Farmland fragmentation due to anthropogenic activity in rapidly developing region

Measuring farmland fragmentation and its interactions with anthropogenic activities can advance our understanding of complexity in agricultural systems. Majority of previous studies focused on farmland ownership fragmentation rather than physical landscape fragmentation. This paper characterized the farmland landscape fragmentation dynamics in Tiaoxi watershed (China) from 1985 to 2013 using a set of variables (area-weighted mean patch area, patch density, area-weighted mean shape index, mean Euclidean nearest neighbor distance, splitting index, and effective mesh size). Four categories of anthropogenic drivers (demographic, economic, social and cultural, and scientific and technological) and their relative importance were quantified by multiple regression and variance partitioning. Results showed a linear increasing trend of farmland fragmentation in Tiaoxi watershed during the study period. Drivers for farmland fragmentation differed with variables. In general, non-agricultural population and migration population were the key demographic drivers, while road mileage and investment in real estate were the principal social drivers. Two groups of economic drivers were identified: one group included fruit and seafood production, another included per capita income and proportion of tertiary industry. Besides, education expenses increases and technological improvement could significantly reduce farmland fragmentation. Considering the relative importance for different categories of drivers, economy was the most influential driver; its joint influences with social and cultural drivers and those with scientific and technological drivers were relatively stronger. Our study advanced the understanding of principle anthropogenic drivers influencing farmland fragmentation dynamics.