1. Changes in leaf area index (LAI) due to ice storm damage at Harvard Forest
Lauren Sanchez, Middlebury College
In collaboration with Harvard University
Spring Student Symposium 2010

2. Introduction Global carbon balance Net Ecosystem Exchange (NEE)
Carbon sink
Net Ecosystem
Exchange (NEE)
Long-term
measurements
Factors affecting
NEE measurements

3. Disturbance- Ice Storms
Impacts on ecosystems
Variable damage
Tree species
Nature of stand
New England ice storms
Winter 1998 and 2008
Potential impacts due to the changing climate

4. Leaf Area Index Interaction between vegetation and the atmosphere
Ratio = foliage surface area
ground area
Values range from 0-7
Eddy covariance method
Whole-ecosystem function approach
Measurements- sonic anemometer and eddy flux tower

5. Research Question:
Is there a correlation between ice storm damage and change in LAI values?
Hypothesis:
Plots with more ice storm damage, particularly CWD, would experience a greater decrease in LAI

6. Methods Site description Measurement locations and plots
Harvard Forest, Petersham, MA
Measurement locations and plots
Biometry component
CWD and FWD survey
Classifications, observations

7. Observed LAI values at Harvard Forest

8. A comparison of 2008 and 2009 LAI values

9. The average amount of woody biomass in each plot due to the ice storm
With D4
Without D4

10. The relationship between ice storm woody debris and the change in peak LAI for each plot
= 0.191
P= 0.172
With D4
Without D4

11. The relationship between ice storm FWD and the change in peak LAI for each plot, excluding D4
 = 0.442 P=

12. Comparing the CWD, FWD, and change in LAI values between two deciduous plots

13. Discussion The total FWD biomass is comparable to CWD
High variability between plots
Importance of FWD survey
Strong correlation between amount of ice storm damage and decrease in peak LAI
Significant relationship for FWD data
Also significant correlation for FWD
data in deciduous plots

14. Future Study Continue to extensively track LAI values
Investigate LAI trajectories and changes in green up and peaks
Climatic modeling and PAR data to determine effect of weather

15. Acknowledgements Steve Trombulak and Andi Lloyd
Dr. Steven C. Wofsy
Leland Werden
Tammy Connell
Department of Energy GCEP Program
Harvard School of Engineering and Applied Sciences
Harvard Forest