摘要
根据2001年中国东北样带土壤全氮和有效氮的实测数据,结合CO2浓度倍增与不同土壤湿度的模拟试验数据,对土壤全氮和有效氮的梯度分布、影响因子分析及其对气候变化的响应进行研究.结果表明,样带土壤表层全氮和有效氮的梯度分布与土壤有机碳的分布基本一致沿经度呈现东高西低的趋势,局部由于土壤退化而出现低谷.土壤全氮的剖面分布和土壤有机碳相似,而土壤有效氮则有所不同.样带土壤全氮和有效氮与土壤pH、有机碳、全磷、全硫、全锌、土壤活性碳、有效磷、有效钾、有效锰、有效锌、土壤容重、田间持水量、土壤总孔度等因子均呈显著或极显著的相关关系.样带土壤全氮和有效氮与降雨量之间呈极显著的正相关关系(r=0682,P<0001和0688,P<0001).短期培养试验中,CO2浓度倍增和不同土壤湿度下土壤全氮和有效氮的变异较小(变异系数分别是555%和384%),但可反映一定的变化趋势.
Terrestrial transect is an important and effective method for global change study.The Northeast China Transect (NECT),which is assigned along the latitude 43°30'N in the mid-latitude of temperate zone and located at 112°～130°30'E and 42～46° N,is one of the fifteen global transects recognized by IGBP.It is about 1 600 km in length and 300 km in width.The NECT is mainly driven by precipitation,and becomes an effective platform of global change study in China.Based on the field survey in 2001 and a simulated experiment,this paper analyzed the gradient distribution of soil nitrogen and its response to climate change along the Transect.The results indicated that soil total and available nitrogen in NECT were significantly related to longitude,with a correlation coefficient being 0.695(P<0.001) and 0.636 (P<0.001),respectively,and had a similar horizontal distribution with soil organic carbon.Soil available nitrogen content in the NECT was decreased from east to west,and could be one of factors restricting plant growth.The decreasing rate of soil total and available nitrogen from topsoil to subsoil was different with ecosystems along the NECT.Soil total and available nitrogen contents had a close linear relationship with soil pH,total and labile carbon,total and available phosphorus,total sulphur,total and available zinc,available potassium,available manganese,bulk density,water holding capacity,and total porosity.They also had a significant linear relationship with precipitation,the correlation coefficient being 0.682(P<0.001) and 0.688(P<0.001),respectively.The short-term simulated experiment showed that doubled ambient CO_2 concentration and soil moisture regime had no significant effects on soil total and available nitrogen,the variation coefficients being 5.55% and 3.84%,respectively.
出处
《应用生态学报》
CAS
CSCD
北大核心
2005年第2期279-283,共5页
Chinese Journal of Applied Ecology
基金
国家重点基础研究发展规划项目(G1999043407)
中国科学院知识创新工程项目(KZCX1SW0112
KSCX2107)
国家自然科学基金资助项目(40231018).
关键词
中国东北样带
土壤氮分布
气候变化
CO2浓度倍增
干旱胁迫
Northeast China Transect (NECT), Soil nitrogen distribution, Climate change, Doubled ambient CO_2 concentration, Drought stress.
