Number of forest stands (transects), number of plots, and mean (±1 SE) earthworm biomass (ash-free dry mass, AFDg/m2) of upland deciduous forests sampled in 2010 and 2011 at Horicon, Ottawa, Rice Lake, Seney, Shiawassee, and Tamarac National Wildlife Refuges in the Upper Midwest region of the United States, ranked in order of biomass.