“…The increasing number of eddy-covariance sites across the globe has encouraged the application of data-driven models by machine learning (ML) methods such as artificial neural networks (ANNs, Papale and Valentini, 2003), random forest (RF, Tramontana et al, 2015), model trees ensemble (MTE, Jung et al, 2009;Xiao et al, 2008Xiao et al, , 2010 or support vector regression (SVR, Yang et al, 2006Yang et al, , 2007 to estimate land surface-atmosphere fluxes from site level to regional or global scales (e.g., Beer et al, 2010Kondo et al, 2015;Schwalm et al, 2010Schwalm et al, , 2012Yang et al, 2007;Xiao et al, 2008Xiao et al, , 2010. The ML upscaled outputs are also increasingly used to evaluate process-based land surface models (e.g., Anav et al, 2013;Bonan et al, 2011;Ichii et al, 2009;Piao et al, 2013).…”