References of "Carnol, Monique"
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See detailElevated atmospheric CO2 influences ammonia oxidiser community structure and net nitrification
Carnol, Monique ULg; Malchair, Sandrine ULg

Conference (2003, September)

The control of soil nitrogen (N) availability under elevated atmospheric CO2 is central to predicting changes in ecosystem carbon storage and primary productivity. The effects of elevated CO2 on ... [more ▼]

The control of soil nitrogen (N) availability under elevated atmospheric CO2 is central to predicting changes in ecosystem carbon storage and primary productivity. The effects of elevated CO2 on belowground processes have so far attracted limited research and they are assumed to be controlled by indirect effects through changes in plant physiology and chemistry. In this study, we investigated the effects of a 4-year exposure to elevated CO2 (ambient + 400 μmol mol-1) in open top chambers under Scots pine (Pinus sylvestris L.) on net nitrification and the community of ammonia-oxidising bacteria. Net nitrate production was significantly increased for soil from the elevated CO2 treatment in the field when incubated in the laboratory under elevated CO2, but there was no effect when incubated under ambient CO2. Net nitrate production of the soil originating from the ambient CO2 treatment in the field was not influenced by laboratory incubation conditions. These results indicate that a direct effect of elevated atmospheric CO2 on soil microbial processes might take place. Molecular analysis of the ammonia-oxidising bacteria from the same soils before laboratory incubation was investigated using a PCR-based approach targeting the 16S rRNA gene of beta-subgroup ammonia oxidisers. After specific PCR, DGGE (Denaturing Gradient Gel Electrophoresis) and sequence analysis were used to determine ammonia-oxidiser community structure. First results indicate the disappearance of Nitrosospira clusters I, II and III under elevated CO2 but also call for systematic analysis of replicates to take into account methodological and sample variability. [less ▲]

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See detailLa récolte des résidus de coupe face au développement durable de la forêt
Carnol, Monique ULg

Conference given outside the academic context (2003)

Actuellement, la discussion sur les enjeux environnementaux de l’utilisation des ‘déchets’ ligneux pour la production d’énergie porte exclusivement sur la contribution de cette pratique dans les efforts ... [more ▼]

Actuellement, la discussion sur les enjeux environnementaux de l’utilisation des ‘déchets’ ligneux pour la production d’énergie porte exclusivement sur la contribution de cette pratique dans les efforts de réduction des émissions de gaz à effet de serre et sur l’augmentation de la contribution des énergies renouvelables à la production totale d’énergie. Dans ces ‘déchets’ on trouve les sciures, les chutes de bois et d’autres résidus de l’industrie du bois, mais également les résidus d’exploitations forestières, généralement laissés sur site. Ces ‘déchets ligneux abandonnés en forêt’ jouent cependant un rôle important dans le recyclage des éléments nutritifs et donc dans la fertilité à long terme du site. Dans une approche budgétaire, quantifiant les entrées (pluies, pluviolessivats, altération des roches) et les sorties (lessivage, exploitation forestière) en nutriments de l’écosystème forêt, on peut estimer l’importance relative de l’exploitation forestière par rapport aux réserves nutritives du sol. Pour les sols pauvres de l’Ardenne, il apparaît que les éléments nutritifs des résidus de coupe peuvent jouer un rôle important dans le maintien du capital en nutriments du site. Dans le cadre des préoccupations du développement durable de la forêt, il apparaît donc indispensable de mener une réflexion globale sur l’utilisation bois-énergie et d’effectuer les récoltes des résidus sur des sites adéquats afin de ne pas aboutir aux excès de la surexploitation. [less ▲]

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See detailElevated atmospheric CO2 influences ammonia oxidiser community structure and net nitrification
Carnol, Monique ULg; Malchair, Sandrine ULg

in International Symposium: Structure and Function of Soil Microbiota, Philipps-University Marburg, Germany, September 18-20, 2003 (2003)

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See detailImpacts of management strategies on nutrient fluxes in a temperate Picea abies (L. Karst) plantation
Carnol, Monique ULg

in Jansen, Jörg; Spiecker, Heinrich; von Teuffel, Konstantin (Eds.) Berichte Freiburger Forstliche Forschung, Heft 47, The question of conversion of coniferous forests, Abstracts, International Conference, 27 Septembre - 02 october, 2003, Freiburg im Breisgau, Germany (2003)

