草业学报2018，Vol.27Issue(2)：1-14,14.DOI:10.11686/cyxb2017303
黄土高原草地和农田系统碳动态对降雨、温度和CO2浓度变化响应的模拟
Modeled effects of precipitation, temperature, and CO2 changes on carbon dynamics in grassland and cropland on the Loess Plateau
摘要
Abstract
Global climate change usually involves simultaneous and continuous changes under different environmental conditions.However,it is very difficult and expensive to explore those climate change in manipulative experiments.Applying models can help us to understand the responses of ecosystem structure and function to global climate change.To explore the effects of climate change on carbon processes in grassland and cropland on the Loess Plateau,the Terrestrial Ecosystem (TECO) model was applied to identify patterns of ecosystem carbon processes in response to changes in CO2 concentration,temperature,and precipitation.The results showed that net primary production (NPP) and heterotrophic respiration (Rh) increased with temperature up to +4 ℃ and then declined,except that the highest Rh in cropland ecosystem was at 0 ℃ (ambient conditions).Net ecosystem exchange (NEE) showed the opposite trend with the lowest value at +4 ℃,and the highest C sequestration was at +4 ℃ in both systems.Changes in precipitation and CO2 concentration affected the responses of NPP,Rh,and NEE to temperature change.The NPP,Rh,and NEE became more sensitive to temperature change with increased precipitation.Changes in precipitation affected the turning points of temperature responses for NPP,Rh,and NEE in the grassland ecosystem,but not in the cropland ecosystem.With increased CO2 concentration,the patterns of NPP,Rh,and NEE became flatter when temperature change was greater than +4 ℃.The interaction between increased precipitation and warming had the highest relative strength in terms of effects on NPP,Rh,and NEE,with values of 51.0％ and 30.0％,51.3％ and 16.6％,and-46.1％ and-28.9％ in the grassland and cropland ecosystem,respectively.The interaction between increased precipitation and increased CO2 concentration had the smallest relative strength in terms of effects on NPP,Rh,and NEE,with values of 2.4％ and 7.5％,3.7％ and 3.4％,and 8.1％ and-9.0％,in the grassland and cropland ecosystems,respectively.Three-factor interactions were not significant for these ecosystems.Our results suggest that carbon dynamics are less sensitive in the cropland ecosystem than in the grassland ecosystem to interactions among climatic factors under climate change.关键词
气候变化/异养呼吸/净生态系统碳交换/净初级生产力/陆地生态系统(TECO)模型Key words
climate change/heterotrophic respiration/net ecosystem carbon exchange/net primary production/Terrestrial Ecosystem (TECO) model引用本文复制引用
郭丁,郭文斐,赵建,特木其勒图,李旭东,傅华,骆亦其..黄土高原草地和农田系统碳动态对降雨、温度和CO2浓度变化响应的模拟[J].草业学报,2018,27(2):1-14,14.基金项目
国家重点研发计划(2016YFC0500505),国家自然科学基金(31502010),新疆维吾尔自治区重大科技专项项目(2016A03006)和草地农业生态系统国家重点实验室开放基金(SKLGAE201401)资助. （2016YFC0500505）
