Nitrogen in soils beneath 18 65 year old stands of subtropical evergreen broad-leaved forests in Laoshan Mountains in Eastern China
Nitrogen in soils beneath 18 65 year old stands of subtropical evergreen broad-leaved forests in Laoshan Mountains in Eastern China作者机构:Department of Forest Science Anhui Agricultural University Hefei 230036 China
出 版 物:《Journal of Forestry Research》 (林业研究(英文版))
年 卷 期:2011年第22卷第4期
页 面:583-590页
核心收录:
学科分类:09[农学] 0903[农学-农业资源与环境] 090301[农学-土壤学]
基 金:supported by National Natural Science Foundation of China (NSFC Nos. 30771719 and 30471386)
主 题:microbial biomass nitrogen nitrogen availability nitrogenmineralization soil horizon subtropical forest
摘 要:Monitoring of soil nitrogen (N) cycling is useful to assess soil quality and to gauge the sustainability of management practices. We studied net N mineralization, nitrification, and soil N availability in the 0-10 cm and 11-30 cm soil horizons in east China during 2006-2007 using an in situ incubation method in four subtropical evergreen broad-leaved forest stands aged 18-, 36-, 48-, and 65-years. The properties of surface soil and forest floor varied between stand age classes. C:N ratios of surface soil and forest floor decreased, whereas soil total N and total organic C, available P, and soil microbial biomass N increased with stand age. The mineral N pool was small for the young stand and large for the older stands. NO3^--N was less than 30% in all stands. Net rates of N mineralization and nitrification were higher in old stands than jn younger stands, and higher in the 0-10 cm than in the 11-30 cm horizon. The differences were significant between old and young stands (p 〈 0.031) and between soil horizons (p 〈 0.005). Relative nitrification was somewhat low in all forest stands and declined with stand age. N trans- formation seemed to be controlled by soil moisture, soil mierobial biomass N, and forest floor C:N ratio. Our results demonstrate that analyses of N cycling can provide insight into the effects of management disturbances on forest ecosystems.