摘要
以祁连山东段青海云杉(Picea crassifolia)林分布带土壤为研究对象,采用顶盖埋管的野外取样法和室内分析法,对海拔梯度上土壤铵态氮(NH+4-N)、硝态氮(NO-3-N)净矿化速率、氮净矿化量和净矿化速率进行测定分析,旨在探讨土壤净氮矿化量与气温降水和土壤理化性质的相关关系,以期建立环境变量与土壤氮矿化量和矿化速率模型,进而提高祁连山青海云杉林生产力及水源涵养能力。其结果表明:(1)土壤硝态氮、铵态氮净矿化速率、土壤净氮矿化量和矿化速率随海拔的升高差异性均极显著;土壤氮净矿化量和矿化速率随海拔梯度的升高呈"W"形变化,与硝态氮净矿化速率随海拔升高的变化规律一致,与铵态氮净矿化速率变化规律相反;在海拔2 800m处,硝态氮净矿化速率、土壤净氮矿化量和矿化速率均达到最大值,为0.372,160.3,0.44 mg/(kg·d),铵态氮净矿化速率出现最低值0.067 mg/(kg·d);在海拔2 900m处出现最低值,为0.155,94.7,0.26mg/(kg·d),在海拔3 100m处,铵态氮的净矿化速率出现最大值0.13mg/(kg·d);(2)回归分析表明,土壤净氮矿化量与年均气温呈极显著负相关(P<0.01),R2=0.717 3;与年降水量呈极显著正相关(P<0.01),R2=0.383 5;得出气候变化对土壤净氮矿化量的影响程度为:年均气温>年降水量;(3)回归分析表明,土壤氮净矿化量与土壤全氮、有机质、含水量、pH值呈极显著正相关(P<0.01),其R2依次为0.910 1,0.906 0,0.842 8,0.797 9;与土壤容重呈极显著负相关(P<0.01),其R2为0.222 4;由R2值大小可知土壤养分对土壤净氮矿化量的影响程度为:土壤全氮>土壤有机质>土壤含水量>土壤pH>土壤容重。
The research used the soil of Picea crassifoliaforest distribution on altitude of 2 500~3 100 min the eastern of Qilian mountains as the research object,and using the close-top tube at field sampling methods and laboratory analysis method to study on soil NH＋4-N and NO-3-N net mineralization rate and net N mineralization and mineralization rate,aimed to explore the relationship between the soil net nitrogen mineralization rate and temperature,precipitation,soil nutrient.With a view to improve productivity of Picea crassifoliaforest in Qilian Mountain and guide the Picea crassifoliaforest ecosystems of sustainable development and management to provide basal reference materials.The results were summarized as follows：（1）Therewas different significantly about net mineralization rate of soil nitrate with the increase of altitude.The net ammonia nitrogen mineralization rate,soil net nitrogen mineralization rate and mineralization rate as well.Soil net nitrogen mineralization and the mineralization rate showed the ＂ W＂ word in the altitude gradient,and changes of the same with nitrate net mineralization rate with increasing of altitude,contrary to the law of nitrogen net mineralization rate.At an altitude of 2 800 m,net nitrate nitrogen mineralization rate and amount of soil net nitrogen mineralization and the mineralization rate achieved the maximum value,which was 0.372,160.3,0.44mg/（kg·d）,respectively,the net ammonia nitrogen mineralization rate had mini-mum value（0.067mg/（kg·d））;the lowest value appeared at an altitude of 2 900 m,which was 0.155,94.7,0.26mg/（kg·d）,respectively.At an altitude of 3 100 m,the net mineralization rate of ammonia nitrogen achieved the maximum 0.13mg/（kg·d）.（2）Regression analysis showed that soil net nitrogen mineralization were very significantly negative correlation with annual average temperature（P0.01）,R2=0.717 3;which were very significantly positive correlation with annual rainfall（P0.01）,R2=0.383 5,concluded that climate change affecti
出处
《水土保持学报》
CSCD
北大核心
2016年第5期218-223,共6页
Journal of Soil and Water Conservation
基金
国家自然科学基金"祁连山土壤氮矿化特征及分异规律研究(31260141)"
关键词
土壤净氮矿化
海拔
气温降水
土壤养分
青海云杉
soil net nitrogen mineralization
altitude
temperature and precipitation
soil nutrient
Picea crassifolia
