Non-native plant invasion of boreal forest gaps : implications for stand regeneration in a protected area shaped by hyperabundant herbivores
Thesis (M.Sc.)--Memorial University of Newfoundland, 2009. Biology Includes bibliographical references (leaves 169-176) While Canada thistle (Cirsium arvense) is notorious as an aggressive, invasive non-native weed in agricultural fields, grasslands, and roadsides throughout North America, it has no...
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ftmemorialunivdc:oai:collections.mun.ca:theses4/77914 2023-05-15T13:13:46+02:00 Non-native plant invasion of boreal forest gaps : implications for stand regeneration in a protected area shaped by hyperabundant herbivores Humber, Jessica M. (Mary), 1983- Memorial University of Newfoundland. Dept. of Biology Canada--Newfoundland and Labrador--Gros Morne National Park; 2009 xi, 214 leaves : ill. (some col.) Image/jpeg; Application/pdf http://collections.mun.ca/cdm/ref/collection/theses4/id/77914 Eng eng Electronic Theses and Dissertations (25.48 MB) -- http://collections.mun.ca/PDFs/theses/Humber_JessicaM.pdf a3242497 http://collections.mun.ca/cdm/ref/collection/theses4/id/77914 The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. Paper copy kept in the Centre for Newfoundland Studies, Memorial University Libraries Balsam fir--Effect of browsing on--Newfoundland and Labrador--Gros Morne National Park Balsam fir--Regeneration--Newfoundland and Labrador--Gros Morne National Park Canada thistle--Newfoundland and Labrador--Gros Morne National Park Herbivores--Newfoundland and Labrador--Gros Morne National Park Noxious weeds--Newfoundland and Labrador--Gros Morne National Park Taigas--Newfoundland and Labrador--Gros Morne National Park Text Electronic thesis or dissertation 2009 ftmemorialunivdc 2015-08-06T19:22:11Z Thesis (M.Sc.)--Memorial University of Newfoundland, 2009. Biology Includes bibliographical references (leaves 169-176) While Canada thistle (Cirsium arvense) is notorious as an aggressive, invasive non-native weed in agricultural fields, grasslands, and roadsides throughout North America, it has not typically posed a threat to boreal forests. However, in the balsam fir (Abies balsamea) -dominated lowland boreal forests in Gros Morne National Park (GMNP- Newfoundland, Canada), Canada thistle has recently invaded natural areas on a large landscape scale, occurring in 42% to 55% of anthropogenic and natural forest gaps, respectively, and frequently forming dense monocultures. It is important to determine if and how Canada thistle invasion will affect regeneration of native trees, particularly since regeneration of gaps in GMNP is already threatened by non-native, hyperabundant moose (Alces alces) populations, which exert extreme browsing pressure on forests. This study assessed the condition of forest gaps to support conifer regeneration by describing the current level of balsam fir regeneration, quality of seedbeds, and degree of Canada thistle invasion. Balsam fir seed and seedling addition experiments were performed in gaps to determine the effect of thistle presence on emergence, growth, and survival of balsam fir. Finally, the potential for allelopathic impacts on native conifers from Canada thistle was assessed in greenhouse experiments. Results revealed that gaps are not regenerating, contain poor seedbeds for conifer recruitment, and are heavily disturbed by moose browsing. Canada thistle invasion further threatens balsam fir emergence and early seedling survival. However, older, transplanted fir seedlings were not negatively affected by thistle, suggesting that seedling planting may be an effective management strategy to encourage fir regeneration in thistle-invaded gaps, and potentially even phase out shade-intolerant thistle plants over time. Thesis Alces alces Gros Morne National Park Newfoundland studies University of Newfoundland Memorial University of Newfoundland: Digital Archives Initiative (DAI) Newfoundland Canada Gros Morne National Park ENVELOPE(-57.531,-57.531,49.613,49.613) |
institution |
Open Polar |
collection |
Memorial University of Newfoundland: Digital Archives Initiative (DAI) |
op_collection_id |
ftmemorialunivdc |
language |
English |
topic |
Balsam fir--Effect of browsing on--Newfoundland and Labrador--Gros Morne National Park Balsam fir--Regeneration--Newfoundland and Labrador--Gros Morne National Park Canada thistle--Newfoundland and Labrador--Gros Morne National Park Herbivores--Newfoundland and Labrador--Gros Morne National Park Noxious weeds--Newfoundland and Labrador--Gros Morne National Park Taigas--Newfoundland and Labrador--Gros Morne National Park |
spellingShingle |
