RATP

The model computes the spatial distribution of the radiation balance, the energy balance and leaf gaz exchanges of a leaf crown. Input data are the microclimate variables, physical and physiological features of the leaves, and a 3D representation of the leaf crown. The latter is a matrix of voxels, each voxel is characterized by a leaf area density value. Computation of the radiation balance is based on a turbid medium approach at the voxel scale. Solving the energy balance at the same scale needs to involve stomatal conductance and leaf transpiration computation for estimating the latent heat flux. Leaf photosynthesis is estimated by using the Farquhar model. All output variables (mainly leaf temperature, stomatal conductance, transpiration and photosynthesis) are computed for sunny and shaded leaves, at a half-hourly to hourly time step.

Some recent studies using RATP:

- Le Roux, X. , Bariac, T. , Sinoquet, H. , Genty, B. , Piel, C. , Mariotti, A. , Girardin, C. and Richard, P. (2001), Spatial distribution of leaf water‐use efficiency and carbon isotope discrimination within an isolated tree crown. Plant, Cell & Environment, 24: 1021-1032. https://doi.org/10.1046/j.0016-8025.2001.00756.x

- Saudreau, M., Pincebourde, S., Dassot, M., Adam, B., Loxdale, H.D., Biron, D.G., 2013. On the canopy structure manipulation to buffer climate change effects on insect herbivore development. Trees Struct. Funct. 27 (1), 239–248. https://doi.org/10.1007/s00468-012-0791-7

- Ngao, J., Adam, B. and Saudreau, M., 2017. Intra-crown spatial variability of leaf temperature and stomatal conductance enhanced by drought in apple tree as assessed by the RATP model. Agricultural and Forest Meteorology, 237–238: 340-354. https://doi.org/10.1016/j.agrformet.2017.02.036