Integrating the effects of climate change and caribou herbivory on vegetation community structure in low Arctic tundra
Thesis (Ph.D, Biology) -- Queen's University, 2013-06-07 15:13:21.698 Arctic tundra vegetation communities are rapidly responding to climate warming with increases in aboveground biomass, particularly in deciduous shrubs. This increased shrub density has the potential to dramatically alter the...
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ftqueensuniv:oai:https://qspace.library.queensu.ca:1974/8071 2024-06-02T07:54:33+00:00 Integrating the effects of climate change and caribou herbivory on vegetation community structure in low Arctic tundra Zamin, Tara Biology Grogan, Paul 2013-06-07 13:51:24.384 application/pdf http://hdl.handle.net/1974/8071 eng eng Canadian theses http://hdl.handle.net/1974/8071 This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner. climate change terrestrial ecology nutrient cycling caribou browsing experimental warming soil fertility arctic tundra shrub expansion thesis 2013 ftqueensuniv 2024-05-06T10:47:32Z Thesis (Ph.D, Biology) -- Queen's University, 2013-06-07 15:13:21.698 Arctic tundra vegetation communities are rapidly responding to climate warming with increases in aboveground biomass, particularly in deciduous shrubs. This increased shrub density has the potential to dramatically alter the functioning of tundra ecosystems through its effects on permafrost degradation and nutrient cycling, and to cause positive feedbacks to global climate change through its impacts on carbon balance and albedo. Experimental evidence indicates that tundra plant growth is most strongly limited by soil nutrient availability, which is projected to increase with warming. Therefore research to date into the mechanisms driving tundra 'shrub expansion' has taken a 'bottom-up' perspective, overlooking the potential role of herbivory in mediating plant-soil interactions. In this thesis, I integrate the impacts of climate warming and caribou browsing on tundra vegetation community structure, and specifically investigate if increases in soil fertility with warming might lead to changes in vegetation biomass and chemistry that could fundamentally alter herbivore-nutrient cycling feedbacks, shifting the role of caribou browsing from restricting shrub growth to facilitating it. Using experimental greenhouses, nutrient addition plots, and caribou exclosures at Daring Lake Research Station in the central Canadian low Arctic, I showed that warming increased soil nutrient availability and plant biomass, and that caribou browsing restricted tundra shrub growth under present conditions. Plant and soil nutrient pool responses to warming demonstrated that increased growing season temperatures enhanced tundra plant growth both by increasing soil nutrient availability and by inferred increases in the rate of photosynthesis, however that the former process was comparatively more limiting. Species- and plant part-specific changes in biomass and chemistry with warming and fertilization clearly indicated the rate and magnitude of change in soil ... Thesis albedo Arctic Climate change permafrost Tundra Queen's University, Ontario: QSpace Arctic Daring Lake ENVELOPE(-111.635,-111.635,64.834,64.834) |
institution |
Open Polar |
collection |
Queen's University, Ontario: QSpace |
op_collection_id |
ftqueensuniv |
language |
English |
topic |
climate change terrestrial ecology nutrient cycling caribou browsing experimental warming soil fertility arctic tundra shrub expansion |
spellingShingle |
climate change terrestrial ecology nutrient cycling caribou browsing experimental warming soil fertility arctic tundra shrub expansion Zamin, Tara Integrating the effects of climate change and caribou herbivory on vegetation community structure in low Arctic tundra |
topic_facet |
climate change terrestrial ecology nutrient cycling caribou browsing experimental warming soil fertility arctic tundra shrub expansion |
description |
Thesis (Ph.D, Biology) -- Queen's University, 2013-06-07 15:13:21.698 Arctic tundra vegetation communities are rapidly responding to climate warming with increases in aboveground biomass, particularly in deciduous shrubs. This increased shrub density has the potential to dramatically alter the functioning of tundra ecosystems through its effects on permafrost degradation and nutrient cycling, and to cause positive feedbacks to global climate change through its impacts on carbon balance and albedo. Experimental evidence indicates that tundra plant growth is most strongly limited by soil nutrient availability, which is projected to increase with warming. Therefore research to date into the mechanisms driving tundra 'shrub expansion' has taken a 'bottom-up' perspective, overlooking the potential role of herbivory in mediating plant-soil interactions. In this thesis, I integrate the impacts of climate warming and caribou browsing on tundra vegetation community structure, and specifically investigate if increases in soil fertility with warming might lead to changes in vegetation biomass and chemistry that could fundamentally alter herbivore-nutrient cycling feedbacks, shifting the role of caribou browsing from restricting shrub growth to facilitating it. Using experimental greenhouses, nutrient addition plots, and caribou exclosures at Daring Lake Research Station in the central Canadian low Arctic, I showed that warming increased soil nutrient availability and plant biomass, and that caribou browsing restricted tundra shrub growth under present conditions. Plant and soil nutrient pool responses to warming demonstrated that increased growing season temperatures enhanced tundra plant growth both by increasing soil nutrient availability and by inferred increases in the rate of photosynthesis, however that the former process was comparatively more limiting. Species- and plant part-specific changes in biomass and chemistry with warming and fertilization clearly indicated the rate and magnitude of change in soil ... |
author2 |
Biology Grogan, Paul |
format |
Thesis |
author |
Zamin, Tara |
author_facet |
Zamin, Tara |
author_sort |
Zamin, Tara |
title |
Integrating the effects of climate change and caribou herbivory on vegetation community structure in low Arctic tundra |
title_short |
Integrating the effects of climate change and caribou herbivory on vegetation community structure in low Arctic tundra |
title_full |
Integrating the effects of climate change and caribou herbivory on vegetation community structure in low Arctic tundra |
title_fullStr |
Integrating the effects of climate change and caribou herbivory on vegetation community structure in low Arctic tundra |
title_full_unstemmed |
Integrating the effects of climate change and caribou herbivory on vegetation community structure in low Arctic tundra |
title_sort |
integrating the effects of climate change and caribou herbivory on vegetation community structure in low arctic tundra |
publishDate |
2013 |
url |
http://hdl.handle.net/1974/8071 |
long_lat |
ENVELOPE(-111.635,-111.635,64.834,64.834) |
geographic |
Arctic Daring Lake |
geographic_facet |
Arctic Daring Lake |
genre |
albedo Arctic Climate change permafrost Tundra |
genre_facet |
albedo Arctic Climate change permafrost Tundra |
op_relation |
Canadian theses http://hdl.handle.net/1974/8071 |
op_rights |
This publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner. |
_version_ |
1800740973050855424 |