油松刺槐混交林土壤生物学特性研究

通过对油松(Pinus tabulaeformis Carr.)、刺槐(Robinia pseudoacacia L．)混交林、油松纯林及刺槐纯林多种土壤微生物种群数量、酶活性及其季节变化的对比分析。结果表明，油松刺槐混交显著改善了林地土壤生物学特性，土壤细菌、真菌和放线菌以及固氮菌、磷细菌、钾细菌的种群数量较纯林均明显增多，土壤质量明显改善。油松刺槐混交提高了土壤过氧化氢酶、脲酶和磷酸酶活性。此外，研究还显示，混交林土壤生物学特性的改变与生长季土壤含水量密切相关。

Study on the Biological Properties of Soil under the Mixed Forests of Pinus tabulaeformis Carr.and Robinia pseudoacacia L.

Many studies have revealed that the impact of artificial forest on the soil chemical, physical and biological properties is the main cause resulting in the reduction of soil fertility. One of the effective measures for controlling the reduction of soil fertility is to afforest the mixed forests or transform the pure forests into the mixed forests. In this paper, the main soil biological properties, such as the populations of soil-inhabiting microorganisms and enzyme activity in soils under the mixed forests of Pinns tabulaeformis Carr. and Robinia pseudoacacia L. , pure forests of Pinus tabulaeformis Carr. and pure forests of Robinia jpseudoacacia L. , are analyzed and compared. The results show that the biological properties of soil under the mixed forests of Pinus tabulaeformis Carr. and Robinia pseudoacacia L. are significantly improved, the populations of bacteria, fun gi, actinomycetes, azotobacter, potassium bacteria and phosphorus bacteria inhabiting in soil under the mixed forests of Pinus tabulaeformis Carr. and Robinia pseudoacacia L. are obviously increased than that under the pure forests, the soil quality is obviously improved, and the activity of catalase, urease and phosphatase is also increased. Moreover, it is revealed that the change of biological properties in soil under the mixed forests is closely related to the soil moisture content during the growth season.