References of "Carnol, Monique"
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See detailDo plant species and climate warming influence nitrification and ammonia oxidiser community structure
Malchair, Sandrine ULg; Carnol, Monique ULg

in Belgian Biodiversity Platform, 2007 Conference: Biodiversity and Climate Change, 21-22 May 2007, Brussels (2007)

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See detail'Canopy-atmosphere interaction in forests: a key process in nutrient cycling and pollution interception
Carnol, Monique ULg; Guillaume, Patricia

Conference (2006, October 17)

An efficient way for assessing the nutrient status of an ecosystem is the establishment of nutrient input-output mass balance budgets at the catchment scale. For example, outputs (i.e. losses in ... [more ▼]

An efficient way for assessing the nutrient status of an ecosystem is the establishment of nutrient input-output mass balance budgets at the catchment scale. For example, outputs (i.e. losses in streamwater, through havesting etc.) greater than inputs (i.e. weathering, dry and wet deposition, fertiliser) indicate that a depletion of the given element is taking place. In forest ecosystems, element input via throughfall is an important pathway in nutrient cycling. Precipitation interacts with the stand canopy, resulting in increased/decreased solute inputs to the forest floor. For example, acid deposition (H, N) may be substantially increased through the filtering action of the tree canopy. Indeed, canopy throughfall chemical composition includes wet deposition (rainfall), dry deposition intercepted by the canopy and elements leached from the foliar tissue (canopy leaching). Moreover, interactions between canopy and atmosphere or precipitation depend on several factors such as: season, tree species and physiology, stand structure and health. However, canopy leaching results from an internal nutrient cycling process. Ignoring this component in throughfall measurements thus leads to an overestimation of the inputs to the ecosystem. In this paper, main results of studies performed in the Belgian Ardennes at the watershed (80 ha) and plot scale are summarised. The aim of this research was to quantify long-term nutrient budgets in a forested watershed, within a context of sustainable management. In this area, soils are naturally acidic and poor in magnesium, so that forest dieback symptoms reported from 1983 onwards were related to increased pollution exacerbating magnesium deficiency. There is concern that acid (S and N) deposition, together with sylvicultural management (harvesting, spruce monocultures etc.) could deplete the available cation pool and that soils would not be able to support intensive sylviculture on the long term. We measured concentrations and fluxes of major ions in bulk deposition, throughfall and stream water over 13 years. Throughfall deposition under coniferous (Picea abies (L.) Karst.) and several deciduous tree species was also compared. A canopy budget method was used for distinguishing between external (dry deposition) and internal (canopy leaching) sources of ions in the throughfall flux. The contribution of canopy leaching in throughfall measurements and consequences for mass balance calculations will be discussed. Furthermore, nutrient fluxes through the ecosystem will be examined with regard to the long term nutrient status of the system. [less ▲]

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See detailHow do climate warming and plant species richness affect water use in experimental grasslands?
De Boeck, H. J.; Lemmens, CMHM; Bossuyt, H. et al

in Plant and Soil (2006), 288

Climate warming and plant species richness loss have been the subject of numerous experiments, but studies on their combined impact are lacking. Here we studied how both warming and species richness loss ... [more ▼]

Climate warming and plant species richness loss have been the subject of numerous experiments, but studies on their combined impact are lacking. Here we studied how both warming and species richness loss affect water use in grasslands, while identifying interactions between these global changes. Experimental ecosystems containing one, three or nine grassland species from three functional groups were grown in 12 sunlit, climate-controlled chambers (2.25 m(2) ground area) in Wilrijk, Belgium. Half of these chambers were exposed to ambient air temperatures (unheated), while the other half were warmed by 3 degrees C (heated). Equal amounts of water were added to heated and unheated communities, so that warming would imply drier soils if evapotranspiration (ET) was higher. After an initial ET increase in response to warming, stomatal regulation and lower above-ground productivity resulted in ET values comparable with those recorded in the unheated communities. As a result of the decreased biomass production, water use efficiency (WUE) was reduced by warming. Higher complementarity and the improved competitive success of water-efficient species in mixtures led to an increased WUE in multi-species communities as compared to monocultures, regardless of the induced warming. However, since the WUE of individual species was affected in different ways by higher temperatures, compositional changes in mixtures seem likely under climatic change due to shifts in competitiveness. In conclusion, while increased complementarity and selection of water-efficient species ensured more efficient water use in mixtures than monocultures, global warming will likely decrease this WUE, and this may be most pronounced in species-rich communities. [less ▲]

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See detailCanopy-atmosphere interaction in forests: a key process in nutrient cycling and pollution interception
Carnol, Monique ULg; Guillaume, Patricia ULg

in Book of Abstracts, SCK-CEN-BLG-1032, Topical day on: Biogeochemical response of forest vegetation to chronic pollution: processes, dynamics and modelling (2006)

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See detail'Do plant species and climate warming influence nitrification and ammonia oxidiser community structure
Malchair, Sandrine ULg; Carnol, Monique ULg

in 11th International symposium on microbial ecology (ISME-11) 'The Hidden Powers – Microbial Communities in Action', Vienna, Austria, August 20-25, 2006, Book of Abstracts (2006)

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See detailEnd-of-season effects of elevated temperature on ecophysiological processes of grassland species at different species richness levels
Lemmens, CMHM; De Boeck, H. J.; Gielen, B. et al

in Environmental and Experimental Botany (2006), 56

The combined effect of declining diversity and elevated temperature is a less-studied aspect of global change. We investigated the influence of those two factors and their possible interactions oil leaf ... [more ▼]

