[Impacts of Shenzhen basic ecological control line on landscape ecological risk]

The Shenzhen Basic Ecological Control Line (SZBECL) has been in operation for more than ten years since its implementation in 2005, which has a significant protective effect on the ecological space. Landscape ecological risk refers to the possible adverse consequences caused by the natural or human-induced interactions between landscape pattern and ecological processes. The scien-tific management of ecological risk is an important prerequisite for the sustainable development of human beings. Therefore, it is of great significance to explore the changes of landscape ecological risk inside and outside the SZBECL. Combining two indicators (ecological sensitivity and landscape vulnerability), we comprehensively evaluated the landscape ecological risk of Shenzhen in 2005 and 2015. The difference-in-difference method was used to explore the impacts of the SZBECL on the landscape ecological risk inside the line. Results showed that the landscape ecological risk in Shen-zhen presented a spatial structure of "high west and low east", which decreased by 13.5% during 2005 to 2015. Inside and outside the SZBECL, the declines of the landscape ecological risk were 0.7% and 14.4%, respectively. For the five subzones, declines were more significant outside the SZBECL, except for the eastern coastal zone. After controlling the effects of other variables, at the municipal level, there was 1.8% higher landscape ecological risk inside the line compared with the region outside the line. Furthermore, at the subzone level, there was 1.6%, 1.6%, 1.4%, and 1.9% higher landscape ecological risk inside the line in the central urban zone, the western coastal zone, the middle zone, and the eastern zone, respectively. There was no significant difference between the inside and outside of the line in the eastern coastal zone. With the implementation of SZBECL, habitat quality and landscape vulnerability inside the line were lowered, but NDVI and population density did not change.