## 4 Conclusions  
This study evaluated the performance of the SITE model when incorporated with parameters and input data consistent with in situ observations from the Caatinga biome, which is a seasonally dry tropical forest in the Brazilian semiarid region. In general, the SITE model exhibited reasonable applicability to simulate variations in CO\({}_{2}\) and energy fluxes. We believe that the SITE model could be used to simulate a satisfactory vegetation response if we take into consideration the remarkable phenological seasonality of the Caatinga. The LE flux was the output variable with the most unsatisfactory adjustment, overestimating observed values in the dry season. Furthermore, our ecophysiological approach offers the possibility to explore morphoanatomical and physiological mechanisms determinants of GPP and NEE in the Caatinga biome. Evaluating and improving the representation of the vegetation structure, dynamics, energy and carbon cycle of the Caatinga in vegetation models will help further develop our understanding on the impacts of land-use changes on regional and global carbon cycle.  
Conceptualization, K.R.M., B.G.B. and C.M.S.e.S.; methodology, K.R.M., B.G.B., C.M.S.e.S., S.C., R.R.F., T.M.R., T.V.M., J.S.d.R., M.M.d.L.V., A.C.N.S., A.M.S.M., D.T.C.d.S. and D.F.d.S.; validation, K.R.M., B.G.B. and C.M.S.e.S.; formal analysis, P.R.M., C.P.O., W.A.G., G.B.C., M.F.P., R.A.M., A.C.D.A. and R.S.C.M.; investigation, K.R.M., B.G.B. and C.M.S.e.S.; writing--original draft preparation, K.R.M.; writing--review and editing, K.R.M., B.G.B., C.M.S.eS, P.R.M., G.B.C., R.A.M., C.P.O. and W.A.G. All authors have read and agreed to the published version of the manuscript.  
This research was funded by National Council for Scientific and Technological Development (CNPq), Process n\({}^{\circ}\) 303802/2017-0 and National Observatory of Water and Carbon Dynamics in the Caatinga Biome (INCT -MCTI/CNPq/CAPES/FAPs 16/2014, grant: 465764/2014-2 and MCTI/CNPq N\({}^{\circ}\) 28/2018, grant 420854/2018-5).  
Not applicable.  
The data presented in this study are available on request from the corresponding author. The data are not publicly available due to privacy.  
The authors are thankful to the Brazilian National Institute of Semi-Arid (INSA) for funding the project which originated the EC data used in this study. We are also thankful to ICMBio (Chico Mendes Institute for Biodiversity Conservation) for providing access to the experimental site and to ESEC-Serido (Ecological Station of Serido) for supporting experimental activities. The authors are also thankful to the Coordination for the Improvement of Higher Education Personnel (CAPES) for the postdoctoral funding granted to the first author. This work was partially supported by the high-performance computing facilities of NPAD/UFRN. Finally, we are thankful to the National Council for Scientific and Technological Development (CNPq) for the research productivity grant of the last author (Process n\({}^{\circ}\) 303802/2017-0) and the financial support in the NOWCDCB project: National Observatory of Water and Carbon Dynamics in the Caatinga Biome (INCT -MCTI/CNPq/CAPES/FAPs 16/2014, grant: 465764/2014-2 and MCTI/CNPq N\({}^{\circ}\) 28/2018, grant 420854/2018-5).  
The authors declare no conflict of interest.