Chin J Plan Ecolo ›› 2009, Vol. 33 ›› Issue (2): 338-346.DOI: 10.3773/j.issn.1005-264x.2009.02.011

• Research Articles • Previous Articles     Next Articles

SPATIAL HETEROGENEITY OF SOIL RESOURCES OF CARAGANA TIBETICA COMMUNITY

ZHANG Pu-Jin1;YANG Jie1,2*; SONG Bing-Yu1;ZHAO Li-Qing1; QING Hua1,3   

  1. 1School of Life Sciences, lnner Mongolia University, Hohhot 010021, China; 2Sino-US Center for Conservation, Energy and Sustainability Science in Inner Mongolia, Hohhot 010021, China; 3School of Life Sciences, Nanjing University, Nanjing 210093, China
  • Online:2009-03-31 Published:2009-03-31
  • Contact: YANG Jie

Abstract: Aims Caragana tibetica is commonly found in the ecotone between desert steppe and desert of the Inner Mongolian Plateau. It is often used as an indicator species in vegetation regionalization. Due to its dwarf shrub characteristics C. tibetica can easily initiate nebkha (dune) formation in sand-covered habitats. The objective of the paper is to understand C. tibetica ecological adaptability by investigating soil heterogeneity of C. tibetica community.
Methods Nebkhas formed by C. tibetica were classified into three size groups. Small and medium nebkhas corresponded to a development stage, and large nebkhas represented a stable stage. Soil organic mater (SOM), total phosphorus (TP) and water content (Wm) were measured at the top each nebkha, in the middle of the nebkha slope, in the interspace between nebkhas, and under the nebkhas. We then also averaged these properties for each nebkha (mean of top and middle samples)
Important findings Average content of SOM, TP and Wm of nebkhas and the soil underlying them increased with nebkha age. For large and medium nebkhas and the soil underlying them these properties were higher than that in the interspaces between them. Average SOM of small nebkhas was higher than that in the interspace between them. However,average TP and Wm of the soil underlying small nebkhas were lower than in the interspace. At the top and middle of nebkhas of all sizes, SOM and TP first increased and then decreased vertically while Wm decreased gradually. Plant residues content captured by C. tibetica nebkhas increased gradually with nebkha development stage. We conclude that the “fertility island effect” formed inside and below nebkhas increases as nebkhas develop. At the same time, we found that spatial heterogeneity of SOM, TP and Wm is high.