Dynamics of soil inorganic nitrogen and their responses to nitrogen additions in three subtropical forests, south China

作     者：FANG Yun-ting ZHU Wei-xing MO Jiang-ming ZHOU Guo-yi GUNDERSEN Per 

作者机构：Dinghushan Forest Ecosystem Research Station South China Botanical Garden Chinese Academy of Sciences Zhaoqing 526070 China Biological Sciences Binghamton University-SUNY Binghamton NY 13902-6000 USA Forest and Landscape DenmarkHoersholm Kongevej 11 2970 Denmark The Graduate School of the Chinese Academy of Sciences Beijing 100039 China 

出 版 物：《Journal of Environmental Sciences》 (环境科学学报（英文版）)

年 卷 期：2006年第18卷第4期

页      面：752-759页

核心收录：

学科分类：0830[工学-环境科学与工程（可授工学、理学、农学学位）] 082803[工学-农业生物环境与能源工程] 08[工学] 0828[工学-农业工程] 09[农学] 0903[农学-农业资源与环境] 

基　　金：TheNationalNaturalScienceFoundationofChina(No.30270283) theFieldFrontiersProjectofChineseAcademyofSciencesKnowledgeInnovationProgram(KSCX2-SW-133) theDirectorFoundationofSouthChinaInstituteofBotany,ChineseAcademyofSciencesandtheProvincialNaturalScienceFoundationofGuangdong,China(No.021524) 

主　　题：N deposition N saturation extractable inorganic N soil solution inorganic N subtropical China 

摘      要：Three forests with different historical land-use, forest age, and species assemblages in subtropical China were selected to evaluate current soil N status and investigate the responses of soil inorganic N dynamics to monthly ammonium nitrate additions. Results showed that the mature monsoon evergreen broadleaved forest that has been protected for more than 400 years exhibited an advanced soil N status than the pine （Pinus massoniana） and pine-broadleaf mixed forests, both originated from the 1930＇s clear-cut and pine plantation. Mature forests had greater extractable inorganic N pool, lower N retention capacity, higher inorganic N leaching, and higher soil C/N ratios. Mineral soil extractable NH4^＋-N and NO3-N concentrations were significantly increased by experimental N additions on several sampling dates, but repeated ANOVA showed that the effect was not significant over the whole year except NH4^＋-N in the mature forest. In contrast, inorganic N （both NH4^＋-N and NO3^--N） in soil 20-cm below the surface was significantly elevated by the N additions. From 42% to 74% of N added was retained by the upper 20 cm soils in the pine and mixed forests, while 0%-70% was retained in the mature forest. Our results suggest that land-use history, forest age and species composition were likely to be some of the important factors that determine differing forest N retention responses to elevated N deposition in the study region.