## 2 Materials and Methods
### The CARAIB Dynamic Vegetation Model  
CARAIB (CARBon Assimilation in the Biosphere) is a process-based model originally developed to understand the role of vegetation in the global carbon cycle [68; 69]. It has also been used to reconstruct potential vegetation distribution under past climates (e.g., [46; 70]) and to project land ecosystem evolution in the future [47], including in tropical regions [49; 50]. It calculates the carbon and water transfers between the atmosphere, the vegetation and the soil. Depending on the studied area, vegetation is represented by plant functional types (PFTs) or by a set of selected species that are ecologically or economically important. Each species corresponds to a pool of carbon biomass (wood, leaves) per unit area calculated on every grid cell of the simulated domain. It is not an individual-based model. More detailed descriptions of CARAIB modules can be found in previous studies [47; 48; 71; 72]. [PERSON] et al. [49; 50] showed evidence of the rather good accuracy of the model to simulate distribution of species in the tropical Brazilian Atlantic Forest. The environmental inputs of the model are climate data first: the monthly fields of the mean surface air temperature, diurnal temperature range, precipitation, wind speed, relative sunshine \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline  & & & & & \multicolumn{4}{c}{**Ecosystem Services**} \\ \cline{3-10}  & _Species_ (Family) & & & & & **fooler** & **met** & **rit/soc** & **envi** & **poison** & **constr** & **mat** & **fuel** \\ \hline
1 & _Ceibn pentandra_ (Malvacaeae) & x & x & x & & x & & x & x & \\
2 & _Cola acuminata_ (Malvacaeae) & x & x & & & x & & x & \\
3 & _Elekis quinensis_ (Arecaceae) & x & x & & & & & x & x \\
4 & _Guiburta demeusel_ (Fabaceae) & x & x & x & x & x & x & x & x \\
5 & _Lophira alata_ (Ochnaceae) & & & x & & x & & x & x & x \\
6 & _Musang acceptioides_ (Utricaceae) & x & & x & x & & & x & x & \\
7 & _Nuclea diiderichi_ (Rubiaceae) & & x & x & x & x & & x & x & x \\
8 & _Perciopsis elata_ (Fabaceae) & & & & & & & & x & x \\
9 & _Percatorus soyauxii_ (Fabaceae) & & & x & & & & x & x & x \\
10 & _Pycranthus angelensis_ (Myristicaceae) & & & x & & x & x & x & x \\
11 & _Symphonia globulifera_ (Clusiaceae) & & & x & & x & & x & x & x \\
12 & _Llapuca quinensis_ (Euphoriaceae) & x & & x & & x & & x & x & x \\ \hline \hline \end{tabular}
\end{table} 
Table 1: The selected species and the ecosystem services they provide as reported by the BIOSERF (Sustainability of tropical forest biodiversity and services under climate and human pressure) project [54] supplemented with data from the PROTA (Plant Resources of Tropical Africa) database (www.prota4u.org). The services are food, fodder, medicinal uses (med), ritual or social uses (rit/soc), environmental uses (envi), poison, construction (constr), materials (mat) and fuel. hours and air relative humidity; the daily values being determined by a stochastic generator [73]. Other environmental input data include soil characteristics, such as texture and color, the average altitude of the grid cell, and the atmospheric CO\({}_{2}\) mixing ratio (which is assumed to be constant on the simulated domain, but varies from year to year). The outputs of the model are, among others, carbon fluxes and stocks, soil hydrology and surface energy balance. Those of main interest for this study focusing on provisioning services by plants are the calculation of species net primary productivity (NPP expressed per unit area, g C m\({}^{-2}\) yr\({}^{-1}\)) and species biomass (g C m\({}^{-2}\)) by taking interspecific competition for space, light and water into account [47; 71]. Besides the impacts of temperature, precipitation or sunshine on plant productivity that are easy to infer, relative humidity and wind speed influence respectively the stomatal regulation and the aerodynamics at the top of the canopy. If air relative humidity is low, the plant will tend to close its stomata to prevent water loss.