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Assessing historical and projected carbon balance of Alaska: A synthesis of results and policy/management implications.

https://arctichealth.org/en/permalink/ahliterature303011
Source
Ecol Appl. 2018 09; 28(6):1396-1412
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Date
09-2018
Author
A David McGuire
Hélène Genet
Zhou Lyu
Neal Pastick
Sarah Stackpoole
Richard Birdsey
David D'Amore
Yujie He
T Scott Rupp
Robert Striegl
Bruce K Wylie
Xiaoping Zhou
Qianlai Zhuang
Zhiliang Zhu
Author Affiliation
U.S. Geological Survey, Alaska Cooperative Fish and Wildlife Research Unit, University of Alaska Fairbanks, Fairbanks, Alaska, 99775, USA.
Source
Ecol Appl. 2018 09; 28(6):1396-1412
Date
09-2018
Language
English
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Keywords
Alaska
Carbon Cycle
Climate change
Ecosystem
Environmental Policy
Forecasting
Abstract
We summarize the results of a recent interagency assessment of land carbon dynamics in Alaska, in which carbon dynamics were estimated for all major terrestrial and aquatic ecosystems for the historical period (1950-2009) and a projection period (2010-2099). Between 1950 and 2009, upland and wetland (i.e., terrestrial) ecosystems of the state gained 0.4 Tg C/yr (0.1% of net primary production, NPP), resulting in a cumulative greenhouse gas radiative forcing of 1.68 × 10-3  W/m2 . The change in carbon storage is spatially variable with the region of the Northwest Boreal Landscape Conservation Cooperative (LCC) losing carbon because of fire disturbance. The combined carbon transport via various pathways through inland aquatic ecosystems of Alaska was estimated to be 41.3 Tg C/yr (17% of terrestrial NPP). During the projection period (2010-2099), carbon storage of terrestrial ecosystems of Alaska was projected to increase (22.5-70.0 Tg C/yr), primarily because of NPP increases of 10-30% associated with responses to rising atmospheric CO2 , increased nitrogen cycling, and longer growing seasons. Although carbon emissions to the atmosphere from wildfire and wetland CH4 were projected to increase for all of the climate projections, the increases in NPP more than compensated for those losses at the statewide level. Carbon dynamics of terrestrial ecosystems continue to warm the climate for four of the six future projections and cool the climate for only one of the projections. The attribution analyses we conducted indicated that the response of NPP in terrestrial ecosystems to rising atmospheric CO2 (~5% per 100 ppmv CO2 ) saturates as CO2 increases (between approximately +150 and +450 ppmv among projections). This response, along with the expectation that permafrost thaw would be much greater and release large quantities of permafrost carbon after 2100, suggests that projected carbon gains in terrestrial ecosystems of Alaska may not be sustained. From a national perspective, inclusion of all of Alaska in greenhouse gas inventory reports would ensure better accounting of the overall greenhouse gas balance of the nation and provide a foundation for considering mitigation activities in areas that are accessible enough to support substantive deployment.
PubMed ID
29923353 View in PubMed
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Biodiversity influences plant productivity through niche-efficiency.

https://arctichealth.org/en/permalink/ahliterature265134
Source
Proc Natl Acad Sci U S A. 2015 May 5;112(18):5738-43
Publication Type
Article
Date
May-5-2015
Author
Jingjing Liang
Mo Zhou
Patrick C Tobin
A David McGuire
Peter B Reich
Source
Proc Natl Acad Sci U S A. 2015 May 5;112(18):5738-43
Date
May-5-2015
Language
English
Publication Type
Article
Keywords
Alaska
Biodiversity
Biomass
Climate change
Conservation of Natural Resources
Forests
Models, Theoretical
Plant Development
Plant Physiological Phenomena
Plants - classification
Poverty
Species Specificity
Trees
Abstract
The loss of biodiversity is threatening ecosystem productivity and services worldwide, spurring efforts to quantify its effects on the functioning of natural ecosystems. Previous research has focused on the positive role of biodiversity on resource acquisition (i.e., niche complementarity), but a lack of study on resource utilization efficiency, a link between resource and productivity, has rendered it difficult to quantify the biodiversity-ecosystem functioning relationship. Here we demonstrate that biodiversity loss reduces plant productivity, other things held constant, through theory, empirical evidence, and simulations under gradually relaxed assumptions. We developed a theoretical model named niche-efficiency to integrate niche complementarity and a heretofore-ignored mechanism of diminishing marginal productivity in quantifying the effects of biodiversity loss on plant productivity. Based on niche-efficiency, we created a relative productivity metric and a productivity impact index (PII) to assist in biological conservation and resource management. Relative productivity provides a standardized measure of the influence of biodiversity on individual productivity, and PII is a functionally based taxonomic index to assess individual species' inherent value in maintaining current ecosystem productivity. Empirical evidence from the Alaska boreal forest suggests that every 1% reduction in overall plant diversity could render an average of 0.23% decline in individual tree productivity. Out of the 283 plant species of the region, we found that large woody plants generally have greater PII values than other species. This theoretical model would facilitate the integration of biological conservation in the international campaign against several pressing global issues involving energy use, climate change, and poverty.
Notes
Cites: Proc Natl Acad Sci U S A. 2013 Jul 16;110(29):11911-623818582
Cites: Nature. 2004 Jun 10;429(6992):651-415190350
Cites: J Theor Biol. 1976 Feb;56(2):253-671271821
Cites: Science. 2012 Jun 15;336(6087):1401-622700920
Cites: Nat Commun. 2013;4:134023299890
Cites: Am J Bot. 2011 Mar;98(3):572-9221613148
Cites: Science. 2012 May 4;336(6081):589-9222556253
Cites: Nature. 2012 Jun 7;486(7401):59-6722678280
Cites: Science. 2004 Nov 12;306(5699):1146-915539593
Cites: Nature. 2011 Apr 7;472(7341):45-621475190
PubMed ID
25901325 View in PubMed
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Climate change in Kivalina, Alaska: strategies for community health.

