Synergy/trade-offs and differential optimization of production, living, and ecological functions in the Yangtze River economic Belt, China

The high-quality development of the Yangtze River Economic Belt (YREB) is a major strategy related to China's overall national development. Based on the synergy/trade-offs of production, living, and ecological functions (PLEFs) in the YREB from 2000 to 2020, this paper puts forward suggestions for the optimization of territorial space to promote the high-quality development of the YREB. The mechanistic equilibrium model was applied to determine the synergy/trade-off relationship of PLEFs, and the key factors affecting the coordination degree were analyzed with the help of a geographical detector and a geographically weighted regression (GWR) model to further identify the trade-off zones and propose differential optimization strategies. The results showed that the average degree of synergy of PLEFs decreased from 0.18 to 0.08 in YREB during the study period, and the coordination developed to a higher level, forming a local patchwork of coordination "highlands" in space, with a gradient divergence of coordination from west to east. The land-use degree, landscape, slope, traffic, and nightlight index were the dominant factors influencing PLEFs, and their q-values were 0.30, 0.27, 0.20, 0.18 and 0.14 in order, with significant spatial differences in the effects of each factor's role. Based on the deviation of the coordination degree of PLEFs, three major function-dominated zones were divided, and it was found that the YREB showed an evolutionary trend of ecological function domination (2000) to production function domination (2010) to ecological function domination (2020). The trade-off zones in antagonistic and dysregulated states were further identified, and the study proposed targeted optimization strategies. The findings provide theoretical reference to promote the sustainable use of territorial resources and high-quality regional development in the YREB and the rest of the country.