Transcript Part I - Chequamegon Ecosystem

Old-Growth Carbon Sequestration in the
Sylvania Wilderness
Ottawa National Forest, U.P. Michigan
Ankur Desai
Penn State, Meteorology
January 2002
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)
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
Location
Ottawa National Forest – Upper Peninsula Michigan
To: Willow Creek, Lost Creek, WLEF
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
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
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
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?
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
Primary methods
Stem / Leaf respiration
CO2/H2O Eddy fluxes
CO2 profile
37m tower
Sapflux
Soil/stump respiration
Soil temp/moisture
Micrometeorology
Spring-Summer 2001
Preliminary site investigation
Measuring fluxes in the lab
Building the tower
Working on Willow Creek
Tower safety training
Summer-Fall 2001
Inside the shed
Look out below!
The control shed and storage area
Endless fieldwork…
Another day, another climb…
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 > 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
Preliminary Results: Micrometeorology (9/17/01-10/5/01)
Temp
Dewpoint
Pressure
Wind spd
Wind dir
Preliminary Results: Micrometeorology 2 (9/17/01-10/5/01)
PAR
H2O
Rainfall
Soil H2O
Preliminary Results: H2O, Temp, Soil Fluxes (9/17/01-10/5/01)
Sensible
Latent
Soil
Net Rad
Preliminary Results: CO2 Fluxes (9/17/01-10/5/01)
CO2
Storage
NEE
u*
Preliminary Results: CO2 Profile (9/17/01-10/5/01)
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
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?
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.