Multi-functional trade-offs and synergy research on land systems are hotspots in geography and land science research, and are of great significance for achieving sustainable development of land use and the effective allocation of land resources. Recently, the development of the western region and The Belt and Road Initiative have become key topics, bringing opportunities and challenges to Xi’an. The rapid development of cities is accompanied by drastic changes in land use, and the ecological problems in the Qinling Mountains are becoming increasingly severe. This study took Xi’an as a case study and quantitatively evaluated the spatial-temporal patterns and trade-offs of land system functions such as economic development (ED), grain production (GP), ecological service (ES), etc. on the scale of 1 km × 1 km by fusing the data on land use, topography, soil, climate, and social economy. The results showed that the ED function of the land system continued to rise between 1980 and 2015, the GP function first declined and then increased; however, the ES function continued to decline. The ED, GP and ES functions respectively present a spatial pattern of high-value agglomeration, high in the north and low in the south, and high in the south and low in the north. In general, the three land system functions were trade-offs between each other. In terms of spatial pattern, ED and ES functions showed trade-offs in the south and a synergy distribution in the north; ESs and GP function trade-off zone significantly larger than the synergy zone, the trade-off between the two was significant; while the trade-off and the synergy zone for GP and ED was relatively small, the trade-off zone was the main one. The significant trade-off between GP and ES functions of the land system is a serious problem in land use in Xi’an. Under the premise of limited arable land, it is the current feasible strategy to promote the high-quality development of agriculture to increase the cultivation rate and efficiency, and to strengthen the ecological protection of arable land. In addition, the continued decline of ES functions is also worthy of attention. It is necessary to focus on increasing the greening rate of the city and strengthening the ecological management of the northern foot of the Qinling Mountains.
Temporal changes in greenspace in a highly urbanized region