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See detailNitrosomonas europaea-like bacteria detected as the dominant beta-subclass Proteobacteria ammonia oxidisers in reference and limed acid forest soils
Carnol, Monique ULg; Kowalchuk, G. A.; De Boer, W.

in Soil Biology & Biochemistry (2002), 34

Net nitrification in intact soil cores and the community of ammonia-oxidising bacteria were studied in acid Norway spruce (Picea abies (L.) Karst) and sessile oak (Quercus petraea (Matt. Lieb.)) soils ... [more ▼]

Net nitrification in intact soil cores and the community of ammonia-oxidising bacteria were studied in acid Norway spruce (Picea abies (L.) Karst) and sessile oak (Quercus petraea (Matt. Lieb.)) soils (Haute Ardenne, east Belgium) 18 months after treatment with 5 t ha(-1) dolomite lime. Liming caused a significant increase in nitrification in the upper soil layers (0.15 m) of both stands. DGGE (denaturing gradient gel electrophoresis) profiling after P-subclass ammonia oxidiser-specific polymerase chain reaction (PCR), combined with hybridisation and sequencing of excised DGGE bands revealed a dominance of Nitrosomonas europaea-like sequences, independent of soil horizon, tree species and lime treatment. A minority Nitrosospira-like population was detected, which showed affinity to nitrosospiras previously detected in acid soil. These results contrast with several reports suggesting a dominance of Nitrosospira-like organisms among ammonia oxidiser communities in acid soils. (C) 2002 Elsevier Science Ltd. All rights reserved. [less ▲]

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See detailElevated atmospheric CO2 in open top chambers increases net nitrification and potential denitrification
Carnol, Monique ULg; Hogenboom, L.; Jach, M. E. et al

in Global Change Biology (2002), 8

The control of soil nitrogen (N) availability under elevated atmospheric CO2 is central to predicting changes in ecosystem carbon (C) storage and primary productivity. The effects of elevated CO2 on ... [more ▼]

The control of soil nitrogen (N) availability under elevated atmospheric CO2 is central to predicting changes in ecosystem carbon (C) storage and primary productivity. The effects of elevated CO2 on belowground processes have so far attracted limited research and they are assumed to be controlled by indirect effects through changes in plant physiology and chemistry. In this study, we investigated the effects of a 4-year exposure to elevated CO2 (ambient + 400 mumol mol(-1) ) in open top chambers under Scots pine (Pinus sylvestris L) seedlings on soil microbial processes of nitrification and denitrification. Potential denitrification (DP) and potential N-2 O emissions were significantly higher in soils from the elevated CO2 treatment, probably regulated indirectly by the changes in soil conditions (increased pH, C availability and NO3 (-) production). Net N mineralization was mainly accounted for by nitrate production. Nitrate production was significantly larger for soil from the elevated CO2 treatment in the field when incubated in the laboratory under elevated CO2 (increase of 100%), but there was no effect when incubated under ambient CO2 . Net nitrate production of the soil originating from the ambient CO2 treatment in the field was not influenced by laboratory incubation conditions. These results indicate that a direct effect of elevated atmospheric CO2 on soil microbial processes might take place. We hypothesize that physiological adaptation or selection of nitrifiers could occur under elevated CO2 through higher soil CO2 concentrations. Alternatively, lower microbial NH4 assimilation under elevated CO2 might explain the higher net nitrification. We conclude that elevated atmospheric CO2 has a major direct effect on the soil microbial processes of nitrification and denitrification despite generally higher soil CO2 concentrations compared to atmospheric concentrations. [less ▲]

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See detailEffects of liming on forest soil algal communities
Kostinov, I.; Carnol, Monique ULg; Dulière, J.-F. et al

in Algological Studies (2001), 102

The effects of the application of dolomite lime (5 t ha-1) on soil algal communities were investigated in sessile oak (Quercus petraea (MATT.) LIEB.) and Norway spruce (Picea abies (L.) KARST.) plots ... [more ▼]

The effects of the application of dolomite lime (5 t ha-1) on soil algal communities were investigated in sessile oak (Quercus petraea (MATT.) LIEB.) and Norway spruce (Picea abies (L.) KARST.) plots situated in the Belgian Ardenne. Chlorophyta (60 taxa) were by far the most diverse group, followed by Xanthophyceae (10 taxa), Bacillariophyceae (3 taxa), Cyanophyceae (2 taxa) and Euglenophyceae (1 taxon). In both forest types, liming lead to a significant increase in soil pH, exchangeable magnesium and calcium. In the limed Quercus plots available phosphorus and soil solution nitrate concentrations were also increased. The soil algal diversity was similar in oak and spruce control plots and in limed spruce plots. However, in the limed oak plots a significantly higher algal diversity was observed. On the basis of a CCA analysis, three clusters of plots could be distinguished: a) Picea control plots, b) limed Picea and control Quercus plots, c) limed Quercus plots. Both soil pH and nutrient availability seem to be important in determining algal species composition in these forest soils. [less ▲]

