Experiments on Breakdown of Sphagnum in Two Bogs

Abstract

Weighed amounts of air dry Sphagnum species were sewn into nylon bags and replaced in two bogs. The bogs were later recovered and the plants reweighed. The main results were 1Losses of weight from bags at the surface, at the water table and at 75 cm down were roughly in the ratio 13:9:2. 2. Losses were more rapid in a low land bog (where temperatures average four to five degrees higher) than in an upland bog. 3. Losses of S. papillosum were only half those of S. cuspidatum and S. acutifolium. 4. The addition of inorganic salts or peptone had little effect on rates of loss. Reasons are given for supposing that the main loss is due to microbiological activity. It is suggested that the most important variable in determining the proportion of original material which survives as peat is the time which elapses before the plants pass below a level close to the uppermost position at which sulphide can be detected. The implications of these results in the interpretation of recurrence and retardation surfaces, and in reconstruction of past bog surfaces from peat remains, are discussed.