Volume No. 2 Issue No.: 1 Page No.: 6-19 July-September 2007

 

VERTEBRATE DIVERSITY OF A REGENERATED FOREST IN SOUTH-WESTERN WET ZONE OF SRI LANKA WITH SPECIAL REFERENCE TO AVIFAUNA

 

Wasantha K.D.D. Liyanage*, Lai Xulong1, Saman N. Gamage and Devaka K. Weerakoon2

1. School of Environmental Studies, China University of Geosciences, 388, Lumo Road, Wuhan, Hubei, 430074 (P.R. Chin).
2. Field Ornithology Group of Sri Lanka, Department of Zoology, University of Colombo, Colombo 03 (Sri Lanka)

 

Received on : March 21, 2007

 

ABSTRACT

 

At least two-thirds of the earth’S terrestrial environment consists of managed ecosystems such as agricultural systems, forest plantations and human settlements. The value of these ecosystems for biodiversity conservation cannot be neglected. However, the habitat quality, richness and abundance of naturally occurring species in these ecosystems can be improved further through planned management. This will not only help biodiversity conservation but also improve the productivity of these ecosystems through stabilizing natural processes such as nutrient recycling, pollination, soil conservation and regulation of pest populations. Further, emerging new economic initiatives such as carbon trading and ecotourism has paved the way to accrue higher economic benefits through semi natural ecosystems. Therefore, in recent decades, there has been a major paradigm shift, around the world, from the extractive industrial model towards ecology-based approaches variously called eco-agriculture, agro-forestry or analog forestry. Sri Lanka had a tradition of conserving natural resources from prehistoric times. However, during the colonial era large extents of land were converted to mono crop plantations such as tea and rubber. At present almost two thirds of the land in Sri Lanka is classified as managed ecosystems. Some of these plantations have been abandoned due to various reasons and are regenerating in to semi natural ecosystems. Bangamukanda Estate (BKE), situated in Galle, Sri Lanka is an example, where an 18 hectare plantation (tea, rubber and cinnamon) has been converted to an analog forest. The land is formed into an undulating terrain with an altitudinal range of 100m to 300m. Further, BKE is surrounded by number of forest reserves. This study was carried out with the objective of documenting the vertebrate diversity of this analog forest in order to determine the value of analog forestry for biodiversity conservation with special reference to the birds. The study was conducted between 2003 and 2006 using two visual encounter survey methods, the line transect and quadrate sampling. A total of 207 species of vertebrates belonging to 79 families were observed including 17 amphibian species, 25 snake species, 17 tetrapod reptile species, 23 fish species, 89 bird species and 34 mammal species. Among these 48 species (23%) were endemic to Sri Lanka of which freshwater fish showed the highest endemism (48%). The vertebrate assemblage of BKE also included 12 globally threatened species. The highest diversity among all the vertebrate groups was observed among the birds including 11 endemic species and one globally threatened, 3 near threatened and 10 nationally threatened species. The results indicate that BKE is an agro-ecosystem that supports a high avifaunal diversity and richness. It was further observed that most bird species use this habitat as a temporary refugia or a feeding area, as they move from one forest patch to another. Thus, these results demonstrate the value of analogue forests in connecting the fragmented forest patches.

 

Keywords : Analog Forest, Biodiversity, Fragmentation, Vertebrates, Conservation

 

 

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