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See detailElement removal in harvested tree biomass: scenarios for critical loads in Wallonia, south Belgium
Bosman, Bernard ULg; Remacle, Jean; Carnol, Monique ULg

in Water, Air & Soil Pollution : Focus (2001), 1

The critical load concept is now widely used as a tool for developing emission control policies in Europe. As a signatory country of the Convention of Long-Range Transboundary Air Pollution, critical ... [more ▼]

The critical load concept is now widely used as a tool for developing emission control policies in Europe. As a signatory country of the Convention of Long-Range Transboundary Air Pollution, critical loads for acidity, nutrient nitrogen, nitrogen and sulphur have been calculated for the Flemish and Walloon regions in Belgium. This paper describes the methodology used for estimating critical loads for forest soils in the Walloon region according to the Steady-State Mass Balance equations. As an example the methodology was applied to the catchment `Waroneu', situated in a sensitive area of the Haute Ardenne. Main input parameters to the equations were derived from precipitation and runoff data of the catchment study. Improved estimates of nitrogen uptake (Nu) and base cation uptake (BCu) were obtained by intensive sampling of Picea abies and Quercus robur trees. Nutrient contents (Ca, Mg, K, N) and nutrient to nitrogen ratios of Picea abies reflected the poor soil quality at a site with high N deposition. Quercus robur nutrient contents increased from stem to higher order branches with a high proportion of nutrients located in the bark. However the simulation of stem only harvesting had a minor effect on critical loads. Measured wood densities were lower than reported literature values with a main effect on Nu and BCu estimates. The use of recommended default values and/or data derived from the experimental site resulted in a wide range of critical loads, some of which were largely overestimated. Results demonstrated the importance of site specific data for critical load calculations. [less ▲]

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See detail'Dolomite lime effects on acid forest soils: traditional and molecular approaches
Carnol, Monique ULg

Conference (2000, November)

The study of biogeochemical processes in soil has long been restricted by the techniques available for investigating the micro-organisms concerned. In particular, isolated nitrifying bacteria are not ... [more ▼]

The study of biogeochemical processes in soil has long been restricted by the techniques available for investigating the micro-organisms concerned. In particular, isolated nitrifying bacteria are not active in culture media below pH 5.5-6.0, and it is not clear to what extent these strains, if at all, are active in the acid soils of temperate forests. Since DNA/RNA based microbiological techniques do not require isolation of bacterial strains, they provide a new, powerful approach to gain insight into the nitrification process. We therefore combined the use of a large scale field experiment and laboratory soil incubations with molecular analysis of the nitrifying bacterial community to investigate the effect of dolomite lime on the nitrification process in the soil of the Belgian Ardenne. In this area, soils are naturally poor in magnesium and liming at moderate doses has been suggested to alleviate soil acidification and nutritional deficiencies. However, possible side effects needed to be evaluated, in particular on the nitrification process. As nitrification may be linked to soil acidification, cation leaching, aluminium mobilisation and N2O emission, increased knowledge is essential when evaluating effects of global environmental change and management strategies on forest ecosystems. The effects of dolomite lime (3-5 T/ha) were investigated at the watershed (80 ha, mainly Picea abies), plot (Quercus petraea and Picea abies stands) and laboratory level. Runoff chemistry, soil solution, net nitrate production in the laboratory and the community structure of ammonium oxidising bacteria (by PCR amplification of 16S-RNA genes, Denaturing Gradient Gel Electrophoresis - DGGE, sequence analysis and hybridisation) were analysed. In the watersheds, consequences on runoff water chemistry were minor. However, in the plot study, soil solution nitrate concentrations were significantly increased through liming in the Quercus plots. Increased net nitrification in the Quercus stand was confirmed by potential net nitrification measurements in the laboratory, whereas soil pH rose in both stands. The impact of liming on potential net nitrification was not related to a shift in the 16S rDNA DGGE community profile of ammonia-oxidising bacteria. The DDGE profile, combined with hybridisation and sequencing of cut out bands revealed a dominance of Nitrosomonas europea-like sequences and a minor presence of Nitrosospira cluster 2-like sequences. These results contrast with several reports suggesting a dominance of Nitrosospira-like organisms among ammonia oxidiser communities in acid soils. Our study reflects the great potential of combining new molecular techniques with conventional methods for improving our knowledge on the ecology of biogeochemical processes. [less ▲]

