Twenty years of change in a northern hardwood forest

Abstract

Forests undisturbed by logging play a vital role in our understanding and management of forest ecosystems. The Bowl Research Natural Area (RNA) in the White Mountains of New Hampshire is such a forest. The Bowl RNA and an adjacent area known to have been logged in 1888 were inventoried in 1974 and 1994. The mean basal area of the mixed forest below an elevation of 915 m in the RNA increased from 29 m 2 ha −1 in 1974 to 32 m 2 ha −1 in 1994. There was no significant difference in basal areas of the RNA forest and the adjacent forest cut in 1888, in either the 1974 or 1994 sampling. Beech was the most numerous species in all areas of the Bowl followed by spruce-fir. Yellow birch had the greatest basal area followed by spruce-fir and beech. Results from this study indicate that northern hardwood forests of several hundred hectares can be expected to maintain average basal areas of ca. 30 m 2 ha −1 and above-ground biomass of 150–250 Mg ha −1. Comparisons of the Bowl and nearby Hubbard Brook Experimental Forest indicate that, within 100 years following heavy forest cutting, the northern hardwood forest can be expected to regrow to the point where numbers of stems, basal-area, and biomass will be comparable with old-growth forests.