Plant Diversity ›› 2021, Vol. 43 ›› Issue (03): 181-191.DOI: 10.1016/j.pld.2020.09.001

• Articles •     Next Articles

Spatial phylogenetics of two topographic extremes of the Hengduan Mountains in southwestern China and its implications for biodiversity conservation

Yazhou Zhanga,c, Lishen Qiana,c, Daniel Spalinkb, Lu Suna,c, Jianguo Chena, Hang Suna   

  1. a CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, Yunnan, PR China;
    b Department of Ecology and Conservation Biology, Texas A&M University, College Station 77843-2138, TX, USA;
    c University of Chinese Academy of Sciences, Beijing 100049, PR China
  • Received:2020-06-05 Revised:2020-08-30 Published:2021-06-28
  • Contact: Jianguo Chen, Hang Sun
  • Supported by:
    This study was supported equally by the National Key R & D Program of China (2017YFC0505200 to H Sun) and the Major Program of the National Natural Science Foundation of China (31590823 to H Sun), the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA20050203 to H Sun), and USDA National Institute of Food and Agriculture (McIntire Stennis #101869 to DS). We thank XX Zhu, B Xu, XH Li, WG Sun and JH Chen for providing the original distribution data. We would like to thank R Tang and YC Yang for their help with data analysis. Thanks to XG Ma, D Luo and HL Chen for writing advice. We also thank S Christian for his useful suggestions about organizing this study and data analyses.

Abstract: Previous attempts to elucidate the drivers of speciation mechanisms and spatial distribution patterns of biodiversity in mountain regions have treated different floras within a single geological region as one flora, ignoring the potential contributions of high habitat/ecosystem heterogeneity. Furthermore, current conservation strategies largely focus on forest ecosystems and/or specific flagship species, ignoring marginal ecosystems, leaving species in these ecosystems at risk. Here, we compared the spatial patterns of biodiversity and the potential drivers of these patterns in the river valley and subnival ecosystems of the Hengduan Mountains region (HDM) in southwestern China. Specifically, we compared spatial patterns of diversity, endemism, and threatened species in these ecosystems based on both traditional measurements and recent phylogenetic approaches. We then examined how those patterns were related to environmental factors and human activity in these same regions. We found that the middle-southern HDM supports the highest diversity and endemism for the river valley and subnival ecosystems; however, the distribution patterns of neo- and paleo-endemism in these two ecosystems differ. Regression models indicate that habitat diversity and paleo-climatic fluctuation are important drivers of diversity and endemism for these two ecosystems. Temperature and precipitation, however, showed different influences on the spatial patterns in different ecosystems. Categorical analysis of neo- and paleoendemism (CANAPE) indicated that most endemism centers are not covered by current nature reserves. Moreover, the intensity of human activity is highest in the southern and southeastern HDM, which coincides with the distribution patterns of diversity, mixed-endemism and high-priority (and threatened) species. These findings suggest that different floras within a single geographic/floristic region respond differently to environmental factors and show different spatial phylogenetic patterns. We, therefore, recommend that future research into the drivers of biodiversity consider the contributions of various ecosystem types within a single geological region. This study also provides a theoretical basis for protecting habitat diversity. Our work confirms that current conservation efforts are insufficient to protect ecosystem diversity in the river valley and subnival ecosystems of the Hengduan Mountains. Therefore, we recommend the establishment of nature reserves in the regions identified in this study; furthermore, we strongly recommend improving current and establishing new management policies for biodiversity conservation in this region.

Key words: Biodiversity conservation, Human activity, Nature reserves, Plant diversity, Subnival belt, River valley