Invertebrates (spiders, insects and slugs) were collected weekly using pitfall traps at four sites near the Arctic LTER at Toolik Field Station, Alaska. Traps were placed along transects in shrub (shrub-dominant) and open (tussock-dominant) tundra sites. Pitfall traps were placed for 48-hour intervals once per week from early June until mid-July 2010. Collected invertebrates were counted and identified to class (all invertebrates), order or family (for some of the most common families collected).
In 2008, Relative percent cover of plant species was measured in the Arctic LTER's experimental and control plots across several habitats: moist acidic, dry heath, and moist non-acidic tundra; in new variable (low) nutrient addition experimental plots established in 2006; and for Sagavanirktok River toposequence plots in tussock and heath tundra.