Fan Ailian, Wang Xue, Yan Xiaojun, Chen Tingting, Jiang Qi, Jia Linqiao, Wang Weiwei, Xiong Decheng, Huang Jinxue, Chen Guangshui
Key Laboratory of Humid Subtropical Eco-geographical Process of Ministry of Education, School of Geographical Sciences, Fujian Normal University, Fuzhou, China.
Fujian Sanming Forest Ecosystem National Observation and Research Station, Fujian Normal University, Fuzhou, China.
Front Plant Sci. 2024 Dec 11;15:1481323. doi: 10.3389/fpls.2024.1481323. eCollection 2024.
The coordination between leaf and root traits is crucial for plants to synchronize their strategies for acquiring and utilizing above- and belowground resources. Nevertheless, the generality of a whole plant conservation gradient is still controversial. Such testing has been conducted mainly among communities at large spatial scales, and thus evidence is lacking within communities. This is noteworthy because factors that influence leaf and root trait variation differ across scales. Here, we measured pairs of analogous leaf and first-order root traits, including morphological (leaf thickness (LT) and root diameter (RD), leaf mass per unit area (LMA) and specific root length (SRL), and leaf and root tissue density (LTD and RTD)) and chemical traits (carbon (C) and nitrogen (N) concentrations in leaf and root tissues), on the same plants from 60 woody species within a subtropical broad-leaved evergreen forest. The trade-off patterns in and correlations between leaf and root traits were examined using (phylogenetic) principal component analysis and correlation analysis. Our results revealed two dominant dimensions of leaf trait variation, the leaf economics spectrum (LES) and the LT-LTD trade-off axis. Variations in root traits were mainly accounted for by a two-dimensional root economics space (RES) (i.e., root conservation gradient (RTD-RN) and root collaboration gradient (RD-SRL)). The LES and root conservation gradient were correlated and could be integrated into one whole plant conservation gradient, independent of the root collaboration gradient and the leaf LT-LTD trade-off dimension. Leaf and root N concentrations correlated positively, independent of phylogeny, whereas analogous leaf and root morphological traits varied independently of each other. These results support the existence of a whole plant conservation gradient, but also highlight a complex integration of multiple above- and belowground adaptive strategies of plants within a forest community, which offer new insight into ecological trade-offs, species coexistence and community assembly in the forest ecosystem.
叶片和根系性状之间的协调对于植物同步获取和利用地上与地下资源的策略至关重要。然而，整个植株保守性梯度的普遍性仍存在争议。此类测试主要在大空间尺度的群落间进行，因此群落内部缺乏相关证据。这一点值得注意，因为影响叶片和根系性状变异的因素在不同尺度上存在差异。在此，我们对亚热带常绿阔叶林内60种木本植物的同一植株测量了成对的类似叶片和一级根系性状，包括形态学性状（叶片厚度（LT）和根直径（RD）、单位面积叶质量（LMA）和比根长（SRL），以及叶片和根系组织密度（LTD和RTD））和化学性状（叶片和根系组织中的碳（C）和氮（N）浓度）。使用（系统发育）主成分分析和相关分析研究了叶片和根系性状之间的权衡模式及相关性。我们的结果揭示了叶片性状变异的两个主要维度，即叶片经济谱（LES）和LT-LTD权衡轴。根系性状的变异主要由二维根系经济空间（RES）（即根系保守性梯度（RTD-RN）和根系协作梯度（RD-SRL））解释。LES与根系保守性梯度相关，并且可以整合为一个整个植株保守性梯度，独立于根系协作梯度和叶片LT-LTD权衡维度。叶片和根系的N浓度呈正相关，与系统发育无关，而类似的叶片和根系形态学性状彼此独立变化。这些结果支持了整个植株保守性梯度的存在，但也突出了森林群落中植物地上和地下多种适应策略的复杂整合，这为森林生态系统中的生态权衡、物种共存和群落组装提供了新的见解。
