金沙江干热峡谷中退化的土壤生态系统生物学特征初探

Distribution characteristics of soil animals,microorganisms and enzymatic activity were studied in the dry red soil and Vertisol ecosystems with different degradation degrees in the Yuanmou dry hot valley of the Jinsha River,China.Results showed that Hymenoptera,Araneae and Collembola were the dominant groups of soil animals in the polts studied.The numbers of groups and individuals and density of soil animals in the dry red soil series were higher than those in the Vertisol series,and the numbers of individuals and density of soil animals decreased with the degree of soil degradation.Bacteria dominated microbiococnosis not only in the dry red soils but also in the Vertisols.Microbial numbers of the dry red soil series were higher than those of Vertisol series,and decreased with the degree of soil degradation.The activities of catalase,invertase,urease and alkaline phosphatase declined with the degradation degree and showed a significant decline with depth in the profiles of both the dry red soils and the Vertisols,but activities of polyphenol oxidase and acid and neutral phosphatase showed the same tendencies only in the Vertisols.It was concluded that the characteristics of soil animals,microorganisms and enzymatic activity could be used as the bio-indicators to show the degradation degree of the dry red soils and Vertisols.Correlation among these soil bio-indicators was highly significant.

Preliminary study on biological characteristics of degraded soil ecosystems in dry hot valley of the Jinsha River

Distribution characteristics of soil animals, microorganisms and enzymatic activity were studied in thedry red soil and Vertisol ecosystems with different degradation degrees in the Yuanmou dry hot valley of theJinsha River, China. Results showed that Hymenoptera, Araneae and Collembola were the dominant groupsof soil animals in the plots studied. The numbers of groups and individuals and density of soil animals in thedry red soil series were higher than those in the Vertisol series, and the numbers of individuals and density ofsoil animals decreased with the degree of soil degradation. Bacteria dominated microbiocoenosis not only inthe dry red soils but also in the Vertisols. Microbial numbers of the dry red soil series were higher than thoseof Vertisol series, and decreased with the degree of soil degradation. The activities of catalase, invertase,urease and alkaline phosphatase declined with the degradation degree and showed a significant decline withdepth in the profiles of both the dry red soils and the Vertisols, but activities of polyphenol oxidase andacid and neutral phosphatase showed the same tendencies only in the Vertisols. It was concluded that thecharacteristics of soil animals, microorganisms and enzymatic activity could be used as the bio-indicators toshow the degradation degree of the dry red soils and Vertisols. Correlation among these soil bio-indicatorswas highly significant.