CO2 exchange in three Canadian High Arctic ecosystems: response to long-term experimental warming

2004 ◽  
Vol 10 (12) ◽  
pp. 1981-1995 ◽  
Author(s):  
Jeffrey M. Welker ◽  
Jace T. Fahnestock ◽  
Greg H. R. Henry ◽  
Kevin W. O'Dea ◽  
Rodney A. Chimner
Keyword(s):  
High Arctic ◽  
Co2 Exchange ◽  
Experimental Warming ◽  
Arctic Ecosystems ◽  
Canadian High Arctic

scholarly journals Changes in plant composition and diversity in an Alpine heath and meadow after 18 years of experimental warming

2020 ◽  
Author(s):  
Juha Alatalo ◽  
Mohammad Bagher Erfanian ◽  
Ulf Molau ◽  
Shengbin Chen ◽  
Yang Bai ◽  
...  
Keyword(s):  
Species Composition ◽  
Plant Communities ◽  
Phylogenetic Diversity ◽  
Dominant Species ◽  
Experimental Warming ◽  
Alpine Plant ◽  
Arctic Ecosystems ◽  
Alpine Plant Communities ◽  
The Impact

Background and aim Global warming is expected to have large impacts on high alpine and Arctic ecosystems in future. Here we report the effects of 18 years of experimental warming on two contrasting high alpine plant communities in subarctic Sweden.Methods Using open-top chambers (OTCs), we analysed the effects of long-term passive experimental warming on two high alpine plant communities, a species- and nutrient-poor heath and a more nutrient- and species-rich mesic meadow. We determined the impact on species composition, species diversity (at the level of rare, frequent and dominant species in each community), and phylogenetic and functional diversity.Key results Long-term warming drove differentiation in the species composition in both heath and meadow vegetation, with the warmed plots having distinctly different species composition in 2013 compared with 1995. In addition, variability in species composition increased in the meadow, while it decreased in the heath. The long-term warming had a significant negative effect on the three orders of phylogenetic Hill diversity in the meadow. There was a similar tendency in the heath, but only the phylogenetic diversity of dominant species was significantly affected. Long-term warming caused a reduction in graminoids in the heath, while deciduous shrubs increased. In the meadow, cushion-forming plants showed an increase in abundance from 2001 to 2013 in the warmed plots. Conclusions Responses in species and phylogenetic diversity to experimental warming varied over both time (medium vs long-term responses) and space (i.e. between the two neighbouring plant communities heath and meadow). The meadow community was more negatively affected in terms of species and phylogenetic diversity than the heath community. A potential driver for the changes in the meadow may be decreased soil moisture caused by the long-term warming.

The Effects of Predicted Soil Moisture and Temperature Increase on CO2 Exchange within a High Arctic Ecosystem

2018 ◽  
Author(s):  
Sarah Jackson
Keyword(s):  
Soil Moisture ◽  
Soil Temperature ◽  
Co2 Flux ◽  
High Arctic ◽  
Co2 Exchange ◽  
The Arctic ◽  
Co2 Production ◽  
Arctic Ecosystems ◽  
Arctic Regions ◽  
Snow Fences

With 2014 being the warmest year on record and 10 of the warmest years occurring after 1997, it is essential to understand the effects of this warming on CO2 exchange. It was also discovered that much of this warming is focused in the Arctic regions, which are sensitive to changes in temperature (Cole & McCarthy, 2015). My research examines the effects of enhanced snowfall and soil temperature on the exchange of CO2 between the land and the atmosphere in a high arctic environment. The research is taking place at Cape Bounty Arctic Watershed Observatory (CBAWO) on Melville Island, Nunavut as part of the International Tundra Experiment (ITEX). The goal of ITEX is to better understand the effects of increased summer temperature and increased snowfall on arctic ecosystems. This is a full factorial experiment including treatments varying precipitation (and likely soil moisture), soil temperature, moisture and temperature together, and a control that is at ambient soil moisture and temperature. Snow fences are used to enhance precipitation, while open-topped transparent chambers are used to increase soil temperature. In a companion lab experiment, I look at the effects of different soil moisture levels and temperatures on soil CO2 production in a more controlled environment. Two temperatures, two moisture levels, and eight replicates of each will be established in sealed incubation chambers, and soils will be incubated for 33 days. Presently a significant relationship has been found between soil moisture and CO2 flux within the field experiment.

Responses of surface SOC to long-term experimental warming vary between different heath types in the high Arctic tundra

2020 ◽  
Vol 71 (4) ◽  
pp. 752-767
Author(s):  
Ji Young Jung ◽  
Anders Michelsen ◽  
Mincheol Kim ◽  
Sungjin Nam ◽  
Niels M. Schmidt ◽  
...  
Keyword(s):  
Arctic Tundra ◽  
High Arctic ◽  
Experimental Warming

Effects of Permafrost Disturbance on Trace Gas Flux in a High Arctic Ecosystem

2016 ◽  
Author(s):  
Alison Beamish
Keyword(s):  
Active Layer ◽  
Global Climate ◽  
High Arctic ◽  
Co2 Exchange ◽  
The Arctic ◽  
Trace Gas ◽  
Arctic Ecosystems ◽  
Gas Flux ◽  
Temperature And Precipitation ◽  
The Impact

High Arctic ecosystems are likely to experience some of the earliest and most extreme changes in climate as a result of future global climate change. These changes will likely include both increases in temperature and precipitation. High-Arctic ecosystems are very sensitive to climatic disruption, and the response of these ecosystems to changes in climate could have a strong influence on future climate. In particular, changes in temperature and moisture will cause the active layer to deepen as a result of enhanced permafrost melting. This deepening will decrease stability in shallow slopes leading to soil disturbances known as active layer detachments.. We are exploring the impact of active layer detachments on net ecosystem trace gas (CH4, N2O and CO2) exchange at the Cape Bounty Arctic Watershed Observatory on Melville Island. Eight plots were established in four different detachments, covering a range of disturbance intensities (control, disturbed and highly disturbed). Based on collected and analysed gas samples, it appears disturbance has an effect on trace gas exchange. Initial results show a distinct difference across the disturbance gradient. These findings have important implications if summer temperatures are to rise and disturbance frequency increases. Continued monitoring of these sites is important to assess the changes in trace gas flux over time since disturbance. Quantifying the impact of active layer detachments is crucial to furthering our understanding of the arctic carbon and trace gas cycles.

Changes in high arctic tundra plant reproduction in response to long-term experimental warming

2010 ◽  
Vol 17 (4) ◽  
pp. 1611-1624 ◽  
Author(s):  
REBECCA A. KLADY ◽  
GREGORY H. R. HENRY ◽  
VALERIE LEMAY
Keyword(s):  
Plant Reproduction ◽  
Arctic Tundra ◽  
High Arctic ◽  
Experimental Warming
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