La sylviculture des boisements de protection, la problématique de leur renouvellement

Après un état des lieux avec données chiffrées et urgence du renouvellement, décrit les contraintes de ce renouvellement, les solutions envisagées, les réalisations concrètes et les besoins en connaissances techniques

Amélioration des techniques de reconstitution en espèces feuillues de la forêt méditerranéenne

Le reboisement est une des techniques de reconstitution possible de la forêt méditerranéenne, notamment après incendie. Si les techniques d'installation des résineux sont aujourd'hui bien maîtrisées, celles concernant les feuillus sont moins connues. Cette étude, à partir de dispositifs expérimentaux mis en place au début des années 1990, permet de tirer les premiers enseignements sur l'installation des plants feuillus

Notes for genera: basal clades of Fungi (including Aphelidiomycota, Basidiobolomycota, Blastocladiomycota, Calcarisporiellomycota, Caulochytriomycota, Chytridiomycota, Entomophthoromycota, Glomeromycota, Kickxellomycota, Monoblepharomycota, Mortierellomycota, Mucoromycota, Neocallimastigomycota, Olpidiomycota, Rozellomycota and Zoopagomycota)

Compared to the higher fungi (Dikarya), taxonomic and evolutionary studies on the basal clades of fungi are fewer in number. Thus, the generic boundaries and higher ranks in the basal clades of fungi are poorly known. Recent DNA based taxonomic studies have provided reliable and accurate information. It is therefore necessary to compile all available information since basal clades genera lack updated checklists or outlines. Recently, Tedersoo et al. (MycoKeys 13:1--20, 2016) accepted Aphelidiomycota and Rozellomycota in Fungal clade. Thus, we regard both these phyla as members in Kingdom Fungi. We accept 16 phyla in basal clades viz. Aphelidiomycota, Basidiobolomycota, Blastocladiomycota, Calcarisporiellomycota, Caulochytriomycota, Chytridiomycota, Entomophthoromycota, Glomeromycota, Kickxellomycota, Monoblepharomycota, Mortierellomycota, Mucoromycota, Neocallimastigomycota, Olpidiomycota, Rozellomycota and Zoopagomycota. Thus, 611 genera in 153 families, 43 orders and 18 classes are provided with details of classification, synonyms, life modes, distribution, recent literature and genomic data. Moreover, Catenariaceae Couch is proposed to be conserved, Cladochytriales Mozl.-Standr. is emended and the family Nephridiophagaceae is introduced

Rapport de mission en Arménie

After describing the purpose of the mission, this document presents Armenia and its forestry problems, especially illegal timber harvesting. It makes proposals of french-armenian cooperation as regards environment protection and reforestation. / Après la description du pays et de la mission, ce rapport présente la problématique des coupes de bois illégales et formule des propositions de coopération franco-arménienne en matière de protection de l'environnement et de reconstitution forestière

Nutrition minérale et mycorhization contrôlée : compte rendu des travaux effectués en 1993

This document describes the 1993 programm about mediterranean forest seedling mineral nutrition and controlled mycorrhization. / Synthèse des travaux 1993 sur la nutrition minérale et la mycorhization contrôlée des plants forestiers méditerranéens

Complex biotic interactions mediated by shrubs: Revisiting the stress‐gradient hypothesis and consequences for tree seedling survival

International audienceUsing nurse shrubs to improve tree seedling establishment in stressed environments is a common practice in forestry. Recent refinements of the stress-gradient hypothesis suggest that positive nurse effects occur under intermediate stress and decline in the harshest conditions. Additionally, indirect facilitation (e.g. protection from herbivory) is expected in low-stressed/productive systems according to the initial stress-gradient hypothesis. However, there have been fewer investigations into the use of nurse shrubs to decrease herbivore impacts in stressed systems compared with the role of nurses in stress alleviation. This raises the need to clarify conditions in which the use of nurse shrubs would be most appropriate.We conducted a field experiment in the sand dune forest of southwest France characterized by severe summer water shortages and the presence of different types of wild herbivores. In 2015 and 2016, Pinus pinaster seedlings were planted under shrubs Arbutus unedo or in shrub-removed locations, in fenced/unfenced areas. Survival, cause of mortality and water stress were monitored for 1 year after plantation.Summer drought was the main cause of mortality. Water stress increased in both years as summer progressed. We found direct facilitation only in July 2016 at intermediate water stress, due to a decrease in vapour pressure deficit under shrubs. These positive effects declined in late summer when stress was at a maximum. Rodent damage occurred under shrubs in spring whereas ungulate browsing was observed in open areas in autumn/winter. Overall seedling survival was equivalent under or outside shrubs during the first year, but was better under shrubs in the second one.Synthesis and applications. Our results partially validate the refinement of the stress-gradient hypothesis, with a decline of positive interactions in the most water-stressed conditions. This draws attention to the difficulty of using shrubs as nurses to improve tree regeneration in the most xeric systems. In addition, we show that indirect associational effects, both positive and negative, could be as important as abiotic stress alleviation in a stressful ecosystem, and using shrubs to facilitate seedling survival could be efficient depending on the type of herbivore involved. This highlights the fact that considering plant-plant interactions can help in the design of management options, providing that up-to-date ecological theories are considered and that the different biotic and abiotic constraints are accurately evaluated

REVUELTA DOMÍNGUEZ, F. I.; PÉREZ SÁNCHEZ, L. «Interactividad en los entornos de formación on-line». Barcelona: UOC, 2009

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