Exploring the Effects of Urban Development in Ten Chinese Node Cities along the Belt and Road Initiative on Vegetation Net Primary Productivity

Abstract

Urbanization and economic growth in node cities surged due to the Belt and Road Initiative (BRI), leading to significant environmental changes, notably in vegetation net primary productivity (NPP). Investigating the ecological impact of these urban changes was crucial, despite scarce relevant studies. We employed Sen’s slope estimation and Mann–Kendall trend analysis to study NPP trends (2005–2020) in ten Belt and Road node cities. The Optimized Parameters Geographic Detector Model (OPGD) analyzed factors impacting NPP and their interactions. Results revealed significant NPP variations among the ten cities, ranging from 656.47 gCm−2a−1 to 250.55 gCm−2a−1, with over 79% showing increasing trends. Since 2013, Chongqing, Wuhan, Hefei, Nanchang, and Changsha experienced declining NPP, while the other five cities saw an increase. Natural factors like temperature, precipitation, and DEM predominantly influence rising NPP trends, while anthropogenic factors like land use changes and nighttime light drive NPP decline. Land use changes, with 39.0% explanatory power, primarily affect NPP. After 2013, construction land increased by 117.7 km2 on average, while arable land decreased by 274.8 km2, contributing to decreased vegetation cover NPP. Nighttime lights explained up to 25% of NPP variance. Regions with high nocturnal light values exhibited more developed urbanization but comparatively lower NPP levels.