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Cited Reference Count: 40 ref.International Formulae Group (IFG)Dschang, Cameroon; L’étude in situ de l’architecture et la croissance des systèmes racinaires ont été réalisées sur des jeunes plants en milieu naturel et en station. Les fronts racinaires verticaux et horizontaux sont déterminés à partir de la méthode d’excavation. Les coordonnées spatiales obtenues manuellement sur le terrain alimentent un logiciel AMAPmod de modélisation qui transforme d’une part les coordonnées spatiales en coordonnées standards puis d’autre part, donne les représentations 3D des systèmes racinaires des jeunes plants. En milieu naturel, les systèmes racinaires sont constitués de 3 ordres de racines. Les racines d’ordre 2 sont les plus abondantes. La profondeur d’enracinement de B. aegyptiaca est la plus importante. A. tortilis développe une longueur totale racinaire plus importante. La longueur totale des racines d’ordre 2 d’A. tortilis est plus importante que celle de B. aegyptiaca. En station, l’ordre maximal des ramifications est de 5 chez A. tortilis et Z. mauritiana et de 7 chez B. aegyptiaca. Les types 2 et 3 chez A. tortilis et Z. mauritiana et les types 2, 3 et 4 chez B. aegyptiaca forment l’essentiel du système racinaire. La densité totale des racines de B. aegyptiaca est plus importante. Les profondeurs d’enracinement d’A. tortilis et de B. aegyptiaca sont différentes de celle de Z. mauritiana. B. aegyptiaca dispose une longueur totale plus importante. Les ordres 2 et 3 sont les plus longs du système racinaire. Ensuite suivent les racines d’ordre 4. Celles des racines d’ordre 1, 5, 6 et 7 sont de longueurs égales

Se indican los números cromosómicos de cinco taxones pertenecientes a cinco familias de Angiospermas de Marruecos: Allium porrum 2n=32; Armeria simplex 2n=18; Asphodelus ramosus subsp. ramosus n=28; Delphinium nanum subsp. nanum 2n=16 et Dipcadi serotinum 2n=8 et 32. Cada taxon se acompaña de una fotografía en mitosis o meiósis así como de un breve comentario. "Chromosome numbers of some Moroccan angiosperm". Chromosome numbers of five taxa from five families of Moroccan angiosperms are reported: Allium porrum 2n=32; Armeria simplex 2n=18; Asphodelus ramosus subsp. ramosus n=28; Delphinium nanum subsp. nanum 2n=16 and Dipcadi serotinum 2n=8 and 32. Mitotic or meiotic metaphases microphotographs and brief comments are detailed for each taxa studied.

The response of traits to the environment has been studied mainly at the level of trait means within and across species and lineages and has recently been extended to intraspecific trait variability. However, traits may respond to the constraints of a given environment also in terms of (i) increased mutual determination of traits within individuals and populations, i.e. increased phenotypic integration, and (ii) decreased variation of traits within entire phylogenetic lineages. Here we tested: (i) the effects of abiotic and biotic environments on phenotypic integration within sub-Antarctic plant species and the ecological and biogeographic consequences of a strong phenotypic integration, and (ii) the effects of abiotic and biotic environments on the phenotypic variability realized within Angiosperm genera of Central Europe. Regarding the first aspect, we found that phenotypic integration is higher under stressful abiotic conditions. The increase in phenotypic integration occurs at small spatial scales and may constrain the large scale flexibility of growth and reproductive strategies. We also found that strong phenotypic and environmental integration may contribute to endemism of some sub-Antarctic species, probably through a long-term specialization of these species to their habitat. Regarding the second aspect, we found that phenotypic variability realized within genera of Central Europe is higher under intermediate abiotic conditions, reflecting increased independence of traits from the abiotic environment. We also found that the number of coexisting species is highly conserved within genera. Intermediate levels of coexistence tend to correspond to both intermediate positions along abiotic gradients and to highest levels of variability of certain traits. This suggests a role of numerous but still predictable biotic interactions for the maintenance (or evolution) of high levels of trait variability within clades. Overall, the results of both aspects suggest the capacity of species to respond to environmental variations may be strongly constrained at the level of both individual phenotypes and entire clades, notably under abiotically but also biotically extreme environments., La réponse des traits à l'environnement a été étudiée essentiellement à travers la moyenne des attributs de trait des espèces et des lignées et a récemment été étendue à la variabilité intraspécifique. Cependant, les traits peuvent également répondre aux contraintes de l‟environnement par (i) une forte détermination mutuelle des traits au sein des individus ou des populations, i.e. une forte intégration phénotypique, et (ii) une faible variation des traits au sein de lignées phylogénétiques entières. Nous avons testé : (i) les effets de l'environnement abiotique et biotique sur l'intégration phénotypique chez des espèces végétales subantarctiques et les conséquences écologiques et biogéographiques d'une forte intégration phénotypique, et (ii) les effets de l‟environnement abiotique et biotique sur la variabilité phénotypique réalisée au sein des genres d'Angiospermes de l'Europe Centrale. Pour le premier aspect, nous avons constaté que l'intégration phénotypique est plus forte en conditions abiotiques stressantes. Le renforcement de l'intégration phénotypique se produit sur de petites échelles spatiales et peut limiter la flexibilité à grande échelle des stratégies de croissance et de reproduction. Nous avons également montré que la forte intégration phénotypique et environnementale peut contribuer à l'endémisme de certaines espèces subantarctiques, probablement par une spécialisation sur le long terme de ces espèces à leur habitat. Pour le second aspect, nous avons observé que la variabilité phénotypique réalisée au sein des genres de l'Europe Centrale est plus élevée dans des conditions abiotiques intermédiaires, ce qui reflète une plus grande indépendance des traits vis-à-vis de l'environnement abiotique. Nous avons également montré que le nombre d'espèces en coexistence est très conservé au sein des genres. Un niveau intermédiaire de coexistence semble coïncider avec à la fois une position intermédiaire des genres le long de gradients abiotiques et une plus grande variabilité de certains traits. Ceci suggère un rôle des interactions biotiques nombreuses, mais toujours prévisibles, pour le maintien (ou l'évolution) de niveaux élevés de variabilité des traits au sein des clades. Finalement, l'ensemble de nos résultats suggèrent que la capacité des espèces à répondre aux variations de l'environnement pourrait être fortement limitée aussi bien au niveau des phénotypes individuels qu'à l'échelle des clades entiers, notamment dans des environnements abiotiques et biotiques extrêmes.

