Land is an important carrier of resource elements, and improving land green use efficiency (LGUE) is the key to achieving “smart growth” in cities. This study takes 269 cities in China from 2008 to 2020 as the research object and integrates multisource remote sensing data, GIS spatial analysis, and spatial econometric models to explore the evolutionary characteristics of LGUE and the spatiotemporal effects of urban expansion on LGUE. The results show that (1) urban LGUE increases over time and has certain gradient distribution and spatial dependence characteristics; (2) urban expansion has a significant inverted U-shaped relationship with LGUE, indicating that maintaining reasonable urban expansion is the key to improving LGUE, but excessive urban expansion has a strong negative spatial effect on LGUE. In terms of spillover effect, for every 1% increase in the square term of urban expansion, the LGUE of the local city decreases by 0.0673%, but the neighboring city increases by 0.2283%; and (3) urban expansion has significant spatiotemporal heterogeneous effects on LGUE, and spatial development boundaries must be reasonably determined to achieve “smart growth”. Currently, some cities in China are expanding rapidly, and we hope to provide key support for promoting the “smart growth” of cities and improving LGUE.

In the context of green development, it is very important to explore the impact of investment in forestry resource management (IFRM) on atmospheric haze pollution and carbon emissions. Based on long time series data of 30 provincial administrative regions in China from 2008 to 2019, this study used ArcGIS spatial analysis and spatial econometric models to investigate the impact of IFRM on haze pollution and carbon emissions and its potential spatial spillover effects. The results show that areas with higher haze pollution concentrations in China were mainly distributed in the Sichuan Basin and the North China Plain; areas with high carbon emission intensity were mainly distributed in Beijing, Shanghai, Tianjin, Shandong, Hebei, etc. For every 1% increase in IFRM, haze pollution and carbon emissions decreased by 0.0655% and 0.1169%, respectively, indicating that IFRM has significantly improved the ecological environment. In addition, IFRM not only significantly reduced haze pollution and carbon emissions in local areas, but also had a strong negative effect on haze pollution in neighboring areas. This study provides important strategies for promoting forestry resource management and regional green development.