Environmental effects on community productivity of aquatic macrophytes are mediated by species and functional composition
Environmental effects on community productivity of aquatic macrophytes are mediated by species and functional composition
复制标题
环境对水生大型植物群落生产力的影响是由物种和功能组成介导的
DOI：
10.1002/eco.2147
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发表时间：
2019
期刊：
影响因子：
2.6
通讯作者：
Huang Zhenrong
中科院分区：
文献类型：
--
作者：
Fu Hui;Yuan Guixiang;Li Wei;Ge Dabing;Zou Dongsheng;Huang Zhenrong
环境变化正在迅速改变植物物种和功能组成，这可能对生态系统功能产生影响。对云贵高原和长江流域24个淡水湖泊的1,008个样地进行了水生植物群落的物种多样性、功能多样性和环境因子的测定。利用广义多水平通径模型研究了环境对水生植物生产力的直接和间接影响。我们发现不同的物种和功能的四组环境变量：水质，异质性，气候和地形。在富营养化、异质性、高海拔或深水生境中，大型植物群落往往具有较高的丰富度，并以茎干质量含量高、开花持续时间长的物种为主。具有高比叶面积的沉水和一年生物种在异质和高海拔条件下占主导地位，而具有高茎和叶干物质含量以及薄茎和叶片的物种在异质和低海拔条件下占主导地位。功能离散度（FDis）在异质和高海拔生境中降低，在深水中增加。这些功能组成的变化随后对群落生产力产生了重大影响，涉及群落加权平均（CWM）性状的正效应和FDis的负效应的相反途径，最终有助于观察到的恒定的大型水生植物生产力沿着测试的环境梯度。我们的研究结果提供了强有力的证据，物种和功能组成介导的级联效应的环境对大型植物生产力。
Environmental variations are rapidly altering plant species and functional composition, which may have consequent influences on ecosystem functioning. We measured species and functional diversity of macrophyte community as well as environmental variables in 1,008 plots in 24 freshwater lakes across Yunnan–Guizhou plateau and Yangtze River in south China. We used generalized multilevel path models to test how the environmental effects on macrophytes productivity directly and indirectly through changes in species and functional diversity. We found distinct species and functional responses to the four groups of environmental variables:water quality, heterogeneity, climate, and topography. Macrophyte communities tended to be high richness and dominated by species with high‐stem dry mass content and long flowering duration at eutrophic, heterogeneous, high altitude, or deepwater habitats. Submersed and annual species with high‐specific leaf area dominated in heterogeneous and high altitude conditions, whereas species with high shoot and leaf dry mass content as well as thin stem and lamina dominated in heterogeneous and low‐altitude conditions. Functional dispersion (FDis) decreased in heterogeneous and high‐altitude habitats and increased at deepwater. These changes in functional composition have subsequently significant influences on community productivity, involving the opposite pathways of positive effects of community‐weighted mean (CWM) traits and negative effects of FDis, ultimately contributing to the observed invariable macrophytes productivity along the tested environmental gradients. Our results provide strong evidences that both species and functional composition mediate the cascading effects of environments on macrophytes productivity.