县域土地利用景观格局演变及其生态响应——以河南省新郑市为例

Ecological response to change in land use at the county level:A case study of landscape patterns in Xinzheng City,Henan Province

为了定量分析新郑市土地利用景观格局演变的生态响应及其对生态系统服务价值(ESV)的影响。基于新郑市2005、2010和2015年3期遥感影像解译结果,选取典型的景观格局指数,定量分析新郑市10年间的土地利用景观格局变化特征,并运用ESV估算方法,定量分析新郑市10年间ESV时空变化,以及由景观格局演变引起的生态价值损益,探讨ESV对景观格局演变的响应。结果表明:新郑市景观类型以耕地和建设用地为主,10年间耕地大幅减少,建设用地明显增加,景观类型主要由耕地、林地、草地向建设用地和水域转化;各类景观斑块密度、最大斑块指数及空间格局发生了不同程度的变化,整体景观优势类别控制作用减弱,景观破碎化程度降低,异质性程度提高;新郑市ESV整体呈现先缓慢后急剧的下降趋势,10年间减少了3 494万元,其中,耕地ESV减少最多,为3 406万元,建设用地ESV变化最显著,变化率为59.17%,耕地大量转为建设用地是其ESV降低的根本原因;在空间上新郑市ESV呈现中心区低,西南和西北区高的分布规律,10年间ESV低值区进一步向四周扩散,ESV空间分布愈发不均衡。该研究为新郑市水土保持工程的生态效益提供科学评估,为土地利用总体规划提供科学参考。

[Background] Rapid economic development and population growth in China have led to both environmental deterioration and ecological disturbance in different regions. By studying the effects of change in landscape patterns on Ecological Services Value（ ESV）,we can gain a better understanding of the changes in regional environments and ecologies. This understanding can lead to the creation of a healthier environment and more harmonious ecosystems. [Methods] We examined remotely sensed satellite images of Xinzheng City that were obtained in 2005,2010,and 2015. Changes in land use were quantified in order to create landscape patterns for Xinzheng City over ten years. Then we analyzed thechanges in landscape patterns using values of typical landscape pattern indexes. A method developed from Costanza＇s calculation was used to estimate ESV. We also analyzed the effects of landscape pattern change on ESV. [Results]Farm land and build-up land were the two main landscape types in Xinzheng City. The total area of farm land decreased,but the total area of build-up land increased significantly over ten years. The landscape types were mainly changed from farm land,forest land and grassland to the build-up land and waters. The patch density,the maximum patch index and the spatial pattern of different landscape types changed in varied degrees,while the landscape diversity index increased as the dominance index and the extent of fragmentation decreased.. The ESV of Xinzheng City declined slowly at first and then declined sharply. The total decrease in ESV of Xinzheng City was 34. 94 × 106 RMB Yuan over ten years,of which the ESV of farm land decreased by a maximum of 34. 06 × 106 RMB Yuan.The ESV of build-up land showed the most significant change,an increase of 59. 17%. In terms of spatial distribution,the ESV of Xinzheng downtown was low,while in the southwestern and northwestern areas the ESV was high. During the 10 years from 2005 to 2015,the areas with low ESV grew,and thus the spatial distribution of ESV became more uneven. [Conculsions]This study shows that the reduction of farm land and forest land and the increase in build-up land are the main reasons for ecological deterioration and the related decrease in total ESV. We provide a scientific assessment of the ecological benefits of soil and water conservation projects and a scientific baseline for the overall planning of future land use in Xinzheng City.