Relationships of NDVI, Biomass, and Leaf Area Index (LAI) for six key plant species in Barrow, Alaska

15 16 Here we investigate relationships between NDVI, Biomass, and Leaf Area Index (LAI) for 17 six key plant species near Barrow, Alaska. We explore how key plant species differ in 18 biomass, leaf area index (LAI) and how can v e g e t a t i o n spectral indices be used to 19 estimate biomass and LAI for key plant species. A vegetation index (VI) or a spectral 20 vegetation index (SVI) is a quantitative predictor of plant biomass or vegetative vigor, 21 usually formed from combinations of several spectral bands, whose values are added, 22 divided, or multiplied in order to yield a single value that indicates the amount or vigor of 23 vegetation. For six key plant species, NDVI was strongly correlated with biomass (R 2 = 24 0.83) and LAI (R 2 = 0.70) but showed evidence of saturation above a biomass of 100 g/m 2 25 and an LAI of 2 m 2 /m 2 . Extrapolation of a biomass-plant cover model to a multi26 decadal time series of plant cover observations suggested that Carex aquatilis and 27 Eriophorum angustifolium decreased in biomass while Arctophila fulva and Dupontia 28 fisheri increased 1972-2008. 29