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Monograph represents short reviews on the genetics and breeding of introduced to Europe forest tree species. The management of tree species non-native to European geographical regions has a long tradition within forestry management practice. Their introduction to Europe (initially focused on growing tree species) dates back to the 18th century when enormous demands were being made on natural resources to sustain the on-going industrialization of Europe. Today issues of biomass production and C sequestration as well as the question of whether these species could increase the adaptive capacity of forests to long-term climate change patterns have fueled a growing interest in non-native tree species in Europe.

National audience; 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.

International audience; Case studies are necessary to assess the effects of changes to tree species on the physicochemical and chemical properties of soils. To achieve this, the fine earth under five tree species was investigated. This study was performed in the Breuil-Chenue experimental forest site located in the Morvan Mountains (France). This site contains two adjacent blocks with replicated stands. The native forest (old beech and oak coppice with standards) was partially clear-felled and replaced in 1976 with mono-specific plantations of European beech, Norway spruce, Laricio pine and Douglas fir. The same changes in soil properties were revealed in both blocks, thus confirming the tree species effect. The percentage of exchangeable acidity on the cation exchange capacity (CEC) was greater under spruce, Douglas fir and pine than under the other species. Spruce stands, and to a lesser extent those of Douglas fir and pine, had a less acidic soil pH than hardwood stands (which was unusual in view of the data in the literature) and smaller CEC values. The small quantities of carbon added to the soil under these tree species provide an explanation for these effects through a partial control of both CEC and pH. This case study thus demonstrated that the tree species effect was not unequivocal and different criteria are necessary for its interpretation. Tree species significantly influenced certain aspects of the chemical properties of topsoil and have the potential to have an impact on current soil fertility.

The author uses an analytical procedure he developed, and simulated data of self-thinned even-aged mixed stands of Quercus robur+Pinus pinaster, Pseudotsuga menziesii+Picea sitchensis, and Pinus nigra ssp.laricio+Pinus pinaster, to scrutinize the allometry and fractal geometry of this type of stands. He verified that they are highly variable. They continuously change with initial proportions of each population, and age. O autor usa um procedimento analítico que desenvolve e simulações de povoamentos auto-desbastados regulares mistos de Quercus robur+Pinus pinaster, Pseudotsuga menziesii+Picea sitchensis, e Pinus nigra ssp.laricio+Pinus pinaster, para propor uma clarificação da alometria e geometria fractal deste tipo de povoamentos. Verifica-se que estas são altamente instáveis, variando com as proporções inicias das populações e idade. L'auteur simule des peuplements auto-éclaircis réguliers mixtes de Quercus robur+Pinus pinaster, Pseudotsuga menziesii+Picea sitchensis, et Pinus nigra ssp.laricio+Pinus pinaster. Il utilise les résultats de ces simulations pour clarifier l'allométrie, et la géométrie fractale de ces mêmes peuplements. Sa conclusion est que toute la géométrie des peuplements mixtes change avec les proportions initiales des espèces et avec l'âge.

Cet article est une contribution à l’étude des potentialités photosynthétiques hivernales des conifères en zone tempérée. Il met en évidence une action du régime thermique sur l’activité photosynthétique du douglas à deux niveaux d’échelle dans le temps. A l’échelle instantanée, la réponse photosynthétique à la température se caractérise par un large domaine optimal plutôt que par un optimum marqué. A l’échelle de la décade, la capacité photosynthétique oscille en permanence sous l’action d’un jeu d’endommagement - réparation de la fonction photosynthétique liée à l’alternance de périodes de gel et de dégel. A l’approche du débourrement, notre étude permet de relier les modifications intervenant dans les échanges gazeux de CO2 au niveau du rameau au développement des bourgeons., In the eastern France, near Nancy, at different days from 02.16th.1979 to 05.16th.1979, shoots of a 19 year old Douglas-fir stand were cut and their net-photosynthesis response to temperature determined in laboratory under light-saturation conditions.1. Until beginning of April : - The response of net-photosynthesis to temperature was characterized by a wide optimal zone centered on 16-18 °C rather than by a marked optimum. No significative transformation in the shape of that response curve was observed during the measurement period. - The photosynthetic capacity is submitted to important changes corresponding to a damage and reparation action on the photosynthetic function linked to the alternation of frost and thaw periods. The after-effects of the thermal regime act upon photosynthesis in a cumulative way and with a 10 day retentivity. 2. From beginning of April to bud-flushing (05.16th) - In a first time, a more and more important impairment of the CO2 assimilation rate of the shoot was observed at the higher temperatures. Simultaneously the thermal optimum underwent a slight down to 8-10 °C, without the above mentionned climatic determinism of the photosynthetic capacity being significantly affected. That transformation appeared to be due to an increase of the respiratory activity of the developing buds. - In a second time, a few days before bud flushing, the photosynthetic capacity decreased in its turn under the influence of physiological changes which seemed to affect the photosynthetic apparatus itself. The Douglas-fir is characterized by a great capacity of reparation after a cold stress which allows it to turn to account mild temperature winter periods in a climate like that of Nancy. In the temperate zone such an evergreen conifer winter photosynthesis pattern is intermediate between the total winter photosynthetic rest which haracterizes the continental and mountain cold winter situations and a pattern without any winter depression as has been observed in mild winter oceanic conditions.