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See detailEffects of dolomite lime and clearcut on nitrate leaching from acid forest soils
Carnol, Monique ULg

Conference (1999, May)

Forest liming has received increased attention since the 1980s, when unusual needle yellowing and fall were observed in large parts of Europe and North America. This ‘new forest decline’ has been ... [more ▼]

Forest liming has received increased attention since the 1980s, when unusual needle yellowing and fall were observed in large parts of Europe and North America. This ‘new forest decline’ has been attributed to several causes acting individually or in synergy, amongst which were 'acid rain', nitrogen saturation and nutritional imbalances. Liming at moderate doses was suggested as a counteracting measure against soil acidification and to remove nutritional deficiencies. Another major forest management operation is whole tree harvesting. Both liming and clearcut may however affect the water quality leaving the treated areas. In particular, nitrate leaching is of major concern, as nitrate leaching may be linked to soil acidification, associated cation and/or aluminium release, and nitrate contamination of surface and groundwater. In this paper, I summarise main results of studies performed in the Belgian Ardennes. In this area, the acid brown soils are naturally poor in magnesium and the observed forest dieback symptoms were supposed to be the consequence of increased pollution exacerbating magnesium deficiency. Liming was suggested for prevention and correction. However, possible side effects, in particular on soil solution and stream water chemistry needed to be evaluated. Another major concern was the effects of clearcut operations on the streamwater quality in this area important for drinking water collection. The effects of dolomite lime were investigated at the watershed, plot and laboratory level. Paired watersheds of approximately 80 ha were mainly covered with Picea abies. One watershed of each pair was limed with 3 T/ha of fine ground dolomite and 200 kg/ha K2SO4. Runoff chemistry was analysed for major cations and anions and time series intervention analysis was used to detect statistically significant changes in stream water chemistry. Results showed increased magnesium concentrations immediately after liming, but a major part of the lime was retained by the soil system, and consequences on water chemistry were minor. However, in the plot study, where 5 T ha-1 of a dolomite lime suspension were applied to adjacent Quercus petraea and Picea abies stands, soil solution nitrate concentrations were significantly increased through liming in the Quercus plots. Increased net nitrification in the Quercus stand was confirmed by potential net nitrification measurements in the laboratory. The effects of tree harvesting on streamwater ion concentrations were investigated by clear felling 22 ha (9650 m3 wood) of a 81 ha watershed. This area represented one third of the forested area, the remaining area being covered equally with young plantations and 70-100 year old Picea abies. First data indicate increased potassium, iron, lead and organic carbon concentrations, but no major change in streamwater nitrate concentrations. Results will be discussed in relation to literature data and known controlling factors of the nitrification process. This analysis reveals that the speed, extent and duration of a perturbation in nitrate leaching after liming or felling vary at different sites. Risks assessment for nitrate leaching is therefore difficult and prediction of nitrate leaching in response to a perturbation remains an important challenge for further studies. In particular, basic controls of the nitrification process and relation nitrification/immobilisation need further investigation. [less ▲]

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See detailImpact of dolomite lime on the ground vegetation and on potential net N transformations in Norway spruce (Picea Abies (L.) Karst.) and sessile oak (Quercus Petraea (Matt.) Lieb.) stands in the Belgian Ardenne
Duliere, J.-F.; Carnol, Monique ULg; Dalem, S. et al

in Annals of Forest Science : a Multidisciplinary and International Journal (1999), 56

The impact of dolomite lime (5 T·ha-1) on the ground vegetation and on potential net nitrogen (N) transformations was investigated in two Belgian forest ecosystems. Norway spruce (Picea abies (L.) Karst ... [more ▼]

