The Importance of Different Forms of Regeneration to Secondary Succession in a Maine Hardwood Forest

Abstract

WHITE, A. S. (Department of Forest Biology, University of Maine, Orono, ME 04469). The importance of different forms of regeneration to secondary succession in a Maine hardwood forest. Bull. Torrey Bot. Club. 118: 303-311. 1991.-Regeneration by woody species on a 1-year-old whole-tree harvested clearcut in a Maine hardwood stand was examined with respect to stem origin (advance regeneration, new seedlings, or sprouts) by species. Sprouts dominated (79%) the biomass with new stems and advanced regeneration contributing 13% and 8%, respectively. In contrast, density was about evenly divided between sprouts (50%) and new stems (47%). The most important contributors to sprout density were Fagus grandifolia (50%) and Populus spp. (25%), but Populus spp. contributed the most to sprout biomass (52%) due to the greater size of their stems. Advance regeneration density (only 3% of total density) was due almost entirely to Acer saccharum (56%) and Acer rubrum (41%), but the latter dominated the biomass of advance stems (81%) due to a few large individuals in one plot. Prunus pensylvanica (18%), Rubus spp. (34%), and Betula spp. (35%) dominated new stem density, but the first two contributed 83% of the new stem biomass. Frequency of occurrence for the abovementioned species ranged from 37-80%, and each species, with the exception of A. pensylvanicum and Betula spp., dominated (accounted for > 80%) the biomass of at least one plot. Most species were represented primarily by one form of regeneration: A. pensylvanicum, F. grandifolia, and Populus spp. (sprouts); Betula spp., Prunus pensylvanica, and Rubus spp. (new seedlings). A. saccharum and A. rubrum were represented by a mixture of sprouts, advanced seedlings, and/or new seedlings.