Chin J Plan Ecolo ›› 2016, Vol. 40 ›› Issue (6): 554-563.DOI: 10.17521/cjpe.2015.0446

• Research Articles • Previous Articles     Next Articles

Effects of exclosure on community inter-specific relationships in a typical temperate grassland

Rong GONG1,2, Qiong GAO1,2,*(), Ya-Lin WANG1,2   

  1. 1State Key Laboratory of Earth Surface Processes and Resource Ecology, Beijing Normal University, Beijing 100875, China

    2Academy of Disaster Reduction and Emergency, Beijing Normal University, Beijing 100875, China
  • Received:2015-12-07 Accepted:2016-04-23 Online:2016-06-30 Published:2016-06-15
  • Contact: Qiong GAO

Abstract:

Aims This study aimed to understand the impact of exclosure on interspecific associations of species in a typical temperate grassland. We compared the species associations of dominant and companion species in grassland plots with the six-year exclosure and grazing in Taips County, Nei Mongol.Methods We selected 14 species according to important values in each plot, using variance ratio to analyze the overall association. The χ2 test with 2 × 2 contingency table, Ochiai index and spearman rank correlation test were applied to analyze the inter-specific associations of dominant and companion species. We used the niche breadth index to analyze the ability of resource utilization of species and inter-specific competition for grazed plots and ones with exclosure.Important findings The inter-specific associations among 91 species pairs inside the exclosure showed that nine species pairs were significantly positive but 4 pairs were negative based on the χ2 test with 2 × 2 contingency table. Ten species pairs had significantly positive correlations and 16 species pairs were negative through the Spearman correlation test. For the plots outside the exclosure, we found 19 species pairs were positively associated but 8 pairs were negative associated using the χ2 test, and 12 species pairs were significantly positively correlated but 30 pairs were negatively correlated using the Spearman correlation test. The results indicated that the community inside the exclosure was in a continuous development state while the outside community was degradating. The Ochiai indices of dominant species were high both inside and outside the exclosure but the differences using the χ2test were nonsignificant. It implied that there was some connection among dominant species but their patterns of distribution were relatively independent. The niche breadth for dominant species inside the exclosure was higher than ones outside, which suggested the exclosure has an important role in protecting dominant species.

Key words: exclosure, importance value, interspecific association, niche breadth, resources utilization