|
What Does a MODIS Pixel Actually “See” in a Mixed Deciduous Forest?
Abdullah
Faiz
Rahman, Indiana University, farahman@indiana.edu
(Presenter)
The photosynthetic reflectance index (PRI) calculated from the MODIS ocean bands may be useful for estimation of photosynthetic light use efficiency (LUE) of vegetation. However, in addition to LUE, PRI values can vary due to species differences, changes in bulk leaf pigment contents, and background effects. MODIS 1 km pixels can include wide variation in all these factors. We are measuring PRI at leaf and tree canopy scales and using these values to better understand the components of PRI response within MODIS pixels. Here we report preliminary results from the leaf and canopy scales at the Morgan Monroe State Forest in southern Indiana. Leaf PRI was significantly higher for shade than for sun leaves for all species. PRI did not vary much between species overall. However there were significant seasonal trends for several of the species and these trends differed between species. Analysis of the spectral data suggests that these seasonal changes may reflect changes in bulk pigment contents, rather than the xanthophyll per se. We collected canopy level reflectance images using a low-flying aircraft to scale up the leaf level reflectance to MODIS pixel scales. Our analysis shows what a 1-km MODIS PRI pixel really “sees” in a mixed deciduous forest of the US Midwest as the growing season progresses. Presentation Type: Poster Session: Coupled Processes at Land-Atmosphere-Ocean Interfaces (Mon 4:00 PM) Associated Project(s):
Poster Location ID: 66
|