Tropical forests, which harbour most of the world’s plant diversity, continue to be
destroyed at unprecedented rates (Myers et al., 2000; Pittman & Jorgenson 2002). The
faunal species associated with these forests are also affected due to one or another
reason. The wet evergreen forests of the Western Ghats of India are one of the global
biodiversity hotspots, being rich in biodiversity and endemic species (Myers et al., 2000), it
is also under the threat of deforestation. It harbours some of the relic elements in the
remnant forests, which are in patchy distribution. Myristica swamps are one such
threatened ecosystems occurring in these remnant forests of Western Ghats. They are
undoubtedly priceless assets for the evolutionary biologist, since many features of
Myristicaceae are primitive in origin and hence regarded as ‘living fossils’.
What are Myristica swamps?
Swamps are wetlands dominated by woody plants. They have a fairly deep settlement
of water and minimal growth of emergent plants. A marsh, though sometimes used
synonymously with swamp is more applicable to a large area of wetland where the
dominant vegetation consists of low-lying grasses, rushes and sedges. Swamps have a
high water table and occur near rivers, streams, and lakes. The soils are saturated (or
soaked) with water. The soil is thick, black, and nutrient-rich, providing an environment for
water tolerant trees and other organisms. Freshwater swamps occur in many parts of the
world, namely, Valleys of Mississippi and its tributaries, in Sweden, Odzala National Park,
Congo, in the Malaysian region, Papua New Guinea, Swamp forests fringe the Amazon
and its tributaries, etc. In India, freshwater swamps are reported from the Siwalik and
Doon Valley and the Brahmaputra Valley (Rao, 1994).
Myristica swamp is any freshwater swamp where any one or both of the exclusive
swamp growing trees of the family Myristicaceae namely Gymnacranthera canaria or
Myristica fatua var. magnifica are present. These swamp species may occur in
association with some other, usually evergreen trees having varied degrees of flood
Distribution of Myristica swamps
Davis et al. (1934), in their working plan for North Mangalore Forest Division
Madras reported about “swampy evergreens” with Myristica spp. confined to low lying
poorly drained areas, without specifying the exact locations. However, KrIishnamoorthy
(1960) reported Myristica swamps, for the first time, as a special type of habitat from
Travancore. These swamps were found in the valleys of Shendurney, Kulathupuzha and
Anchal forest ranges in the southern Western Ghats. Champion and Seth (1968) classified
such swamps under a newly introduced category ‘Myristica Swamp Forests' under the
Sub Group 4C. Talbot (1911), in The Forest Flora of the Bombay Presidency and Sind vol. II,
reported just one locality, near Malemane, in Siddapur of Uttara Kannda for Myristica
magnifica. The northernmost swamp that is known is associated with a sacred grove in
the Satari taluk of Goa (Santhakumaran et al. 1995). However, they have not reported M.
fatua or G. canarica from the Goa locality. The photographs in their paper, however, are
indicative of the presence of G. canarica, thereby meriting the classification of the
habitat as a Myristica swamp.
Varghese and Kumar (1997) differentiate between two types of swamps having
Myristicaceae, in the Travancore region: 1. Myristica swamp forest, restricted to below
300 m, fringing sluggish streams. 2. Tropical sub-montane hill valley swamp forest- found
as narrow strips of water-logged areas. Whereas, the former has M. fatua as well as G.
canarica, in the latter, G. canarica is found along with Mastixia arborea and several
others. Such bifurcation of these swamps does not have enough justification. The Atlas of
Endemics of the Western Ghats (India) by Ramesh and Pascal (1997) shows that G.
canarica and M. fatua occur from sea level to 700 m and 1000 m altitudes respectively.
More detailed studies on the Myristica swamps of Uttara Kannada in Central
Western Ghats have been made recently. These swamps are isolated and situated in
localities from near sea level to about 450 m altitude (Figure 1)(Chandran et al., 1999;
Chandran and Mesta, 2001).