Vegetation indices calculated from reflectance spectra collected at Arctic LTER plots at Toolik Lake, Alaska during the 2007-2016 growing seasons. Canopy reflectance was measured using a dual channel spectrophotometer (Unispec DC, PP Systems, Amesbury, Massachusetts, USA). Spectral indices were calculated for NDVI (MODIS, EVI (MODIS), EVI2 (MODIS), PRI (550 Reference), PRI (570 Ref), WBI and Chl Index
Summary of three methods used to estimate the Leaf Area Index (LAI) of 19 1m x 1m plots sampled with a point frame near the LTER Shrub plots at the Toolik Field Station in AK the summer of 2012. The methods used were: (1) exponential relationship between LAI and NDVI as measured above the canopy with a Unispec spetroradiometer; (2) Delta-T SunScan canopy analyzer held at 5 cm above the ground under both direct and diffuse light conditions; (3) pin-drop point frame tequnique. Where values have been averaged (such as for the NDVI and SunScan measurements), the standard deviation is given.
Normalized difference vegetation index (NDVI) and Leaf area index (LAI) data from tussocks in the reciprocal transplant gardens at Toolik Lake, Coldfoot, and Sagwon in 2016.