An inverted U-shaped curve relating farmland vulnerability to biological disasters: Implications for sustainable intensification in China.

Sustainable farmland intensification is necessary in order to harmonize relationships between food security, socioeconomic development, and ecological civilization. However, the degradation of farmland sustainability because of biological disasters represents a major challenge if we are to achieve this intensification. Our understanding of farmland vulnerability to biological disasters (FVBD) remains relatively rudimentary and subjective, limiting its effectiveness as a tool for farmland sustainability analysis. Limited research has also been carried out on FVBD changes taking into account human decisions on farmland use. The aim of this study is to achieve a novel understanding of FVBD change and its implications for sustainable intensification using evidence from Chinese farmland use. A theoretical framework based on an inverted U-shaped curve that depicts FVBD as well as an assessment framework for FVBD were established using induced substitution of agricultural production. Across China and considering 15 provincial districts with scarce farmland, the relationship between FVBD and socio-economic development was identified as consistent with an inverted U-shaped curve at both national and provincial levels. FVBD values in 2016 across Southern China, on the Huang-Huai-Hai Plain, and on the middle-lower Yangtze Plain were 45.44, 40.58, and 37.22, respectively. These values also decreased in provinces on the middle-lower Yangtze Plain between 1995 and 2016, but increased markedly across provinces in Southern China and on the Huang-Huai-Hai Plain. Contributions to FVBD changes during stages of growth and decline were also analyzed between 1995 and 2016. An inverted U-shaped curve was effective in investigating the responses of farmland sustainability to a range of alternative future socioeconomic development pathways. Thus, in the Chinese settings, a typical country with scarce farmland, policies on FVBD control are essential if we are to promote sustainable farmland intensification. The findings of this work are important and present us with a new way to understand FVBD from a human perspective.