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Old-Growth Carbon Sequestration in the Sylvania
Wilderness Ottawa National Forest, U.P. Michigan
Ankur Desai Penn State, Meteorology January 2002
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Proposal Title
Quantifying carbon sequestration potential of
mid and late successional forests in the upper
midwest
View to the south from flux tower
Funding agency Department of Energy, Terrestial
Carbon Processes
PI Eileen Carey (University of Minnesota
Forest Resources) Co-PIs Ken Davis (Penn
State - Meteorology) Paul Bolstad (University of
Minnesota Forest Resources) Margaret Davis
(University of Minesota Ecology, Evolution,
Behavior)
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With additional technical support from Bruce
Cook University of Minnesota, Forest
Resources Ankur Desai Penn State,
Meteorology Bob Evans Ottawa National Forest,
Watersmeet, MI Art Johnston Chequamegon
National Forest, Park Falls, WI U.S. Forest
Service, North Central Experiment Station Jud
Isebrands, Ron Teclaw, Aaron Berger
View to the northeast from flux tower
Helen Lake
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Location Ottawa National Forest Upper
Peninsula Michigan
To Willow Creek, Lost Creek, WLEF
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Location Sylvania Wilderness (tower just outside
of wilderness area)

• 8,500 ha (18,000 acres)

• 35 named lakes

• Mostly flat topography

• 6 km e. of Watersmeet, MI

• Hemlock, maple, basswood dominant stands (3-30
  ha)

• 0.5 turnover rate

• 187 year average canopy lifetime for Hemlocks

• One of two remaining large old-growth sites in
  upper Great Lakes region

• Numerous studies of area (M. Davis, L. Frelich,
  etc), 3000 year pollen record

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Location Near Helen Lake

• Site has some lakes to north and east, fewer to
  west and south

• Maple dominant stands right by tower, hemlock
  dominant within radius, yellow birch

• Typical canopy DBH 40-70 cm, height 25-30 m

• Mostly flat topography

• In Lake Superior watershed, occasional lake
  effect snow

• Close to campground

• No Hodags have been spotted

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Why study old-growth forest fluxes?

• Assumed to be insignificant sink, possibly
  source of CO2, largely based on simple conceptual
  models

• Very few actual measurements of NEE in old-growth

• Existing old-growth flux sites suggest
  old-growth may actually be strong carbon sinks.
  100-yr old boreal-northern hardwood site in Maine
  had 2.1 Mg C ha-1 yr-1 NEE in 1996 (Hollinger et
  al., 1999). 450-yr Douglas fir site in Oregon
  had 2.3 Mg C ha-1 yr-1 in 1998 (Chen, 1999). On
  the other hand, NEE in 90-yr old Black spruce
  only 0.1 Mg C ha-1 yr-1 (Goulden et al., 1997).

• We need a way to infer change in NEE over time
  as younger forests age

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Why study Sylvania wilderness?

• Only one of two remaining old-growth sites in
  upper Great Lakes regions. Can help predict
  future course of NEE as post-logging forests of
  the Great Lakes region mature. Sylvania has
  changed little over 1000 years.

• Close to ChEAS sites Willow Creek, Lost Creek,
  WLEF. Can compare NEE and component fluxes among
  similar sites along a succesional gradient.

Helen Lake?
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Principal Objectives of study

• Characterize NEE of an undisturbed old-growth
  forest
• Quantify the relative response of old-growth
  versus regrowing forests to climate variability
  and climate change
• Determine to what degree component carbon fluxes
  differ between early and late successional stands
• Characterize how physiological processes change
  as function of tree or stand age

Hypotheses

• Sylvania old-growth is a carbon sink
• The carbon sink is smaller than younger forests
  but not insignificant
• Overall respiration is greater than younger
  forests, though not necessarily due to increased
  stem respiration (maybe related to water
  limitations)
• More NPP is allocated belowground as trees slow
  in growth

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Primary methods
Stem / Leaf respiration
Micrometeorology
Sapflux
CO2/H2O Eddy fluxes CO2 profile 37m tower
Soil/stump respiration Soil temp/moisture
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Spring-Summer 2001
Building the tower
Preliminary site investigation
Measuring fluxes in the lab
Working on Willow Creek
Tower safety training
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Summer-Fall 2001
Inside the shed
Look out below!
The control shed and storage area
Endless fieldwork
Another day, another climb
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Measurements

• CO2 and H2O 10Hz Fluxes at 36 m using Licor 6262
  and Campbell CSAT-3 Sonic
• CO2 mixing ratio profile (.6, 1.8, 3, 7.6, 13.7,
  21.3, 36 m) using Licor 6252
• H2O mixing ratio profile (2, 21, 36 m)
• Air temperature profile (.6, 2, 7.6, 12, 18, 21,
  24, 30, 36 m)
• Wind speed (8 and 36 m)
• Above canopy net radiation and direct PAR (36
  m), ground-level PAR (1 m)
• Leaf wetness (36 m)
• Soil temperature and moisture profile (surface,
  5, 10, 20, 50, 100 cm)
• Soil heat flux (7.5 cm)
• Precipitation (tipping-bucket), rain and snow (2
  locations open and shaded)
• Tree sap flux at 48 trees, north and south side,
  Granier-type probe
• Soil, stem and stump respiration on gt 150 trees
  using Licor 6400 and 6200
• Leaf area index measurement with LAI-2000
• Canopy characterization in 40,000 m2 area around
  tower

Lost Creek Shed
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Preliminary Results Micrometeorology
(9/17/01-10/5/01)
Temp
Dewpoint
Pressure
Wind spd
Wind dir
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Preliminary Results Micrometeorology 2
(9/17/01-10/5/01)
PAR
H2O
Rainfall
Soil H2O
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Preliminary Results H2O, Temp, Soil Fluxes
(9/17/01-10/5/01)
Sensible
Latent
Soil
Net Rad
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Preliminary Results CO2 Fluxes (9/17/01-10/5/01)
CO2
Storage
NEE
u
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Preliminary Results CO2 Profile (9/17/01-10/5/01)
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Preliminary Results Sap Fluxes (Sept. and Oct.
2001)

• Ensemble average daily sap flow for three tree
  species in cm / hour (just direct flow, not
  volume or leaf area flow)

Yellow Birch
Hemlock
Sugar Maple

• South side of tree is light gray/dotted, north
  is dark gray/solid lines

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Future Plans and Issues

• Continue year-round flux measurement. Fix up
  bugs, calibration, errors

• Simultaneous component (soil and stem) flux
  measurements at Willow Creek and Helen Lake (and
  Lost Creek, too)

• Possibly expand sap flux measurements

• Examine effect of lake on fluxes (look at fluxes
  based on wind direction)

• Compare micrometeorology between Willow Creek
  and Helen Lake (effect of different watershed,
  lake effect snow, etc)

• Expand area of canopy characterization

• Increase leaf area index measurements

• Obtain and analyze aerial and remote sensing
  products (ASTER/MODIS?)

• Compare fluxes against roving flux tower?

• Compare fluxes against WLEF, other old-growth
  towers, other Ameriflux sites?

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Conclusion
The Sylvania Wilderness/Helen Lake old-growth
flux experiment will add knowledge about NEE
uptake as forests age, and allow for an
additional point of flux comparison among ChEAS
and Ameriflux sites.
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