Sites are located within the southern section of the Anaktuvuk River Fire (ARF) scar approximately 37 km NW of Toolik Field Station at a severely burned (68.99°N, 150.28°W) and unburned (68.93°N, 150.21°W) location established previously by Rocha and Shaver in 2008 (Rocha and Shaver 2011a, b). At both sites, a randomized block, factorial N and P fertilization experiment was established in 2016 (9 years post-fire). The experimental design consisted of 5 blocks each containing a control (CT), nitrogen (N), phosphorus (P), and nitrogen plus phosphorus (N+P) treatment.  CT plots recieved no treatment, N plots received 5 g/m2 of NH4 as NH4Cl and 5 g/m2 of NO3 as NaNO3, P plots received 5 g/m2 of P as P2O5 and N+P plots received both of the N and P fertilizer treatment. Fertilizer amounts mimiced treatment amounts at the Arctic LTER sites at Toolik Lake. Each plot was 20 m2.

Leaf area measurements were taken once in late July of each year between 2016 and 2019 (9-12 years after the fire). Measurements were taken at ground level in the inter-tussock spaces around the perimeter of each treatment plot using a LI-COR 2200C plant canopy analyzer (LI-COR, Lincoln, NE). A 25% cover lens cap was used on both the above- and below-canopy sensors to avoid recording shadows. The control, above-canopy sensor was placed above the vegetation canopy facing south to actively record current light levels. Leaf area index (LAI) was calculated using the LI-COR software.

Detailed site descriptions are published in

Rocha, A.V. and G.R. Shaver, 2011, Ecological Applications, v21, pg 477 and Rocha, A.V. and G.R. Shaver, 2011, Global Change Biology, v17, pg 2831.