https://arctichealth.org/en/permalink/ahliterature296263
Source
Alaska Native Tribal Health Consortium (ANTHC) and United State Indian Health Service Cooperative.
Publication Type
Report
Date
2011
Climate Change in Kivalina, Alaska Strategies for Community Health ANTHC Center for Climate and Health Funded by Through adaptation, negative health effects can be prevented. Cover Art: Whale Bone Mask by Larry Adams © Alaska Native Tribal Health Consortium (ANTHC), January 2011. Advisors
  1 document  
Author
Brubaker, Michael
Berner, James
Bell, Jacob
Warren, John
Source
Alaska Native Tribal Health Consortium (ANTHC) and United State Indian Health Service Cooperative.
Date
2011
Language
English
Geographic Location
U.S.
Publication Type
Report
File Size
7989753
Keywords
Alaska
Kivalina
Climate change
Subsistence
Health web
Sanitation
Documents

Climate-Change-HIA-Report_Kivalina.pdf

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Climate change in Point Hope, Alaska: strategies for community health.

https://arctichealth.org/en/permalink/ahliterature296264
Source
Alaska Native Tribal Health Consortium (ANTHC) and United States Indian Health Service Cooperative. 39 p.
Publication Type
Report
Date
2010
Climate Change in Point Hope, Alaska Strategies for Community Health ANTHC Center for Climate and Health Funded by ANTHC Advisors: Tim Gilbert MPH Jeff Smith MS Mike Bradley DVM MPH Kathy Graves PhD Steve Weaver PE Gary Ferguson ND Jennifer Johnson MPH Desirae Roehl Troy Ritter MPH Aaron
  1 document  
Author
Brubaker, Michael
Berner, James
Bell, Jacob
Warren, John
Rolin, Alicia
Source
Alaska Native Tribal Health Consortium (ANTHC) and United States Indian Health Service Cooperative. 39 p.
Date
2010
Language
English
Geographic Location
U.S.
Publication Type
Report
File Size
6285714
Keywords
Alaska
Point Hope
Climate change
Sea level
Health web
Subsistence
Erosion
Permafrost
Water sanitation
Documents

Climate-Change-HIA-Report_Point-Hope_0.pdf

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Climate change in Selawik, Alaska: strategies for community health.

https://arctichealth.org/en/permalink/ahliterature296266
Source
Alaska Native Tribal Health Consortium (ANTHC). 42 p.
Publication Type
Report
Date
2012
Climate Change in Selawik, Alaska Strategies for Community Health ANTHC Center for Climate and Health Funded by jobradley Stamp © Alaska Native Tribal Health Consortium (ANTHC), May 2012. Through adaptation, negative health effects can be prevented. Report prepared by: Michael Brubaker
  1 document  
Author
Brubaker, Michael
Chavan, Prithviraj
Berner, James
Black, Mike
Warren, John
Source
Alaska Native Tribal Health Consortium (ANTHC). 42 p.
Date
2012
Language
English
Geographic Location
U.S.
Publication Type
Report
File Size
9077605
Keywords
Alaska
Selawik
Climate change
Water sanitation
Health web
Food security
Permafrost
Erosion
Documents

Climate-Change-in-Selawik-Alaska.pdf

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Foreword: Synthesis of the Greenland Ecosystem Monitoring program.