The impact of dolomite lime (5 T·ha-1) on the ground vegetation and on potential net nitrogen (N) transformations was investigated in two Belgian forest ecosystems. Norway spruce (Picea abies (L.) Karst.) and sessile oak (Quercus petraea (Matt.) Lieb.) stands were situated in the Haute Ardenne (east Belgium) on acid-brown soil. The herb-layer floristic richness increased during the 2 years following liming, with the appearance of light and N-demanding species, which are also found in clear-cut areas or on road verges. Mosses reacted rapidly, showing a decrease acidophilous-dominant species and the establishment of some ruderal species. Six months after liming, the pH was significantly increased in the organic horizon of both stands and in the organomineral horizon of the oak stand. Soils originating from the two stands showed distinct responses in net NO3- production to the dolomite lime treatment. In the organic layer of the Quercus soil, net NH4+ production was decreased, NO3- production increased, and total N mineralisation remained unchanged. In the organomineral layer, NO3 - production was increased. In the Picea soil, NO3 - production was decreased in the organomineral soil layer. These results indicate the possibility of differences in the control of the N transformation processes occurring in the two sites. [less ▲]

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See detailAbiotic factors controlling nitrification in acid forest soils
Carnol, Monique ULg

in Rastin, N.; Bauhus (Eds.) Going underground - Ecological studies in forest soils (1999)

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See detailImpacts of (NH4)2SO4 deposition on Norway spruce (Picea abies [L.] Karst) roots
Carnol, Monique ULg; Cudlin, Pavel; Ineson, Phil

in Water, Air & Soil Pollution (1999), 116

The effects of enhanced (NH4)(2)SO4 (NS) deposition on Norway spruce (Picea abies [L.] Karst) fine root biomass, vitality and chemistry were investigated using root-free in-growth cores reproducing native ... [more ▼]

The effects of enhanced (NH4)(2)SO4 (NS) deposition on Norway spruce (Picea abies [L.] Karst) fine root biomass, vitality and chemistry were investigated using root-free in-growth cores reproducing native organic and mineral soil horizons. The cores were covered and watered every 2 weeks with native throughfall or throughfall supplemented with NS to increase deposition by 75 kg ha(-1) a(-1) NH4+-N (86 kg ha(-1) a(-1) SO42--S). The in-growth cores were sampled after 19 months and assessed for root biomass, necromass, length, tip number, tip vitality and fine root chemistry. Root biomass and fine root aluminium (Al) concentration were negatively correlated, but NS deposition had no effect on root growth or root tip vitality. NS deposition caused increased fine root nitrogen (N) concentrations in the organic horizon and increased Calcium (Ca) concentrations in the mineral horizon. Fine root biomass was higher in the organic horizon, where fine root Al and potassium (K) concentrations were lower and Ca concentrations higher than in the mineral horizon. Results highlighted the importance of soil stratification on fine root growth and chemical composition. [less ▲]

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See detailEnvironmental factors controlling NO3- leaching, N2O emissions and numbers of NH4+ oxidisers in a coniferous forest soil
Carnol, Monique ULg; Ineson, Phil

in Soil Biology & Biochemistry (1999), 31

Main and interactive effects of temperature, throughfall volume and NH4+ deposition on soil solution NO3- concentrations, N2O emissions and numbers of NH4+ oxidisers were investigated in a controlled ... [more ▼]

Main and interactive effects of temperature, throughfall volume and NH4+ deposition on soil solution NO3- concentrations, N2O emissions and numbers of NH4+ oxidisers were investigated in a controlled laboratory experiment. Large intact soil cores from a Picea abies (L.) Karat. stand were incubated according to an 'incomplete factorial design' at 4, 12 or 20 degrees C and watered every 2 weeks with 300, 500 or 700 ml (442, 737 and 1032 mm yr(-1)) of a natural throughfall solution enriched with 0, 37.5 or 75 kg NH4+-N ha(-1) yr(-1). Watering and sampling were performed every 2 weeks, during a 112 d period. At d 112, a temperature optimum for NO3--N concentrations in the leachate, NO3--N fluxes and numbers of NH4+ oxidisers in the mineral soil layer was determined at ca. 11 degrees C. NO3--N concentrations also decreased with throughfall volume, towards a minimum at 590 ml, with temperature however contributing most to modelling NO3--N concentrations and the two factors acting independently. The model explained 59% of the variability in the data, and the regression between observed and predicted concentrations was highly significant (P < 0.0001, r(2) = 0.93). NO3--N fluxes increased quadratically with throughfall volume, and throughfall volume and NH4+ deposition interacted significantly in determining the numbers of NH4+ oxidisers in the mineral soil layer. Numbers of NH4+ oxidisers were higher in the humus layer and decreased with increasing temperatures. N2O fluxes increased quadratically with temperature, and the linear and quadratic effects of throughfall volume (maximum at 500 ml). Results suggest that optimum temperatures for net nitrification may have been overestimated in previous studies by the use of disturbed soils. [less ▲]

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