On April 16, the kick-off meeting of the French project SYLVABIOM was held in Orléans. All partners were present: INRA Orléans (coordinator), INRA Nancy, University of Orléans, FCBA and IDF (institute for forest develoment). The project (2008 - 2012) will focus on short and very short coppice plantations established in northern France (for very short rotation coppice: 4 willow, poplar and black locust plantations) or already existing plantations (for short rotation coppice: notably composed of various conifer species). he goal of the project is to re-define the concept of energetic crop of perennial forest species in the context of the "plant x environment x crop-system" relationships. Two production methods will be evaluated: short rotation coppice and short rotation plantation. These two systems are justified by the reproduction biology of the two groups of fast growing species tested. The project is centered on a short rotation plantation network, that will be planted in contrasted environments, where local pedo-climatic and sylvicultural parameters will be monitored. In the specific case of short rotation coppices (SRC) and for three species (poplar, willow and black locust), the project will also improve our knowledge of water and nutriment use efficiency, two key factors of the sustainability of this type of culture. Adequation between vegetal material and environment will be thoroughly looked at, with a goal of fertilization and irrigation minimization depending on site characteristics. Several contrasted pedo-climatic and sylvicultural conditions will be tested.This project will also evaluate the perspectives offered by the genetic variability of some forest species on their total biomass productivity and their adaptability in the sylviculture x environment complex. In order to follow the tree growth and water / nitrogen needs in SRC, study plots will be created in ecologically contrasted sites, where initial spacing and genetic diversity will be controlled. In one of the study sites, urban waste water will be spread with the goal to evaluate the interest to combine a remediation function and a biomass production function in order to improve the economical value. An important output of the project will be a network of experimental sites in which various fast growing conifer species will be simultaneously compared for biomass production in a rotation frame compatible with E.U. subsidies for energetic crops. In these sites, initial spacing as well as genetic variability will be also controlled. Other sites will finally make possible the construction of volume / biomass yield tables (stem, bark, branches, and needles) and the evaluation of nutriment storage for some species not yet documented.This project is original at different levels: - Strong collaboration between a group of scientists and technicians whose expertise covers sylviculture, genetics, genomics and ecophysiology- Simultaneous association of fundamental and finalized goals (i.e. ecophysiological determinism of tree functioning vs. definition of sylvicultural itineraries)- Creation of a study sites network that will be valorized beyond the present project duration. New question will then be studied such as evolution of biodiversity or evolution of soil physicochemical properties. At longer term, this network will be used for fundamental studies such as water use efficiency at various scales (from tree to stand) or for studying logging techniques. The vegetal products of these experimental sites will be themselves valorized to study pilot transformation process.