不同退耕还林模式对土壤生物学性质的影响效果评价

在测定土壤微生物、土壤酶活性基础上,应用主成分因子分析法建立了不同退耕还林模式下的土壤生物学性质评价体系。结果表明,土壤放线菌、真菌数量与转化酶、脲酶、纤维素酶、过氧化氢酶活性之间的相关性达到了极显著或显著水平优势微生物中的微球菌与转化酶,芽孢杆菌与纤维素酶,木霉和游动放线菌与过氧化氢酶,酵母菌与脲酶呈显著正相关关系放线菌、真菌及其微生物优势类群多样性指标在评价土壤生物学肥力质量时具有十分重要的作用4种土壤酶活性是土壤生物学肥力质量评价的重要指标而细菌、酵母等生物量较小的微生物对土壤生态肥力评价的贡献较小。用土壤综合肥力指标值(IFI)进一步评价各样地的土壤生物学肥力质量的顺序依次为:苦竹林表层>桦木林表层>农耕地表层>农耕地亚表层>农耕地深层>桦木和苦竹林亚表层>桦木林深层>苦竹林深层。苦竹对退耕地的生态改善效果,如水土保持、水源涵养和土壤生态肥力的增加等方面要优于桦木。

Evaluation on Effect of Grain-for-Green Models on Soil Biological Properties

Based on the determination of soil microbes and soil enzyme activities,principle component factor analysis was used to build a soil biological properties' effect evaluation system under different models of Grain-for-Green.The results showed that the correlations of the amount of actinomycetes and fungi were significant or very significant with the activities of invertase,urease,cellulose and catalase.The correlations between the dominant microbes and the enzyme activities,including Micrococcus and invertase,Bacillus and ce11u1ase,Trichoderma and catalase,Actinoplanes and catalase,Saccharomyces and urease were positively significant.It indicated that the diversity indices of actinomycetes' and fungal dominant groups were very important to evaluate the soil fertility,as well as the four soil enzymes activities.But bacteria and yeast which had little biomass were less important.The integrated fertility index(IFI)was used to evaluate the plots quality of soil biological fertility.The study indicated that the soil fertility could be ranked as follows:the surface of Pleiohlastus amarus forest>the surface of Betula Luminifera forest>the surface of cropland>the subsurface of cropland>the deep cropland>the subsurface of B.Luminifera forest and P.amarus forest the deep B.Luminifera forest>the deep P.amarus forest. It stated that the ecological improvement of P.amarus forest was better than that of B.Luminifera forest.