基于地形梯度的南方丘陵山地带生态系统服务价值对城市化的空间响应--以粤北地区为例

Ecosystem service value and its spatial response to urbanization based on terrain gradient in southern hilly and mountainous region--A case study in northern Guangdong,China

南方丘陵山地带是我国华南和西南地区重要的生态安全屏障带,具有重大的生态保护意义,而在当今快速城市化的进程下,保障该地区的生态资源与生态稳定对于我国实现可持续发展具有十分重要的战略意义。以丘陵山地带的典型区域粤北为例,依据地形位指数将研究区划分为5个地形梯度,并基于1990—2015年6期的土地利用遥感数据和社会经济的统计数据,利用地理信息技术和空间统计的方法,评估了粤北地区不同时期随地形梯度变化的各区域生态系统服务价值(Ecosystem service value,ESV)与城市化水平(Urbanization level,UL),之后探究了生态系统服务价值与城市化的空间相关性。研究结果表明:(1)1990—2015年期间,粤北地区城市化水平上升,且地形位指数为0.003—0.368的梯度1区域城市化水平最高。(2)研究期间粤北地区的生态系统服务价值呈轻微下降趋势,随着时间推移,ESV在低坡度、低海拔的地形梯度1区域下降率最高,而各个年份的ESV均随着地形梯度的升高而增加。(3)研究区自2000年后的土地利用类型转移的活跃程度加剧,其中主要是地形梯度1区域及周围的耕地、林地与建筑用地间发生转移。(4)空间相关性分析表明,粤北地区生态系统服务价值与城市化水平具有较强的负相关关系,且在研究期间负相关性明显增强;同时两者具有较显著的空间聚集效应,其中低ESV-高UL型集中分布于地形梯度1的韶关市与清远市区以及南雄市,高ESV-低UL型则分布在梯度相对较高、人口相对分散的少数民族自治县。研究探讨了粤北地区生态系统服务与城市化的时空关系并了解了各区域的发展模式,有助于进一步认识生态系统对于社会经济发展的支持作用,保持生态保护建设与经济发展的协调与平衡,从而保障和维护南方丘陵山地带的生态价值。

The southern hilly and mountainous region is an important ecological barrier in south and southwest China,which is of great significance for ecological protection.With the rapid development of urbanization,it is of great strategic significance to ensure the ecological resources and ecological stability in this region for the sustainable development of China.In this study,the north region of Guangdong was taken as the study area and divided into 5 terrain gradients according to the terrain index.Then we used data of land use and social economy from 1990 to 2015 and evaluated urbanization level and ecosystem service value(ESV)in the study area on the basis of the terrain gradient by using spatial statistical methods.In addition,we analyzed the spatial correlation between the ESV and urbanization level(UL)on the terrain gradient.The results showed that(1)during 1990—2015,the urbanization level in the study area showed an uptrend,and the level of urbanization was the highest in the gradient 1 region with the terrain index between 0.003 and 0.368.(2)During the study period,the ecosystem service value the study area showed a slight downward trend.As time went on,the decline rate of ESV was the highest in the terrain gradient 1 region.The ESV increased with the increase of the terrain gradient in each year.(3)After 2000,there was the highest active transfer of land use types in gradient 1 and its surrounding regions,among which the transfer was mainly between farmland,forestland and build-up land.(4)The spatial correlation analysis showed that there was a significantly negative correlation between urbanization level and ecosystem service value in the study area,and the negative correlation was significantly increased during the study period.At the same time,they had a significant spatial aggregation effect,in which the low ESV-high UL type was concentrated in Shaoguan urban districts,Qingyuan urban districts and Nanxiong City of terrain gradient 1,and the high ESV-low UL type was mainly distributed in the minority autonomous regions with a relatively dispersed population and higher terrain gradient.This research discussed the spatio-temporal relationship between ecosystem services and urbanization innorthern Guangdong and understood the development patterns of each region,which is helpful to further understand the supporting role of ecosystem in social and economic development.The purpose is to maintain the coordination and balance between ecological protection construction and urban development,so as to safeguard and maintain the ecological value of southern hilly and mountainous region.