Evaluation And Management Division Of Carbon Sequestration And Sink Enhancement Potential Of Land Ecosystem

Human living environment and food security are seriously threatened by global climate change.Controlling greenhouse gas emissions,especially carbon dioxide（CO₂）emissions,is an important issue to mitigate climate change.Giving full play to the carbon sequestration potential based on land ecosystem and carbon sequestration through reasonable agroforestry measures and land use adjustment is an effective way to mitigate climate change.AFOLU（Agriculture,Forestry and Other Land Use）activities affect global food security and energy production,so it is very important to clarify the carbon sequestration potential of AFOLU system,which puts forward an urgent need for the study of terrestrial ecosystem carbon cycle,carbon sequestration rate,exchange increase potential and so on.At present,the related research on carbon sequestration potential is mainly based on the evaluation of carbon sequestration potential,and less attention is paid to the stability of carbon sequestration,and the existing research pays less attention to the zoning of carbon sequestration management based on land spatial planning.Therefore,this study takes Lishui City,Zhejiang Province as the study area,calculates the current situation of carbon reserves and theoretical value of Lishui AFOLU system based on remote sensing data and model,constructs a carbon sequestration potential evaluation system with carbon sequestration potential,carbon sequestration change trend and carbon sequestration stability as the main indicators,evaluates the importance of carbon sequestration of AFOLU system,and the spatial characteristics of different importance zones are clarified.Combining the three control lines of land spatial planning and the importance zoning of carbon sinks,this paper delineates the management zone of carbon sequestration enhancement of AFOLU system in Lishui City,and puts forward different zoning management tasks and measures.The research results can provide a new perspective for the evaluation of carbon sequestration and sequestration potential of regional terrestrial ecosystem,and contribute to the coordinated development of land space optimization and carbon sequestration capacity construction and the realization of the goal of"carbon neutralization and carbon peak".The main findings of this study are as follows:（1）The carbon storage status of AFOLU system in Lishui is evaluated.The total carbon storage of Lishui AFOLU system is 242.25 million tons,and the carbon reserves of vegetation and soil are 60.03 million tons and 182.22 million tons respectively.The vegetation carbon storage of forest ecosystem and garden grass ecosystem was 57.46million tons and 2.57 million tons respectively,and the soil carbon storage of forest ecosystem,garden grass ecosystem and farmland ecosystem was 157.23 million tons,8.49 million tons and 16.50 million tons,respectively.At the same time,there are significant differences in carbon storage among AFOLU subsystems.Forest ecosystem has the largest carbon storage with 88.62%of carbon reserves.In addition,there is spatial heterogeneity in the distribution of carbon reserves in AFOLU system.Areas with good ecological environment and high vegetation coverage and urban areas with low vegetation coverage are high and low value areas of carbon reserves.（2）The carbon sequestration importance evaluation system based on carbon sequestration potential,carbon sequestration change trend and carbon sequestration stability is constructed,and the carbon sequestration importance division of Lishui AFOLU system is divided.The AFOLU system of Lishui City has great carbon sequestration potential and significant spatial heterogeneity,which is high in the west and low in the east as a whole.Under the condition that the current natural environment and land use do not change significantly,the carbon sequestration potential that can be realized is 445.85 million tons,of which the soil carbon pool will be the largest carbon sequestration potential pool of the future AFOLU system,and its carbon sequestration potential will be 4.19 times that of the vegetation carbon pool,and the forest ecosystem will be the largest carbon sequestration potential subsystem of the future AFOLU system.In the past ten years,the change of carbon sequestration of Lishui AFOLU system showed a maintenance and upward trend as a whole,and there were differences within the system,such as forest ecosystem>garden and grass ecosystem>farmland ecosystem,and the overall stability of carbon sequestration of Lishui AFOLU system was good,accounting for 99.26%of the more stable and stable areas.Based on the evaluation system composed of three indexes,the carbon sequestration importance zone of Lishui AFOLU system is divided.There are significant spatial differences in the zoning,showing the distribution features of high in the west and low in the east.Among them,the average carbon sequestration importance index of forest ecosystem is the highest.In the future,forest ecosystem will become an important carbon sequestration and sequestration area of Lishui AFOLU system.（3）Based on the three control lines of land and space,seven management zones of carbon sequestration and increasing carbon sinks are delineated,and different zoning management strategies are put forward.This study is divided into seven management zones:important carbon sequestration protection zone,sustainable carbon sequestration construction area,ecological protection and restoration promotion area,agricultural carbon sequestration protection area,agricultural carbon sequestration and sequestration development area,urban carbon sequestration area and urban ecological restoration promotion area.combined with the leading functions and environmental conditions of the zone,different zoning management tasks are established.In order to provide some guidance for the future ecological restoration of Lishui and the formulation of carbon sequestration policy.To sum up,the carbon sequestration potential of Lishui AFOLU system is large,the overall carbon sequestration shows a trend of maintenance and rising in the past ten years,and the carbon sequestration capacity is relatively stable,but the carbon sequestration potential,the changing trend of carbon sequestration,the stability of carbon sequestration and its spatial distribution are extremely uneven and significantly different of each subsystem.In the future,in order to enhance the potential and ability of carbon sequestration of Lishui AFOLU system,we should combine the management zoning of carbon sequestration and sinks improvement,according to the spatial heterogeneity of the importance of carbon sequestration in different zones,comprehensively consider the regional leading functions and natural conditions,formulate management strategies,promote the refinement of carbon sequestration management of Lishui AFOLU system,and further release the potential and space of carbon sequestration and sequestration enhancement of AFOLU system.At the same time,it provides a new perspective for the evaluation of carbon sequestration and sequestration potential of regional terrestrial ecosystem,and provides a collaborative strategy for the improvement of carbon sequestration capacity from the perspective of land spatial planning.