Abstract:

Due to adaptive to the infertile habitat,Acacia mangium is widely planted as pioneer species in tropical and south subtropical regions in China.In order to understand the soil fertilities changes in A.mangium plantation,the soil physical and chemical properties and enzyme activities with different age classes were studied.The results showed that with the stand age increases,soil water-stable aggregate,non-capillary porosity,capillary porosity,maximum moisture capacity,minimum moisture capacity and field moisture capacity of A.mangium plantation increased,there was similar tendency changes on the content of soil humus(humic acid and fulvic acid),total N,hydrolyzable N,total P,available P,and the activities of catalase,urease,protease and acid phosphatase,but the rate of structure destroy and density of soil were in reverse trend.Enzyme activities in soil were closed related to soil fertilities,it could also be used as an evaluation index of soil fertility.Therefore,the A.mangium plantation could significantly improve soil structure and moisture condition,improve the content of soil organic matter and nutrients,prevent soil degradation and protect eco-environment,which was advantageous to the sustainable development of forestry.

Key words: Acacia mangium plantation, soil moisture-physical properties, soil chemical properties, soil enzyme activity