Grassland degradation fundamentally reshapes the relationship between biodiversity and ecosystem multifunctionality: shifting it from plant-dominated to increasingly soil microbes mediated, according to a new study led by Prof. YANG Yuanhe from the Institute of Botany, Chinese Academy of Sciences (IBCAS). The findings, published in Nature Plants, provide the first large-scale field evidence that grassland degradation alters biodiversity–multifunctionality relationships across natural ecosystems.
Grasslands, covering nearly 40% of Earth’s land surface, provide critical ecosystem functions such as carbon storage, forage production, and water regulation. However, nearly half of the world’s grasslands are now degraded, largely due to overgrazing and climate change. The Tibetan Plateau hosts the largest and most fragile alpine grasslands on Earth, where moderate degradation has become the most widespread condition. Grassland degradation is typically accompanied by changes in plant and soil microbial communities, which may profoundly reshape the relationships between biodiversity and ecosystem functioning. Yet, it remains unclear whether and how grassland degradation alters the relationship between biodiversity and ecosystem multifunctionality across large-scale natural ecosystems.
To address this gap, the research team conducted an extensive transect survey spanning about 2,600 km across the Tibetan Plateau, covering 44 paired sites of non-degraded and moderately degraded grasslands. They quantified 20 indicators of ecosystem functioning, including plant productivity, water holding capacity, soil carbon, nitrogen and phosphorus pools, and organic matter decomposition. Based on the combination of quadrats survey and amplicon sequencing, they assessed both above- and below-ground biodiversity, including species richness of plant, bacteria, fungi and protists.
The results showed that moderate degradation significantly reduced individual ecosystem functions and multifunctionality, while increased both plant and soil biodiversity. Further analyses revealed that, following degradation, the influence of soil biodiversity on multifunctionality was strengthened, whereas that of plant richness was weakened. These shifts were associated with a decline in the selection and complementarity effects of plant diversity, but a strengthening of microbial complementarity.
These findings highlight the critical role of soil microbial diversity in sustaining ecosystem functioning under degradation. They also suggest that grassland restoration efforts should extend beyond vegetation recovery to prioritize the conservation and rehabilitation of soil microbial communities, thereby providing theoretical guidance for developing microbe-based ecological restoration strategies for degraded grasslands.
Effects of grassland degradation on ecosystem functioning, biodiversity, and the biodiversity–ecosystem multifunctionality relationship (Image by GAO Xiaoxia and BAI Yuxuan)
Grassland degradation fundamentally reshapes the relationship between biodiversity and ecosystem multifunctionality: shifting it from plant-dominated to increasingly soil microbes mediated, according to a new study led by Prof. YANG Yuanhe from the Institute of Botany, Chinese Academy of Sciences (IBCAS). The findings, published in Nature Plants, provide the first large-scale field evidence that grassland degradation alters biodiversity–multifunctionality relationships across natural ecosystems.
Grasslands, covering nearly 40% of Earth’s land surface, provide critical ecosystem functions such as carbon storage, forage production, and water regulation. However, nearly half of the world’s grasslands are now degraded, largely due to overgrazing and climate change. The Tibetan Plateau hosts the largest and most fragile alpine grasslands on Earth, where moderate degradation has become the most widespread condition. Grassland degradation is typically accompanied by changes in plant and soil microbial communities, which may profoundly reshape the relationships between biodiversity and ecosystem functioning. Yet, it remains unclear whether and how grassland degradation alters the relationship between biodiversity and ecosystem multifunctionality across large-scale natural ecosystems.
To address this gap, the research team conducted an extensive transect survey spanning about 2,600 km across the Tibetan Plateau, covering 44 paired sites of non-degraded and moderately degraded grasslands. They quantified 20 indicators of ecosystem functioning, including plant productivity, water holding capacity, soil carbon, nitrogen and phosphorus pools, and organic matter decomposition. Based on the combination of quadrats survey and amplicon sequencing, they assessed both above- and below-ground biodiversity, including species richness of plant, bacteria, fungi and protists.
The results showed that moderate degradation significantly reduced individual ecosystem functions and multifunctionality, while increased both plant and soil biodiversity. Further analyses revealed that, following degradation, the influence of soil biodiversity on multifunctionality was strengthened, whereas that of plant richness was weakened. These shifts were associated with a decline in the selection and complementarity effects of plant diversity, but a strengthening of microbial complementarity.
These findings highlight the critical role of soil microbial diversity in sustaining ecosystem functioning under degradation. They also suggest that grassland restoration efforts should extend beyond vegetation recovery to prioritize the conservation and rehabilitation of soil microbial communities, thereby providing theoretical guidance for developing microbe-based ecological restoration strategies for degraded grasslands.
Effects of grassland degradation on ecosystem functioning, biodiversity, and the biodiversity–ecosystem multifunctionality relationship (Image by GAO Xiaoxia and BAI Yuxuan)