毛竹扩张对常绿阔叶林土壤氮素矿化及有效性的影响  

Effects of Phyllostachys edulis expansion on soil nitrogen mineralization and its availability in evergreen broadleaf forest

作　　者：宋庆妮[1] 杨清培[1] 刘骏[1] 余定坤[1] 方楷[1] 徐佩[1] 何宇娟[1] 

机构地区：[1]江西农业大学/江西省竹子种质资源与利用重点实验室,南昌330045

出　　处：《应用生态学报》2013年第2期338-344,共7页Chinese Journal of Applied Ecology

基　　金：国家自然科学基金项目(31260120;31170306);江西省自然科学基金项目(20122BAB204019);江西省教育厅科学技术研究项目(GJJ08192);大岗山生态站基金项目资助

摘　　要：采用时空替代法和PVC顶盖原位培养法,分析了江西大岗山毛竹扩张形成的竹-阔混交林与邻近常绿阔叶林土壤中的无机氮含量、氮矿化速率和吸收速率等指标.结果表明:两种林分土壤总无机氮含量时空变化趋势相同;竹-阔混交林年均矿化速率低于常绿阔叶林,前者以氨化作用为主,后者氨化作用与硝化作用相当,但生长季硝化作用明显占优势.两林分全年都以吸收NH4+-N为主,但生长季常绿阔叶林对NO3--N的吸收明显占优势.说明毛竹向常绿阔叶林扩张会增强土壤氮素氨化作用、减弱硝化作用和总矿化作用,同时也会增加对NH4+-N的吸收,减少对NO3--N和总无机氮的吸收.By the methods of space-time substitution and PVC tube closed-top in situ incubation,this paper studied the soil mineralized-N content,N mineralization rate,and N uptake rate in Phyllostachys edulis-broadleaf mixed forest（PBMF） formed by P.edulis expansion and its adjacent evergreen broadleaf forest（EBF） in Dagangshan Mountain of Jiangxi Province,China.There existed the same spatiotemporal variation trend of soil total mineralized-N（TMN） content between the two forests.The annual average N mineralization rate was slightly lower in PBMF than in EBF.In PBMF,soil N mineralization was dominated by ammonification;while in EBF,soil ammonification and nitrification were well-matched in rate,and soil nitrification was dominated in growth season（from April to October）.The N uptake by the plants in PBMF and EBF in a year was mainly in the form of NH4＋-N,but that in EBF in growth season was mainly in the form of NO3--N.These findings indicated that the expansion of P.edulis into EBF could promote the ammonification of soil N,weakened soil nitrification and total N mineralization,and also,increased the NH4＋-N uptake but decreased the NO3--N and TMN uptake by the plants.

关 键 词：毛竹扩张 氮素矿化 氮素有效性 常绿阔叶林 江西大岗山 

分 类 号：S714[农业科学—林学]