State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; China National Botanical Garden, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 100049, China.
State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; China National Botanical Garden, Beijing 100093, China; Key Laboratory of Vegetation Ecology of Ministry of Education, Institute of Grassland Science, Northeast Normal University, Changchun 130024, Jilin, China.
Sci Total Environ. 2023 Aug 20;887:164158. doi: 10.1016/j.scitotenv.2023.164158. Epub 2023 May 13.
Ecosystem functioning plays a crucial role in maintaining human welfare. Terrestrial ecosystems provide multiple ecosystem services simultaneously, such as carbon sequestration, nutrient cycling, water purification, and biodiversity conservation, known as ecosystem multifunctionality (EMF). However, the mechanisms by which biotic and abiotic factors, and their interactions regulate EMF in grasslands are unclear. We conducted a transect survey to illustrate the single and combined effects of biotic factors (including plant species diversity, trait-based functional diversity, community-weighted mean (CWM) of traits, and soil microbial diversity) and abiotic factors (including climate and soil) on EMF. Eight functions were investigated, including aboveground living biomass and litter biomass, soil bacterial biomass, fungal biomass, arbuscular mycorrhizal fungi biomass, and soil organic carbon storage, total carbon storage and total nitrogen storage. We detected a significant interactive effect between plant species diversity and soil microbial diversity on the EMF; Structural equation model showed that soil microbial diversity indirectly affected EMF by regulating plant species diversity. These findings highlight the importance of the interaction effect of above- and below-ground diversity on EMF. Both plant species diversity and functional diversity had similar explanatory power for the variation in EMF, implying that niche differentiation and multifunctional complementarity among plant species and traits are essential in regulating the EMF. Furthermore, the effects of abiotic factors on EMF were stronger than those of biotic factors via direct and indirect pathways affecting above- and below-ground biodiversity. As a dominant regulator, the soil sand content was negatively correlated with EMF. These findings indicate the vital role of abiotic mechanisms in affecting EMF, and deepen our understanding of the single and combined effects of biotic and abiotic factors on EMF. We conclude that soil texture and plant diversity, representing crucial abiotic and biotic factors, respectively, are important determinants of the EMF of grasslands.
生态系统功能对维持人类福祉起着至关重要的作用。陆地生态系统同时提供多种生态系统服务，如碳固存、养分循环、水净化和生物多样性保护，这些服务被称为生态系统多功能性（EMF）。然而，生物和非生物因素及其相互作用调节草原 EMF 的机制尚不清楚。我们进行了一个沿横断面的调查，以说明生物因素（包括植物物种多样性、基于性状的功能多样性、性状的群落加权均值（CWM）和土壤微生物多样性）和非生物因素（包括气候和土壤）对 EMF 的单一和综合影响。我们研究了包括地上生物量和凋落物生物量、土壤细菌生物量、真菌生物量、丛枝菌根真菌生物量以及土壤有机碳储量、总碳储量和总氮储量在内的 8 种功能。我们检测到植物物种多样性和土壤微生物多样性对 EMF 存在显著的交互作用；结构方程模型表明，土壤微生物多样性通过调节植物物种多样性间接影响 EMF。这些发现强调了地上和地下多样性相互作用对 EMF 的重要性。植物物种多样性和功能多样性对 EMF 的变异都具有相似的解释能力，这表明植物物种和性状之间的生态位分化和多功能互补是调节 EMF 的关键。此外，通过直接和间接途径影响地上和地下生物多样性，非生物因素对 EMF 的影响大于生物因素。作为一个主要的调节因子，土壤砂含量与 EMF 呈负相关。这些发现表明，非生物机制在影响 EMF 中起着至关重要的作用，并且加深了我们对生物和非生物因素对 EMF 的单一和综合影响的理解。我们得出结论，土壤质地和植物多样性分别代表关键的生物和非生物因素，是草原 EMF 的重要决定因素。
