School of Geography and Ocean Science;
Nanjing University;
Nanjing 210023;
China;
Key Laboratory of Coastal Zone Exploitation and Protection;
Ministry of Land and Resources;
Nanjing 210023;
China;
Natural Resources Research Center;
Nanjing University;
Nanjing 210023;
China;
cultivated land fragmentation; agricultural specialization; regional differentiation; impact;