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Gobat, Jean-Michel
Nom
Gobat, Jean-Michel
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Professeur honoraire
Email
jean-michel.gobat@unine.ch
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Voici les éléments 1 - 10 sur 54
- PublicationMétadonnées seulementDo-It-Your-Soil 2.0 – revision, extension and translation of the established e-learning course(2013-1-1)
; ; Schulin, R. - PublicationMétadonnées seulementEtude sur la purification des eaux de gravité passant à travers le sol forestier(2012)
Cette étude réalisée sur deux sites de terrain, le Gibloux dans le Canton de Fribourg et la Côte de Champ-du-Moulin dans la République et Canton de Neuchâtel, se focalise sur les propriétés des eaux atmosphériques et de gravité percolant à travers le sol. Après un suivi complet d'une année de ces eaux, des essais en laboratoire sur des paramètres ciblés permettent de mieux saisir l'importance de la gestion forestière sur le blocage de micropolluants. Les récoltes des eaux sur le terrain ne présentent pas de polluants organiques mais contiennent, en revanche, une faible concentration en éléments traces métalliques que le sol ne filtre pas, qu'importe sa nature. Les essais en laboratoire sur le benzène (polluant du trafic routier), le tétrachloréthène (produit par l'activité industrielle) et la cyperméthrine (insecticide utilisé pour le traitement des bois) illustrent notamment que la forme d'humus influence le taux de filtration et que l'épisolum humifère est directement en lien avec le travail de l'ingénieur forestier. Les principaux résultats montrent que le pH influence peu la fixation de ces molécules ; le calcaire est antagoniste à l'adsorption du benzène et du tétrachloréthène ; un sol fi filtre moins bien qu'un sol épais ; l'épisolum humifère acide et accumulant retient moins bien la cyperméthrine mais, globalement, tous ces polluants sont retenus à près de 90% dans les sols testés.
Il est donc possible d'affirmer que les choix des praticiens sylvicoles peuvent influencer positivement ou négativement la qualité des eaux souterraines. Ce travail met en avant également le rôle essentiel de la structure, mais aussi, à un degré moindre, celui de la texture sur la conductivité hydraulique. Finalement, il présente un nouvel outil, la carte des unités écosystémiques, qui permet, par l'intégration des groupements végétaux, du peuplement, des formes d'humus et des sols, un suivi temporel de la forêt du sol à la cime des arbres., French-Swiss silvicultural people wishes to know its impact on the quality of groundwater. The Interreg Alpeau project combines forest engineers, managers of water resources and scientists to measure this influence. The geographical distribution of the project shines around the Jura mountains between Chambéry (F) and Neuchâtel (CH).
This study carried out on two sites of ground, Gibloux in the Canton of Fribourg and the Côte de Champ-du-Moulin in the Republic and Canton of Neuchâtel, focuses on the properties of atmospheric and percolant water through the humus forms and the soil. After a complete water's follow-up of one year, essays in laboratory on targeted parameters allow to seize better the importance of the forest management on the blocking of micropollutants.
The collected waters on the soil do not present organic pollutants but contain, a low concentration in elements metallic tracks which the soil doesn't filter, it doesn't matter to its nature. The essays in laboratory on the benzene (pollutant of the road traffic), the tetrachlorethylene (produced by the industrial activity) and the cypermethrin (insecticide used for the treatment of wood) illustrate that the humus form influences the rate of filtration and that the humifer episolum is directly in connection with the work of the forest engineer. The main results show that the pH influences little the binding of these molecules ; the limestone is conflicting in the adsorption of the benzene and the tetrachlorethylene ; a thin soil leaks out although a thick soil ; the acid and accumulating humus form retains less well the cypermethrin but, globally, all these pollutants are retained about 90 % in the tested soils. It is possible to assert that the choices of the silvicultural practitioners can influence positively or negatively the quality of ground waters. This work also puts forward the essential role of the structure, but also, in a lesser degree, that of the texture on the hydraulic conductivity. Finally, it presents a new tool, the map of the ecosystematic units, which allows, by the integration of forest compartiment, a temporal follow-up. - PublicationMétadonnées seulement
- PublicationMétadonnées seulementErfolgskontrolle der Vegetationskynamik(2006)
- PublicationMétadonnées seulementSeasonal dynamics of plant species at fine scale in wooded pastures(Budapest: Akademiai Kiado, 2005)
; ; - PublicationMétadonnées seulementSoil microbial community changes in wooded mountain pastures due to simulated effects of cattle grazing(2005)
; ; Buttler, AlexandreThe effect of cattle activity on pastures can be subdivided into three categories of disturbances: herbage removal, dunging and trampling. The objective of this study was to assess separately or in combination the effect of these factors on the potential activities of soil microbial communities and to compare these effects with those of soil properties and plant composition or biomass. Controlled treatments simulating the three factors were applied in a fenced area including a light gradient (sunny and shady situation): (i) repeated mowing; (ii) trampling; (iii) fertilizing with a liquid mixture of dung and urine. In the third year of the experiment, community level physiological profiles (CLPP) (Biolog Ecoplates (TM)) were measured for each plots. Furthermore soil chemical properties (pH, total organic carbon, total nitrogen and total phosphorus), plant species composition and plant biomass were also assessed. Despite differences in plant communities and soil properties, the metabolic potential of the microbial community in the sunny and in the shady situations were similar. Effects of treatments on microbial communities were more pronounced in the sunny than in the shady situation. In both cases, repeated mowing was the first factor retained for explaining functional variations. In contrast, fertilizing was not a significant factor. The vegetation explained a high proportion of variation of the microbial community descriptors in the sunny situation, while no significant variation appeared under shady condition. The three components of cattle activities influenced differently the soil microbial communities and this depended on the light conditions within the wooded pasture. Cattle activities may also change spatially at a fine scale and short-term and induce changes in the microbial community structure. Thus, the shifting mosaic that has been described for the vegetation of pastures may also apply for below-ground microbial communities. - PublicationMétadonnées seulementSpatio-temporal pattern of bog pine (Pinus uncinata var. rotundata) at the interface with the Norway spruce (Picea abies) belt on the edge of a raised bog in the Jura Mountains, Switzerland(2004)
- PublicationMétadonnées seulement
- PublicationMétadonnées seulementLe référentiel pédagogique : premier bilan au bout de 11 années(2004)
- PublicationMétadonnées seulement