Déterminants de l'hétérogénéité du recul de la lande à lichens dans la Réserve de Parc National de l'Archipel-de-Mingan
In the Mingan Archipelago National Park Reserve (MANPR) of Québec, Canada, an important greening has been observed at the expense of terricolous lichens since 1967. This phenomenon occurring in lichen heaths is most likely linked to the encroachment of shrubs like the black crowberry (Empetrum nigru...
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fttriple:oai:gotriple.eu:http://hdl.handle.net/20.500.11794/30380 2023-05-15T15:45:54+02:00 Déterminants de l'hétérogénéité du recul de la lande à lichens dans la Réserve de Parc National de l'Archipel-de-Mingan Determinants of the heterogeneity of the decline of the Lichens heath in the Archipel-de-Mingan National Park Reserve Caouette, Marianne Boudreau, Stéphane Simard, Martin Québec (Province) 2018-01-01 https://hdl.handle.net/20.500.11794/30380 fr fre Université Laval http://hdl.handle.net/20.500.11794/30380 CorpusUL envir geo Thesis https://vocabularies.coar-repositories.org/resource_types/c_46ec/ 2018 fttriple https://doi.org/20.500.11794/30380 2023-01-22T16:33:42Z In the Mingan Archipelago National Park Reserve (MANPR) of Québec, Canada, an important greening has been observed at the expense of terricolous lichens since 1967. This phenomenon occurring in lichen heaths is most likely linked to the encroachment of shrubs like the black crowberry (Empetrum nigrum L.) and the dwarf birch (Betula pumila L.). Aerial photos of the Mingan archipelago acquired in 1967, 1988 and 2009 reveal a retreat that appears heterogeneous at a local scale, with some lichen heaths decreasing rapidly in extent and others appearing stable over time. Our aim was to determine which local-scale characteristics (substrate, aspect, etc.) promote the retreat of the lichen heaths on the islands. Using supervised classification on the aerial photos, vegetation maps of seven islands of the MANPR have been generated to track the plant communities’ changes and quantify the retreat in lichen cover. Maps results show an average decrease of 71% between 1967 and 2009, with the majority of the retreat observed between 1967 and 1988 (50%). Models built with local characteristics suggest that the soil organic layer (SOL) thickness is important to explain the retreat (AICcWt = 0.44). However, explanative factors and vascular plant colonization patterns differ depending on the time interval studied (1967-1988 and 1988-2009). In fact, SOL thickness seems only important to explain the lichen heath retreat observed during the first time period, during which extensive lichen heaths areas were colonized by an advancing front of vascular plants. This study extends our comprehension of northern ecosystems dynamics. Tableau d'honneur de la Faculté des études supérieures et postdoctorales Dans la Réserve de Parc National du Canada de l'Archipel-de-Mingan (RPNCAM), Québec, un important verdissement des landes à lichens est observé depuis 1967 et serait surtout lié à l’établissement d'espèces arbustives telles que la camarine noire (Empetrum nigrum L.) et le bouleau nain (Betula pumila L.). L’analyse de photos aériennes de ... Thesis Bouleau nain Crowberry Dwarf birch Empetrum nigrum Unknown Canada Nain ENVELOPE(-61.695,-61.695,56.542,56.542) Noire ENVELOPE(140.019,140.019,-66.666,-66.666) |
institution |
Open Polar |
collection |
Unknown |
op_collection_id |
fttriple |
language |
French |
topic |
envir geo |
spellingShingle |
envir geo Caouette, Marianne Déterminants de l'hétérogénéité du recul de la lande à lichens dans la Réserve de Parc National de l'Archipel-de-Mingan |
topic_facet |
envir geo |
description |
In the Mingan Archipelago National Park Reserve (MANPR) of Québec, Canada, an important greening has been observed at the expense of terricolous lichens since 1967. This phenomenon occurring in lichen heaths is most likely linked to the encroachment of shrubs like the black crowberry (Empetrum nigrum L.) and the dwarf birch (Betula pumila L.). Aerial photos of the Mingan archipelago acquired in 1967, 1988 and 2009 reveal a retreat that appears heterogeneous at a local scale, with some lichen heaths decreasing rapidly in extent and others appearing stable over time. Our aim was to determine which local-scale characteristics (substrate, aspect, etc.) promote the retreat of the lichen heaths on the islands. Using supervised classification on the aerial photos, vegetation maps of seven islands of the MANPR have been generated to track the plant communities’ changes and quantify the retreat in lichen cover. Maps results show an average decrease of 71% between 1967 and 2009, with the majority of the retreat observed between 1967 and 1988 (50%). Models built with local characteristics suggest that the soil organic layer (SOL) thickness is important to explain the retreat (AICcWt = 0.44). However, explanative factors and vascular plant colonization patterns differ depending on the time interval studied (1967-1988 and 1988-2009). In fact, SOL thickness seems only important to explain the lichen heath retreat observed during the first time period, during which extensive lichen heaths areas were colonized by an advancing front of vascular plants. This study extends our comprehension of northern ecosystems dynamics. Tableau d'honneur de la Faculté des études supérieures et postdoctorales Dans la Réserve de Parc National du Canada de l'Archipel-de-Mingan (RPNCAM), Québec, un important verdissement des landes à lichens est observé depuis 1967 et serait surtout lié à l’établissement d'espèces arbustives telles que la camarine noire (Empetrum nigrum L.) et le bouleau nain (Betula pumila L.). L’analyse de photos aériennes de ... |
author2 |
Boudreau, Stéphane Simard, Martin |
format |
Thesis |
author |
Caouette, Marianne |
author_facet |
Caouette, Marianne |
author_sort |
Caouette, Marianne |
title |
Déterminants de l'hétérogénéité du recul de la lande à lichens dans la Réserve de Parc National de l'Archipel-de-Mingan |
title_short |
Déterminants de l'hétérogénéité du recul de la lande à lichens dans la Réserve de Parc National de l'Archipel-de-Mingan |
title_full |
Déterminants de l'hétérogénéité du recul de la lande à lichens dans la Réserve de Parc National de l'Archipel-de-Mingan |
title_fullStr |
Déterminants de l'hétérogénéité du recul de la lande à lichens dans la Réserve de Parc National de l'Archipel-de-Mingan |
title_full_unstemmed |
Déterminants de l'hétérogénéité du recul de la lande à lichens dans la Réserve de Parc National de l'Archipel-de-Mingan |
title_sort |
déterminants de l'hétérogénéité du recul de la lande à lichens dans la réserve de parc national de l'archipel-de-mingan |
publisher |
Université Laval |
publishDate |
2018 |
url |
https://hdl.handle.net/20.500.11794/30380 |
op_coverage |
Québec (Province) |
long_lat |
ENVELOPE(-61.695,-61.695,56.542,56.542) ENVELOPE(140.019,140.019,-66.666,-66.666) |
geographic |
Canada Nain Noire |
geographic_facet |
Canada Nain Noire |
genre |
Bouleau nain Crowberry Dwarf birch Empetrum nigrum |
genre_facet |
Bouleau nain Crowberry Dwarf birch Empetrum nigrum |
op_source |
CorpusUL |
op_relation |
http://hdl.handle.net/20.500.11794/30380 |
op_doi |
https://doi.org/20.500.11794/30380 |
_version_ |
1766380535365500928 |