Jiang Feng, Xun Yanhan, Cai Huiying, Jin Guangze
Center for Ecological Research, Northeast Forestry University, Harbin, 150040, China.
Oecologia. 2018 Mar;186(3):783-792. doi: 10.1007/s00442-018-4060-3. Epub 2018 Jan 10.
Ecologists often determine the relative importance of niche- and dispersal-based processes via variation partitioning based on species composition. Functional traits and their proxies of phylogeny are expected to increase the detection of niche-based processes and reduce the unexplained variation relative to species identity. We collected eight adult tree traits and phylogenetic data of 41 species and employed a phylogenetic fuzzy weighting method to address this issue in a 9-ha temperate forest dynamics plot. We used redundancy analysis to relate species, phylogenetic and functional compositions to environmental (soil resources and topography) and spatial variables. We also performed multi-scaled analyses on spatial variables by adding environment as the covariates to determine if functional traits increase the detection of niche-based processes at broad scales. The functional traits and intraspecific variation of the wood density among ontogenetic stages could dramatically increase the detection of niche-based processes and reduce the unexplained variation relative to species identity. Phylogenetic and functional compositions were mainly driven by total soil P and elevation, while species composition was weakly affected by multiple environmental variables. After controlling for the environment, a larger amount of the compositional variations in seed mass and maximum height were explained by finer-scaled spatial variables, indicating that dispersal processes may be important at fine spatial scales. Our results suggested that considering functional traits and their intraspecific variations could improve our understanding of ecological processes and increase our ability to predict the responses of plants to environmental change.
生态学家通常通过基于物种组成的变异划分来确定基于生态位和扩散过程的相对重要性。功能性状及其系统发育替代指标有望增加对基于生态位过程的检测，并减少相对于物种身份的未解释变异。我们收集了41个物种的8个成年树木性状和系统发育数据，并采用系统发育模糊加权方法在一个9公顷的温带森林动态样地中解决这个问题。我们使用冗余分析将物种、系统发育和功能组成与环境（土壤资源和地形）及空间变量联系起来。我们还通过将环境作为协变量添加到空间变量上进行多尺度分析，以确定功能性状是否能在大尺度上增加对基于生态位过程的检测。木材密度在个体发育阶段的功能性状和种内变异能够显著增加对基于生态位过程的检测，并减少相对于物种身份的未解释变异。系统发育和功能组成主要由土壤总磷和海拔驱动，而物种组成受多个环境变量的影响较弱。在控制环境因素后，种子质量和最大高度的组成变异中有更大比例可由更精细尺度的空间变量解释，这表明扩散过程在精细空间尺度上可能很重要。我们的结果表明，考虑功能性状及其种内变异能够增进我们对生态过程的理解，并提高我们预测植物对环境变化响应的能力。
