岩溶与非岩溶区不同林分根际土壤微生物及酶活性

Microbial and enzyme activities in rhizosphere soil of different forest stand in karst and non karst areas

【目的】为明确不同地质条件下、不同林分对根际土壤微生物及土壤酶活性的影响,该研究为今后深入探究岩溶自然生态系统的恢复提供理论依据。【方法】本文以云南建水岩溶与非岩溶区人工桉树林、人工云南松林和天然次生林根际土壤为研究对象,通过对根际土壤微生物数量和土壤酶活性的测定,探究不同地质、不同林分对根际土壤微生物及土壤酶活性的影响,及其微生物与土壤酶间的相关性。【结果】本研究表明,在相同地质背景条件下,两种不同人工林土壤中桉树(阔叶林)与云南松(针叶林)放线菌的数量存在显著性差异,天然次生林微生物数量为18.2×10~5cfu/g。受地质条件、植被恢复模式等影响,各样地土壤酶活性各异。相关分析表明,脲酶、过氧化氢酶活性与放线菌数量呈显著正相关,脲酶、酸性磷酸酶、碳酸酐酶、过氧化氢酶4种酶活之间存在相互联系。【结论】土壤微生物群落及土壤物质的转化受地质条件、林分差异和恢复模式的影响。

[Objective] This paper aims to clarify the effects of different forests on soil microorganism and soil enzyme activity under different geological conditions,providing a theoretical basis for further research on restoration of natural ecological system. [Method] The soil samples were collected separately in rhizosphere of Eucalyptus robusta plantation,Pinus yunnanensis plantation and natural secondary forest growing up in karst and non-karst areas of Jianshui,Yunnan of southwestern China. The correlations between microorganisms and soil enzymes from different geological backgrounds and forests were studied by dilution coating and soil enzyme measurement. [Result] The results showed that there was a significant difference between the number of actinomycetes in the rhizosphere soil of E. robusta and P. yunnanensis forests under the same geological background. The microbial quantity of secondary forest in karst area was 18. 2 × 10~5 cfu/g. Generally,influenced by the restoration patterns and geologicalconditions,the activities of soil enzymes were different. Correlation analysis showed that urease and catalase activity were positively correlated with the number of actinomycetes. There were interrelations between urease,acid phosphatase,carbonic anhydrase and catalase. [Conclusion] The results reveal that geological backgrounds,forest stand and the restoration patterns will affect soil microbial community composition and transformation of soil substance.