B. Courbaud - Mountain v 2.2 - april 2003

Benoît Courbaud (IRSTEA) Cemagref 2 rue de la papeterie BP76 38402 Saint Martin d'Hères cedex.

Mountain is a model of forest dynamics designed to the study of stand structure / stand dynamics / silviculture interactions.

It can be used to compare thinning strategies and to understand how demographic processes at the tree level (regeneration, growth, death) generate patterns at the stand level.

As a spatial individual tree model, it is especially devoted to study spatial structure dynamics.

Mountain is a spatial individual tree model (Distance Dependent Tree Model).

Trees are characterized by their position (x, y, z), height, diameter at breath height, crown base height and crown base radius.

Plot is rectangular, with mean slope and aspect. It is divided in square cells (1 to 5 m. wide) characterised by the presence of regeneration.

Light interception is calculated for every tree and every cell taking into account stand structure, slope and aspect.

Growth, death and competition are modelled at the tree level for every individuals higher than 1.30 m. Regeneration is modelled at the ground cell level.

Tree height and diameter increments are calculated as the product of a potential increment by a reducer depending on the ratio between light intercepted by the tree and potential light intercepted by a tree of the same size in free growth.

Tree death is stochastic and depends on light ratio.

Seedling emergence, growth and death depend on light on cell surface.

• Real stands :

File with the characteristics of each tree (Id, x, y, z, height, diameter, crown base height).

Missing data can be evaluated using virtual stand tools.

• Virtual stands (link with F. Goreaud's spatial library) :

Trees can be generated from diameter distributions and height/diameter curves.

Tree positions can be generated with different spatial characteristics.

A map of tree crowns, light at soil surface and regeneration.

Various curves, histograms and scatterplots of tree and stand dendrometric characteristics.

Mountain has been validated for Norway spruce uneven-aged stands of the French Alps.

Courbaud, B., Goreaud, G., Dreyfus, Ph., Bonnet, F.R., 2001 : Evaluating thinning strategies using a Tree Distance Dependent Growth Model: Some examples based on the CAPSIS software “Uneven-Aged Spruce Forests” module. Forest Ecology and Management.

Courbaud, B., deColigny, F., Cordonnier, Th., 2002 : Evaluating qualitatively and quantitatively a light transmission model in spatially heterogeneous Norway spruce (Picea abies, L. Karst) mountain forests. Submitted to Forest and Agricultural Meteorology.