Abstract
Climate change and overgrazing are accelerating grassland degradation and the concomitant encroachment of poisonous plants worldwide. Effective restoration of degraded grassland and management of poisonous plants rely critically on identifying the ecological thresholds of poisonous plants encroachment, but this information remains uncertain. Here, we analyzed the responses of 20 structural and functional grassland variables to the increasing coverage of poisonous plants across 465 standardized field plots in alpine grasslands on the Qinghai-Tibetan Plateau. Asynchronous responses emerged across ecosystem variables: root productivity declined at 10% poisonous plants coverage, biodiversity decreased at 30%, but soil nutrients increased beyond 50%. In addition, ecosystem multifunctionality and plant–soil network also recovered slightly after 50%. We propose that 50% coverage represents a critical threshold where poisonous plants transition from a driver to a mitigator of degradation. We suggest stage-specific management strategies to mitigate poisonous plants encroachment in grasslands based on these thresholds.
Acknowledgements
This work was supported by the Second Tibetan Plateau Scientific Expedition and Research (STEP) Program (2019QZKK0302-02), the National Natural Science Foundation of China (U21A20183), the Chief Scientist Program of Qinghai Province (2024-SF-101), the Science-based Advisory Program of The Alliance of National and International Science Organizations for the Belt and Road Regions (ANSO-SBA-2023-02), and the Gansu Provincial Science and Technology Key Project (24ZD13NA016). We are grateful to Xiaochun Wang, Haijun Zeng, Lin Ma, Wenyan Li, Xudong Li, Haonan Guo for fieldwork.
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Qi, L., Liu, Y., Huang, M. et al. Ecological thresholds of poisonous plants encroachment in grassland ecosystems of the Qinghai-Tibetan Plateau.
Commun Earth Environ (2026). https://doi.org/10.1038/s43247-026-03581-1
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DOI: https://doi.org/10.1038/s43247-026-03581-1
Source: Ecology - nature.com
