Impact of Cropland Reclamation on Ecological Security in the Yangtze River Economic Belt, China

Feng Yin,Xinli Ke,Ting Zhou

doi:10.3390/su132212735

Abstract

Ecological security is important both for maintaining the function of an ecosystem and for providing ecosystem services to the human wellbeing. The impact of land use change/cover on ecological security has attracted considerable attention, whereas the role of cropland reclamation remains unclear. The indirect loss of ecological land that occurs upon the request of cropland requisition-compensation policies offer further changes to ecological security. In order to ascertain the impact of cropland reclamation on ecological security, in this study three scenarios are established, addressing cropland returning to ecological lands without a slope limitation, with a slope <25°, and with a reclaimed cropland slope ≥25°. This study was conducted in the Yangtze River economic belt (YREB) due to its important contribution to ecological security in China. Land uses in different scenarios in 2030 are projected using the land use simulation model LANDSCAPE. Accordingly, ecological security in each scenario was evaluated using the contribution–vigour–organization–resilience framework, comprising the variables carbon storage, water purification, water yield, habitat quality, net primary productivity, mean patch area, Shannon’s diversity index, largest patch index and contagion, as well as the normalized difference vegetation index. The results indicate that about 62% of YREB land is projected to remain stable in terms of ecological security, while about 21% will deteriorate and 17% will improve between 2015–2030. Land where ecological security is projected to improve is concentrated in areas where broad and connected croplands are distributed. The fact that a higher proportion of areas will deteriorate than improve suggests that the negative impact of cropland change on ecological security should not be ignored. Comparing different scenarios, croplands returning to ecological lands pose a particularly significant impact on ecological security, particularly in the upper reaches of the YREB, where steep croplands are concentrated.

Highlights

Introduction published maps and institutional affilEcological security refers to the state of anatural ecosystem that can sustain its organization and function and has the capability to provide sustainable ecosystem services, as proposed by the International Institute for Applied Systems Analysis (1989).Today, ecological security is under unprecedented pressure due to rapid urbanization and frequent interference from human activities
Using a calibrated LANDSCAPE model, the land uses of the Yangtze River economic belt (YREB) in different scenarios in 2030 were simulated (Figure 3)
This fit well to our case, which revealed cropland reclamation resulting from urban expansion in a hierarchical allocation strategy of land use change, first of urban expansion, followed by cropland reclaimed from ecological lands (SC1, SC2 and SC3) and reclaimed cropland ≥ 25◦ returning to ecological lands (SC3)

Summary

Introduction

Ecological security refers to the state of a (semi-)natural ecosystem that can sustain its organization and function and has the capability to provide sustainable ecosystem services, as proposed by the International Institute for Applied Systems Analysis (1989). Previous research has debated the impacts on ecological security posed by natural disasters [1], urbanization [2,3,4] and land use change/cover (LUCC) [5]. The evaluation of ecological security dates back to the 1980s, when the concept of ecosystem health was first proposed [6,7]. A framework of vigour–organization–resilience (VOR) was developed to evaluate ecosystem health, in line with the definition of health in stress ecology as “system organization, resilience and vigour, as well as the absence of signs of ecosystem distress” [6,8].

Methods

Results

Discussion

Conclusion