PI Bruno Hérault, European Structural Funds 920K€, 2016-2018
Presently, the extension of areas devoted to forest production is particularly rapid in the neotropics, even in the most sparsely-populated forests, such as in the Guiana Shield. For example, in Suriname, production areas have increased from 2.5 M–4.0 M ha in the last twenty years when timber production has doubled from 200,000–400,000 m3 in the last three years. In French Guiana, forests areas managed for production also increased by 2.2 M ha in the last twenty years, but mean annual timber production is still limited to about 75,000 m3, with a very low logging rate of one to six trees ha−1. It is expected that the timber demand will increase, as demographic projections forecast a doubling of the Guianan population before 2030. In both countries, timber selection is concentrated on a few species: Dicorynia guianensis Amsh. (common name: Angélique) and Qualea rosea (Gongolo Rose) constitute 60% of the wood logged in French Guiana and 35% of the wood logged in Suriname. Studies about the possible interactions between climate and logging on forest dynamics are hampered by data availability. The intervals between censuses are often long, and climatic variables need to be aggregated over these long periods, erasing exceptionally wet or dry seasons’ effects. In this project, we took advantage of the Guyafor network made of very long-term logging experiments, where all trees with DBH > 10 cm were censused over a 30-year post-logging period.
We will first develop a methodological framework to estimate and predict the above-ground carbon fluxes from diverse selective logging adn land-use change scenarios. Carbon fluxes will be assessed first at the current logging unit scale, i.e. the elementary management unit of the forest estate, and then integrated in space and time to predict the regional carbon balance over time.
We will then focus on 20 forest species have been identified, together with forest managers, as potentially interesting for the Guianan timber industry using criteria, including natural abundance, current level of exploitation or future logging potential. We will test their vulnerability (both demographic and ecophysiological) to climate change, focusing on the water stress component.
PIs Jerome Chave & Bruno Hérault, Labex CEBA 250K€, 2016-2019
There is mounting interest for applying modeling approaches to project future states of biodiversity and ecosystem functions in response to environmental changes. Although these approaches are currently being developed, few of them offer to study both biodiversity and ecosystem functioning facets in a single modeling framework. This is in part because modeling approaches have a different history and have been developed at different spatial scales. Individual-based dynamic forest simulators provide a means to bridge ecosystem-based and biodiversity viewpoints and to assimilate field and remote sensing data efficiently. The need for such integrated models is particularly pressing in tropical forests, as these forests play a pivotal role in the carbon cycle and they are exposed to major risks, such as land-use conversion, climatic changes, and logging. In the METIST project, we propose to (1) develop an individual-based forest dynamic simulator including the carbon, water, and nutrient balances, and including a species-level parameterization of the main plant-level processes for the tropical forest of French Guiana; (2) mobilize high-resolution remote-sensing data (aerial LiDAR scanning) to inform plant allometry and canopy structural properties, as well as topographical features; (3) mobilize forest dynamic data to validate the model, implement a forest management module and a forest fire module; (4) as a exercise of the model’s scaling properties, scale-up the simulations to the entire area of French Guiana (c.a. 84,000 km 2 ) making use of recent progress in our understanding of tree species distribution and ecological processes at this scale; (5) provide scenarios to assess the impacts of land use change, forest management and climatic change on selected forest types of French Guiana.
The findings of this project should have an impact beyond French Guiana, in other Neotropical forests. It should also provide to the scientific community of Labex CEBA a modeling tool to assimilate information from several research lines (forest ecology, remote sensing, climate science, socio-economics), and suggest optimal development paths for the coastal forests for regional policy and local managers of natural areas, who are faced with practical challenge of maintaining wood production while protecting biodiversity and carbon stocks.
PI Bruno Hérault, Fondation pour la Recherche sur la Biodiversité 250K€, 2011-2015, Webpage
PIs Vivien Rossi & Bruno Hérault, European Structural Funds 450K€, 2011-2015, Webpage
PIs Etienne Dambrine, Sylvie Jérémie & Bruno Hérault, CNRS Amazonie 100K€, 2007-2010
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