Arctic Research at the MBL The Ecosystems Center carries out Arctic research at the Toolik Field...
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Transcript of Arctic Research at the MBL The Ecosystems Center carries out Arctic research at the Toolik Field...
Arctic Research at the MBL
The Ecosystems Center carries out Arctic research at the Toolik Field Station of the University of Alaska Fairbanks. The Dalton Highway and the oil pipeline are nearby.
AON - Carbon/Water/Energy Project (IPY)
• Toolik Observatory
• Cherskii Observatory
• PanArctic Network
• Arctic Ecology Course
National Ecological Observatory Network
Proposed NEON sites in Alaska. Toolik and Caribou/Poker Creek will be core (intensive) sites.
http://www.uaf.edu/toolik/Current/webcam.html
LTER APPROACHES: EXPERIMENTS & MODELS
• Tundra: heat soil, reduce light, fertilize, exclude grazers
• Land/water: increase soil moisture
• Stream: fertilize, add or remove predators
• Lake: fertilize, add or remove top predator (lake trout), add predator (sculpin)
-50
0
50
100
150
200
250
300
350
400
1900 1950 2000 2050 2100Year
Cu
mu
lati
ve
ch
an
ge
in C
(g
C m
-2)
Change in ecosystem N
Change in vegetation C:N
Change in soil C:N
Soil-plant N redistribution
interaction
Total
-50
CO2
VC BC DC
VN BN DN
Ni
VegetationVegetation SOMSOMRespiration
RespirationPhotosynthesis
N uptakeImmobilization
Mineralization
N deposition N loss
Litter C
Litter N
DON loss
CO2
VC BC DC
VN BN DN
Ni
VegetationVegetation SOMSOMRespiration
RespirationPhotosynthesis
N uptakeImmobilization
Mineralization
N deposition N loss
Litter C
Litter N
DON loss
Rastetter et al 2004
Linked-process, dynamic ecosystem models allow us to project knowledge from plot-based studies through time
Responses to increasing CO2 and temperature over the next century are constrained by carbon-nutrient interactions,but such projections still do not account for spatial interactions on the Arctic landscape.
ALASKA
149° W150° W
69°
N70
°N
Arctic Ocean
Photosynthesisin 1995
Mg C km-2 yr-1
0 – 5050 – 100
100 – 150150 – 200200 – 250250 – 300300 – 400
ACM
Kuparuk RiverBasin
ALASKAALASKA
149° W150° W
69°
N70
°N
Arctic Ocean
Photosynthesisin 1995
Mg C km-2 yr-1
0 – 5050 – 100
100 – 150150 – 200200 – 250250 – 300300 – 400
ACM
Kuparuk RiverBasin
Williams et al 2001
Spatial Extrapolation of Ecosystem Productivity in Arctic Tundra
Williams et al 2001
Simple process models linked to satellite and spatially referenced climate data allow us to project knowledge from plot-based studies to regions and the Pan Arctic....
but such projections do not account for spatial interactions on the Arctic landscape.
Photo courtesy Ted Hogg
Other MBL Research Projects in the Arctic
• The PARTNERS project of the ARCSS Freshwater Initiative is examining the land-ocean linkages via river biogeochemical fluxes at the larger pan-arctic scale.
• SNACS (Study of the Northern Alaska Coastal System) project led by Marc Stieglitz investigates the linkage between hydrologic variables and the fluxes of nutrients and organic matter (constituents) from the North Slope of Alaska to the Beaufort Sea.
Photo courtesy Ted Hogg
Other MBL Research Projects in the Arctic
• The LANDSCAPES project, with support from NSF-DEB, studies terrestrial C-N interactions, the N cycle, and the limitation of the tundra C cycle by N.
• The ITEX project, with support from NSF-Arctic System Science (ARCSS), studies controls on canopy structure of arctic vegetation, variation in ecosystem CO2 exchange, and C and N allocation in tundra vegetation
• How Arctic shrubs get their nitrogen through symbiosis with mushrooms (Hobbie and Hobbie).