基于改进的InVEST模型的韶关市生态系统服务功能时空变化特征及影响因素

Spatial-Temporal Changes and Influencing Factors of Ecosystem Services in Shaoguan City Based on Improved InVEST

基于改进的InVEST模型,评估了1990—2017年4个时期韶关市生态系统水源涵养、水土保持、生物多样性、碳储存服务功能时空演变趋势,并通过地理探测器方法分析了影响服务功能时空变化特征的主要因素。结果表明:(1)研究区单位面积水源涵养、水土保持量均呈先上升后下降趋势,分别以2000年、2010年达到最高,主要是由于年际气象条件的影响;生境质量、碳储存则受土地利用变化影响,呈逐年下降趋势。(2)1990—2017年4个时期生态系统服务低值区主要分布在区内韶关中心城区及南雄、翁源、乐昌盆地区域,高值区则各有差异,水源涵养高值区分布在研究区南部,与区域降水量南高北低的趋势一致;水土保持高值区集中分布在乐昌—乳源县中部的大东山、始兴仁化县交界处的瑶岭,与区域地形一致;生物多样性、碳储存高值区分布与土地利用类型较高一致性。随着韶关中心城区及各县城区的扩张,以各城区为中心的生态系统服务功能低值区范围持续扩大。(3)水源涵养量空间异质性主要受土地利用类型、降水量影响,生境质量、碳储存主要由土地利用类型、坡度、海拔影响,土壤保持量则受各因素影响相对均等。除土壤保持量外,土地利用类型对生态系统服务功能空间异质性的影响显著大于其他因素。(4)气象因素在很大程度上决定了生态系统服务功能的年际差异,土地利用类型则是影响其空间分布的主要因素。

Based on the improved InVEST model,the spatial-temporal evolution trends of water conservation,soil conservation,biodiversity,and carbon storage service functions in Shaoguan City during the four periods from 1990 to 2017 were evaluated,and the main factors affecting service functions were analyzed by using methods such as geographic detectors.The results showed that:(1)the water conservation and soil conservation per unit area in the study area first increased and then decreased,mainly due to the impact of interannual meteorological conditions;habitat quality and carbon storage had been decreasing year by year,and affected by land use change;(2)in the four periods from 1990 to 2017,the areas with low values of ecosystem services mainly distributed in the central cities of Shaoguan and Nanxiong,Wengyuan,and Lechang basins;the areas with high values were different,and areas with the high values of water conservation distributed in the south of the study area,which was consistent with the distribution of precipitation;the areas with high soil conservation values concentrated in the Dadong Mountain at the middle of Lechang-Ruyuan County and Yaoling at the junction of Shixing Renhua County,which was consistent with the topography;the distribution areas with high values of biodiversity and carbon storage was highly consistent with land types;with the expansion of Shaoguan′s central and county districts,the area with low value of ecosystem service functions continued to expand;(3)the analysis of geographic detectors indicated that the spatial heterogeneity of water conservation was mainly affected by land type and precipitation,habitat quality and carbon storage were mainly affected by land type,slope,and altitude,and soil conservation was affected by various factors.Except soil conservation services,the impacts of land types on spatial heterogeneity of ecosystem service functions were significantly greater than other factors;(4)meteorological factors largely determined the inter-annual differences in ecosystem service functions,and land types were the main factors affecting their spatial distribution.