Regional Sustainability ›› 2026, Vol. 7 ›› Issue (2): 100330.doi: 10.1016/j.regsus.2026.100330

• Research article • Previous Articles     Next Articles

Elevational patterns of plant species and phylogenetic diversity in the eastern Pamir Plateau

WEI Susua,b,c,d,e, ZHANG Yuanyuana,b,c,d, TAO Yea,b,c,d,*(), ZHANG Yuea,b,c,d, DAI Linga,b,c,d, Mekhrovar OKHONNIYOZOVf,g, MA Xuexia,b,g, LI Yaominga,b,g, ZHANG Yuanminga,b,c,d   

  1. aChina-Tajikistan Belt and Road Joint Laboratory on Biodiversity Conservation and Sustainable Use, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, China
    bState Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, China
    cXinjiang Field Scientific Observation Research Station of Tianshan Wild Fruit Forest Ecosystem, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Xinyuan, 844900, China
    dXinjiang Key Laboratory of Biodiversity Conservation and Application in Arid Lands, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi, 830011, China
    eCollege of Life Sciences, Shihezi University, Shihezi, 832003, China
    fChina-Taikistan Belt and Road Joint Laboratory on Biodiversity Conservation and Sustainable Use, Dushanbe, 734063, Tajikistan
    gResearch Center for Ecology and Environment of Central Asia (Dushanbe), Dushanbe, 734063, Tajikistan
  • Received:2025-09-04 Revised:2025-11-21 Accepted:2026-02-07 Published:2026-04-30 Online:2026-03-17
  • Contact: * E-mail address: taoye@ms.xjb.ac.cn (TAO Ye).

Abstract:

Mountain ecosystems offer natural gradients for exploring biodiversity patterns; however, the elevational patterns of plant species and phylogenetic diversity in the eastern Pamir Plateau remain poorly understood. As a biogeographical junction of the Central Asian mountain ranges, the eastern Pamir Plateau in China is geographically connected to the main part of the Pamir Plateau in Tajikistan, resulting in significant climatic and topographical heterogeneity and unique regional vegetation communities. In this study, we established 5 elevational transects and 91 plots (1500-4870 m) in the eastern Pamir Plateau to investigate the patterns and environmental drivers of plant diversity at both regional and local spatial scales. We examined diversity patterns and community composition using regression models and community structure analysis and quantified the relative importance of environmental factors using a random forest model. The results showed a distinct differentiation along elevation gradients, with overall plant diversity, herbaceous plant diversity, and phylogenetic diversity index increasing with elevation, whereas woody plant diversity declined. The phylogenetic structure indices (including net relatedness index and nearest taxon index) exhibited heterogeneous elevational responses, indicating that community assembly was jointly driven by environmental filtering and niche differentiation. Soil nutrients, water availability, and temperature were the primary environmental drivers, with soil factors predominantly influencing herbaceous plant diversity, while climatic variables dominated woody plant diversity. These findings demonstrate that plant diversity along elevational gradients of the eastern Pamir Plateau exhibits the characteristic patterns of a unique arid mountain ecosystem, where enhanced soil fertility and moderate moisture at higher elevations partly offset energy limitations, thereby maintaining plant diversity through functional convergence of closely related lineages. This pattern of biodiversity maintenance contrasts with the divergence-driven community assembly processes commonly observed in humid mountain systems. Overall, this study contributes to a better understanding of biodiversity maintenance in the eastern Pamir Plateau. Given its geographical continuity with the Pamir Plateau in Tajikistan, our findings can provide a basis for alpine conservation efforts across arid Central Asia.

Key words: Species diversity, Phylogenetic diversity, Phylogenetic structure, Elevational gradients, Eastern Pamir Plateau