Mieux gérer la qualité du hêtre c’est aussi mieux comprendre les mécanismes à l’origine des contraintes de croissance des arbres en développement. Ces contraintes sont délicates à appréhender par le forestier. En l’état des connaissances actuelles, les auteurs de cet article conseillent de maintenir un faible niveau de concurrence entre les houppiers des arbres. Reste à traiter le cas des futaies irrégulières pour lesquelles les relations semblent plus complexes. Les travaux en cours devraient permettre une avancée importante sur ce sujet.

English; An architectural model is proposed to simulate 3D leaf area distribution for contrasting ( Vitis vinifera) vine training systems. Operating at the shoot level, the model describes stochastically prospected shoot volume (8 parameters) and leaf orientation (2 parameters) using distribution laws. Mean shoot leaf area is an input of the model. Parameterization was led for four genotype * training system (G * T) combinations. Validation was undertaken at two levels. At the canopy level, observed and simulated radiation interception efficiencies were compared. At the organ level, leaf irradiance distributions of simulated and 3D-described sample vines were evaluated. At both scales, observed and simulated values were closely correlated. The model tended to systematically overestimate self-shading into the canopies. However, its ability to discriminate and correctly rank the different G * T pairs was confirmed.

International audience; Cet article présente des éléments sur l'efficacité du génie biologique par bouturage en petite correction torrentielle. Après une présentation des techniques existantes, il expose les principaux résultats d'une étude sur l'efficacité de ces techniques, réalisée dans deux départements alpins en France. La prise en compte de ces résultats permet alors de proposer des éléments de stratégie pour le choix des ouvrages de génie biologique à utiliser lors de chantiers de petite correction torrentielle.

National audience

Cameroon has a remarkable abundance of vegetable species. A great variety of local and introduced vegetable crops are grown and together with a significant number of wild and semi-wild plants, occasionally cultivated, form a valuable complementary food in the daily diet.Primarily the aim of this study is to present an inventory of traditional vegetable species in Cameroon, indicating their importance in local agriculture, their significance as food and their nutritional value. The second objective is a taxonomical study of these vegetable crops, in order to expose, and where feasible eliminate, the existing widespread confusion in their scientific nomenclature. Botanical descriptions and practical differential keys, based on those parts of the plants that are actually used, are provided. This study deals with 67 traditional vegetables, 20 species of which are discussed in greater detail. The materials and data were gathered mainly in Cameroon during the period 1975 - 1979, and subsequently elaborated upon at the Department of Plant Taxonomy of the Agricultural University, Wageningen, The Netherlands.Chapter I contains a general introduction. The working plan (chapter 2) clarifies the selection of the 20 primary species (paragraph 2.1). Further detailed information is supplied regarding the materials used and the applied methods of investigation (paragraph 2.2).Chapter 3 presents the five agro-ecological regions into which Cameroon can be divided (paragraph 3. 1). A review is given of the physical and biological environment (paragraph 3.2) and of the agriculture and animal husbandry (paragraph 3.3). Various aspects pertaining to vegetables are discussed, such as the different types of vegetable crops (paragraph 3.4. 1), local and introduced vegetables (paragraph 3.4.2), the inventory of the vegetables in the different agro- ecological regions (paragraph 3.4.3) and a classification of wild and/or cultivated species (paragraph 3.4.4). Finally the various types of vegetable production are dealt with (paragraph 3.5).Chapter 4 is based on nutritional research and surveys which have been carried out in Cameroon since 1953. The first part is devoted to a survey of food and nutrition in the different agro-ecological regions (paragraph 4. 1). In the second part an account is given of the preparation and utilisation of vegetables including their nutritional value (paragraph 4.2).Chapter 5 deals with the botanical study of the vegetable species. Differential keys to groups of species (paragraph 5. 1. 1) and to individual species (paragraph 5.1.2), based on characteristics of the edible product, are supplied. In the next paragraph (5.2) all 67 species are arranged in alphabetical order, primarily in family order and subsequently according to the genera and species. This paragraph also provides concise information concerning the 47 secondary species.The 20 primary species are considered in a final paragraph (5.3), also in alphabetical order.The format of the text in the paragraphs 5.2 and 5.3 is essentially similar for each species. In paragraph 5.2 the author and the original publication of the species are cited, along with the current synonyms, pertinent literature, vernacular names, the occurrence in each of the five agro-ecological regions, a concise botanical description, a few relevant notes, representative herbarium specimens from Cameroon and finally the applicability as a vegetable. Furthermore paragraph 5.3 provides an etymological explanation of the scientific name and the typification, while synonymy, literature, geographic distribution and botanical description are discussed at length. Notes in this paragraph elaborate the typification. Any other relevant questions are subsequently dealt with, such as the recurring confusion with other species of the same genus, infraspecific variation and the distinction of cultivar-groups or cultivars, some cytogenetic and evolutionary aspects, and the use as a vegetable. Finally all the herbarium material examined from Cameroon is listed.Each species is accompanied by a botanical drawing of the edible parts of the plant in paragraph 5.2. Species dealt with in paragraph 5.3 are fully illustrated. In some cases a photograph is added. In conclusion a general bibliography and indices of scientific and vernacular plant names are provided.

