Response of NDVI, biomass, and ecosystem gas exchange to long-term warming and fertilization in wet sedge tundra.
This study explores the relationship between the normalized difference vegetation index (NDVI), aboveground plant biomass, and ecosystem C fluxes including gross ecosystem production (GEP), ecosystem respiration (ER) and net ecosystem production. We measured NDVI across long-term experimental treatments in wet sedge tundra at the Toolik Lake LTER site, in northern Alaska. Over 13 years, N and P were applied in factorial experiments (N, P and N + P), air temperature was increased using greenhouses with and without N + P fertilizer, and light intensity (photosynthetically active photon flux density) was reduced by 50% using shade cloth. Within each treatment plot, NDVI, aboveground biomass and whole-system CO(2) flux measurements were made at the same sampling points during the peak-growing season of 2001. We found that across all treatments, NDVI is correlated with aboveground biomass ( r(2)=0.84), GEP ( r(2)=0.75) and ER ( r(2)=0.71), providing a basis for linking remotely sensed NDVI to aboveground biomass and ecosystem carbon flux.
206a Oceanography, Lamont-Doherty Earth Observatory, Department of Earth and Environmental Sciences, Columbia University, 61 Route 9 W, Palisades, NY 10964, USA. nboelman@LDEO.columbia.edu
Natalie T
NT
Boelman
Marc
M
Stieglitz
Heather M
HM
Rueth
Martin
M
Sommerkorn
Kevin L
KL
Griffin
Gaius R
GR
Shaver
John A
JA
Gamon
D018533:Biomass; D002245:Carbon Dioxide / Q000032:analysis* / Q000378:metabolism*; D017753:Ecosystem; D004784:Environmental Monitoring; D005740:Gases; D009584:Nitrogen / Q000378:metabolism; D010758:Phosphorus / Q000378:metabolism; D010788:Photosynthesis; D018521:Plant Physiological Phenomena; D018531:Spacecraft
D005740:Gases; D002245:Carbon Dioxide; D010758:Phosphorus; D009584:Nitrogen