A strategy of building a beautiful and harmonious countryside: Reuse of idle rural residential land based on symbiosis theory

In most of China's rural areas, there lies in a misallocation conflict between abundance of idle rural residential land (IRRL) and the scarcity of land used for the construction of beautiful and harmonious countryside (CBHC). It's a key challenge to effectively utilize and allocate these idle construction land resources to promote CBHC. This study developed a theoretical framework employing symbiosis theory to establish symbiotic system among multiple rural stakeholders, applied the selection principle of symbiotic interface to create the criteria for the IRRL reuse, and selected one IRRL to verify the construction strategy of public spaces. Using Silong village in Chongqing as a case study, the study unveiled the process and allocation mechanisms governing IRRL reuse from a patch-level perspective. The findings demonstrate that: (1) rural multi-subjects can use IRRL as a symbiotic interface to foster symbiotic relationships; (2) 26.92% and 73.08% of IRRL were allocated to public space and industrial land, respectively; (3) 57.14% of the IRRL for public space can serve residents across multiple village groups; and (4) retaining the original landscape pattern, enhancing infrastructure and incorporating local culture elements are principles for reusing IRRL in the development of public spaces. This study holds significant theoretical and practical implications for advancing CBHC, contributing to the United Nations Sustainable Development Goals (SDGs) and providing a Chinese sample for other developing countries worldwide.