Chin J Plan Ecolo ›› 2017, Vol. 41 ›› Issue (2): 165-174.DOI: 10.17521/cjpe.2015.0448

• Research Articles • Previous Articles     Next Articles

Population structure and spatial pattern of Caragana tibetica communities in Nei Mongol shrub-encroached grassland

Pu-Jin ZHANG1,2,3, Hua QING4, Lei ZHANG5, Yan-Da XU6, Lan MU1,2, Ru-Han YE1,2, Xiao QIU1,2, Hong Chang1,2, Hai-Hua SHEN3, Jie YANG4,*()   

  1. 1Inner Mongolia Academy of Agricultural and Animal Husbandry Sciences, Hohhot 010031, China

    2 Inner Mongolia Prataculture Research Center, Chinese Academy of Sciences, Hohhot 010031, China

    3State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China

    4School of Ecology and Environment, Inner Mongolia University, Hohhot 010021, China

    5Inner Mongolia Academy of Forestry Sciences, Hohhot 010010, China

    6State Environmental Protection Key Laboratory of Regional Ecological Processes and Functions Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012
  • Received:2015-12-07 Accepted:2016-09-21 Online:2017-02-10 Published:2017-03-16
  • Contact: Jie YANG
  • About author:

    KANG Jing-yao(1991-), E-mail: kangjingyao_nj@163.com

Abstract:

Aims The community structure and function of the shrub-encroached grassland, as well as its formation mechanism, is one of hot scientific problems in vegetation science. The spatial pattern analysis is an important means for studying plant population interactions and the relationships between plant population and environment. The shrub-encroached grassland is one major vegetation type in Nei Mongol. Knowledge on the spatial pattern of shrub can improve our understanding on adaptive characteristics of shrub to steppe environment.
Methods We chose Caragana tibetica encroached grassland distributed in Ordos City as research objects. The spatial position of each C. tibetica individual in 64 m × 64 m study plot was determined by a method of “three-distance location method”, and then the spatial pattern and intraspecific associations of C. tibetica individuals was analyzed with the point pattern analysis.
Important findings The results showed that C. tibetica population was at the rising stage. The mature individuals showed a uniform distribution at the scale of less than 3.7 m, subsequently exhibiting a random distribution with an increased scale. The juvenile individuals showed an aggregation distribution at the scale of 0.3-20.4 m, but a uniform distribution at other scales. The dead C. tibetica individuals were distributed aggregately at the scale from 0.7 to 1.4 m, but randomly at other scales. An indistinctive positive association was found for live C. tibetica individuals to dead individuals at the scale of less than 9.9 m, but no associations was found between them at other scales. The mature individuals negatively interacted with juveniles at the scale of larger than 2.2 m, but unassociated at the other scales.

Key words: shrub-encroached grassland, Caragana tibetica, point pattern, spatial distribution pattern