ABSTRACT

Introduction of agriculture three millennia ago in Peninsular India’s Western Ghats   altered substantially ancient tropical forests. Early agricultural communities, nevertheless, strived to attain symbiotic harmony with nature as evident from prevalence of numerous sacred groves, patches of primeval forests sheltering biodiversity and hydrology.  Groves enhanced heterogeneity of landscapes involving elements of successional forests and savannas favouring rich wildlife. A 2.25 sq.km area of relic forest was studied at Kathalekan in Central Western Ghats.  Interspersed with streams studded with Myristica swamps and blended sparingly with shifting cultivation fallows, Kathalekan   is a prominent northernmost relic of southern Western Ghat vegetation.  Trees like Syzygium travancoricum (Critically Endangered), Myristica magnifica (Endangered) and Gymnacranthera canarica (Vulnerable) and recently reported Semecarpus kathalekanensis, are exclusive to stream/swamp forest (SSF).   SSF and non-stream/swamp forest (NSSF) were studied using 18 transects covering 3.6 ha.  Dipterocarpaceae, its members seldom transgressing tropical rain forests, dominate SSF (21% of trees) and NSSF (27%). The ancient Myristicaceae ranks high in tree population (19% in SSF and 8% in NSSF). Shannon-Weiner diversity for trees is higher (>3) in six NSSF transects compared to SSF (<3). Higher endemism (45%), total endemic tree population (71%) and significantly higher above ground biomass (349 t/ha) cum carbon sequestration potential (131 t/ha) characterizes SSF. Faunal richness is evident from amphibians (35 species - 26 endemics, 11 in IUCN Red List). This study emphasizes the need for bringing to light more of relic forests for their biodiversity, carbon sequestration and hydrology.  The lives of marginal farmers and forest tribes can be uplifted through partnership in carbon credits, by involving them in mitigating global climatic change through conservation and restoration of high biomass watershed forests.

Keywords: biodiversity hot spots, carbon credit, carbon sequestration, conservation, hydrology, Myristica swamps, Uttara Kannada

Running title: Relic forests of Central Western Ghats. Chandran et al.

Abbreviations: AGB,  above ground biomass; BA,  basal area; GBH, girth at breast height; IUCN, International Union for Conservation of Nature and Natural Resources; IVI,  importance value index; NSSF, non-stream/swamp forest; SD,  standard deviation; SSF, stream/swamp forest