Spectral Indices to Monitor Nitrogen Driven Carbon Sequestration in Vegetation
Lawrence
A.
Corp, SSAI, lawrence.a.corp@nasa.gov
(Presenting)
Elizabeth
M.
Middleton, NASA GSFC, elizabeth.m.middleton@nasa.gov
Petya
K.E.
Campbell, JCET UMBC, pcampbel@pop900.gsfc.nasa.gov
Karl
F.
Huemmrich, JCET UMBC, karl.f.huemmrich@nasa.gov
Yen
Ben
Cheng, NASA GSFC, ybcheng@ucdavis.edu
Craig
S.T.
Daughtry, USDA HRSL, craig.daughtry@ars.usda.gov
A major goal of the U.S. Carbon Cycle Science Program is to monitor the vegetation processes related to carbon dioxide uptake. Biological carbon (C) sequestration is driven by nitrogen (N) availability since N is a key component in photochemical enzymes and light harvesting pigments. Large scale monitoring of vegetation processes are currently possible only with remote sensing systems that rely heavily on passive reflectance (R) information. Fluorescence (F) emitted from chlorophyll has been extensively used for the elucidation of the photosynthetic pathways and is more directly linked to photochemical reactions. However, remote utilization of the relatively weak F signal in C cycle science as been elusive. Recent advances in high resolution spectral radiometers have enabled mathematical manipulations based on the Fraunhofer Line Depth (FLD) principle to isolate the solar induced F (SIF) signal from the high resolution R continuum. Here we will present data describing Light use Efficiency (LUE, ratio of C secured by vegetation per unit of absorbed photosynthetic active radiation) of vegetation under variable N availability and present considerations for both F and R sensing methodologies to remotely quantify this key regulator of ecosystem/biome productivity.
NASA Carbon Cycle & Ecosystems Active Awards Represented by this Poster: