Chin J Plant Ecol ›› 2008, Vol. 32 ›› Issue (4): 838-847.DOI: 10.3773/j.issn.1005-264x.2008.04.012

• Original article • Previous Articles     Next Articles


HAO Xing-Ming1,2, LI Wei-Hong1,2, and CHEN Ya-Ning1,2,*()   

  1. 1Key Laboratory of Oasis Ecology and Desert Environmental, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China
    2Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China
  • Received:2007-04-25 Accepted:2007-10-30 Online:2008-04-25 Published:2008-07-30
  • Contact: and CHEN Ya-Ning


Aims Intensive utilization of water resources in the Tarim River watershed during the past five decades has reduced flows in a 320-km section in the lower reaches, drying lakes and lowering groundwater levels. This has degraded Populus euphratica forests over large areas, reducing biodiversity and impairing ecosystem structure and function. Our objectives are to study ecological responses of the natural vegetation to changes in the water table and determine the water table depth needed for the survival of desert riparian forest.

Methods We divided water table depths into a gradient of six levels based on annual mean groundwater level and sampled vegetation plots for each of the six levels. We analyzed niche characteristics and species diversity of the primary populations for the six water table levels.

Important findings With an increase of groundwater depth, the niche breadth of plant populations increases approximately monotonically, reaching a maximum at a groundwater depth of 4-6 m, after which the niche breadth decreases. Niche overlap is the smallest and plant species abundance highest at groundwater depth of 4-6 m. The Hill species diversity index showed highest species diversity with groundwater depth of 2-4 m, followed by 4-6 m and then 0-2 m. At groundwater depth > 6 m, diversity is low and the diversity curve becomes smooth. Therefore, to restore the degraded vegetation in the lower reaches of Tarim River, the groundwater depth should be at least 6 m, with 4-6 m in most areas and 2-4 m in some areas near the water course.

Key words: niche breadth, niche overlap, species diversity, groundwater table, lower reaches of Tarim River