Primary productivity and nitrogen, carbon, and biomass distribution in a dense Myrica gale stand

Abstract

Aboveground vascular vegetation was harvested in twenty 0.25-m2 plots at the end of the growing season in a weakly minerotrophic, central Massachusetts peatland. The materials were separated by species and component and the Myrica gale fractions analyzed for N and C content. Myrica gale strongly dominated the site, contributing 66% of the total aboveground biomass and 74% of the main canopy leaf area. Its shoots had a mean density of 69 stems m−2 and mean height of 63 cm and reached a maximum age of 7 years. Myrica gale aboveground biomass was 604 g m−2 with stems contributing 75%, leaves 24%, and reproductive organs 2%. Similar patterns of biomass distribution have been reported in other peatland low shrubs. Above-ground net production was 392 g m−2 year−1 and total net production estimated to be 549 g m−2 year−1. Nitrogen contents were higher than in other peatland shrubs and ranged from 0.94% in stems ≥ 3 years old to about 2.4% in leaves, nodules, and male flower buds. Carbon contents ranged from 50% in stems s ≥ 3 years old to 56% in male flower buds. The N content of total annual net production was estimated to be 8.6 g m−2 and the C content 281 g m−2. Nitrogen fixation provided 43% of the estimated annual N requirement.