不同林龄麻疯树林地土壤细菌分布特征

通过现场采样,室内培养、观察、测定,对3种林龄麻疯树林地土壤细菌数量的生态分布、类群动态特征以及与相关土壤养分的关系进行了比较分析。结果表明:不同林龄土壤细菌数量由多到少依次为1～10年生、越来越少,组成也发生了改变。不同土壤养分对细菌的影响不同,全钾、有效氮、有效钾、有效磷与细菌数量呈极显著的正相关,全氮与细菌数量呈显著的正相关,全磷与细菌数量相关性不显著,有机质与细菌数量呈极显著的负相关。

Distribution Characteristics of Soil Bacteria in Jatropha curcas Forests of Different Ages

Ecological distribution of soil bacteria quantity and dynamic characteristics of ecological groups in the soil of Jatropha curcas forests of three different ages were analyzed through field sampling,indoor cultivation,observation,and determination.The correlations between soil bacteria quantity and nutrient contents were analyzed.Results indicated that the soil bacteria quantity in the 1 to 10-year-old forests was the highest,followed by 11 to 20-year-old forest and 21 to 30-year-old forest,and there was a significant difference between the forests.The soil bacteria exhibited an obvious vertical distribution pattern,and the soil bacteria quantity in 10-15cm soil layer was the highest and that in 25-30cm soil layer was the lowest.A total of 37 ecological groups of bacteria were identified in the forests of different ages.The bacterial species decreased and the bacteria composition changed with increasing forest age.Different soil nutrients had various influences on the bacteria.There were highly significant positive correlations between total potassium,effective nitrogen,effective potassium,effective phosphorus and bacteria quantity,a significant positive correlation between total nitrogen and bacteria quantity,an insignificant correlation between total phosphorus and bacterial quantity,and a highly significant negative correlation between organic matter content and bacteria quantity.