Xiang Xuemei, De Kejia, Lin Weishan, Feng Tingxu, Li Fei, Wei Xijie
College of Animal Husbandry and Veterinary Science, Qinghai University, Xining, Qinghai Province, China.
PLoS One. 2025 Mar 24;20(3):e0319581. doi: 10.1371/journal.pone.0319581. eCollection 2025.
Plant species and functional diversity play an important role in the stability and sustainability of grassland ecosystems. However, the changes and mechanisms of plant species and functional diversity under warming and nitrogen deposition are still unclear. In this study, we investigated the plant and soil characteristics of alpine meadows on the Qinghai-Tibet Plateau to explore the changes in species and functional diversity of plant communities under warming and nitrogen deposition, as well as their interrelationships and key determinants. The results showed that warming, nitrogen deposition, and their interactions had significant effects on plant species diversity (plant Shannon-Wiener index) and functional diversity (functional richness index, functional differentiation index, functional dispersion, and Rao's quadratic entropy index). With the increase of warming and nitrogen deposition, the Shannon-Wiener index of plants increased first and then decreased. The plant functional richness index, functional diversity index, functional dispersion index, and Rao's quadratic entropy index showed a decreasing trend. At the same time, with the increase in temperature and nitrogen deposition, the relationship between plant species diversity index and functional diversity index in the alpine meadow of Qinghai-Tibet Plateau gradually weakened. Redundancy analysis and structural equation modeling showed that both warming and nitrogen deposition had significant negative effects on the plant species diversity index and plant functional diversity index. Plant factors (Grasses importance value, leaf nitrogen weighted mean, specific leaf area-weighted mean, leaf area-weighted mean, and leaf weight weighted mean) and soil environmental factors (soil total nitrogen and soil carbon-nitrogen ratio) directly or indirectly affect plant community diversity under warming and nitrogen deposition.
植物物种和功能多样性在草地生态系统的稳定性和可持续性中发挥着重要作用。然而，在变暖和氮沉降条件下植物物种和功能多样性的变化及机制仍不清楚。在本研究中，我们调查了青藏高原高寒草甸的植物和土壤特征，以探讨变暖和氮沉降条件下植物群落物种和功能多样性的变化，以及它们之间的相互关系和关键决定因素。结果表明，变暖和氮沉降及其相互作用对植物物种多样性（植物香农-威纳指数）和功能多样性（功能丰富度指数、功能分化指数、功能离散度和Rao二次熵指数）有显著影响。随着变暖和氮沉降的增加，植物的香农-威纳指数先增加后降低。植物功能丰富度指数、功能多样性指数、功能离散度指数和Rao二次熵指数呈下降趋势。同时，随着温度和氮沉降的增加，青藏高原高寒草甸植物物种多样性指数与功能多样性指数之间的关系逐渐减弱。冗余分析和结构方程模型表明，变暖和氮沉降对植物物种多样性指数和植物功能多样性指数均有显著负面影响。植物因素（禾本科重要值、叶片氮加权平均值、比叶面积加权平均值、叶面积加权平均值和叶重加权平均值）和土壤环境因素（土壤全氮和土壤碳氮比）在变暖和氮沉降条件下直接或间接影响植物群落多样性。
