巨桉人工林根际可培养土壤微生物数量的季节变化

巨桉人工林生态系统根际与根外可培养土壤微生物数量季节变化研究表明,根际与根外细菌和放线菌季节变化规律基本一致,都表现为秋季显著高于冬季,而真菌数量季节之间差异不显著;巨桉人工林土壤微生物具有明显的根际效应(R/S值为1.40),各季节根际土壤细菌、真菌和放线菌的数量显著高于根外;巨桉人工林根际土壤好气性细菌、真菌数量显著高于毗邻青冈次生林,根际土壤有效养分指标大多显著或极显著高于青冈次生林;根际土壤微生物与根际土壤养分之间存在密切的关系,根际土壤有机质、水解N、速效P与根际土壤微生物数量都呈极显著正相关。

Seasonal Variation of Rhizosphere Culturable Soil Microorganism Quantity in Eucalyptus grandis Plantation Ecosystem

Researches were conducted on seasonal dynamics of rhizosphere and non-rhizosphere culturable soil microorganism quantity in Eucalyptus grandis plantation ecosystem.The result showed that the seasonal dynamics of rhizosphere and non-rhizosphere soil bacteria and actinomyces was generally consistent,which in autumn was significantly higher than in winter,while the fungus quantity was no significant difference between seasons.Soil microorganism in Eucalyptus grandis plantation had an obvious rhizosphere effect（R/S value of 1.40）,rhizospheric soil bacteria,fungi and actinomyces quantity were significantly higher than the non-rhizospheric in each season.Rhizosphere aerobic bacteria and fungi quantity of Eucalyptus grandis were significantly higher,rhizosphere soil nutrient index was also mostly better than secondary Cyclobalanopsis glauca forest,and many nutrient indicators reached significant difference.There was a close relationship between rhizosphere microorganisms and rhizosphere soil nutrients,and rhizospheric soil organic matter,hydrolysis N,available P and rhizosphere soil microorganism quantity had a very significant positive correlation.