Dynamic simulation of land use and its response to the ecosystem service value in Puding county from 1973 to 2030

LI Yue; FENG Xia; WU Luhua

doi:10.11932/karst2024y036

Abstract：Puding county is located in the west-central part of Guizhou Province,covering a total area of 1,091 km2.It experiences a humid subtropical monsoon climate,characterized by an average annual precipitation of 1,378.2 mm and an average annual temperature of 15.1 ℃.As of 2021,Puding county had a resident population of 376,300,including an urban population of 144,900,resulting in an urbanization rate of 38.51％.The county's annual Gross Domestic Product(GDP)was 15.463 billion yuan,with the value added of the primary industry contributing 2.808 billion yuan,reflecting a year-on-year increase of 8.2％.The value added of the secondary industry was 4.785 billion yuan,a year-on-year increase of 10.06％,while the value added of the tertiary industry contributed 7.870 billion yuan,up 11.10％.This region is characterized by the typical development of karst geomorphology,and it frequently faces ecological challenges such as soil erosion and rocky desertification.Therefore,uncovering and predicting the impacts of land use change on Ecosystem Service Value(ESV)in karst mountainous areas under different scenarios is of great significance for maintaining regional ecological security,enhancing the value of ecosystem services,and formulating ecological protection and restoration policies.In order to deeply analyze the land use patterns and their response to ecosystem service value over an extended time series in Puding county,research and discussion were carried out across the three temporal dimensions:past,present,and future.This study aims to provide a scientific foundation and valuable insights for the sustainable development of ecosystems in the study area. Based on five periods of land use data from 1973,1989,2003,2010 and 2020,the equivalent factor method,which incorporates localized adjustments of food prices,was used to assess the ESV for each historical period.Additionally,the PLUS model was applied to simulate land use and ESV changes projected for 2030 under three scenarios,natural evolution,ecological protection,and economic development.The results indicate as follows. (1)The area of cultivated land in Puding county decreased sharply from 1973 to 2020,with a total reduction of 25.08％over the last 50 years.In contrast,the areas of forest land and construction land increased annually,with increases of 6,338.56 hm2 and 9,408.00 hm2,respectively. (2)The ESV of the study area from 1973 to 2020 was recorded at 3.100 billion yuan,2.238 billion yuan,2.598 billion yuan,3.277 billion yuan,and 3.510 billion yuan,respectively,exhibiting a general fluctuating upward trend.Regarding the ESV of various land types,the ESVs of forest land,grassland,and watershed all showed annual increases from 1989 to 2020,serving as main contributors to the overall increase in ESV.Specifically,in terms of the value of individual ecosystem service functions,hydrological regulation and climate regulation services made the most significant contribution to ESV,with the combined total of these two services accounting for 47.97％of the total ESV. (3)In the natural evolution scenario,the ecological protection scenario,and the economic development scenario projected for 2030,the areas of cultivated land,grassland,and unused land in Puding county are all expected to decline,mainly converted into forested land and construction land.Notably,the area of cultivated land is projected to experience the greatest loss under the ecological protection scenario,amounting to 5,196.42 hm2.The spatial distribution across the three simulation scenarios shows that the area of construction land is point-surface in the central part of the study area. (4)The ESVs for the natural evolution scenario,ecological protection scenario,and economic development scenario are projected to be 3.638 billion yuan,3.778 billion yuan,and 3.597 billion yuan,respectively,all of which exceed the ESVs recorded for the study area in 2020.From a spatial distribution perspective,the ESVs for Puding county as a whole present the characteristics of being higher in the east and west and lower in the center.Furthermore,the ESV of each land use type has passed the sensitivity test,indicating strong credibility in the results.