Hu Yu-Kun, Pan Xu, Liu Xu-Yan, Fu Zhi-Xi, Zhang Man-Yin
Beijing Key Laboratory of Wetland Services and Restoration, Institute of Wetland Research, Chinese Academy of Forestry, Beijing, China.
Hengshuihu National Wetland Ecosystem Research Station, Hengshui, China.
Front Plant Sci. 2021 Jun 28;12:658883. doi: 10.3389/fpls.2021.658883. eCollection 2021.
Plant functional composition, defined by both community-weighted mean (CWM) traits and functional diversity, can provide insights into plant ecological strategies and community assembly. However, our understanding of plant functional composition during succession is largely based on aboveground traits. Here we investigated community-level traits and functional diversity for six pairs of analogous leaf and fine root traits of understory plants in a temperate forest swamp during succession with a decrease in soil pH and nutrient availability. CWMs of traits related to resource acquisition (including specific leaf area, specific root length, leaf N, leaf P, root N, and root P) decreased with succession, whereas those related to resource conservation (leaf dry matter content, root dry matter content, leaf tissue density, leaf C, and root C) increased along the forest swamp successional gradient. Multi-trait functional dispersion (FDis) of both leaf and fine root traits tended to decrease along the successional gradient, but functional richness and evenness were highest at the middle successional stage. Moreover, FDis of individual plant traits except N showed the same pattern as multi-trait FDis. Soil pH and nutrient availability were the main drivers of successional changes in both CWM traits and FDis. The changes of community-level traits along succession indicated a shift from acquisitive to conservative strategy of understory plants during forest swamp succession. Similar trends in leaf and fine root functional diversity along succession may indicate above- and belowground functional diversity are coordinated during the processes of plant community assembly. These findings of linkages between above- and belowground plant functional composition have important implications for plant community dynamics and assembly rules.
由群落加权平均（CWM）性状和功能多样性所定义的植物功能组成，能够为植物生态策略和群落构建提供见解。然而，我们对演替过程中植物功能组成的理解很大程度上基于地上性状。在此，我们调查了温带森林沼泽演替过程中林下植物六对类似叶片和细根性状的群落水平性状及功能多样性，该过程伴随着土壤pH值和养分有效性的降低。与资源获取相关的性状（包括比叶面积、比根长、叶片氮、叶片磷、根氮和根磷）的CWM值随演替而降低，而与资源保守相关的性状（叶片干物质含量、根干物质含量、叶片组织密度、叶片碳和根碳）则沿森林沼泽演替梯度增加。叶片和细根性状的多性状功能离散度（FDis）均沿演替梯度趋于降低，但功能丰富度和均匀度在演替中期最高。此外，除氮以外的个体植物性状的FDis呈现出与多性状FDis相同的模式。土壤pH值和养分有效性是CWM性状和FDis演替变化的主要驱动因素。群落水平性状沿演替过程的变化表明，在森林沼泽演替过程中，林下植物从获取性策略向保守性策略转变。沿演替过程叶片和细根功能多样性的相似趋势可能表明，在植物群落构建过程中，地上和地下功能多样性是协调一致的。这些关于地上和地下植物功能组成之间联系的发现，对植物群落动态和组装规则具有重要意义。
