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).