Decreased Landscape Ecological Security of Peri-Urban Cultivated Land Following Rapid Urbanization: An Impediment to Sustainable Agriculture

The sustainable management of peri-urban agriculture requires cultivated land to not only be a source of food production, but also contribute ecological resources. This paper presents a method for assessing the landscape ecological security (LES) of peri-urban cultivated land that considers both cultivated landscape and interactions with the surrounding landscape. The situation in Changchun City was assessed at three time nodes. Furthermore, its spatiotemporal variations in several landscape characteristics were also measured. The results suggest that the peri-urban cultivated landscape was affected to varying extents by urbanization. The metrics of PD (patch density), ED (edge density), AWMSI (area-weighted mean shape index), FRAC (fractal dimension) and DIVISION (landscape division index) progressively increased during urbanization for cultivated land within 20 km of the urban gravity center. Elevated fragmentation and vulnerability of the cultivated landscape was also detected. The traditional method for quantifying LES of cultivated land neglects interactions with other landscape types. When the impacts of the ecological and construction landscapes were included, the results better reflected the dynamics of cultivated landscape in a peri-urban area. Decreased LES of cultivated land poses an impediment to the sustainable peri-urban agriculture, and better management practices should be applied for maintaining the LES of peri-urban cultivated land resources.