Rehabilitation of slash and burn agricultural lands in

Rehabilitation of slash and burn agricultural lands in the dry zone of Sri Lanka by low cost silvicultural method M. A. A. B. Dilhan1, J. Amarasinghe1, R. M. C. S. Rathnayake2 and T. D. Weerasinghe1 1 IFS - Popham Arboretum, Dambulla, Sri Lanka, 2Department of Botany, University of Kelaniya, Sri Lanka

Regeneration is a long term process, when it begins from an abandoned shifting cultivation lands. Therefore, present study highlights the effectiveness of Popham method, which can apply for rehabilitation of degraded lands in order to accelerate natural regeneration by native trees. The survey was conducted in Dambulla Arboretum, which is considered as sanctuary of tropical trees in Sri Lanka. The principle behinds the Popham method is not to plant seedlings of native trees, but allow to germinate seeds of native trees present in the soil seed bank. To promote young tree seedlings, grasses and excludes creepers and thorny shrubs were controlled. Removal of excessive tillering, dead branching and pruning in growing tree seedlings were done. Popham method (rehabilitation project of Dambulla Arboretum, Sri Lanka) reduces the cost for rehabilitation compared to Miyawaki method (rehabilitation project of Bintulu, Sarawak, Malaysia). The total cost for rehabilitation of Miyawaki method was US$ 15, 329 /ha, while it was US$ 143/ha for Popham method. Popham method facilitate to increase the richness of plants, where we documented 225 plant species comes under 58 families. Which consist of native species, 94 trees 42 shrubs, 66 herbs, 19 climbers and 4 parasitic plants. Among 8 of them were endemic to Sri Lanka. Biodiversity of the arboretum includes, 85 bird species comprising 69 residents, 9 migrants and 7 endemic species. Furthermore, 40 butterflies were also recorded. Present results indicate silvicultural management of abandoned agricultural lands by Popham method would useful to accelerate natural plant regeneration towards secondary climax vegetation, while facilitating rich biodiversity compared to shifting cultivation land in Sri Lanka.