THE BOTANICAL COMPOSITION AND MORPHOLOGICAL FEATURES OF “HIGHMOOR” PEAT PROFILES IN MAINE

Abstract

The 3 peat profiles studied showed phases of Sphagnnm peat 5-17 ft. thick, with a water table 3-10 in. below the surface. The layer of Sphagnum peat is superimposed upon a layer of woody peat moderately decomposed, followed in deeper depressions by a fibrous reed-sedge peat over sedimentary peat resting upon a clayey to sandy mineral substratum. Strati-graphically the peat profiles represent the conifer heath-sphagnum moss series and the sedimentary-reed sedge-conifier heath-sphagnum moss series. The layers of peat are throughout under anaerobic conditions. The rate of decomposition is exceedingly slow at present. The areas may be grouped into the category of immature, virgin peatlands. Physiognomically the surface vegetation may be designated as shrubby heath-moor. The raised, dome-shaped surface is due chiefly to an upward mode of growth and periodic accumulation of Sphagnum; it is probably related to a maritime climate (von Post''s region of ombrogene peat deposits) which was until recently much moister than now. The areas of peat appear to have come into existence during relatively recent post-glacial times. The general agreement in stratigraphic features probably relates to a common age of the deposits, the Lewiston peat being relatively older than the Veazie or the Denbo peat. The peat areas may be included into a major division characterized on the one hand by the lack or the removal of nutrient mineral salts (low ash content) in any layer of peat or horizon near the surface (oligotrophic group of peat lands), and by the presence, on the other hand, of conditions which give to the organic material an acid reaction.