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Abstract: Urban land development substantially alters the terrestrial carbon cycle, particularly the net primary productivity (NPP), from local to global scales. However, limited attempts have been undertaken to elucidate the differences in NPP between pre- and post-urban land development in China. In this paper, the terrestrial NPP after urbanization in China was assessed by using the Carnegie-Ames-Stanford approach (CASA), toward which a calibration was conducted for adapting this model on the fine-scale application. In addition, a method of neighborhood proxy was applied to acquire the NPP in the absence of urban land development, assuming that non-urban lands can represent their nearby urban lands before they were transformed. Our analyses indicate that urban land development had overall negative effects on terrestrial NPP. They reduced the NPP at an accelerating rate of 0.31×10−3 PgCyear−1, approximately 5.88% of the annual reduction during the period of 2000–2006 in China. Furthermore, these effects of NPP variations exhibited obvious differences in the amounts and spatial distributions. However, the NPP showed a slight increase around some regions that experienced rapid urbanization, as well as the arid regions in northwest China. These were probably caused by the effects of Urban Heat Island (UHI) and Urban Rain Island (URI), an introduction of faster growing exotics, various resource augmentations and so on. [Copyright &y& Elsevier]

• How vegetation greenness and carbon flux respond to extreme droughts was quantified. • Drought caused the largest reduction in GPP than NEP and LAI across China. • Forest was less sensitive to extreme droughts. • Loess Plateau was highlighted as the most vulnerable region. Increasing drought stress under climate change exerting large impacts on vegetation has aroused growing concern, yet how vegetation greenness and carbon cycle respond to extreme drought is not well understood. In this paper, we studied this issue with various data sources including satellite observation, flux sites upscaling estimation, atmospheric inversion, and Dynamic Global Vegetation Model (DGVM) simulations over China during the period 2000–2015. We found a highly consistent negative response of greenness and carbon fluxes to extreme droughts, with the largest reduction in Gross Primary Productivity (GPP, a standardized anomaly of -1.26 ~ -0.33), a slightly smaller extent decrease of Net Ecosystem Productivity (NEP, -0.74 ~ -0.14) due to concurrent decrease of respiration, and reduced Leaf Area Index (LAI, -0.39 ~ -0.20). Besides, there was a large spatial heterogeneity across different regions and biomes, where Loess Plateau was one of the most vulnerable regions. The ambient climate conditions were found to modulate the drought response. Drought sensitivity of greenness and GPP peaked where mean annual temperature is around 25 °C, while that of NEP decreased along increasing precipitation gradients. [ABSTRACT FROM AUTHOR]