Role of green alder in boreal conifer growth: competitor or facilitator?

Sustainable forest management implies successful regeneration after disturbances. Low N availability and competition can, however, limit tree establishment in boreal ecosystems. To develop silviculture strategies that maintain productivity in such context, we established a field trial in northern Qu...

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Main Authors: Morgane Urli, Nelson Thiffault, Daniel Houle, Sylvie Gauthier, Yves Bergeron
Format: Article
Language:English
Published: Canadian Science Publishing 2021-03-01
Series:FACETS
Subjects:
Online Access:https://www.facetsjournal.com/doi/full/10.1139/facets-2019-0064
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spelling doaj-07c2b5094a0a4a6e9433ea179847d4b52021-01-15T13:06:38ZengCanadian Science PublishingFACETS2371-16712021-03-015166 18110.1139/facets-2019-0064Role of green alder in boreal conifer growth: competitor or facilitator?Morgane Urli0Nelson Thiffault1Daniel Houle2Sylvie Gauthier3Yves Bergeron4Université Laval, Centre d’étude de la forêt, Faculté de foresterie, de géographie et de géomatique, rue de la Terrasse, Québec, QC G1V 0A6, Canada Direction de la recherche forestière, Ministère des Forêts, de la Faune et des Parcs, 2700 Einstein, Québec, QC G1P 3W8, CanadaInstitut de Recherche sur les Forêts, Université du Québec en Abitibi-Témiscamingue, 445 boul. de l’Université, Rouyn-Noranda, QC J9X 5E4, Canada Natural Resources Canada, Canadian Forest Service, Canadian Wood Fibre Centre, 1055 du P.E.P.S., P.O. Box 10380, Stn. Sainte-Foy, Québec, QC G1V 4C7, CanadaDirection de la recherche forestière, Ministère des Forêts, de la Faune et des Parcs, 2700 Einstein, Québec, QC G1P 3W8, Canada Science and Technology Branch, Environment Canada and Climate Change, 105 McGill St., Montreal, QC H2Y 2E7, CanadaNatural Resources Canada, Canadian Forest Service, Laurentian Forestry Centre, 1055 du P.E.P.S., P.O. Box 10380, Stn. Sainte-Foy, Québec, QC G1V 4C7, CanadaInstitut de Recherche sur les Forêts, Université du Québec en Abitibi-Témiscamingue, 445 boul. de l’Université, Rouyn-Noranda, QC J9X 5E4, Canada Département des sciences biologiques, Université du Québec à Montréal, C.P. 8888, Succursale Centre-Ville, Montréal, QC H3C 3P8, CanadaSustainable forest management implies successful regeneration after disturbances. Low N availability and competition can, however, limit tree establishment in boreal ecosystems. To develop silviculture strategies that maintain productivity in such context, we established a field trial in northern Québec, Canada. We evaluated if a companion N2-fixing species (Alnus alnobetula) promotes or hinders Picea mariana and Pinus banksiana establishment over six growing seasons. We tested if Alnus has a facilitation effect through nutritional processes and a competition effect through light interception. Foliar stable nitrogen isotope ratio (δ15N = 15N/14N, ‰) results confirmed that Alnus obtains a substantial part of its N through biological fixation and represents an N source in this system. Although we did not observe increased foliar N concentrations in either conifer species in the presence of Alnus, Pinus growth was nonetheless higher in presence of Alnus, whereas no difference was observed for Picea. In the plots where Alnus cohabited with the conifers, the former had a negative impact on seedling growth, suggesting a significant competition for light. Overall, the net effect of Alnus was positive for Pinus and neutral for Picea. Our results have significant implications for silviculture in N-limited systems, especially in the context of climate change that imposes increased levels of stress on regeneration.https://www.facetsjournal.com/doi/full/10.1139/facets-2019-0064biotic interactionsboreal forestsn fixationnurse plantharsh subarctic ecosystemrestoration plantations
collection DOAJ
language English
format Article
sources DOAJ
author Morgane Urli
Nelson Thiffault
Daniel Houle
Sylvie Gauthier
Yves Bergeron
spellingShingle Morgane Urli
Nelson Thiffault
Daniel Houle
Sylvie Gauthier
Yves Bergeron
Role of green alder in boreal conifer growth: competitor or facilitator?
FACETS
biotic interactions
boreal forests
n fixation
nurse plant
harsh subarctic ecosystem
restoration plantations
author_facet Morgane Urli
Nelson Thiffault
Daniel Houle
Sylvie Gauthier
Yves Bergeron
author_sort Morgane Urli
title Role of green alder in boreal conifer growth: competitor or facilitator?
title_short Role of green alder in boreal conifer growth: competitor or facilitator?
title_full Role of green alder in boreal conifer growth: competitor or facilitator?
title_fullStr Role of green alder in boreal conifer growth: competitor or facilitator?
title_full_unstemmed Role of green alder in boreal conifer growth: competitor or facilitator?
title_sort role of green alder in boreal conifer growth: competitor or facilitator?
publisher Canadian Science Publishing
series FACETS
issn 2371-1671
publishDate 2021-03-01
description Sustainable forest management implies successful regeneration after disturbances. Low N availability and competition can, however, limit tree establishment in boreal ecosystems. To develop silviculture strategies that maintain productivity in such context, we established a field trial in northern Québec, Canada. We evaluated if a companion N2-fixing species (Alnus alnobetula) promotes or hinders Picea mariana and Pinus banksiana establishment over six growing seasons. We tested if Alnus has a facilitation effect through nutritional processes and a competition effect through light interception. Foliar stable nitrogen isotope ratio (δ15N = 15N/14N, ‰) results confirmed that Alnus obtains a substantial part of its N through biological fixation and represents an N source in this system. Although we did not observe increased foliar N concentrations in either conifer species in the presence of Alnus, Pinus growth was nonetheless higher in presence of Alnus, whereas no difference was observed for Picea. In the plots where Alnus cohabited with the conifers, the former had a negative impact on seedling growth, suggesting a significant competition for light. Overall, the net effect of Alnus was positive for Pinus and neutral for Picea. Our results have significant implications for silviculture in N-limited systems, especially in the context of climate change that imposes increased levels of stress on regeneration.
topic biotic interactions
boreal forests
n fixation
nurse plant
harsh subarctic ecosystem
restoration plantations
url https://www.facetsjournal.com/doi/full/10.1139/facets-2019-0064
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AT danielhoule roleofgreenalderinborealconifergrowthcompetitororfacilitator
AT sylviegauthier roleofgreenalderinborealconifergrowthcompetitororfacilitator
AT yvesbergeron roleofgreenalderinborealconifergrowthcompetitororfacilitator
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