Cellulose mass loss in ombrotrophic bogs of northeastern North America

• Published in: Canadian Journal of Botany
• Main Author: Santelmann, Mary V.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1992
• Subjects: Plant Science; Newfoundland
• Online Access: http://dx.doi.org/10.1139/b92-297; http://www.nrcresearchpress.com/doi/pdf/10.1139/b92-297

Profiles of cellulose mass loss were measured for six Sphagnum bogs in eastern North America as an index of decomposition rates. After 2 years, mass loss rates in the upper 5 cm of the profiles averaged 49% in hummocks, 52% in hollows where the water table was more than 5 cm below the surface, and 21% in hollows where the water table was within 5 cm of the surface. Hummock profiles were of three types: (i) mass loss highest at the surface, gradually decreasing to very low rates below the water table; (ii) mass loss highest at the surface, decreasing for 10 – 20 cm, with a second peak in the region of the water table; and (iii) mass loss low at the surface with a subsurface peak. Mass loss rates for all profiles reached minimum values below the water table, averaging 3% in hummocks and 5% in hollows after 2 years. Cellulose mass loss was quite variable in upper portions of the profiles; within-site variance was almost as great as between-site variance, reflecting similarity among these bogs and heterogeneity within each site. Analysis of variance of mass loss at the hummock surface showed no significant effect of site; however, contrasts among means showed that mass loss rates at the surface of hummocks of the northern (Newfoundland) bogs were significantly lower (p < 0.05) than those from the sites farthest south (in Nova Scotia and Maine). Key words: cellulose mass loss, Sphagnum bog, decomposition.