Quantitative Analysis Of Ecosystem Service In Sanjiang Plain And Its Application In Land Use Planning

Sanjiang Plain is an important commodity grain base and the largest marsh wetland distribution area in China.It has significant economic and ecological value.With the rapid development of China’s economy and society and the implementation of the agricultural development strategy,the urban and rural land and agricultural land in the Sanjiang Plain have gradually increased in recent years,while the forest land,grassland,wetland and other natural ecosystems have been occupied and cultivated,resulting in varying degrees of disturbance and irreversible damage to the regional natural ecological environment.Human activities have changed the land use pattern of underlying surface,and then affected the ecosystem service function of the region through direct and indirect effects.At present,food security and ecological environment protection are the major needs of the country in the new era.How to formulate the land development and utilization mode for the coordinated development of agriculture,ecology and other economic,social and ecological environments is the key issue to be answered urgently.Therefore,this study takes Sanjiang Plain in Northeast China as the study area,and selects habitat quality,carbon storage,water yield,water purification and agricultural output as typical ecological service functions to characterize the regional ecological environment and economic and social service functions.Firstly,the spatial and temporal variation of ecosystem service capacity in Sanjiang Plain in recent 40 years was analyzed,and the hot spots of agricultural production and ecological service functions were selected based on specific principles;Based on this,it further puts forward suggestions for future land use development that weigh the ecological environment and agricultural production.Combined with the land use simulation prediction model and the ecological service function quantification model,it clarifies the spatial pattern distribution under different land use schemes and the tradeoff and synergy of the service capacity of each ecosystem.The study provides scientific reference for in-depth understanding of historical ecological service function changes and their driving forces in the Sanjiang Plain,provides scientific support for the rational allocation of regional land use resources and spatial layout planning in the future,and serves food security and ecological environment protection.The results of this study are as follows:(1)Quantifying the characteristics of land use change in Sanjiang Plain from 1980 to 2020,it is mainly that the area of farmland(especially paddy field)has increased significantly,with an increase of 54.86% in the past 40 years,the urban and rural land has increased by 34.75%,and the rest of the land use areas have decreased sharply;(2)From 1980 to 2020,there was a significant synergistic and trade-off relationship between ecosystem service functions: carbon reserves(-21.8%)and habitat quality(-12.3%)showed a synergistic relationship of increase and decrease,and the two showed a trade-off relationship with water yield(19.2%),water quality purification(23.5% nitrogen loss,18.9%phosphorus loss)and farmland yield(1140.8%).(3)Based on the analysis of historical ecological service function,the key land protection areas in Sanjiang Plain,namely hot spots,are defined.Agricultural hot spots account for 18.67%of the total farmland area,providing 26.1% of the grain output.Ecological hot spots account for 8.55% of the total area,providing 15.06% of the total carbon reserves;The average value of habitat quality exceeded the average value of overall habitat quality by more than 64%;Its performance in terms of water production and water quality purification is also far better than that in other regions.(4)Based on the in-depth analysis of relevant national and local plans and policies for ecological protection and agricultural development,four future land use development scenarios are set and the land use pattern distribution in 2050 is simulated;The results showed that,under the scenarios of different preferences for agricultural development or ecological protection,various ecological service functions showed different degrees of synergy and trade-off;The development and utilization plan that takes into account agricultural development and ecological protection can obtain a good balance between agricultural production and habitat quality,carbon storage,water yield and water purification service functions,and is the recommended future land development and utilization mode.