Fire is a major type of disturbance that has important influences on ecosystem dynamics and carbon cycles.Yet our understanding of ecosystem fires and their carbon cycle consequences is still limited,largely due to th...Fire is a major type of disturbance that has important influences on ecosystem dynamics and carbon cycles.Yet our understanding of ecosystem fires and their carbon cycle consequences is still limited,largely due to the difficulty of large-scale fire monitoring and the complex interactions between fire,vegetation,climate,and anthropogenic factors.Here,using data from satellite-derived fire observations and ecosystem model simulations,we performed a comprehensive investigation of the spatial and temporal dynamics of China’s ecosystem fire disturbances and their carbon emissions over the past two decades(1997–2016).Satellite-derived results showed that on average about 3.47-4.53×10^(4) km^(2) of the land was burned annually during the past two decades,among which annual burned forest area was about 0.81-1.25×10^(4) km^(2),accounting for 0.33-0.51%of the forest area in China.Biomass burning emitted about 23.02 TgC per year.Compared to satellite products,simulations from the Energy Exascale Earth System Land Model(ELM)strongly overestimated China’s burned area and fire-induced carbon emissions.Annual burned area and fire-induced carbon emissions were high for boreal forest in Northeast China’s Daxing’anling region and subtropical dry forest in South Yunnan,as revealed by both the satellite product and the model simulations.Our results suggest that climate and anthropogenic factors play critical roles in controlling the spatial and seasonal distribution of China’s ecosystem fire disturbances.Our findings highlight the importance of multiple complementary approaches in assessing ecosystem fire disturbance and its carbon consequences.Further studies are required to improve the methods of observing and modelling China’s ecosystem fire disturbances,which will provide valuable information for fire management and ecosystem sustainability in an era when both human activities and the natural environment are rapidly changing.展开更多
Past assessments report negative impacts of the climate crisis in boreal areas;but milder and shorter winters and elevated atmospheric CO_(2) may provide opportunities for agricultural productivity potentially playing...Past assessments report negative impacts of the climate crisis in boreal areas;but milder and shorter winters and elevated atmospheric CO_(2) may provide opportunities for agricultural productivity potentially playing a significant role in future food security.Arable cropping systems are expanding in boreal areas,but the regional mainstay will likely continue to be livestock production.Agroecological models can when appropriately calibrated and evaluated,facilitate improved productivity while minimising environmental impacts by identifying system interactions,and quantifying greenhouse gas emissions,soil carbon stocks and fertiliser use.While models designed for temperate and tropical zones abound,few are developed specifically for boreal zones,and there is uncertainty around the performance of existing models in boreal areas.We reviewed model performance across boreal environments and management systems.We identified a dearth of modelling studies in boreal regions,with the publication of three or less papers per year since the year 2000,constituting a significant research gap.Models IFSM and BASGRA_N performed best in grassland production,DNDC best in predicting soil N_(2)O and NH_(3) emissions.No model outperformed all others,strengthening the case for ensemble modelling.Existing agroecological models would be worthy of further evaluation,providing model improvements designed for boreal systems.展开更多
基金funding was provided by the Carbon Mitigation Initiative(CMI)of the Princeton Environmental Institute,and by an Oak Ridge National Lab research subcontract to A.C.C.Y.and P.C.were supported by the fire_cci project(http://www.esa-fire-cci.org/)funded by the European Space AgencyS.R.was supported by a Graduate Research Fellowship from the U.S.National Science Foundation+1 种基金R.T.,J.M.,X.S.and D.R.were supported by the Terrestrial Ecosystem Science Scientific Focus Area(TES SFA)project and the Reducing Uncertainties in Biogeochemical Interactions through Synthesis and Computing Scientific Focus Area(RUBISCO SFA)project funded by the US Department of Energy,Office of Science,Office of Biological and Environmental ResearchOak Ridge National Laboratory is supported by the Office of Science of the US Department of Energy under Contract No.DE-AC05-00OR22725.
文摘Fire is a major type of disturbance that has important influences on ecosystem dynamics and carbon cycles.Yet our understanding of ecosystem fires and their carbon cycle consequences is still limited,largely due to the difficulty of large-scale fire monitoring and the complex interactions between fire,vegetation,climate,and anthropogenic factors.Here,using data from satellite-derived fire observations and ecosystem model simulations,we performed a comprehensive investigation of the spatial and temporal dynamics of China’s ecosystem fire disturbances and their carbon emissions over the past two decades(1997–2016).Satellite-derived results showed that on average about 3.47-4.53×10^(4) km^(2) of the land was burned annually during the past two decades,among which annual burned forest area was about 0.81-1.25×10^(4) km^(2),accounting for 0.33-0.51%of the forest area in China.Biomass burning emitted about 23.02 TgC per year.Compared to satellite products,simulations from the Energy Exascale Earth System Land Model(ELM)strongly overestimated China’s burned area and fire-induced carbon emissions.Annual burned area and fire-induced carbon emissions were high for boreal forest in Northeast China’s Daxing’anling region and subtropical dry forest in South Yunnan,as revealed by both the satellite product and the model simulations.Our results suggest that climate and anthropogenic factors play critical roles in controlling the spatial and seasonal distribution of China’s ecosystem fire disturbances.Our findings highlight the importance of multiple complementary approaches in assessing ecosystem fire disturbance and its carbon consequences.Further studies are required to improve the methods of observing and modelling China’s ecosystem fire disturbances,which will provide valuable information for fire management and ecosystem sustainability in an era when both human activities and the natural environment are rapidly changing.
基金supported by funding from the Ministry of Agriculture and Forestry Finland(Helsinki,FI)(Project:Clover for biogas,Project NC-GRASS:VN/28562/2020-MMM-2)the support from the Academy of Finland funded ENSINK project(Decision number 334422).
文摘Past assessments report negative impacts of the climate crisis in boreal areas;but milder and shorter winters and elevated atmospheric CO_(2) may provide opportunities for agricultural productivity potentially playing a significant role in future food security.Arable cropping systems are expanding in boreal areas,but the regional mainstay will likely continue to be livestock production.Agroecological models can when appropriately calibrated and evaluated,facilitate improved productivity while minimising environmental impacts by identifying system interactions,and quantifying greenhouse gas emissions,soil carbon stocks and fertiliser use.While models designed for temperate and tropical zones abound,few are developed specifically for boreal zones,and there is uncertainty around the performance of existing models in boreal areas.We reviewed model performance across boreal environments and management systems.We identified a dearth of modelling studies in boreal regions,with the publication of three or less papers per year since the year 2000,constituting a significant research gap.Models IFSM and BASGRA_N performed best in grassland production,DNDC best in predicting soil N_(2)O and NH_(3) emissions.No model outperformed all others,strengthening the case for ensemble modelling.Existing agroecological models would be worthy of further evaluation,providing model improvements designed for boreal systems.
