摘要
Drought can greatly impact the biodiversity of an ecosystem and play a crucial role in regulating its functioning.However,the specific mechanisms by which drought mediate the biodiversity effect(BE)on community biomass in above-and belowground through functional traits remain poorly understood.Here,we conducted a common garden experiment in a greenhouse,which included two plant species richness levels and two water addition levels,to analyze the effects of biodiversity on aboveground biomass(AGB),belowground biomass(BGB)and total biomass(TB),and to quantify the relationship between BEs and functional traits under drought conditions.Our analysis focused on partitioning BEs into above-and belowground complementarity effect(CE)and selection effect(SE)at the species level,which allowed us to better understand the impacts of biodiversity on community biomass and the underlying mechanisms.Our results showed that plant species richness stimulated AGB,BGB and TB through CEs.Drought decreased AGB,BGB and TB,simultaneously.In addition,the aboveground CE was positively associated with the variation in plant height.SEs in above-and belowground were negatively correlated with the community mean plant height and root length,respectively.Furthermore,drought weakened the aboveground CE by decreasing variation in plant height,resulting in a reduction in AGB and TB.Our findings demonstrate that the complementarity of species is an important regulator of community biomass in above-and belowground,the dynamics of biomass under environmental stress are associated with the response of sensitive compartments.
干旱可以显著地影响生态系统的生物多样性,并在调节生态系统功能方面发挥关键作用。然而,目前学术界尚不清楚干旱通过功能性状调节生物多样性对地上和地下部分群落生物量影响的特定机制。本研究设计了一个温室同质园试验,设置了两个植物物种丰富度水平和两个水分添加水平处理,分析了干旱条件下生物多样性对地上、地下和总生物量的影响,并量化了生物多样性效应与功能性状之间的关系。我们的分析侧重于在物种水平上将生物多样性效应划分为地上和地下的互补效应和选择效应,从而更好地理解生物多样性对群落生物量的影响及其潜在机制。结果表明,植物物种丰富度通过互补效应增加了地上、地下和总生物量,而干旱同时降低了植物地上、地下和总生物量。此外,地上互补效应与株高变异呈显著正相关,而地上和地下的选择效应分别与群落平均株高和根长呈负相关。干旱通过降低株高变异减弱了地上互补效应,导致地上生物量和总生物量减少。研究进一步表明,物种的互补性是群落地上和地下生物量的重要调节因子,环境胁迫下的生物量动态与敏感部分的响应有关。
基金
supported by the Natural Science Foundation of Beijing Municipality(5232006)
the Beijing Academy of Agriculture and Forestry Sciences Special Project on Hi-Tech Innovation Capacity(QNJJ202217 and KJCX20230305).
