Functional Groups Dominate Aboveground Net Primary Production under Long-Term Nutrient Additions in a Tibetan Alpine Meadow

• Published in: Plants (Basel) Vol. 13; no. 3; p. 344
• Main Authors: Chen, Xueying, Hou, Ge, Shi, Peili, Zong, Ning, Yu, Jialuo
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 23.01.2024
• Subjects: Alpine ecosystems; alpine grasslands; alpine meadows; ANPP; Anthropogenic factors; Biodiversity; China; Ecological effects; Ecological research; Environmental aspects; field experimentation; Forbs; functional diversity; Functional groups; global change; Grasses; Grasslands; Investigations; Legumes; Meadows; Net Primary Productivity; Nitrogen; Northern Tibetan alpine meadow; nutrient additions; Nutrient release; Nutrients; Phosphorus; Primary production; Primary productivity (Biology); Productivity; Species diversity; Species richness; Structure-function relationships; Terrestrial ecosystems; China; Tibetan Plateau; functional diversity; functional groups; species diversity; ANPP; Northern Tibetan alpine meadow; nutrient additions
• DOI: 10.3390/plants13030344
• ISSN: 2223-7747

Anthropogenic nutrient additions are influencing the structure and function of alpine grassland ecosystems. However, the underlying mechanisms of the direct and indirect effects of nutrient additions on aboveground net primary productivity (ANPP) are not well understood. In this study, we conducted an eight-year field experiment to explore the ecological consequences of nitrogen (N) and/or phosphorous (P) additions on the northern Tibetan Plateau. ANPP, species diversity, functional diversity, and functional groups were used to assess species’ responses to increasing nutrients. Our results showed that nutrient additions significantly increased ANPP due to the release in nutrient limitations. Although N addition had a significant effect on species richness and functional richness, and P and N + P additions altered functional diversity, it was functional groups rather than biodiversity that drove changes in ANPP in the indirect pathways. We identified the important roles of N and P additions in begetting the dominance of grasses and forbs, respectively. The study highlights that the shift of functional groups should be taken into consideration to better predict the structure, function, and biodiversity–ANPP relationship in grasslands, particularly under future multifaceted global change.