https://arctichealth.org/en/permalink/ahliterature279926
Source
Ambio. 2017 Feb;46(Suppl 1):1-2
Publication Type
Article
Date
Feb-2017

Historical and projected trends in landscape drivers affecting carbon dynamics in Alaska.

https://arctichealth.org/en/permalink/ahliterature301980
Source
Ecol Appl. 2017 07; 27(5):1383-1402
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Date
07-2017
Author
Neal J Pastick
Paul Duffy
Hélène Genet
T Scott Rupp
Bruce K Wylie
Kristofer D Johnson
M Torre Jorgenson
Norman Bliss
A David McGuire
Elchin E Jafarov
Joseph F Knight
Author Affiliation
Stinger Ghaffarian Technologies (contractor to the U.S. Geological Survey), Sioux Falls, South Dakota, 57198, USA.
Source
Ecol Appl. 2017 07; 27(5):1383-1402
Date
07-2017
Language
English
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Keywords
Alaska
Carbon Cycle
Carbon Sequestration
Climate change
Permafrost
Taiga
Temperature
Tundra
Abstract
Modern climate change in Alaska has resulted in widespread thawing of permafrost, increased fire activity, and extensive changes in vegetation characteristics that have significant consequences for socioecological systems. Despite observations of the heightened sensitivity of these systems to change, there has not been a comprehensive assessment of factors that drive ecosystem changes throughout Alaska. Here we present research that improves our understanding of the main drivers of the spatiotemporal patterns of carbon dynamics using in situ observations, remote sensing data, and an array of modeling techniques. In the last 60 yr, Alaska has seen a large increase in mean annual air temperature (1.7°C), with the greatest warming occurring over winter and spring. Warming trends are projected to continue throughout the 21st century and will likely result in landscape-level changes to ecosystem structure and function. Wetlands, mainly bogs and fens, which are currently estimated to cover 12.5% of the landscape, strongly influence exchange of methane between Alaska's ecosystems and the atmosphere and are expected to be affected by thawing permafrost and shifts in hydrology. Simulations suggest the current proportion of near-surface (within 1 m) and deep (within 5 m) permafrost extent will be reduced by 9-74% and 33-55% by the end of the 21st century, respectively. Since 2000, an average of 678?595 ha/yr was burned, more than twice the annual average during 1950-1999. The largest increase in fire activity is projected for the boreal forest, which could result in a reduction in late-successional spruce forest (8-44%) and an increase in early-successional deciduous forest (25-113%) that would mediate future fire activity and weaken permafrost stability in the region. Climate warming will also affect vegetation communities across arctic regions, where the coverage of deciduous forest could increase (223-620%), shrub tundra may increase (4-21%), and graminoid tundra might decrease (10-24%). This study sheds light on the sensitivity of Alaska's ecosystems to change that has the potential to significantly affect local and regional carbon balance, but more research is needed to improve estimates of land-surface and subsurface properties, and to better account for ecosystem dynamics affected by a myriad of biophysical factors and interactions.
PubMed ID
28390104 View in PubMed
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Polygonal tundra geomorphological change in response to warming alters future CO2 and CH4 flux on the Barrow Peninsula.

https://arctichealth.org/en/permalink/ahliterature267973
Source
Glob Chang Biol. 2015 Apr;21(4):1634-51
Publication Type
Article
Date
Apr-2015
Author
Mark J Lara
A David McGuire
Eugenie S Euskirchen
Craig E Tweedie
Kenneth M Hinkel
Alexei N Skurikhin
Vladimir E Romanovsky
Guido Grosse
W Robert Bolton
Helene Genet
Source
Glob Chang Biol. 2015 Apr;21(4):1634-51
Date
Apr-2015
Language
English
Publication Type
Article
Keywords
Alaska
Arctic Regions
Carbon Cycle
Carbon Dioxide - analysis
Climate change
Geological Processes
Methane - analysis
Seasons
Soil - chemistry
Tundra
Abstract
The landscape of the Barrow Peninsula in northern Alaska is thought to have formed over centuries to millennia, and is now dominated by ice-wedge polygonal tundra that spans drained thaw-lake basins and interstitial tundra. In nearby tundra regions, studies have identified a rapid increase in thermokarst formation (i.e., pits) over recent decades in response to climate warming, facilitating changes in polygonal tundra geomorphology. We assessed the future impact of 100 years of tundra geomorphic change on peak growing season carbon exchange in response to: (i) landscape succession associated with the thaw-lake cycle; and (ii) low, moderate, and extreme scenarios of thermokarst pit formation (10%, 30%, and 50%) reported for Alaskan arctic tundra sites. We developed a 30 × 30 m resolution tundra geomorphology map (overall accuracy:75%; Kappa:0.69) for our ~1800 km² study area composed of ten classes; drained slope, high center polygon, flat-center polygon, low center polygon, coalescent low center polygon, polygon trough, meadow, ponds, rivers, and lakes, to determine their spatial distribution across the Barrow Peninsula. Land-atmosphere CO2 and CH4 flux data were collected for the summers of 2006-2010 at eighty-two sites near Barrow, across the mapped classes. The developed geomorphic map was used for the regional assessment of carbon flux. Results indicate (i) at present during peak growing season on the Barrow Peninsula, CO2 uptake occurs at -902.3 10(6) gC-CO2 day(-1) (uncertainty using 95% CI is between -438.3 and -1366 10(6) gC-CO2 day(-1)) and CH4 flux at 28.9 10(6) gC-CH4 day(-1) (uncertainty using 95% CI is between 12.9 and 44.9 10(6) gC-CH4 day(-1)), (ii) one century of future landscape change associated with the thaw-lake cycle only slightly alter CO2 and CH4 exchange, while (iii) moderate increases in thermokarst pits would strengthen both CO2 uptake (-166.9 10(6) gC-CO2 day(-1)) and CH4 flux (2.8 10(6) gC-CH4 day(-1)) with geomorphic change from low to high center polygons, cumulatively resulting in an estimated negative feedback to warming during peak growing season.
PubMed ID
25258295 View in PubMed
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Postscript: The future of the Greenland Ecosystem Monitoring programme.