Balsam fir--Effect of browsing on--Newfoundland and Labrador--Gros Morne National Park Balsam fir--Regeneration--Newfoundland and Labrador--Gros Morne National Park Canada thistle--Newfoundland and Labrador--Gros Morne National Park Herbivores--Newfoundland and Labrador--Gros Morne National Park Noxious weeds--Newfoundland and Labrador--Gros Morne National Park Taigas--Newfoundland and Labrador--Gros Morne National Park Humber, Jessica M. (Mary), 1983- Non-native plant invasion of boreal forest gaps : implications for stand regeneration in a protected area shaped by hyperabundant herbivores |
topic_facet |
Balsam fir--Effect of browsing on--Newfoundland and Labrador--Gros Morne National Park Balsam fir--Regeneration--Newfoundland and Labrador--Gros Morne National Park Canada thistle--Newfoundland and Labrador--Gros Morne National Park Herbivores--Newfoundland and Labrador--Gros Morne National Park Noxious weeds--Newfoundland and Labrador--Gros Morne National Park Taigas--Newfoundland and Labrador--Gros Morne National Park |
description |
Thesis (M.Sc.)--Memorial University of Newfoundland, 2009. Biology Includes bibliographical references (leaves 169-176) While Canada thistle (Cirsium arvense) is notorious as an aggressive, invasive non-native weed in agricultural fields, grasslands, and roadsides throughout North America, it has not typically posed a threat to boreal forests. However, in the balsam fir (Abies balsamea) -dominated lowland boreal forests in Gros Morne National Park (GMNP- Newfoundland, Canada), Canada thistle has recently invaded natural areas on a large landscape scale, occurring in 42% to 55% of anthropogenic and natural forest gaps, respectively, and frequently forming dense monocultures. It is important to determine if and how Canada thistle invasion will affect regeneration of native trees, particularly since regeneration of gaps in GMNP is already threatened by non-native, hyperabundant moose (Alces alces) populations, which exert extreme browsing pressure on forests. This study assessed the condition of forest gaps to support conifer regeneration by describing the current level of balsam fir regeneration, quality of seedbeds, and degree of Canada thistle invasion. Balsam fir seed and seedling addition experiments were performed in gaps to determine the effect of thistle presence on emergence, growth, and survival of balsam fir. Finally, the potential for allelopathic impacts on native conifers from Canada thistle was assessed in greenhouse experiments. Results revealed that gaps are not regenerating, contain poor seedbeds for conifer recruitment, and are heavily disturbed by moose browsing. Canada thistle invasion further threatens balsam fir emergence and early seedling survival. However, older, transplanted fir seedlings were not negatively affected by thistle, suggesting that seedling planting may be an effective management strategy to encourage fir regeneration in thistle-invaded gaps, and potentially even phase out shade-intolerant thistle plants over time. |
author2 |
Memorial University of Newfoundland. Dept. of Biology |
format |
Thesis |
author |
Humber, Jessica M. (Mary), 1983- |
author_facet |
Humber, Jessica M. (Mary), 1983- |
author_sort |
Humber, Jessica M. (Mary), 1983- |
title |
Non-native plant invasion of boreal forest gaps : implications for stand regeneration in a protected area shaped by hyperabundant herbivores |
title_short |
Non-native plant invasion of boreal forest gaps : implications for stand regeneration in a protected area shaped by hyperabundant herbivores |
title_full |
Non-native plant invasion of boreal forest gaps : implications for stand regeneration in a protected area shaped by hyperabundant herbivores |
title_fullStr |
Non-native plant invasion of boreal forest gaps : implications for stand regeneration in a protected area shaped by hyperabundant herbivores |
title_full_unstemmed |
Non-native plant invasion of boreal forest gaps : implications for stand regeneration in a protected area shaped by hyperabundant herbivores |
title_sort |
non-native plant invasion of boreal forest gaps : implications for stand regeneration in a protected area shaped by hyperabundant herbivores |
publishDate |
2009 |
url |
http://collections.mun.ca/cdm/ref/collection/theses4/id/77914 |
op_coverage |
Canada--Newfoundland and Labrador--Gros Morne National Park; |
long_lat |
ENVELOPE(-57.531,-57.531,49.613,49.613) |
geographic |
Newfoundland Canada Gros Morne National Park |
geographic_facet |
Newfoundland Canada Gros Morne National Park |
genre |
Alces alces Gros Morne National Park Newfoundland studies University of Newfoundland |
genre_facet |
Alces alces Gros Morne National Park Newfoundland studies University of Newfoundland |
op_source |
Paper copy kept in the Centre for Newfoundland Studies, Memorial University Libraries |
op_relation |
Electronic Theses and Dissertations (25.48 MB) -- http://collections.mun.ca/PDFs/theses/Humber_JessicaM.pdf a3242497 http://collections.mun.ca/cdm/ref/collection/theses4/id/77914 |
op_rights |
The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. |
_version_ |
1766260304610590720 |