Investigating the Relationships Between AVIRIS Reflectance, Foliar Nitrogen, and Nitrogen Deposition across the Northeastern US

Mary E. Martin, University of New Hamsphire, mary.martin@unh.edu (Presenter)
Scott Ollinger, University of New Hampshire, scott.ollinger@unh.edu
Lucie Lepine, University of New Hampshire, lucie.lepine@unh.edu

In recent work, we have demonstrated that canopy-averaged foliar nitrogen (N) concentrations,

shortwave surface albedo and canopy photosynthetic capacity are all closely correlated.

These results suggest an important coupling of the carbon and nutrient cycles with radiant

surface energy exchange. Under our current funding, we begin to investigate whether

disturbance of vegetation alters these observed relationships.

An extensive 2009 AVIRIS data collection comprising long transects throughout

much of the northeastern US (from West Virginia to Maine), is being used to address

two questions to further this work. First, these data provide an opportunity to test,

validate, and refine a generalized foliar nitrogen equation

developed on a suite of AVIRIS and field data collected between 2001-2006.

Canopy nitrogen has been estimated with this algorithm for a number of smaller localized

studies; here we apply this to a broader geographic range, over variable cover type and

topography. Second, a broad-scale nitrogen deposition gradient across the northeastern US

has been characterized through the use of depostion data, and is being integrated with the

AVIRIS reflectance, albedo and nitrogen maps developed from the

transect flight data, as well as with MODIS surface reflectance and albedo data products.

Through this effort, we will also examine whether broad-scale patterns

in surface reflectance and canopy nitrogen have been influenced by regional and continental

patterns of N deposition.

Presentation Type:  Poster

Session:  Coupled Processes at Land-Atmosphere-Ocean Interfaces   (Mon 4:00 PM)

Associated Project(s): 

• Ollinger, Scott: Effects of Disturbance and N Deposition on Nitrogen-Albedo Relations in Forests ...details
• Ollinger, Scott: Exploring Relationships among Carbon Cycling, Vegetation Nitrogen Status and Surface Albedo across North American Ecosystems to Improve Land Surface Models ...details

Poster Location ID: 53