https://arctichealth.org/en/permalink/ahliterature279927
Source
Ambio. 2017 Feb;46(Suppl 1):174-177
Publication Type
Article
Date
Feb-2017

The role of driving factors in historical and projected carbon dynamics of upland ecosystems in Alaska.

https://arctichealth.org/en/permalink/ahliterature302567
Source
Ecol Appl. 2018 01; 28(1):5-27
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Date
01-2018
Author
Hélène Genet
Yujie He
Zhou Lyu
A David McGuire
Qianlai Zhuang
Joy Clein
David D'Amore
Alec Bennett
Amy Breen
Frances Biles
Eugénie S Euskirchen
Kristofer Johnson
Tom Kurkowski
Svetlana Kushch Schroder
Neal Pastick
T Scott Rupp
Bruce Wylie
Yujin Zhang
Xiaoping Zhou
Zhiliang Zhu
Author Affiliation
Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, 99775, USA.
Source
Ecol Appl. 2018 01; 28(1):5-27
Date
01-2018
Language
English
Publication Type
Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.
Keywords
Alaska
Carbon Cycle
Climate change
Ecosystem
Fires
Models, Biological
Seasons
Abstract
It is important to understand how upland ecosystems of Alaska, which are estimated to occupy 84% of the state (i.e., 1,237,774 km2 ), are influencing and will influence state-wide carbon (C) dynamics in the face of ongoing climate change. We coupled fire disturbance and biogeochemical models to assess the relative effects of changing atmospheric carbon dioxide (CO2 ), climate, logging and fire regimes on the historical and future C balance of upland ecosystems for the four main Landscape Conservation Cooperatives (LCCs) of Alaska. At the end of the historical period (1950-2009) of our analysis, we estimate that upland ecosystems of Alaska store ~50 Pg C (with ~90% of the C in soils), and gained 3.26 Tg C/yr. Three of the LCCs had gains in total ecosystem C storage, while the Northwest Boreal LCC lost C (-6.01 Tg C/yr) because of increases in fire activity. Carbon exports from logging affected only the North Pacific LCC and represented less than 1% of the state's net primary production (NPP). The analysis for the future time period (2010-2099) consisted of six simulations driven by climate outputs from two climate models for three emission scenarios. Across the climate scenarios, total ecosystem C storage increased between 19.5 and 66.3 Tg C/yr, which represents 3.4% to 11.7% increase in Alaska upland's storage. We conducted additional simulations to attribute these responses to environmental changes. This analysis showed that atmospheric CO2 fertilization was the main driver of ecosystem C balance. By comparing future simulations with constant and with increasing atmospheric CO2 , we estimated that the sensitivity of NPP was 4.8% per 100 ppmv, but NPP becomes less sensitive to CO2 increase throughout the 21st century. Overall, our analyses suggest that the decreasing CO2 sensitivity of NPP and the increasing sensitivity of heterotrophic respiration to air temperature, in addition to the increase in C loss from wildfires weakens the C sink from upland ecosystems of Alaska and will ultimately lead to a source of CO2 to the atmosphere beyond 2100. Therefore, we conclude that the increasing regional C sink we estimate for the 21st century will most likely be transitional.
PubMed ID
29044791 View in PubMed
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12 records – page 1 of 2.