Chin J Plant Ecol ›› 2007, Vol. 31 ›› Issue (6): 1145-1153.DOI: 10.17521/cjpe.2007.0142

• Research Articles • Previous Articles     Next Articles

DENSITY IN ARTEMISIA ORDOSICA SUCCESSIONAL COMMUNITY IN RESPONSE TO SPATIAL HETEROGENEITY OF SOIL MOISTURE AND ORGANIC MATTER

WANG Hai-Tao, HE Xing-Dong(), GAO Yu-Bao, LU Jian-Guo, XUE Ping-Ping, MA Di   

  1. College of Life Sciences, Nankai University, Tianjin 300071, China
  • Received:2006-07-17 Accepted:2007-05-17 Online:2007-07-17 Published:2007-11-30
  • Contact: HE Xing-Dong

Abstract:

Aims Using environmental spatial heterogeneity to explain the heterogeneity of vegetation is an important issue in ecology. We approached relationships between the spatial heterogeneity of soil moisture, organic matter and densities of Artemisia ordosica and A. frigida in a successional community of A. ordosica. Our objective was to discuss stability mechanisms of the plant community based on changes in spatial heterogeneity.

Methods The study area is located at Tengri Desert (arid zone), which belongs to Alashan League of Inner Mongolia. Our sample plot was 80 m× 80 m, which contained 400 quadrats (4 m×4 m). In every quadrat, we determined soil moisture at 40 cm depth (oven-drying method) and soil organic matter at 0-5 cm top soil (potassium dichromate volumetric method), and recorded density ofA. ordosica and A. frigida. We analyzed densities in response to the spatial heterogeneity of soil moisture and organic matter using statistics and geostatistics.

Important findings The spatial heterogeneities of densities of A. ordosica and A. frigida were related to soil moisture and organic matter at the plot-scale (80 m×80 m). There were a significant positive linear correlation between the heterogeneities of the density ofA. frigida and moisture and a significant positive power cortelation between heterogeneties of the density of A. ordosica and soil organic matter. We suggest that A. ordosica enriched the content of organic matter, thus promoting establishment of A. frigida. Both A. frigida and A. ordosica had clumped distributions, which enhanced soil spatial heterogeneity. Findings indicate a competitive displacement relationship between the two species. Thus, changes of soil spatial heterogeneity are factors in A. ordosica community succession in semi-desert zone.

Key words: Artemisia ordosica, soil moisture, organic matter, spatial heterogeneity, succession of community