The combined effect of declining diversity and elevated temperature is a less-studied aspect of global change. We investigated the influence of those two factors and their possible interactions oil leaf ecophysiological processes in artificial grassland communities. Changes at the leaf level are at the basis of changes at the community level (and vice versa) but have remained largely unexplored in biodiversity experiments. We focused on end-of-season responses to assess whether species richness and air temperature affect the duration of the growing season. Grassland model ecosystems were used in 12 sunlit, climate-controlled chambers. Half of these chambers were exposed to ambient air temperatures, while the other half were Nvarnied 3 degrees C. Each chamber contained 24 plant communities, created with nine grassland species: three grass species. three nitrogen (N) fixers and three non-N-fixing dicots. Each plant community consisted of either one, three or nine species in order to create different species richness levels. Various ecophysiological variables (processes and characteristics) and above ground biomass were influenced by temperature. In several variables, the effects of temperature and species richness varied with species. No single-factor species richness effect was found due to opposite responses of the species canceling out the effect. We expect that these interactions may increase with time. (c) 2005 Elsevier B.V. All rights reserved. [less ▲]

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See detailFeasability of forest conversion: ecological, social and economic aspects (FEFOCON)
Verheyen, Kris; Lust, Noel; Carnol, Monique ULg et al

Report (2006)

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See detailImpact des essences sur la fertilité des sols forestiers
Carnol, Monique ULg; Degrave, Frédéric; Weissen, Frantz

Conference (2005, March)

Depuis plusieurs siècles, l’écosystème forestier subit d’importantes pressions, engendrées p.ex. par la pollution atmosphérique, des modifications climatiques, des attaques de pathogènes et/ou des ... [more ▼]

Depuis plusieurs siècles, l’écosystème forestier subit d’importantes pressions, engendrées p.ex. par la pollution atmosphérique, des modifications climatiques, des attaques de pathogènes et/ou des exploitations intensives. Une prise de conscience au niveau international a mené à l’intégration du concept de développement durable dans les politiques conduites au niveau du secteur forestier, visant au maintien, à long terme, de la capacité de la forêt d’assurer son rôle économique (productivité), écologique (état sanitaire, biodiversité) et social (loisirs). Ainsi, la liste des ‘Indicateurs Paneuropéens améliorés pour une Gestion Forestière durable’ (Experts de la Conférence Ministérielle sur la Protection des Forêts en Europe, Vienne, octobre 2002), comprend les points suivants : ‘Maintien de la santé et de la vitalité des écosystèmes forestiers’, ‘Maintien, conservation et amélioration approprié de la diversité biologique dans les écosystèmes forestiers’ et ‘Maintien et amélioration approprié des fonctions de la protection dans la gestion des forêts – notamment sol et eau’. En particulier, le maintien de la qualité du sol est indispensable afin d’assurer son rôle de filtre, de zone tampon, de minéralisation de la matière organique pour la nutrition végétale et de protection des eaux de surface et des nappes. En Région wallonne, de nombreux sols forestiers se caractérisent par un pH trop faible, associé à une carence en calcium et surtout en magnésium. Cette pauvreté des sols, combinée à la pollution atmosphérique acide et azotée, a été mise en cause dans le cadre du dépérissement du hêtre et de l’épicéa en Ardenne. Parmi les remèdes, l’amendement calcaro-magnésien est efficace, mais la durabilité et le coût de l’intervention ne paraissent pas satisfaisants. Ainsi, le mélange d’essences principales et/ou secondaires a été proposé pour stabiliser les écosystèmes le plus fragiles. Outre l’impact sur la biodiversité, les essences jouent un rôle essentiel dans le fonctionnement de l’écosystème. Ainsi, l’impact des essences sur le cycle des éléments nutritifs se manifeste principalement à trois niveaux : (1) l’interception des polluants, (2) la composition et la décomposition des litières et (3) le lessivage des éléments minéraux. Ces impacts, ainsi que certains mécanismes sous-jacents, seront discutés au travers de plusieurs études menées en Région wallonne. Les résultats montrent notamment une plus grande interception des dépôts acides et potentiellement acidifiants sous épicéa, comparé au hêtre et au chêne. La composition foliaire des essences indique l’intérêt des essences secondaires, plus riches en bases, pour la stabilisation sanitaire de la forêt. Des différences dans le contenu en éléments minéraux des essences, croissant sur un même site, s’expliqueraient par des différences dans les mécanismes d’assimilation (production d’enzymes spécifiques à l’espèce), la production de substances solubilisant les minéraux, la production de protons favorisant les réactions d’échange et la profondeur d’enracinement. De même, l’essence forestière conditionne la composition minérale moyenne des litières, la vitesse de décomposition et la quantité des éléments nutritifs restitués lors de ce processus. Par exemple, comparées aux autres essences, les feuilles du sorbier des oiseleurs se décomposent rapidement avec une restitution importante de Ca et de Mg. Des premières mesures de lessivage d’éléments minéraux sous trois essences principales montrent une perte de nitrates importante sous pessière, comparée à une hêtraie et à une chênaie. Cette perte de nitrates entraîne le lessivage de cations et l’acidification des sols. Une analyse plus détaillée des résultats existants, ainsi que des recherches complémentaires permettront, à terme, l’utilisation d’un choix raisonné d’essences en mélange pour une stabilisation des sols pauvres. [less ▲]

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See detailImpact des essences sur la fertilité des sols forestiers
Carnol, Monique ULg; Degrave, Frédéric; Weissen, Franz

in Branquart, Etienne; Paquet, Jean-Yves; Claessens, Hugues (Eds.) Journée d'étude: Gestion forestière & biodiversité. Gembloux, 23 mars 2005, résumé des interventions. (2005)

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