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Impact of nutrient removal through harvesting on the sustainability of the boreal forest / Louis Duchesne in Ecological Applications, vol 18 n° 7 (October 2008)  

Public [article]  inEcological Applications > vol 18 n° 7 (October 2008) . - pp 1642 - 1651 Titre : Impact of nutrient removal through harvesting on the sustainability of the boreal forest Type de document : Article/Communication Auteurs : Louis Duchesne, Auteur ; Daniel Houle, Auteur Année de publication : 2008 Article en page(s) : pp 1642 - 1651 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Végétation [Termes IGN] acidification des sols [Termes IGN] forêt boréale [Termes IGN] gestion forestière durable [Termes IGN] nutriment végétal [Termes IGN] sol acide Résumé : (auteur) The cycling of base cations (K, Ca, Mg, and Na) was investigated in a boreal balsam fir forest (the Lake Laflamme Watershed) between 1999 and 2005. Base cation budgets were calculated for the soil rooting zone that included atmospheric deposition and soil leaching losses, two scenarios of tree uptake (whole-tree and stem-only harvesting), and three scenarios of mineral weathering, leading to six different scenarios. In every scenario there was a net accumulation of Mg within the soil exchangeable reservoir, while Ca accumulated in four scenarios. Potassium was lost in five of the six scenarios. Contrary to Ca and Mg, immobilization of K within tree biomass (69 mol·ha−1·yr−1) was the main pathway of K losses from the soil exchangeable reservoir, being five times higher than losses via soil leaching (14 mol·ha−1·yr−1). The amounts of K contained within the aboveground biomass and the exchangeable soil reservoir were 3.3 kmol/ha and 4.2 kmol/ha, respectively. Whole-tree harvesting may thus remove 44% of the K that is readily available for cycling in the short term, making this forest sensitive to commercial forestry operations. Similar values of annual K uptake as well as a similar distribution of K between tree biomass and soil exchangeable reservoirs at 14 other coniferous sites, distributed throughout the boreal forest of Québec, suggest that the Lake Laflamme Watershed results can be extrapolated to a much larger area. Stem-only harvesting, which would reduce K exports due to biomass removal by 60%, should be used for these types of forest. Numéro de notice : A2008-665 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1890/07-1035.1 En ligne : https://doi.org/10.1890/07-1035.1 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=88991 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
IFN-001-000244	423 DUC	Tiré à part	Nogent-sur-Vernisson	Bibliothèque Nogent IFN	Exclu du prêt

Base cation cycling in a pristine watershed of the Canadian boreal forest / Louis Duchesne in Biogeochemistry, vol 78 n° 2 (April 2006)  

Public [article]  inBiogeochemistry > vol 78 n° 2 (April 2006) . - pp 195 - 216 Titre : Base cation cycling in a pristine watershed of the Canadian boreal forest Type de document : Article/Communication Auteurs : Louis Duchesne, Auteur ; Daniel Houle, Auteur Année de publication : 2006 Article en page(s) : pp 195 - 216 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Termes IGN] acidification des sols [Termes IGN] Canada [Termes IGN] exploitation forestière [Termes IGN] forêt boréale [Termes IGN] nutriment végétal [Termes IGN] sol acide Résumé : (auteur) Base cation cycling was investigated on the Canadian Shield in a pristine catchment of the boreal forest. An input–output budget (atmospheric deposition – stream exports) for the whole watershed indicated that nitrogen (N) was strongly retained, while sulphur (S) and base cations (K, Ca, Mg) were lost. The S losses are attributed to internal sources, such as SO4 desorption and/or mineralisation of soil organic-S. The base cation losses at the catchment scale, however, might be contributed by weathering of the till below the rooting zone, which has little ecological significance. For this reason, a detailed budget of basic cations, including atmospheric deposition, tree uptake, mineral weathering and leaching losses was constructed for the soil rooting zone of a stand representative of the forest covering the catchment. Different scenarios of tree uptake (whole tree and stem-only harvesting), weathering rates (PROFILE modelled values, PROFILE modelled values corrected for soil Na leaching) and soil leaching losses (depth of 22 and 81 cm) were considered. The element budgets were summed for the 1997–2003 (7 years) period. In every scenario, K was lost (−35.5 to −1.2 kg ha−1) from the exchangeable reservoir. Gain or losses of Ca were observable, depending of the scenario considered (28.8 to −20.1 kg ha−1) while Mg (−0.8 to 13.3 kg ha−1) generally accumulated over the 7-year period. The absolute K losses are very important, given the very small K soil exchangeable reservoir (55.2 kg ha−1) at the site. Because the amount of K sequestered in biomass (110 kg ha−1) is twice the amount found in the exchangeable soil reservoir, this forest is very sensitive to commercial forestry operations and forest harvesting appears as the main pathway of base cation losses. This raises important questions regarding the sustainability of the boreal forest that lies on K-poor soils of the Canadian Shield. Numéro de notice : A2006-662 Affiliation des auteurs : non IGN Thématique : FORET Nature : Article DOI : 10.1007/s10533-005-4174-7 En ligne : https://doi.org/10.1007/s10533-005-4174-7 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=88994 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
IFN-001-000245	423 DUC	Tiré à part	Nogent-sur-Vernisson	Bibliothèque Nogent IFN	Exclu du prêt