Gradient Characteristics and Nonlinear Driving Mechanisms of “Production–Living–Ecological” Space Evolution in Mountainous Villages: A Case from Taiji Town, Chongqing

The evolution of “Production–Living–Ecological” spaces (PLESs) in mountainous rural areas is shaped by complex interactions between terrain gradients and socio-economic factors. However, existing research lacks a targeted exploration of their evolution and driving mechanisms at the town scale. This study takes Taiji Town in Chongqing, China, as a case study and identifies land use data for mountainous rural areas. Based on this, “Production–Living–Ecological” attributes are assigned to each land use class, terrain gradients are delineated using the Terrain Niche Index, and the gradient-specific characteristics and spatiotemporal distribution patterns of PLES evolution in mountainous rural areas are analyzed. Additionally, the nonlinear driving mechanisms of PLES evolution are explored by incorporating variables such as terrain gradient, geographical location, social development, and ecological landscape. The results show that the evolution of PLES in Taiji Town generally follows a trend of decreasing production space, expanding living space, and steadily increasing ecological space. Furthermore, topographic constraints form a bottleneck in the evolution of production space in mountainous rural areas, with some production space boundaries extending into higher-gradient areas. Analysis of the driving mechanisms reveals that the interactions between land use degree evolution and elevation, as well as between land use degree evolution and slope, are key factors influencing the evolution of PLES, with significant differences across villages with varying topographic conditions. This study provides a scientific basis and methodological reference for observing spatial evolution and optimizing spatial planning at the town scale.