Plot size recommendations for biomass estimation in a midwestern old-growth forest

We examine the relationship between disturbance regime and plot size for woody biomass estimation in a midwestern old-growth deciduous forest from 1926 to 1992. Analysis was done on the core 19.6 ac of a 50.1 ac forest in which every tree 4 in. dbh and greater has been tagged and mapped since 1926. Five windows of time are compared-1926, 1976, 1981, 1986 and 1992. The most efficient plot sizes requiring measurement of the feast total area range from 0.02 to 1.6 ac. A small plot size was recommended after grazing disturbance, and a large size was recommended when mortality was high and acceptable error was low.