References of "Carnol, Monique"
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See detailBiomass production in experimental grasslands of different species richness during three years of climate warming
De Boeck, H. J.; Lemmens, CMHM; Zavalloni, C. et al

in Biogeosciences (2008), 5

Here we report on the single and combined impacts of climate warming and species richness on the biomass production in experimental grassland communities. Projections of a future warmer climate have ... [more ▼]

Here we report on the single and combined impacts of climate warming and species richness on the biomass production in experimental grassland communities. Projections of a future warmer climate have stimulated studies on the response of terrestrial ecosystems to this global change. Experiments have likewise addressed the importance of species numbers for ecosystem functioning. There is, however, little knowledge on the interplay between warming and species richness. During three years, we grew experimental plant communities containing one, three or nine grassland species in 12 sunlit, climate-controlled chambers 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 was higher. Biomass production was decreased due to warming, both aboveground (-29%) and belowground (-25%), as negative impacts of increased heat and drought stress in summer prevailed. Complementarity effects, likely mostly through both increased aboveground spatial complementarity and facilitative effects of legumes, led to higher shoot and root biomass in multi-species communities, regardless of the induced warming. Surprisingly, warming suppressed productivity the most in 9-species communities, which may be attributed to negative impacts of intense interspecific competition for resources under conditions of high abiotic stress. Our results suggest that warming and the associated soil drying could reduce primary production in many temperate grasslands, and that this will not necessarily be mitigated by efforts to maintain or increase species richness. [less ▲]

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See detailCombined effects of climate warming and plant diversity loss on above- and below-ground grassland productivity
De Boeck, H. J.; Lemmens, CMHM; Gielen, B. et al

in Environmental and Experimental Botany (2007), 60(1), 95-104

Projections of global change predict both increases of the surface temperature and decreases of biodiversity, but studies on the combined impact of both on terrestrial ecosystems are lacking. We assessed ... [more ▼]

Projections of global change predict both increases of the surface temperature and decreases of biodiversity, but studies on the combined impact of both on terrestrial ecosystems are lacking. We assessed the impact of these two global changes on above- and below-ground productivity of grassland communities. Experimental ecosystems containing one, three or nine grassland species were grown in 12 sunlit, climate-controlled chambers in Wilrijk, Belgium. Half of these chambers were exposed to ambient air temperatures, while the other half were warmed by 3 degrees C. Equal amounts of water were added to heated and unheated communities, so that any increases in evapotranspiration due to warmer conditions would result in a drier soil. Warming led to a decreased productivity of both above-ground plant parts (-18%) and roots (-23%), which coincided with a significantly lower soil water content. Complementarity in resource use and/or facilitation slightly enhanced above-ground productivity in multi-species communities, regardless of the induced warming. Interactive effects between temperature treatment and species richness level were found below-ground, however, where warming nullified the positive effect of richness on root productivity. Future warmer conditions could further increase losses of productivity associated with declining species numbers. (c) 2006 Elsevier B.V. All rights reserved. [less ▲]

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See detailBiomass production in experimental grasslands of different species richness during three years of climate warming
de Boeck, H. J.; Lemmens, CMHM; Gielen, B. et al

in Biogeosciences Discussions (2007), 4

Here we report on the single and combined impacts of climate warming and species richness on the biomass production in experimental grassland communities. Projections of a future warmer climate have ... [more ▼]

Here we report on the single and combined impacts of climate warming and species richness on the biomass production in experimental grassland communities. Projections of a future warmer climate have stimulated studies on the response of terrestrial ecosystems to this global change. Experiments have likewise addressed the importance of species numbers for ecosystem functioning. There is, however, little knowledge on the interplay between warming and species richness. During three years, we grew experimental plant communities containing one, three or nine grassland species in 12 sunlit, climate-controlled chambers 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 was higher. Biomass production was decreased due to warming, both aboveground (-29%) and belowground (-25%), as negative impacts of increased heat and drought stress in summer prevailed. Complementarity effects, likely mostly through both increased aboveground spatial complementarity and facilitative effects of legumes, led to higher shoot and root biomass in multi-species communities, regardless of the induced warming. Surprisingly, warming suppressed productivity the most in 9-species communities, which may be attributed to negative impacts of intense interspecific competition for resources under conditions of high abiotic stress. Our results suggest that warming and the associated soil drying could reduce primary production in many temperate grasslands, and that this will not necessarily be mitigated by efforts to maintain or increase species richness. [less ▲]

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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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