Plant Diversity ›› 2022, Vol. 44 ›› Issue (03): 231-242.DOI: 10.1016/j.pld.2021.09.001

• Articles •    

Diversity patterns of cushion plants on the Qinghai-Tibet Plateau: A basic study for future conservation efforts on alpine ecosystems

Ya-Zhou Zhanga,b, Li-Shen Qiana,b,c, Xu-Fang Chena,b, Lu Suna,b, Hang Suna, Jian-Guo Chena   

  1. a Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, Yunnan, China;
    b University of Chinese Academy of Sciences, Beijing, China;
    c School of Life Sciences, Yunnan University, Kunming, Yunnan, China
  • Received:2021-05-13 Revised:2021-08-25 Published:2022-06-21
  • Contact: Hang Sun,;Jian-Guo Chen,
  • Supported by:
    This study was supported by grants from the Second Tibetan Plateau Scientific Expedition and Research (STEP) program (2019QZKK0502), the Strategic Priority Research Program of Chinese Academy of Sciences (XDA20050203), the Key Projects of the Joint Fund of the National Natural Science Foundation of China (U1802232) and the Yunnan Applied Basic Research Project (202001AT070060).

Abstract: The Qinghai-Tibet Plateau (QTP) is an important cushion plant hotspot. However, the distribution of cushion plants on the QTP is unknown, as are the factors that drive cushion plant distribution, limiting our understanding of the evolution of cushion species in the region. In this study, we assessed spatial patterns of total cushion plant diversity (including taxonomic and phylogenetic) over the entire QTP and compared patterns of diversity of cushion plants with different typologies (i.e., compact vs. loose). We also examined how these patterns were related to climatic features. Our results indicate that the southern QTP hosts the highest total cushion plant richness, especially in the south-central Hengduan Mountains subregion. The total number of cushion species declines from south to north and from southeast to northwest. Compact cushion plants exhibit similar patterns as the total cushion plant richness, whereas loose cushion plants show random distribution. Cushion plant phylogenetic diversity showed a similar pattern as that of the total cushion plant richness. In addition, cushion plant phylogenetic community structure was clustered in the eastern and southwestern QTP, whereas random or overdispersed in other areas. Climatic features represented by annual energy and water trends, seasonality and extreme environmental factors, had significant effects on cushion plant diversity patterns but limited effects on the phylogenetic community structure, suggesting that climatic features indeed promote the formation of cushion plants. Because cushion plants play vital roles in alpine ecosystems, our findings not only promote our understanding of the evolution and formation of alpine cushion plant diversity but also provide an indispensable foundation for future studies on cushion plant functions and thus alpine ecosystem sustainability in the entire QTP region.

Key words: Climatic features, Cushion distribution, Ecosystem engineer, Hengduan mountains, Phylogenetic diversity, Phylogenetic community structure