生态学报2017，Vol.37Issue(8)：2770-2778,9.DOI:10.5846/stxb201509251968
氮输入对东北土壤碳蓄积氮素利用效率的影响
Effects of nitrogen input on nitrogen use efficiency of soil carbon storage in Northeast China
摘要
Abstract
Anthropogenic activities have altered the global nitrogen (N) cycle,leading to increased N input into the ecosystem through N deposition and the use of N fertilizers.Nitrogen is considered to be the limiting factor of plant growth in many ecosystems;therefore,the increased N input into ecosystems has an important impact on the carbon cycle and carbon accumulation.N use efficiency (NUE) can be an important indicator for the coupling relationship between ecosystem carbon and nitrogen cycles.Studies on the temporal and spatial patterns of NUE will aid in assessing the contribution of N input to increases in the terrestrial ecosystem carbon sink,and to predict the carbon balance of terrestrial ecosystems under different N input increase scenarios.We use a newly developed process-based ecosystem model,CEVSA2,to study the spatial and temporal variation in N use efficiency of soil carbon storage (SNUE) in Northeast China during 1961-2010,and to examine the effects of N input and vegetation types on SNUE.Our model simulations show that:(1) enhanced N input induced more soil carbon storage in the Northeast,but it decreased SNUE greatly.(2) Different vegetation types led to different SNUEs;forest had the highest SNUE and cropland had the lowest SNUE.The SNUEs of all vegetation types decreased with an increase in N input;however,the forest had the most stable SNUE compared to other vegetation types.The SNUE of shrubland decreased significantly during the early period of the past 50 years.(3) SNUE was the highest in the Sanjiang Plain,the Changbai Mountains,and parts of the Daxinganling and Xiaoxinganling regions.SNUE was negative in the Inner Mongolia Plateau,Hunlun Buir Plateau,and parts of the Daxinganling and Xiaoxinganling regions.This indicates that exogenous N input decreased the storage of soil carbon.(4) The variations in N input and the different responses of different vegetation type to N input impacted the spatial pattern of SNUE.The effects of N input on soil carbon accumulation are also affected by complex ecological processes.The complex responses and adaptation of soil processes to N addition will result in uncertain predictions for long-term changes if the model is based on short term observation results.Further efforts are required on the mechanisms of responses of soil processes to all environmental changes in order to accurately predict the effects that continued N addition will have on soil carbon storage in the future.关键词
氮沉降/施肥/氮素利用效率/土壤有机碳密度/CEVSA2模型/东北Key words
nitrogen deposition/fertilization/nitrogen use efficiency/soil carbon density/CEVSA2 model/Northeast引用本文复制引用
顾峰雪,黄玫,张远东,李洁,郭瑞,严昌荣..氮输入对东北土壤碳蓄积氮素利用效率的影响[J].生态学报,2017,37(8):2770-2778,9.基金项目
国家自然科学基金项目(31370463,41271118,31070398) （31370463,41271118,31070398）
中国农业科学院科技创新工程项目 （）
