Biomass and Production in Three Contiguous Forests in Northern Wisconsin

Biomass and net primary production were measured in 3 forest communities in northern Wisconsin comprised mainly of Populus tremuloides, Betula papyrifera, Acer rubrum, and Acer saccharum. The estimated total aboveground biomass and production for living plants in the 3 stands, designated as (1) aspen, (2) aspen—maple—birch, and (3) maple—birch—aspen types, were 94.8, 95.6 and 119.0 t/ha [=10 3 kg/ha] and 10.43, 8.45, and 8.69 t°ha ( —1)°yr ( —1), respectively. Shrub and ground vegetation accounted for minor portions of the total standing crop. The tree:shrub:ground biomass ratios were 1:.019:.015 for aspen, 1:.009:.006 for aspen—maple—birch, and 1:.003:.006 for maple—birch—aspen. The contribution to stand production by shrubs and ground vegetation ranged from 17% of the total aboveground production in the aspen type to 9% in the other stands. Inputs to the production equation often neglected in stand analysis, i.e., plant losses by death, shedding, and consumption, amounted to a maximum of 4.5% of total aboveground production. A comparison of biomass data from forests in the lake states suggests that 100 to 200 t/ha (above—ground dry weight) is inclusive of most second—growth forests. The upper and lower bounds for mature forests were projected to be °600 and 60 t/ha. Estimates of aboveground productivity for a variety of forest ecosystems within the lake states had a narrow range from 7.1 to 10.4 t°ha ( —1) @ ?year ( —1).