Old-Growth Carbon Sequestration in the

Sylvania Wilderness

Ottawa National Forest, U.P. Michigan

Ankur DesaiPenn State, Meteorology

January 2002

Quantifying carbon sequestration potential of mid and late successional forests in the upper midwest

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)

Proposal Title:

Funding agency: Department of Energy, Terrestial Carbon Processes

View to the south from flux tower

With additional technical support from:Bruce Cook – University of Minnesota, Forest ResourcesAnkur Desai – Penn State, MeteorologyBob Evans – Ottawa National Forest, Watersmeet, MIArt Johnston – Chequamegon National Forest, Park Falls, WIU.S. Forest Service, North Central Experiment Station:

Jud Isebrands, Ron Teclaw, Aaron Berger

Helen Lake

View to the northeast from flux tower

Location Ottawa National Forest – Upper Peninsula Michigan

To: Willow Creek, Lost Creek, WLEF

Location Sylvania Wilderness (tower just outside of wilderness area)

• 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

• 8,500 ha (18,000 acres)

Location Near Helen Lake

• 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

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

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

• 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

Hypotheses

Primary methods

CO2/H2O Eddy fluxesCO2 profile37m tower

Stem / Leaf respiration

Sapflux

Micrometeorology

Soil/stump respirationSoil temp/moisture

Spring-Summer 2001

Preliminary site investigation Building the tower

Measuring fluxes in the lab Working on Willow Creek Tower safety training

Summer-Fall 2001

The control shed and storage area

Inside the shed

Another day, another climb…

Look out below!

Endless fieldwork…

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

Pressure

Wind spd

Wind dir

Dewpoint

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)

Hemlock

Sugar Maple

Yellow Birch

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

• 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.