Abstract
Anthropogenic global warming, nitrogen addition, and overgrazing alter plant communities and threaten plant biodiversity, potentially impacting community productivity, especially in sensitive mountain grassland ecosystems. However, it still remains unknown whether the relationship between plant biodiversity and community productivity varies across different anthropogenic influences, and especially how changes in multiple biodiversity facets drive these impacts on productivity. Here, we measured different facets of biodiversity including functional and phylogenetic richness and evenness in mountain grasslands along an environmental gradient of elevation in Yulong Mountain, Yunnan, China. We combined biodiversity metrics in a series of linear mixed‐effect models to determine the most parsimonious predictors for productivity, which was estimated by aboveground biomass in community. We examined how biodiversity–productivity relationships were affected by experimental warming, nitrogen addition, and livestock‐grazing. Species richness, phylogenetic diversity, and single functional traits (leaf nitrogen content, mg/g) represented the most parsimonious combination in these scenarios, supporting a consensus that single‐biodiversity metrics alone cannot fully explain ecosystem function. The biodiversity–productivity relationships were positive and strong, but the effects of treatment on biodiversity–productivity relationship were negligible. Our findings indicate that the strong biodiversity–productivity relationships are consistent in various anthropogenic drivers of environmental change.
Highlights
Anthropogenic impacts such as increasing temperature, higher nitrogen addition, and overgrazing all conspire to cause rapid declines in plant biodiversity worldwide, especially in mountain grassland ecosystems, which naturally elicits concern about the consequences for the maintenance of ecosystem functioning (Chapin et al, 2000; Cingolani, Noy-Meir, & Diaz, 2005; Roth, Kohli, Rihm, & Achermann, 2013; Urban, 2015)
We aimed to answer the following questions: (a) Does phylogenetic and functional diversity outperform traditional richness and evenness regardless of environmental heterogeneity and anthropogenic impacts? (b) Does incorporating intraspecific trait variability enhance the explanatory power of functional diversity? (c) Are biodiversity–productivity relationships comparable in experimental warming, nitrogen addition, and grazing along environmental gradient of elevation in mountain grasslands?
Our results show that phylogenetic and functional diversity alone outperformed traditional biodiversity measures, species richness, and Shannon’s evenness, for explaining variation in productivity
Summary
Anthropogenic impacts such as increasing temperature, higher nitrogen addition, and overgrazing all conspire to cause rapid declines in plant biodiversity worldwide, especially in mountain grassland ecosystems, which naturally elicits concern about the consequences for the maintenance of ecosystem functioning (Chapin et al, 2000; Cingolani, Noy-Meir, & Diaz, 2005; Roth, Kohli, Rihm, & Achermann, 2013; Urban, 2015). Some studies (Liu, Zhang et al, 2015) found that statistical models that combined different biodiversity facets maximally explained the effects of biodiversity loss on ecosystem functioning or services. Biodiversity is a major determinant of ecosystem productivity, the estimation of the biodiversity effect might be confounded by environmental factors and potential drivers of environmental change such as elevated temperature, nitrogen addition, and herbivory (Fridley, 2002; Hooper et al, 2005; Seabloom et al, 2017; Steudel et al, 2012; Tilman, Reich, & Isbell, 2012; Tilman et al, 2014). We used a multimodel comparative approach to assess the relative contribution of single and various combinations of multivariate biodiversity indices, both with and without intraspecific variation, to predict the variance in biomass production after accounting for potential confounding factors including local environmental heterogeneity, warming, fertilizing, and grazing. We aimed to answer the following questions: (a) Does phylogenetic and functional diversity outperform traditional richness and evenness regardless of environmental heterogeneity and anthropogenic impacts? (b) Does incorporating intraspecific trait variability enhance the explanatory power of functional diversity? (c) Are biodiversity–productivity relationships comparable in experimental warming, nitrogen addition, and grazing along environmental gradient of elevation in mountain grasslands?
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
