Rapports

Résumé : Understanding how forest tree species behave in different climatic conditions is essential to develop adaptation strategies to ongoing climate warming. This report analyses the sanitary state of some native and exotic tree species over a climatic gradient to understand the climate effects on their susceptibility to be attacked by some pests or diseases. The analysis was based on the REINFFORCE (“REsource INFrastructures for monitoring, adapting and protecting european atlantic FORests under Changing climatE”) arboreta network with the data collected for three native species, with three provenances each, and eight exotic species. We compared the probability of presenting different pests or diseases, depending on environmental conditions, species provenances in their distribution range, region of origin of the species (exotic vs. native) and existence of congeneric species in Europe for exotic species. Results show the importance of climatic conditions on biotic and abiotic damage suffered by the trees, mainly temperature variables (number of frost days or the mean temperature of the coldest month). We also found that native species are more susceptible to health damage than exotic ones, verifying the enemy release hypothesis (ERH). Finally, we showed that exotic tree species with congeneric native species in Europe are more likely to be attacked by biotic agents than exotic species with no native congeneric (spill-over hypothesis). This report is also an exploratory study, in which the REINFFORCE health assessment protocol was tested for a first assessment to ensure that it provides accurate information of the real health state.

Résumé : Global warming is threatening the survival and performances of trees, which are essential for the current dilemma of C sequestration and biomass production. Out of many strategies to maintain those trees abilities, one is the introduction of non-native species, among which the Douglas fir provenances stand out for their qualities and quantity of wood produced and their fast growth. Using two data networks (the REINFFORCE network and a south-east network), we assessed the effect of climate, site and genetic factors on the survival and growth of several Douglas fir provenances including the coastal and interior regions of California. Additionally effects of these factors on architectural defects and bud break were also investigated. In usual environmental conditions for the Douglas fir, northern provenances are known to be the most appropriate. However results from comparisons between Californian and Oregon seed sources, settle the superiority of the Californian provenances in the southern sites. At older ages (23-39 years old) under Mediterranean climate, Californian provenances were far superior to the Oregon provenances for survival rate and showed a competitive growth. However, under Atlantic climate (McKnight T.L., et al., 2000, the Oregon provenances had a better height growth at a young age (5 years old) while the Californian provenances still had a better survival rate. Additionally the Californian provenances did not display architectural defects, except a slight trend in having closed insertion angles and big branches. Therefore this work shows the potentialities of the Californian provenances under two different climates at two different age stages. In the context of climate change the Californian Douglas fir is rated as valuable material for a future breeding program.

Résumé : As a result of climate change the presently used deployment areas for forest reproductive material (FRM) may not be the optimal in the near future. One way to address this problem is assisted migratio n (AM), which is defined as the human assisted movement of species in response to climate change. To estimate the optimal rate of transfer to be recommended, data from provenance trials can be used. Numerous provenance trials have been established during t he last century for many tree species. The response of the provenances to a transfer is the result of a combination of genetic change and phenotypic plasticity. On the other hand, the effects of a transfer on phenology, pests and diseases as well as pertur bations are not covered well by provenance trials. In order for assisted migration to be functional in Europe it is important that transfer of FRM can be applied without bothering political borders . Moreover, phenotypic plasticity is a relevant criterion t o be consider ed, but the adaptive/neutral/non - adaptive nature of plasticity for each trait or groups of traits must be taken into account. I t is very important that climate data on the smallest resolution available is used, and that also the most sophistic ated climate change scenarios are used. This paper presents three practical examples on the use of data from provenance trials for the definition of future deployment areas for FRM in Europe .

Résumé : protocol for field measurement and site description used in sustainability indicator assessment - project FORSEE - www.iefc.net