No abstract

Natural habitat plays an important role in maintaining biodiversity. Both cropland expansion and urban expansion have an influence on natural habitat. However, it is not clear which one impacts more seriously on both the quantity and quality of natural habitat. This study compared the impacts of cropland expansion on the quantity and quality of natural habitat in China between 2000 and 2015 with the impacts of urban expansion. Map algebra in ArcGIS 10.6 was used to calculate the changes in the quantity of natural habitat, while the Integrated Valuation of Ecosystem Services and Trade‐offs (InVEST) Habitat Quality model was used to assess the changes in its quality. The results indicated that cropland expansion led to a loss of 35,811 km2 of natural habitat, which was twelve‐times as much as that from urban expansion. Furthermore, the area of the heaviest habitat degradation due to cropland expansion was 9,530 km2, which was eight‐times as much as that due to urban expansion. Noticeably, the greatest impacts of cropland expansion on natural habitat mostly occurred in areas where the ecological environment is already vulnerable (namely, the resistance and resilience of ecosystems in response to external interference are weak), whereas the impacts of urban expansion were much less in these areas. This study highlights that the impacts of cropland expansion on both the natural habitat loss and degradation far exceeded the impacts of urban expansion. It is necessary to improve cropland protection policies to guarantee food security while ensuring little or no harm to natural habitat.

Land use and land cover change is a critical factor of ecosystem services, while water yield plays a vital role in sustainable development. The impact of urban expansion on water yield has long been discussed, but water yield change resulting from cropland protection is seldom concerned. Therefore, this paper aims to investigate the impacts of cropland protection on water yield by comparing the water yield in two cropland protection scenarios (i.e., Strict Cropland Protection scenario and No Cropland Protection scenario). Specifically, the LAND System Cellular Automata for Potential Effects (LANDSCAPE) model was employed to simulate land use maps in the two scenarios, while Water Yield module in the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model was used to calculate water yield. The results show water yield would increase by 8.7 × 107 m3 in the No Cropland Protection scenario and 9.4 × 107 m3 in the Strict Cropland Protection scenario. We conclude that implementation of strict cropland protection in rapid urbanizing areas may cause more water yield, which is also a prerequisite of potential urban flooding risk. This study throws that it is not wise to implement strict cropland protection policy in an area of rapid urbanization.