摘要
以湘中丘陵区的檵木—南烛—白栎灌草丛(LVR)、檵木—杉木—白栎灌木林(LCQ)、马尾松—柯—檵木针阔混交林(PLL)、柯—红淡比—青冈常绿阔叶林(LAG)作为1个恢复序列,设置固定样地,采集土壤样品,测定土壤可溶性有机氮(SON)、铵态氮(NH_4^(+)—N)、硝态氮(NO_3^(-)—N)含量及其密度,分析SON、NH_4^(+)—N、NO_3^(-)—N含量与土壤黏粒、全氮(TN)、有机碳(SOC)、微生物生物量的相关性。结果表明:各土层SON、NH_4^(+)—N含量随植被恢复而增加,与LVR相比,LAG、PLL、LCQ 0—40 cm土层SON含量分别增加225.78%,121.22%,54.73%,NH_4^(+)—N分别增加22.10%,14.74%,7.80%;而各土层NO_3^(-)—N含量随植被恢复先下降再增加,LAG各土层NO_3^(-)—N含量最高,LCQ最低;0—40 cm土壤层SON、NH_4^(+)—N密度分别为143.82~528.12,55.73~65.57 kg/hm^(2),与LVR相比,LAG、PLL、LCQ土壤SON密度分别增加267.20%,98.40%,86.30%,NH_4^(+)—N密度分别增加17.70%,7.90%和11.60%;0—40 cm土壤层NO_3^(-)—N密度为22.91~25.87 kg/hm^(2),与LVR相比,LAG增加13.16%;SON、NH_4^(+)—N密度各阶段间的增长速率呈快—慢—快的特征,而NO_3^(-)—N呈慢—慢—快的特征;土壤理化性质和微生物生物量对SON、NH_4^(+)—N的影响大于NO_3^(-)—N,表明植被恢复有利于土壤N养分积累,提高土壤可溶性氮组分的含量和密度,增加土壤N的可利用性。
We selected four adjacent plant communities with almost the same habitat conditions in Changsha County,Hunan Province,China.The four vegetation communities were composed of Loropetalum chinense—Vaccinium bracteatum—Rhododendron simsii scrub-grass-land(LVR),L.chinense—Cunninghamia lanceolata—Quercus fabri shrubbery(LCQ),Pinus massoniana—Lithocarpus glaber—L.chinense coniferous-broad leaved mixed forest(PLL),L.glaber—Cleyera japonica—Cyclobalanopsis glauca evergreen broad-leaved forest(LAG)to represent the secondary forest successional sequence in this region.Fixed sample plots were set up,and soil samples(0—40 cm)were collected and divided into four layers(0—10,10—20,20—30 and 30—40 cm).The contents and density of soil soluble organic nitrogen(SON),ammonium nitrogen(NH_4^(+)—N)and nitrate nitrogen(NO_3^(-)—N)were determined,and the correlations between the contents of SON,NH_4^(+)—N and NO_3^(-)—N and soil clay percentage,total nitrogen(TN),organic carbon(SOC)and microbial biomass were analyzed.The results showed that the contents of SON and NH_4^(+)—N in each soil layer increased with the vegetation restoration.Compared with LVR,contents of SON in 0—40 cm soil layers in LAG,PLL and LCQ increased respectively by 225.78%,121.22%and 54.73%,while contents of NH_4^(+)—N increased respectively by 22.10%,14.74%,and 7.80%.The contents of NO_3^(-)—N in each soil layer decreased first and then increased with the vegetation restoration.The NO_3^(-)—N contents in each soil layer of LAG were the highest,while LCQ was the lowest.The densities of SON and NH_4^(+)—N in the 0—40 cm soil layer were 143.82~528.12 kg/hm^(2) and 55.73~65.57 kg/hm^(2) respectively.Compared with LVR,the densities of SON in LAG,PLL and LCQ increased by 267.20%,98.40%,and 86.30%,while NH_4^(+)—N increased by 17.70%,7.90%,and 11.60%,respectively.The densities of NO_3^(-)—N in 0—40 cm soil layer was 22.91~25.87 kg/hm^(2).Compared with LVR,LAG increased by 13.16%.The growth rates of SON and NH_4^(+)—N
作者
何玉姣
陈婵
朱小叶
陈金磊
方晰
HE Yujiao;CHEN Chan;ZHU Xiaoye;CHEN Jinlei;FANG Xi(School of Life Science and Technology,Central South University of Forestry and Technology,Changsha 410004)
出处
《水土保持学报》
CSCD
北大核心
2021年第2期258-264,共7页
Journal of Soil and Water Conservation
基金
国家林业公益性行业科研专项(201504411)
国家自然科学基金项目(31670448,31971455)。
关键词
湘中丘陵区
植被恢复
可溶性有机氮
硝态氮
铵态氮
hilly area in the central Hunan Province
vegetation restoration
soluble organic nitrogen
ammonium nitrogen
nitrate nitrogen
