Global climate change impacts can already be tracked in many physical and biological systems; in particular, terrestrial ecosystems provide a consistent picture of observed changes. One of the preferred indicators is phenology, the science of natural recurring events, as their recorded dates provide a high-temporal resolution of ongoing changes. Thus, numerous analyses have demonstrated an earlier onset of spring events for mid and higher latitudes and a lengthening of the growing season. However, published single-site or single-species studies are particularly open to suspicion of being biased towards predominantly reporting climate change-induced impacts. No comprehensive study or meta-analysis has so far examined the possible lack of evidence for changes or shifts at sites where no temperature change is observed. We used an enormous systematic phenological network data set of more than 125 000 observational series of 542 plant and 19 animal species in 21 European countries . Our results showed that 78% of all leafing, flowering and fruiting records advanced (30% significantly) and only 3% were significantly delayed, whereas the signal of leaf colouring/fall is ambiguous. We conclude that previously published results of phenological changes were not biased by reporting or publication predisposition: the average advance of spring/summer was 2.5 days decade À1 in Europe. Our analysis of 254 mean national time series undoubtedly demonstrates that species' phenology is responsive to temperature of the preceding

No abstract

Grassland-based ruminant production systems are integral to sustainable food production in Europe, converting plant materials indigestible to humans into nutritious food, while providing a range of environmental and cultural benefits. Climate change poses significant challenges for such systems, their productivity and the wider benefits they supply. In this context, grassland models have an important role in predicting and understanding the impacts of climate change on grassland systems, and assessing the efficacy of potential adaptation and mitigation strategies. In order to identify the key challenges for European grassland modelling under climate change, modellers and researchers from across Europe were consulted via workshop and questionnaire. Participants identified fifteen challenges and considered the current state of modelling and priorities for future research in relation to each. A review of literature was undertaken to corroborate and enrich the information provided during the horizon scanning activities. Challenges were in four categories relating to: 1) the direct and indirect effects of climate change on the sward 2) climate change effects on grassland systems outputs 3) mediation of climate change impacts by site, system and management and 4) cross-cutting methodological issues. While research priorities differed between challenges, an underlying theme was the need for accessible, shared inventories of models, approaches and data, as a resource for stakeholders and to stimulate new research. Developing grassland models to effectively support efforts to tackle climate change impacts, while increasing productivity and enhancing ecosystem services, will require engagement with stakeholders and policy-makers, as well as modellers and experimental researchers across many disciplines. The challenges and priorities identified are intended to be a resource 1) for grassland modellers and experimental researchers, to stimulate the development of new research directions and collaborative opportunities, and 2) for policy-makers involved in shaping the research agenda for European grassland modelling under climate change.

No abstract

Abstract• Decay resistance of larch (Larix sp.) to fungi was evaluated on heartwood samples belonging to 3 species (L. decidua, L. kaempferi and their hybrid), 3 races of European larch (polonica, sudetica and alpine), 13 wood lots (populations) and 313 trees.• Larch wood appeared, on average, as moderately durable although a high variability was observed. At the sample level as well as at the mean individual tree level, durability ranged from class 1 to 5 according to EN 350-1 standard. At the population level, larch wood varied from 'durable' to 'slightly durable'. Genetics played a major role in decay resistance at the species, provenance and tree levels. Environmental factors such as the position of heartwood samples and the age of trees were also identified as a source of variability.• The most durable wood was not necessarily from old native alpine stands of European larch: some young larches from faster growing lowland origins also produced durable wood.• Genetic improvement of larch wood durability appeared therefore likely by the selection of the best populations for decay resistance as well as from the selection of individuals. Mots-clés :durabilité naturelle / champignon / Larix / génétique / effet environnemental Résumé -Variabilité de la résistance à la dégradation du bois de mélèze par les champignons.• La résistance à la dégradation du bois de duramen du mélèze (Larix sp.) est évaluée à partir d'un échantillon d'éprouvettes extraites de 313 arbres appartenant à 3 espèces (L. decidua, L. kaempferi et leur hybride), 3 races de mélèze européen (polonica, sudetica et alpine) et 13 lots différents.• Le bois de mélèze apparaît, en moyenne, comme 'modérément durable', mais une grande variabilité due à plusieurs facteurs a été observée. Au niveau arbres et échantillons, la durabilité naturelle s'étend de la classe 1 à 5 suivant la norme EN 350-1. Suivant les origines, le bois de mélèze peut être classé comme 'durable' à 'faiblement durable'. Les facteurs génétiques jouent un rôle significatif sur la résistance à la dégradation du bois aux niveaux espèce, provenance et arbre. Des facteurs environnementaux tels que la position des échantillons au sein du duramen et l'âge des arbres ont également été mis en évidence.• Le bois à plus forte durabilité ne provient pas exclusivement des vieux peuplements naturels de mé-lèze alpin : certaines origines de mélèze cultivées à basse altitude et constituées d'arbres plus jeunes et à croissance rapide peuvent aussi produire du bois durable.• L'amélioration génétique de la durabilité naturelle du mélèze apparaît donc comme envisageable au travers de la sélection des meilleures populations et des meilleurs individus.

-This study compares the efficiency of 3 indirect techniques that evaluate Young's modulus all along the sawing leading to the production of normalised specimens of hybrid larch trees from a clonal test. Ultrasonic speed is demonstrated as an interesting method for clone classification regarding Young's modulus in a clonal selection programme, whatever the sawing stage. However, the quality of results is reduced with standing tree measurements. The use of both the Pilodyn and resonance frequency measures is confirmed as a possibility.

No abstract

No abstract