Ecological characterization of the 40-year-old regenerated rainforest patch in Olaboduwa-Kodigahakanda adds value in promoting forest-based nature tourism.

Abstract

Ecosystem and floristic characteristics have been extensively studied to address environmental disturbances and mitigation measures. However, their importance as key landscape elements in evoking natural attractiveness is less explored. This paper focuses on the ecological evaluation of the scenic beauty, carbon storage and ecosystem health of a forest fragment, Olaboduwa-Kodigahakanda in the suburbs of Colombo, through a quantitative approach to demonstrate the non-consumptive social value marketed for forest-based nature tourism. The forest accommodated 171 species of plants, 202 fauna including 69 bird species and 15 fish species, and 40 macro fungal species. A total of 32 threatened species were reported. The diversity of vegetation varied across the canopy, understory and undergrowth, and exhibited three distinct communities denoted by Dipterocarpus zeylanicus, Mimosops elengi and a mix of species. Plant age structure analysis confirmed a mid-successional forest regeneration phase enriched with endemic species Artocarpus nobilis, and D. zeylanicus in the canopy and Gaertnera vaginans in the understory. The living trees stored 134.82 ± 50.51 Mg/ha carbon, and 494.8 tons of CO2 e/ha greenhouse gasses, and showed satisfactory health in terms of greenness. School children were the key visitors engaged in nature exploration and educational day walks while youth preferred rock climbing as an adventure sport. Removal of invasive plants, enrichment planting of native species with regular monitoring and related follow up actions are recommended for forest management to offset impacts of disturbances while stream restoration initiatives would stimulate aquatic life. Strengthening local community participation in surveillance, management and revenue generation is crucial for sustainable nature tourism. The forest stands as a model for promoting forest-based nature tourism of secondary forest fragments in wet lowlands.