Yan Haoru, Schmid Bernhard, Xu Wubing, Bongers Franca J, Chen Guoke, Tang Ting, Wang Zhiheng, Svenning Jens-Christian, Ma Keping, Liu Xiaojuan
State Key Laboratory of Vegetation and Environmental Change Institute of Botany Beijing China.
University of Chinese Academy of Sciences Beijing China.
Ecol Evol. 2024 May 2;14(5):e11364. doi: 10.1002/ece3.11364. eCollection 2024 May.
Plot-scale experiments indicate that functional diversity (FD) plays a pivotal role in sustaining ecosystem functions such as net primary productivity (NPP). However, the relationships between functional diversity and NPP across larger scale under varying climatic conditions are sparsely studied, despite its significance for understanding forest-atmosphere interactions and informing policy development. Hence, we examine the relationships of community-weighted mean (CWM) and functional dispersion (FDis) of woody plant traits on NPP across China and if such relationships are modulated by climatic conditions at the national scale. Using comprehensive datasets of distribution, functional traits, and productivity for 9120 Chinese woody plant species, we evaluated the distribution pattern of community-weighted mean and functional dispersion (including three orthogonal trait indicators: plant size, leaf morphology, and flower duration) and its relationships with NPP. Finally, we tested the effects of climatic conditions on community-weighted mean/functional dispersion-NPP relationships. We first found overall functional diversity-NPP relationships, but also that the magnitude of these relationships was sensitive to climate, with plant size community-weighted mean promoting NPP in warm regions and plant size functional dispersion promoting NPP in wet regions. Second, warm and wet conditions indirectly increased NPP by its positive effects on community-weighted mean or functional dispersion, particularly through mean plant size and leaf morphology. Our study provides comprehensive evidence for the relationships between functional diversity and NPP under varying climates at a large scale. Importantly, our results indicate a broadening significance of multidimensional plant functional traits for woody vegetation NPP in response to rising temperatures and wetter climates. Restoration, reforestation actions and natural capital accounting need to carefully consider not only community-weighted mean and functional dispersion but also their interactions with climate, to predict how functional diversity may promote ecosystem functioning under future climatic conditions.
地块尺度的实验表明，功能多样性（FD）在维持生态系统功能（如净初级生产力（NPP））方面起着关键作用。然而，尽管功能多样性与NPP之间的关系对于理解森林 - 大气相互作用和为政策制定提供信息具有重要意义，但在不同气候条件下，更大尺度上对它们之间关系的研究却很少。因此，我们研究了中国木本植物群落加权均值（CWM）和功能离散度（FDis）与NPP之间的关系，以及这些关系在全国尺度上是否受到气候条件的调节。利用9120种中国木本植物物种的分布、功能性状和生产力的综合数据集，我们评估了群落加权均值和功能离散度（包括三个正交性状指标：植物大小、叶片形态和花期）的分布模式及其与NPP的关系。最后，我们测试了气候条件对群落加权均值/功能离散度 - NPP关系的影响。我们首先发现了总体功能多样性 - NPP关系，但这些关系的强度对气候敏感，植物大小群落加权均值在温暖地区促进NPP，植物大小功能离散度在湿润地区促进NPP。其次，温暖和湿润条件通过对群落加权均值或功能离散度的积极影响间接增加了NPP，特别是通过平均植物大小和叶片形态。我们的研究为大尺度不同气候条件下功能多样性与NPP之间的关系提供了全面的证据。重要的是，我们的结果表明，多维植物功能性状对木本植被NPP的意义随着温度升高和气候变湿而不断扩大。恢复、造林行动和自然资本核算不仅需要仔细考虑群落加权均值和功能离散度，还需要考虑它们与气候的相互作用，以预测功能多样性在未来气候条件下如何促进生态系统功能。
