Biodiversity, environmental context and structural attributes as drivers of aboveground biomass in shrublands at the middle and lower reaches of the Yellow River basin

• Published in: The Science of the total environment Vol. 774; p. 145198
• Main Authors: Yi, Shijie, Wu, Pan, Peng, Xiqiang, Tang, Zhiyao, Bai, Fenghua, Sun, Xinke, Gao, Yanan, Qin, Huiying, Yu, Xiaona, Wang, Renqing, Du, Ning, Guo, Weihua
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 20.06.2021
• Subjects: aboveground biomass; atmospheric precipitation; basins; Biodiversity; Biomass; community structure; Ecosystem; Ecosystem functioning; environmental factors; Forests; Functional identity; habitats; Piecewise structural equation modelling; Rivers; Selection effect; shrublands; soil; Spatial scale; species richness; specific leaf area; Water availability; water conservation; watersheds; Yellow River; Yellow River; Functional identity; Piecewise structural equation modelling; Selection effect; Ecosystem functioning; Spatial scale; Water availability
• ISSN: 0048-9697; 1879-1026; 1879-1026
• DOI: 10.1016/j.scitotenv.2021.145198

Biodiversity–biomass relationships have been debated for decades and remain subject to controversy. Understanding the relationship between biodiversity and biomass will be crucial for soil and water conservation of the whole basin of the Yellow River. The positive effects of biodiversity on aboveground biomass are altered via two fundamental mechanisms—niche complementarity and selection effects—and are modulated by environmental context and community structure in natural communities. Most studies of biodiversity–biomass relationships have focused on grasslands and forests, rather than on shrublands. We combine multiple biotic variables (biodiversity, functional identity and community structural attributes) and environmental context with aboveground biomass across shrubland habitat types (temperate hilly, temperate montane and subtropical montane) at neighbourhood and community spatial scales, to evaluate the effects of these factors on shrubland aboveground biomass, in the Yellow River basin. We found aboveground biomass was influenced primarily by the community-weighted mean plant maximum height, followed by species richness and community-weighted mean specific leaf area. Furthermore, individual plant size inequality, mean annual precipitation and water availability either directly or indirectly influenced aboveground biomass. The biodiversity–aboveground biomass relationship was stronger at the broader spatial scale. Thus, our findings indicate that both niche complementarity and selection effects shape the effects of biodiversity on shrubland aboveground biomass, although selection effects are more important. Moreover, they indicate that water is the most important environmental factor for determining aboveground biomass, and suggest that community structure and spatial scale could influence shrubland aboveground biomass and its response to biodiversity. [Display omitted] •The selection effect is more crucial for driving shrubland aboveground biomass than the niche complementarity effect.•Water availability and shrubland structural complexity enhance aboveground biomass and its response to biodiversity.•The effect of biodiversity on shrubland aboveground biomass is stronger at broader scale.