Regeneration and Resource Sharing : A model to simulate the dynamic of uneven-aged forest stands and taking explicitly into account the competition for resources, water and light, between the different forest strata.

The model includes the Regeneration library.

Authors :

• Philippe Balandier, Noémie Gaudio

Irstea, Research Unit on Forest Ecosystem (EFNO), 45290 Nogent-sur-Vernisson, France, philippe.balandier@irstea.fr

Present address: Philippe Balandier, INRAE, UMR547 PIAF, 63100 Clermont-Ferrand, France, philippe.balandier@inrae.fr

• Nicolas Donès

INRAE, UMR547 PIAF, 63100 Clermont-Ferrand, France, nicolas.dones@clermont.inra.fr

• François de Coligny

INRA, UMR AMAP, 34398 Montpellier, France, coligny@cirad.fr

Objectives and content

Currently, there is a strong trend to adapt forest management towards silviculture in accordance with natural processes. Modelling forest dynamics is a key tool to assist the management of complex uneven-aged forest stands, particularly in the context of climate change.

The RReShar model (Regeneration and Resource Sharing) is a functional - structural model. Stand structure is described, including all the strata of the forest ecosystem, i.e. adult trees, suppressed trees, saplings and seedlings growing in the understorey (regeneration) and herbaceous/shrubby vegetation. Growth processes of all those components are based on the interactions for light and water.

The simulated scene is a 1 ha plot divided into square cells of a chosen size (a few meters). Adult trees are explicitly spatialised on the plot, whereas understorey vegetation and regeneration are considered as a multi-species layer whose characteristics vary at the cell level. Vegetation is described by its height and cover. Tree regeneration, i.e. seedlings and saplings, are initialised as cohorts characterized by a diameter and height distribution. The overstorey and understorey growth time step is annual, whereas within this annual loop, the light interception and water cycle (interception, evapotranspiration and soil water content) processes are simulated, respectively, monthly and daily.

More recently, herbivory by wild ungulates was added as part of the Regeneration library.

RReShar has been used to simulate uneven-aged mixed Quercus petraea – Pinus sylvestris stands with an understorey colonised by Calluna vulgaris, Pteridium aquilinum and Molinia caerulea in temperate conditions as well as Mediterranean pine stands (Pinus halepensis) with oak (Quercus coccifera) in the understorey and saplings of Arbustus unedo, Fraxinus ornus and Sorbus domestica. More recently bramble (Rubus sp.) and seedlings of Quercus petraea, Carpinus betulus and Fagus sylvatica were added as part of the Regeneration library as a model of herbivory.

However, the model was built to be as generic as possible and can be easily run with other species and climatic conditions.

Technical documentation

A technical page to help connect the regeneration library to a growth model.

References

Article scientifique

HELLUY M., FERNANDEZ C., PREVOSTO B., CAILLERET M., BALANDIER P., 2020. Competition and water stress indices as predictors of Pinus halepensis Mill. radial growth under drought. Forest Ecology and Management, 460, 117877.

Article technique

PREVOSTO B., AUDOUARD M., HELLUY M., LOPEZ J.M., BALANDIER P., 2018. Le bilan hydrique en forêt méditerranéenne : influence des strates et de leur gestion Application au pin d’Alep. Forêt Méditerranéenne, XXXIX, 1, 10 p.

Communication à des colloques

DONES N., GAUDIO N., BALANDIER P., 2009. RReShar, a model to simulate forest regeneration relative to light and water shared with understorey vegetation. In : “gestion des forêts mélangées : apport de la biologie des populations et de l'écologie fonctionnelle”, colloque de restitution du projet “Bases d'une gestion durable des forêts mélangées : écophysiologie, croissance et démogénétique des espèces constitutives”, Nancy, 2010/10/06-07, 1 p.

GAUDIO N., BALANDIER P., DONES N., DE COLIGNY F., GINISTY C., 2010. RReShar (Regeneration and Resource Sharing), a model to simulate the uneven-aged forest stand dynamics. 7th IUFRO Workshop on Uneven-aged Silviculture: 21st Century forestry: Integrating ecologically based, uneven-aged silviculture with increased demand for forests. Ljubljana, Slovenia, 2010/09/23-26, p. 64.

BALANDIER P., DONES N., LE TEXIER E., DE COLIGNY F., 2013. RReShar: a functional –structural forest model to simulate tree regeneration according to resources. ISEM 2013, Ecological Modelling for Ecosystem Sustainability. Toulouse, France, 2013/10/28-31.

HELLUY M., PREVOSTO B., BALANDIER P., DONES N., 2018. Modelling Mediterranean pine stand dynamics: a first functional approach. MedPine6, Rehovot, Israel, 2018/10/08-11.

HELLUY M., PREVOSTO B., BALANDIER P., DONES N., 2019. RReShar: Regeneration and Resource Sharing. État d’avancement et perspective de développement du modèle. Séminaire Caqsis, Aix-En-Provence, France, 2019/03/26-28.

HELLUY M., BALANDIER P., DONES N., BEUDEZ N., DE COLIGNY F., PREVOSTO B., 2019. Modelling Mediterranean pine stands dynamics: a first functional approach with the RReShar model. The international society for ecological modelling (ISEM), Global Conference 2019, Salzburg, Austria, 2019/10/01-05.

BALANDIER P., 2022. Qu’y a-t-il dans la bibliothèque Regeneration de Capsis. Journées FOREM, Orléans, France, 22 – 23 mars 2022.

Doctorat

GAUDIO N., 2010. Interactions multi-strates en forêts hétérogènes : conséquences pour la régénération et modélisation structure – fonction sur les 3 strates de l'écosystème forestier. Université d'Orléans, Orléans, (FRA), Cemagref, Nogent-sur-Vernisson, (FRA).

HELLUY M., 2020. Adapter la gestion des forêts méditerranéennes au changement climatique : rôle des strates de végétation et modélisation fonctionnelle de la dynamique forestière. Thèse de doctorat, Université Aix – Marseille, France.

BARRERE J., 2021. Interactions entre chêne et cervidés durant le processus de renouvellement - cas des peuplements forestiers tempérés de plaine (Quercus robur et Q. petraea). Thèse de doctorat Biologie et écologie des forêts et des agrosystèmes, Université de Lorraine, Nancy, France.

Mémoire d’étudiants

LE TEXIER E., 2013. Modélisation structure – fonction du partage des ressources dans l’écosystème forestier – Modèle RReShar. Master 2 Ecologie, parcours Modélisation des Systèmes Ecologiques, Université Paul Sabatier, Toulouse, France, 31 p. + ann.

PALIE W., 2014. Evaluation de la cohérence et des performances de RReShar, un modèle de dynamique forestière. Master 1, Université Blaise Pascal, Clermont-Ferrand, France, 16 p.

PALIE W., 2015. Modélisation du bilan hydrique en structure forestière irrégulière à plusieurs strates – Application à la simulation de la dynamique forestière. Master 2 Biologie et Environnement, spécialité GEPV, Université de Blaise Pascal, Clermont-Ferrand, France, 46 p. + ann.

HELLUY M., 2017. Une première approche de modélisation fonctionnelle de la dynamique des forêts méditerranéennes. Stage de fin d’ingénieur, AgroSupDijon, Irstea Aix-en-Provence, France, 37 p.

DELAPLACE A., 2018. Validation d’un modèle de régénération du pin sylvestre en forêt mixte. Utilisation du modèle RReShar. Université de Rennes 1, Master modélisation en écologie. 20 p.