中国北方森林和草地生态系统碳氮耦合循环与碳源汇效应研究

全球变化自20世纪80年代以来作为一个科学问题开始出现,现今已超越科学领域,成为影响当今世界发展的重大政治、经济和外交问题。在科技部的 “十三五”期间“全球变化及应对”重点研发计划专项支持下,来自中国科学院沈阳应用生态研究所、西北农林科技大学、中国科学院植物研究所等6个单位31位科学家于2016年7月开始承担“中国北方森林和草地生态系统碳氮耦合循环与碳源汇效应研究”项目。该项目旨在:1)凸显中国北方植物群落演替在温室气体吸收和排放平衡,特别是在我国未来碳汇中的作用;2)绘制森林和草地碳源汇转变的敏感区、脆弱区;3)建立和发展稳定同位素技术研究碳氮循环的多时间序列历史变化及其对全球氮沉降、大气CO2浓度上升和气候变化的响应;4)揭示氮沉降、升温、火干扰和植被演替驱动的碳氮耦合循环生物学机制及其碳源汇响应。通过该项目5年的实施,预期能增加我国北方森林和草地生态系统碳氮耦合循环生物学机制的认识,增强对北方森林和草地生态系统对全球变化响应的预测能力和减少预测的不确定性。 

Coupling of carbon and nitrogen,source and sink of carbon in forest and grassland ecosystems of northern China

Global change was emerged as a scientific issue since 1980s, and hitherto has become a political, economic and diplomatic issues affecting worldwide, beyond the scientific aspect. Under the support of the National Key Research and Development Program of China during the 13rd five-year period, 31 scientists from six institutions ( including Institute of Applied Ecology of CAS, Northwest A&F University, Institute of Botany of CAS, etc. ) have been performing a project “Coupling of carbon and nitrogen, source and sink of carbon in forest and grassland ecosystems of northern China” since July 2016 . The objectives of the project in the study region were:1 ) to assess the role of succession of plant communities in the balance of uptake and emission of three greenhouse gases ( CO2 , N2 O and CH4 ) , particularly the role as a potential carbon sink in the future;2 ) to identify and map the sensitive and vulnerable areas as the transient status of shift from carbon sink to source or from the source to sink; 3 ) to develop the methodologies assessing the historical changes in carbon and nitrogen cycling in response to nitrogen deposition, rising atmospheric CO2 concentration and climate changes at different time scales using mulitple stable isotope techniques; 4 ) to reveal the response patterns of coupled carbon and nitrogen cycles to nitrogen deposition, global warming, fire disturbance and vegetation succession, and their biological mechanisms involved in the response patterns. After five-year efforts through the project, it will be expected to enhance the understanding on biological mechanisms of coupled carbon and nitrogen cycles, and to reduce the uncertainties in predicting the responses of forest and grassland ecosystems in the study region to global changes in the future.