66 
R. H. Yapp. 
Character of the Vegetation. 
Two of the most important “plant formations” which give 
rise to peat deposits are those known to British plant-geographers 
as Marsh and Bog. 1 These correspond respectively to the 
Sumpfmoor and Sphagnummoor of Warming, 2 and to the Flachmoor 
and Hochmoor of Friih and Schroter. 3 According to the latter 
authors, both types may be developed either directly on merely 
boggy soil, or else on the surface formed by the growing up of open 
sheets of water by aquatic and semi-aquatic plants. 4 Thus in many 
cases the marsh or “ Flachmoor ” may directly succeed the reed- 
swamp. 
Marsh vegetation is developed where the water is rich in 
mineral food substances, especially lime: or in running water even 
if poor in salts. Bogs on the other hand are only formed where the 
water is deficient in salts, and especially in lime. Another important 
factor is climate. Bogs can develop fully only in regions with a 
considerable rainfall, while marsh vegetation is more independent 
of the amount of precipitation, provided there is a sufficient supply 
of telluric water. 5 
The Fenland, with its relatively low annual rainfall, 6 and with 
some of its streams directly draining the Chalk 7 or other calcareous 
strata (see Text-fig. 9), is, like the region of the Norfolk Broads, 
suited to the development of marsh rather than bog vegetation. 
The vegetation of Wicken Fen is then, for the most part, that 
of a typical marsh or “ Flachmoor.” The characteristic plants of 
the bog— Sphagnum, Eriophorum, Ericaceae, &c., are absent; but 
instead of these the dominant plants are grass-like Monocoty- 
ledones—Cyperaceae, Gramineae and Juncaceae, which give the 
general facies to the vegetation. Mixed with these are many 
Dicotyledonous herbs, the whole forming, in most places, a dense 
rank vegetation some two to five feet in height (see Plate IV., fig. 1). 
1 R. & W. G. Smith. Botanical Survey of Scotland, III. and IV. 
Forfar and Fife. Scot. Geog. Mag. Vol. XXI., 1905, pp. 117, 
et seq. 
2 Warming. Oekologischen Pflanzengeographie, 1896, p. 171. 
3 Friih & Schroter. Die Moore der Schweiz, 1904, pp. 11, et seq. 
4 Ibid, pp. 12 and 13. 
6 Transitions between the vegetation of marshes and bogs are 
often to be found, cf. Smith, l.c., p. 117. 
G Miller and Skertchly, l.c., p. 239. 
7 The presence of calcium in the water and peat of Wicken Fen 
is proved by the abundance of lime-encrusted Charas in the 
lodes, and by the great numbers of molluscan shells which 
are found everywhere in the peat. 
