| 摘要: |
| 【目的】研究不同氮沉降处理对华西雨屏区天然常绿阔叶林土壤NH4+-N和NO3--N分布及其含量的影响。【方法】设置对照(CK,0 g/(m2·年))、低氮(L,5 g/(m2·年))、中氮(M,15 g/(m2·年))和高氮(H,30 g/(m2·年))4个氮沉降水平，从2013年11月开始，每15 d进行1次模拟氮沉降，于2014年5月和11月采集0～20 cm土层土样，并测定土壤铵态氮、硝态氮含量和pH值等理化指标，分析不同氮沉降处理土壤NH4+-N和NO3--N与其他理化指标的相关性。【结果】无氮沉降背景下（CK），华西雨屏区常绿阔叶林土壤无机氮含量为14.66～16.97 mg/kg，NO3--N占无机氮含量的59.46%。夏季土壤中NH4+-N含量较高，而冬季土壤中NO3--N含量较高。模拟氮沉降降低了土壤的pH值，并且随着氮沉降量的增加，pH下降作用更明显。各处理不同土层土壤NO3--N和NH4+-N含量随着氮沉降量的增加而增大，表现为CK3--N和NH4+-N的累积，且0～10 cm土层累积作用明显高于10～20 cm土层。各氮沉降处理土壤NO3--N、NH4+-N与全氮、有机质、体积含水量之间均存在显著(P<0.05)或极显著(P<0.01)相关性。【结论】模拟氮沉降使华西雨屏区常绿阔叶林土壤NH4+-N和NO3--N含量增加，土壤pH值减小。 |
| 关键词: 常绿阔叶林 华西雨屏区 氮沉降 硝态氮 铵态氮 |
| DOI： |
| 分类号: |
| 基金项目:国家“十二五”科技支撑计划项目（2010BACO1A11）；国家自然科学基金项目（31300522） |
|
| Effects of simulated nitrogen deposition on forms and contents of soil available nitrogen in an evergreen broad leaved forest |
|
XIANG Yuanbin,HUANG Congde,HU Tingxing,et al
|
| Abstract: |
| 【Objective】The aim of this study was to investigate the effects of simulated nitrogen deposition on forms and contents of soil available nitrogen in an evergreen broad-leaved forest in Rainy Area of Western China.【Method】Four nitrogen deposition levels including control (CK,0 g/(m2·year)),low nitrogen (L,5 g/(m2·year)),medium nitrogen (M,15 g/(m2·year)) and high nitrogen (H,30 g/(m2·year)) were set from November 2013 and simulated nitrogen deposition was carried every 15 days.Soil samples of 0-20 cm soil layer were collect in May and November 2014,and the content of soilNH4+-N,NO3--N,and pH were measured.The correlation coefficients between soil NH4+-N,NO3--N and other physical-chemical characters were also analyzed in different treatments.【Result】The change of soil inorganic nitrogen was 14.66-16.97 mg/kg under the background of no nitrogen deposition in rainy area of Western China,and NO3--N accounted for 59.46%.The content of NH4+-N was higher in summer,while the content of NO3--N was higher in winter.Simulated nitrogen deposition reduced the soil pH value,and with the increase of the nitrogen deposition rate,the effect was more significant.The contents of NO3--N and NO3--N increased with the increase of N deposition rate in different soil layers with the order of CK4+-N and NO3--N,and the cumulative effect was significantly higher in 0-10 cm soil layer than in 10-20 cm soil layer.The soil NH4+-N,NO3--N with total nitrogen (TN),organic matter,and volumetric water content had significant (P<0.05) or very significant relationship (P<0.01) in different nitroge deposition treatments.【Conclusion】The soil NH4+-N and NO3--N were increased while and pH values were decreased by simulated nitrogen deposition in an evergreen broad leaved forest in Rainy Area of Western China. |
| Key words: evergreen broad-leaved forest Rainy Area of West China nitrogen deposition NO3--N NH4+-N |
