Chin J Plant Ecol ›› 2008, Vol. 32 ›› Issue (3): 574-581.DOI: 10.3773/j.issn.1005-264x.2008.03.006

• Original article • Previous Articles     Next Articles

ALTITUDINAL PATTERN OF SPECIES DIVERSITY IN WOODY PLANT COMMUNITIES OF MOUNTAIN HELAN, NORTHWESTERN CHINA

ZHU Yuan1(), KANG Mu-Yi1,*(), JIANG Yuan1, LIU Quan-Ru2   

  1. 1College of Resources Science and Technology, China Ecological Capital Assessment Research Center, Beijing Normal University; State Key Laboratory of Earth Surface Processes and Resource Ecology (Beijing Normal University), Beijing 100875, China
    2College of Life Sciences, Beijing Normal University, Beijing 100875, China
  • Received:2007-03-09 Accepted:2007-11-21 Online:2008-03-09 Published:2008-05-30
  • Contact: KANG Mu-Yi

Abstract:

Aims Our objective was to reveal the altitudinal pattern of species diversity in woody plant communities of Mountain Helan, which is located on the ecotone between temperate steppe and desert regions in arid northwestern China.

Methods We surveyed forests and shrublands with the quadrat method and used Generalized additive model (GAM) to model relationships between species richness of tree, shrub and herbaceous layers with altitude.

Important findings Altitude accounted for 30%-40% of the variances of species richness patterns, including tree, shrub, herb and total species richness. Both for forest and shrubland communities, 60%-80% of the species were herbaceous and patterns of total species richness with altitude were almost determined by herbaceous species. In forest communities, species richness of the tree layer peaked at middle altitude, because of favorable precipitation and temperature. Species richness of shrub and herbaceous layers in forest communities decreased with altitude, showing a significant influence of forest canopy cover. For shrub communities, species richness of shrub and herb layers also peaked at middle altitude. Aridity at low altitude and cold at high altitude limited species' survival, and only at middle elevations could coexist large numbers of plant species.

Key words: species richness, forest communities, shrub communities, generalized additive model, altitudinal pattern