1. Field Measurements of Leaf Mass Area (LMA) in Support of Remote Sensing Studies of a Pacific Northwest Old Growth Forest Canopy Katie Berger (UMASS-Amherst) Research & Discover Intern 2005 Advisor: Barry Rock AND Scott Ollinger Mary Martin http://www.riegl.com/distancemeters_/distancemeter_applications_/notes_/e_ps085.htm

2. Outline  Importance of LMA in forests  Applications  Background of Wind River  Methods  Results  NASA Outreach

3. Importance  What is LMA?  Leaf Mass Area: Ratio of leaf dry mass in canopy per unit area  Leaf Area Index: Ratio of area of leaves in canopy per unit area of ground surface  Why study Leaf Mass Area (LMA)?  Less research has been done; tedious to determine LMA  Future research in understanding forest ecosystems: Nitrogen & net photosynthesis modeling, using ecological models and remote sensing  Most importantly:  Indicative of environmental conditions and growth rates of foliage  To parameterize ecological models of forest ecosystems  To calibrate remote sensing images  Ex: mapping canopy chemistry

4. Indicating Environmental Conditions  LMA strongly correlated to foliar N and net photosynthesis of the tree canopy  Can help researchers predict the net growth/health of forest http://www.pnas.org/cgi/reprint/94/25/13730 (Reich et al., 1997)

5. Ecosystem Models  Where remote sensing can give us a global view of reflectance properties, ecological models can give us better insight on the processes that are going on within the ecosystem  PnET-Day (a program designed by scientists at UNH) is an ecological modeling program that incorporates foliar mass, LMA, foliar N concentration, temperature and radiation flux to predict daily and net photosynthesis of entire forest canopies

6. Calibrating Remote Sensing Tools  Ground work makes sense of satellite images by showing differences in field observations that cannot be identified through remote sensing techniques  Gives researchers tangible data to correlate to satellite imagery http://www.ucalgary.ca/UofC/faculties/SS/GEOG/Virtual/Remote%2 0Sensing/multistage.gif

7. Wind River Canopy Crane Research Facility  Western old growth forest  Dominant species  Douglas fir (PSME)  Western hemlock (TSHE)  Pacific silver fir (ABAM)  Western red cedar (THPL)  Located in southern Washington, USA http://research.eeescience.utoledo.edu/lees/pubs/Roberts04.pdf WRCCRF July 1998 (Roberts et al., 2004)

8. Canopy Crane  Canopy crane was used to gather foliar samples from known heights/trees in the canopy  At its max lift and reach capacity, the crane can cover a cylindrical volume of over 54 million cubic feet; reaching over 300 trees accessible via use of the gondola. http://depts.washington.edu/wrccrf/crane.html

9. Methods for Measuring LMA  All measurement methods are imperfect due to needle complexity and variability  Two methods used in published data:  Volume displacement  Optical Scanning

10. Volume Displacement Method  Immersed in H 2 O  Displaced volume recorded by mass  Needles counted & measured  Volume to area conversion:  Ex: Area (elliptical cross- section) = 0.5√((3.14)x) * (1+1/x) * √(Vnl) (Chen et al., 1997)  Completed for a total of over 50 samples  Potential weaknesses  Too many measurements: too many sources of error CLIP H 2 O + Detergent Cross-section of a Western Hemlock

11. Optical Scanning Method  Foliage scanned on a flat bed scanner  Image processing to remove shadows  Convert to LMA using dry weight values  Potential weaknesses  Difficulty in removing edge effects/shadow

12. Vertical Gradients in LMA: Displacement Method  Deviation from the mean LMA for both species suggest that there is a trend of increasing LMA with increase in height through the canopy  This counters assumptions used in several models

13. Comparison of Methods  Trends stronger with optically scanned method  Optically scanned produced higher LMA values

14. More Research Needed  Does increase of LMA with height trend depend on method of LMA used?  More research will be needed to determine this  Implications of future research

15. Applying Gradient to Ecosystem Models Measured Value: 1550-1590 gC m-2 yr-1 (From Paw et al. 2004)

16. Applying Gradient to Ecosystem Models Measured Value: 1550-1590 gC m-2 yr-1 (From Paw et al. 2004)

17. Future Researchers

18. Acknowledgements Thanks Any questions? Special thanks to: Barry Rock Mary Martin Scott Ollinger George Hurtt The Forest Ecosystems Lab Project Smart Everyone else who has helped me out along the way @ EOS Everyone else who has helped me out along the way @ EOS And The Research & Discover Program (UNH-NASA) for providing me with this great opportunity

19. Work Cited Chen, Jing, et al. “Leaf Area Index of Boreal Forests: Theory, Techniques, and Measurements” Journal of Geophysical Research 102 (1997):29,429-29,443 Reich, Peter, et al. “From Tropics to Tundra: Global Convergence in Plant Functioning” Proceedings of the National Academy of Sciences of the United States of America 94 (1997): 13730-13734 Roberts, Dar, et al. “Spectral and Structural Measures of Northwest Forest Vegetation at Leaf to Landscape Scales” Ecosystems 7 (2004): 545-562