Biodiv Sci ›› 2016, Vol. 24 ›› Issue (4): 389-398.DOI: 10.17520/biods.2015243

Special Issue: 中国西南干旱河谷的植物多样性

• Original Papers • Previous Articles     Next Articles

Spatial patterns and determinants of species richness of alien and native plants in the Nujiang River valley

Yue Xu1, Peng Li1, Ye Liu2, Wanjun Zhang3, Siyu Qin4, Zehao Shen1,*()   

  1. 1 Department of Ecology, College of Urban and Environmental Sciences, Key Laboratory for Earth Surface Processes of the Ministry of Education, Peking University, Beijing 100871.
    2 School of Urban Planning and Design, Shenzhen Graduate School, Peking University, Shenzhen, Guangdong 518055
    3 Beijing Guodaotong Highway Design & Research Institute CO., LTD, Beijing 100053.
    4 Conservation International, 2011 Crystal Drive, Arlington, VA 22202
  • Received:2015-09-14 Accepted:2015-09-14 Online:2016-04-20 Published:2016-05-11
  • Contact: Shen Zehao

Abstract:

Biological invasion has attracted widespread attention because invasive species threaten native biodiversity and weaken ecosystem services. Based on field investigation of vegetation in Nujiang River valley, Northwest Yunnan, we analyzed the spatial patterns of native and invasive species richness, and the effects of topography, climate, and roadside habitat disturbance on the invasive versus native plant species richness. We recorded 26 exotic invasive plant species that belong to 13 families and 21 genera, and 1,145 native plant species, belonging to 158 families and 628 genera. Along the Nujiang River valley, species richness of invasive plants decreased with increasing latitude and altitude, while species richness of native plants increased with increasing latitude, and showed a hump-shaped pattern with elevation. A generalized linear model was used to estimate the roles of roadside disturbance, climate, topography and soil nutrients on the distribution of both native and invasive species richness. Results of hierarchical variation partitioning revealed that roadside habitat disturbance had primary impact on the distribution of two groups of species. Precipitation was the climatic determinant of invasive species diversity, and small-scale topographic factors, especially aspect, mainly affected native species diversity. It is likely that native species became drought-resistant in the evolutionary process while invasive species failed to adapt themselves to the local arid environments due to the short colonization time. This research supports the hypothesis that resource availability is the main factor limiting plant invasion, and highlights the negative effects of human activity on biodiversity. In addition, results of structural equation modelling revealed that native communities aren’t resistant to plant invasion. The negative relationship between invasive and native species richness reflects the different responses of the two group species to environmental factors.

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Key words: invasive species, native species, spatial patterns, climate, human activity