Cameroon has a remarkable abundance of vegetable species. A great variety of local and introduced vegetable crops are grown and together with a significant number of wild and semi-wild plants, occasionally cultivated, form a valuable complementary food in the daily diet.Primarily the aim of this study is to present an inventory of traditional vegetable species in Cameroon, indicating their importance in local agriculture, their significance as food and their nutritional value. The second objective is a taxonomical study of these vegetable crops, in order to expose, and where feasible eliminate, the existing widespread confusion in their scientific nomenclature. Botanical descriptions and practical differential keys, based on those parts of the plants that are actually used, are provided. This study deals with 67 traditional vegetables, 20 species of which are discussed in greater detail. The materials and data were gathered mainly in Cameroon during the period 1975 - 1979, and subsequently elaborated upon at the Department of Plant Taxonomy of the Agricultural University, Wageningen, The Netherlands.Chapter I contains a general introduction. The working plan (chapter 2) clarifies the selection of the 20 primary species (paragraph 2.1). Further detailed information is supplied regarding the materials used and the applied methods of investigation (paragraph 2.2).Chapter 3 presents the five agro-ecological regions into which Cameroon can be divided (paragraph 3. 1). A review is given of the physical and biological environment (paragraph 3.2) and of the agriculture and animal husbandry (paragraph 3.3). Various aspects pertaining to vegetables are discussed, such as the different types of vegetable crops (paragraph 3.4. 1), local and introduced vegetables (paragraph 3.4.2), the inventory of the vegetables in the different agro- ecological regions (paragraph 3.4.3) and a classification of wild and/or cultivated species (paragraph 3.4.4). Finally the various types of vegetable production are dealt with (paragraph 3.5).Chapter 4 is based on nutritional research and surveys which have been carried out in Cameroon since 1953. The first part is devoted to a survey of food and nutrition in the different agro-ecological regions (paragraph 4. 1). In the second part an account is given of the preparation and utilisation of vegetables including their nutritional value (paragraph 4.2).Chapter 5 deals with the botanical study of the vegetable species. Differential keys to groups of species (paragraph 5. 1. 1) and to individual species (paragraph 5.1.2), based on characteristics of the edible product, are supplied. In the next paragraph (5.2) all 67 species are arranged in alphabetical order, primarily in family order and subsequently according to the genera and species. This paragraph also provides concise information concerning the 47 secondary species.The 20 primary species are considered in a final paragraph (5.3), also in alphabetical order.The format of the text in the paragraphs 5.2 and 5.3 is essentially similar for each species. In paragraph 5.2 the author and the original publication of the species are cited, along with the current synonyms, pertinent literature, vernacular names, the occurrence in each of the five agro-ecological regions, a concise botanical description, a few relevant notes, representative herbarium specimens from Cameroon and finally the applicability as a vegetable. Furthermore paragraph 5.3 provides an etymological explanation of the scientific name and the typification, while synonymy, literature, geographic distribution and botanical description are discussed at length. Notes in this paragraph elaborate the typification. Any other relevant questions are subsequently dealt with, such as the recurring confusion with other species of the same genus, infraspecific variation and the distinction of cultivar-groups or cultivars, some cytogenetic and evolutionary aspects, and the use as a vegetable. Finally all the herbarium material examined from Cameroon is listed.Each species is accompanied by a botanical drawing of the edible parts of the plant in paragraph 5.2. Species dealt with in paragraph 5.3 are fully illustrated. In some cases a photograph is added. In conclusion a general bibliography and indices of scientific and vernacular plant names are provided.