Spatiotemporal variations of water use efficiency and its driving factors in Inner Mongolia from 2001 to 2020

Water use efficiency (WUE) is an important variable to explore coupled relationships in carbon and water cycles. In this study, we first compared the spatial variations of annual gross primary productivity (GPP) evapotranspiration (ET) using four GPP ET products. Second, selected products closest flux towers data estimate WUE. Finally, quantitatively analyzed impact climate change soil content on The results showed that: (1) Four provided good performance, with GOSIF-GPP FLDAS-ET exhibiting a higher correlation smallest errors tower data. (2) pattern WUE consistent that ET, gradually decreasing from northeast southwest. Higher values appeared forest ecosystem, lower occurred western Gobi Desert, value 0.28 gC m?2 mm?1. increasing trend, while trend (55.15%) 2001 2020. (3) relationship between driving factors reveal Inner Mongolia are mainly affected by moisture 0 10 cm (SM0–10cm), vapor pressure deficit (VPD), precipitation, respectively. (4) arid regions, VPD precipitation exhibit major influence An increase has negative positive effect WUE, threshold approximately 0.36 kPa 426 mm, (5) humid SM0–10cm, VPD, SM10–40cm, SM40–100cm exert significant especially weakens depths, these differences may be related physiological structure living characteristics vegetation types different regimes. Our emphasize importance regional variability