Know more

Our use of cookies

Cookies are a set of data stored on a user’s device when the user browses a web site. The data is in a file containing an ID number, the name of the server which deposited it and, in some cases, an expiry date. We use cookies to record information about your visit, language of preference, and other parameters on the site in order to optimise your next visit and make the site even more useful to you.

To improve your experience, we use cookies to store certain browsing information and provide secure navigation, and to collect statistics with a view to improve the site’s features. For a complete list of the cookies we use, download “Ghostery”, a free plug-in for browsers which can detect, and, in some cases, block cookies.

Ghostery is available here for free: https://www.ghostery.com/fr/products/

You can also visit the CNIL web site for instructions on how to configure your browser to manage cookie storage on your device.

In the case of third-party advertising cookies, you can also visit the following site: http://www.youronlinechoices.com/fr/controler-ses-cookies/, offered by digital advertising professionals within the European Digital Advertising Alliance (EDAA). From the site, you can deny or accept the cookies used by advertising professionals who are members.

It is also possible to block certain third-party cookies directly via publishers:

Cookie type

Means of blocking

Analytical and performance cookies

Realytics
Google Analytics
Spoteffects
Optimizely

Targeted advertising cookies

DoubleClick
Mediarithmics

The following types of cookies may be used on our websites:

Mandatory cookies

Functional cookies

Social media and advertising cookies

These cookies are needed to ensure the proper functioning of the site and cannot be disabled. They help ensure a secure connection and the basic availability of our website.

These cookies allow us to analyse site use in order to measure and optimise performance. They allow us to store your sign-in information and display the different components of our website in a more coherent way.

These cookies are used by advertising agencies such as Google and by social media sites such as LinkedIn and Facebook. Among other things, they allow pages to be shared on social media, the posting of comments, and the publication (on our site or elsewhere) of ads that reflect your centres of interest.

Our EZPublish content management system (CMS) uses CAS and PHP session cookies and the New Relic cookie for monitoring purposes (IP, response times).

These cookies are deleted at the end of the browsing session (when you log off or close your browser window)

Our EZPublish content management system (CMS) uses the XiTi cookie to measure traffic. Our service provider is AT Internet. This company stores data (IPs, date and time of access, length of the visit and pages viewed) for six months.

Our EZPublish content management system (CMS) does not use this type of cookie.

For more information about the cookies we use, contact INRA’s Data Protection Officer by email at cil-dpo@inra.fr or by post at:

INRA
24, chemin de Borde Rouge –Auzeville – CS52627
31326 Castanet Tolosan CEDEX - France

Dernière mise à jour : Mai 2018

Menu Bienvenue sur le site PIAF Logo UCA

Home page

RATP

A model for simulating the spatial distribution of Radiation Absorption, Transpiration and Photosynthesis within canopies

Overview

The model RATP (Radiation Absorption, Transpiration and Photosynthesis) was designed to simulate the spatial distribution of radiation and leaf gas exchanges within vegetation canopies as a function of canopy structure, canopy microclimate within the canopy and physical and physiological leaf properties. The model uses a 3D representation of the canopy (i.e. an array of 3D voxels, each one being characterised by a leaf area density) and allows several vegetation types (e.g. foliage of several plants) to be input at voxel scale (Figure 1). Radiation transfer is computed by a turbid medium analogy, transpiration by the leaf energy budget approach, and photosynthesis by the Farquhar model, each applied for sunlit and shaded leaves at the individual 3D cell-scale. The model typically operates at a 30 min time step. Theoretical background and main equations of the RATP model are given in Sinoquet et al., 2001, Plant Cell and Environment.

 

(a)

(b)

Grille Pommier
Grille Voxel Pommier

Figure 1 : Schematic view of a 3D tree mock-up in an array of 3D voxels.

(a) Original 3D tree

(b) 3D voxels colored by radiation absorption

Implementation

The RATP is basically implemented as a set of Fortran90 modules which can be used as a standalone code or as a Python library in the OpenAlea platform (http://openalea.gforge.inria.fr/dokuwiki/doku.php). A Fortran90 module includes public variables and subroutines, which are all accessible in the OpenAlea environment.

OpenAleaRATPWorkFlow

Figure 2 : A RATP simulation in the OpenAlea platform

Applications

The RATP model has been applied to several tree species to assess the effect of tree foliage structure (distribution, type of shoots, leaf physiology) on tree physiology (transpiration, photosynthesis) and pest development

(a)

(b)

RatpApplications_Massonnet
RatpApplications_Pincebourde

Figure 3 : Illustration of RATP applications on :

(a) the within tree crown variability in leaf photosynthesis and transpiration

(b) the within tree crown variability in insect development

 

Contacts :  marc.saudreau@clermont.inra.fr and jerome.ngao@clermont.inra.fr

 

References

Sinoquet H, Le Roux X, Adam B, Améglio T, Daudet FA, 2001. RATP, a model for simulating the spatial distribution of radiation absorption, transpiration and photosynthesis within canopies: application to an isolated tree crown. Plant Cell and Environment, 24, 395-406.

Massonnet C., J. L. Regnard, Lauri P. E, Costes, E. and Sinoquet H., 2008. Contributions of foliage distribution and leaf functions to light interception, transpiration and photosynthetic capacities in two apple cultivars at branch and tree scales. Tree Physiology 28(6): 665-678.

Pincebourde S., H. Sinoquet, Combes D. and Casas J. 2007. Regional climate modulates the canopy mosaic of favourable and risky microclimates for insects. Journal of Animal Ecology 76(3): 424-438.

Saudreau, M., S. Pincebourde, Dassot M., Adam B., Loxdale H. D. and Biron D. G. 2013. On the canopy structure manipulation to buffer climate change effects on insect herbivore development. Trees-Structure and Function 27(1): 239-248.

logo Piaf_2017

Copyright © INRA,Tous droits réservés