摘要
采用PVC顶盖埋管法,开展退化红壤区不同重建模式森林土壤N素矿化特征研究,结果表明:(1)不同重建模式森林土壤有效N差异极显著(P<0.001),其中铵态N:无林地=阔叶林=针阔混交林>针叶林;硝态N:针阔混交林>阔叶林>针叶林=无林地;矿质N:针阔混交林>阔叶林>无林地>针叶林。(2)在所有重建模式中NH4+-N是有效N的主体部分,氨化过程更强烈。(3)不同重建模式森林土壤氨化速率差异不显著(P=0.354),而硝化速率和矿化速率均为极显著(P<0.001),硝化速率、矿化速率均表现为阔叶林≥针叶林≥针阔混交林=无林地。总体来看,无论是有效N含量还是N矿化速率阔叶林均为最高,是一种比较好的植被重建模式。深入开展生态系统N平衡的研究有利于更好地评价重建森林的功能。
In this study, soil nitrogen mineralization process and its availability were examined by the method of in situ closed - top PVC tube incubation under different rehabilitating forests in degraded red soil. Results indicated： （ 1 ） the available nitrogen was significantly affected by the different rehabilitating forest （ P 〈0.001 ）, NH4＋ - N in these forests ranked as：grassland = broadleaf forest = conifer and broadleaf mixed forest 〉 coniferous forest; NO3- - N ranked as： conifer and broadleaf mixed forest 〉 broadlcaf forest 〉 coniferous forest = grassland; mineral N was conifer and broadleaf mixed forest 〉 broadleaf forest 〉 grassland 〉 coniferous forest. （2） NH4＋ - N was the main form of available nitrogen in all rehabilitating forests, its ammonification process was stronger. （3）The effect on ammonification rate was not significant （P = 0.354）. But both of the rates of nitrification and net mineralization were significant, the rates of nitrification and net mineralization ranked as：broadleaf forest ≥ coniferous forest ≥ conifer and broadleaf mixed forests grassland. Based on the corresponding results,it is concluded that broadleaf forest is selectable rehabilitating forests pattern in the study area. To comprehensively assess the ecosystem functions,the knowledge of N balance in rehabilitating forests is necessary.
出处
《江西农业大学学报》
CAS
CSCD
北大核心
2009年第2期278-282,共5页
Acta Agriculturae Universitatis Jiangxiensis
基金
江西省教育厅科技项目(GJJ08373)
关键词
退化红壤
重建森林
氮矿化
土壤氮素
degraded red soil
rehabilitating forest
N mineralization
soil nitrogen
