiaolong dynamics plot,where interspecific variation(71.70%)in wood density was significantly higher than intraspecific variation(28.30%).In addi-tion,abiotic factors showed more significant influences than biotic factors on the wood density spatial distribution.The CWM of wood density was found significantly associated with topographic(e.g.elevation)and edaphic(e.g.pH value)factors.The trees with higher CWM values usually distributed in the areas at higher elevations with lower soil pH values.However,the CWV value of wood density was significantly positively related to soil pH value.Finally,the intraspecific variation had insignificant effects on the CWM of wood density,while significant effects on the CWV of wood density.【Conclusion】Our results demonstrated the signi-ficant spatial heterogeneity of wood density in coniferous-broadleaved mixed forest dynamics plot in Xiaolong Mountains,Gansu province.Plant adaptation was significantly affected by abiotic factors through overall distribution of functional traits.The species with higher wood densities and unobvious intraspecific differences preferred the habitats at higher altitudes with lower soil pH val-ues.On the contrary,those species with lower wood densities and significant intraspecific variation were observed on the habitats at lower altitudes with higher soil pH values.Therefore,the intraspecific variation in wood density at local scales should not be over-looked,which would affect the understandings of natural community assembly mechanisms.
作者
苏巧灵
李梦琳
田立新
李安民
袁士云
刘文桢
米湘成
黄继红
许玥
丁易
臧润国
SU Qiaoling;LI Menglin;TIAN Lixin;LI Anmin;YUAN Shiyun;LIU Wenzhen;MI Xiangcheng;HUANG Jihong;XU Yue;DING Yi;ZANG Runguo(Key Laboratory of Forest Ecology and Environment of National Forestry and Grassland Administration,Institute of Forest Ecology,Environment and Nature Conservation,Chinese Academy of Forestry,Beijing 100091,China;Key Laboratory of Ecosystem Net-work Observation and Modeling,Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,China;Xiaolong Moutains Forest Experiment Bureau of Gansu Province,Tianshui 741020,China;State Key Laboratory of Vegetation and Environmental Change,Institute of Botany,Chinese Academy of Sciences,Beijing 100093,China;Co-Innovation Center for Sustainable Forestry in Southern China,Nanjing Forestry University,Nanjing 210037,China)
出处
《陆地生态系统与保护学报》
2021年第1期12-22,共11页
Terrestrial Ecosystem and Conservation
基金
中央级公益性科研院所基本科研业务费专项资金中国林科院重点项目(CAFYBB2019ZA002)
国家自然科学基金面上项目(41671047)。
关键词
木材密度
种内差异
生境空间异质性
针阔混交林
小陇山
wood density
intraspecific variation
habitat spatial heterogeneity
coniferous-broadleaved mixed forest
Xiaolong Mountains