Dynamique de la Diversité Forestière

Objectives

Both census of biodiversity and ecosystem monitoring (e.g., by remote sensing) are generating large amounts of data, from which theoretical insights on diversity origin and maintenance should be drawn along with practical information for decision-making about species’ conservation or sustainable utilisation. However, numerical methods to process these data still necessitate a great deal of development to meet the challenge of elucidating and mimicking complex, interacting and multi-scale ecological processes.

Of particular relevance, from both theoretical and practical standpoints, is evaluating the respective influence of niche- vs. dispersal-driven processes on spatial distributions of plant taxa and on plant species assemblages. In close collaboration with research carried out in French Guiana (Amazonian region), we intend to contribute to development, adaptation or refinement of quantitative methods for analysing or modelling tree species diversity at spatial scales ranging from rainforest stands to regional ecological gradients.

Materials and Methods

The Western Ghats of India, one of the tropical biodiversity "hot-spots", provide a very favourable situation for methodological development and testing, thanks to the presence of several interacting ecological gradients (e.g., rainfall, elevation, human pressure) and also thanks to expertise and data available at IFP. It therefore represents a very interesting situation to get insights on topics such as spatial relationships between congeneric or vicariant species, spatial dispersal around supposed quaternary refuges or persistence of scarce species in forest stands...

To get broad scale information on forest structure, we are developing a method for textural analysis of very high spatial resolution (VHR) images of forest canopy, which offers good prospects to predict stand structure parameters (e.g. tree density or average diameter). We have also proposed a multi-scale approach (see references below) unifying diversity indices and multivariate analyses of species assemblages, which is applied to data available for the Western Ghats, such as floristic plots or plant species geographical occurrences. A permanent station (in Uppangala, Karnataka), which is monitored by IFP since 1990, provides multi-temporal data on tree growth and demography, is used to design, calibrate and validate 3-D, spatially explicit models of forest dynamics.

Partners

• AMAP (botAny and bioinforMatics of the Architecture of Plants) laboratory, Montpellier, France. Joint Research Unit of CIRAD, CNRS, EPHE, INRA, IRD, and University of Montpellier II (http://amap.cirad.fr/).
• University Claude Bernard Lyon-1, Laboratory of Biometry and Evolutionary Biology, UMR CNRS 5558 (http://biomserv.univ-lyon1.fr)
• Free University of Brussels, Research Unit in Evolutinary Eco-Ethology, Brussels, Belgium (http://www.ulb.ac.be/rech/inventaire/unites/ULB118.html)

Funding

• Institut Français de Pondichérry
• AMAP
• Ministère de l’Environnement et du Développement Durable (MEDD), France. Programme Ecosystème Tropicaux, projet OSDA (2007-2009) « Organisation spatiale des arbres des forêts tropicales » (Spatial organisation of tree diversity in the tropical forests)

Team

IFP

• Dr. R. Pélissier - Head of Ecology department
• Dr. B.R. Ramesh - Head of Botany laboratory
• Dr. N. Ayyappan - Botanist
• Dr. F. Borne - Head of Geomatics and Applied Informatics laboratory
• C. Madelaine - PhD candidate
• Champak B.R. - PhD candidate
• Quentin Renard - Research Assistant
• D. Venugopal - Research Assistant
• H. Rammohan - Research Assistant
• S. Ramalingam - Assistant

AMAP

• Dr. P. Couteron - Plant ecologist IRD
• Dr. F. Munoz - Plant ecologist UM2
• Dr. G. Vincent - Forest modeler IRD

University C.B. Lyon-1

• Dr. S. Dray - Biometrician

University Libre de Bruxelles

• Dr. O. Hardy, researcher

Main Outputs

Articles

• GIRIRAJ, A., IRFAN-ULLAH, M., RAMESH, B. R., KARUNAKARAN, P. V., JENTSCH, A. AND MURTHY, M. S. R. 2008. Mapping the potential distribution of Rhododendron arboreum Sm. ssp. nilagiricum (Zenker) Tagg (Ericaceae), an endemic plant using ecological modelling. Current Science, 94(12) : 1605-1612.

• MUNOZ F., COUTERON P. & RAMESH B. R. Beta-diversity in spatially implicit neutral models : a new way to assess species migration. The American Naturalist, 172(1) : 116-127. (see Chicago Journals)

• PELISSIER, R., COUTERON, P. & DRAY, S. Analyzing or explaining beta-diversity ? Comment. Ecology, [in press]

• MUNOZ, F., COUTERON, P., RAMESH, B.R. & ETIENNE, R.S., 2007. Inferring parameters of neutral communities : from one Single Large to Several Small samples. Ecology, 88 : 2482-2488.

• MADELAINE, C., PELISSIER, R., VINCENT, G., MOLINO, J.-F., SABATIER, D., PREVOST, M.-F. & DE NAMUR, C., 2007. Mortality and recruitment in a lowland tropical rain forest of French Guiana : effects of soil type and species guild. Journal of Tropical Ecology, 23 : 277-287.

• PELISSIER, R. & COUTERON, P., 2007. An operational, analytical framework for species diversity partitioning and beta-diversity analysis. Journal of Ecology, 95 : 294-300. (see also http://pelissier.free.fr/Diversity.html for illustrations and a free computer library for R).

• PROISY, Ch., COUTERON, P. & FROMARD, F. 2007. Predicting and mapping mangrove forest biomass from canopy grain analysis using Fourier-based textural ordination of IKONOS images, Remote Sensing of Environment, 109 : 379-392.

• MAGNUSSEN S., PÉLISSIER R., HE F. & RAMESH, B.R., 2006. An assessment of sample-based estimators of tree species richness in two wet tropical forest compartments in Panama and India, International Forestry Review, 8 : 417-431

• MUTHURAMKUMAR, S., AYYAPPAN, N., PARTHASARATHY, N., DIVYA MUDDAPPA, SHANKAR RAMAN, T.R., ARTHUR SELWYN & ARUL PRAGASAM, L., 2006. Plant community structure in tropical rainforest fragments of the Western Ghats, India, Biotropica, 38 : 143-160.

• OLLIER S., COUTERON P. & CHESSEL D., 2006. Orthonormal transform to decompose the variance of a life-history trait across a phylogenetic tree. Biometrics, 62:471-477.

• COUTERON P. & OLLIER S., 2005. A generalized, variogram-based framework for multiscale ordination. Ecology, 86 : 828-834. Get preprint. Free computer libraries are available for R (see http://pelissier.free.fr/Diversity.html) or for Matlab® on request to Pierre Couteron.

• COUTERON P., PELISSIER R., NICOLINI E. & PAGET D., 2005. Predicting tropical forest stand structure parameters from Fourier transform of very high-resolution remotely sensed canopy images. Journal of Applied Ecology, 42:1121-1128. Get preprint

• RANI M. KRISHNAN & RAMESH, B.R., 2005. Endemism and sexual systems in the evergreen tree flora of the Western Ghats, India, Diversity and Distribution, 11 : 559-565.

• COUTERON P. & PELISSIER R., 2004. Additive apportioning of species diversity : towards more sophisticated models and analyses. Oikos, 107:215-221. (see also http://pelissier.free.fr/Diversity.html for illustrations and a free computer library for R).

• PASCAL J.-P., RAMESH B.R. & DE FRANCESCHI D., 2004. Wet Evergreen Forest Types of Southern Western Ghats, India. Tropical Ecology, 45:1-12.

Work in progress...