The vegetation of Manu Swamp: a tropical fresh-water swamp forest.
Manu Swamp is at Koyal Ghata in the Eastern Doon Forest Division, Uttar Pradesh, at 389 m alt. and in the Himalayan foothills. It is situated in a depression which is probably an old river bed, and covers about 30 ha, of which about 10 ha is inhabited. The swamp can be divided into the swamp proper and the swamp forest. The swamp proper is on flat ground and composed of algal, hydrophytic, amphibious, sedge, bush and fern, cane (Calamus tenuis) and (some) tree communities; the species found in each are described. The swamp forest is on sloping ground and is composed of trees, shrubs, undershrubs and herbs; epiphytic orchids are also common. The swamp forest has 5 strata: emergent trees of Holoptelea integrifolia; large and medium sized trees of species such as Alstonia scholaris, Albizia procera, Adina cordifolia, Bischofia javanica, Ficus bengalensis [F. benghalensis] and Syzygium cumini, etc.; small sized trees such as Trewia nudiflora, Putranjiva [Drypetes] roxburghii, Schleichera trijuga, Cassia fistula, Carallia integerriana [? C. integerrima = C. lucida], Casearia tomentosa and Mallotus philippensis, etc.; undergrowth; and herbs and tree seedlings. The species composition and dominance is different from that of other swamps in the Doon Valley.