Diversity of tree flora in homegardens in urban proximity of Anuradhapura city, Sri Lanka

摘要

It was hypothesised that the land ownership with clear titles has an influence on incorporating perennial tree flora. Hence, this study compares the types and density of tree species in homegardens of inherited and settled lands in close proximity of Anuradhapura city, with subsistence farming activities. Mean harvestable tree density was 54.5 trees/ac in inherited lands compared to 40.3 trees/ac in settled lands. In spite of the general similarity in tree flora between the two categories of homegardens, certain tree species are more abundant in one than the other. Exotic timber tree flora represented approximately 30% of total tree population in settled compared to 16% in inherited. Exotic timber tree flora mainly dominated by Tectona grandis and Berrya cordifolia in settled lands concerning more economic returns. In inherited lands, multipurpose trees i.e. Artocarpus heterophyllus, Azadirachta indica and Mangifera indica were highly abaundanat concering diversity and food security. Cocos nucifera was the most abaundant tree specis in both categories accounting more than 40% abaundance. Tree species such as Tamarindus indica was restricted to inherited lands and Felicium decipiens and Swietenia macrophylla to the settled lands. It is advocated that the settled farmers should preserve more diversity among trees as inherited farmers, which enhance food and economic security under diminishing climatic suitability for crop production. Nonetheless, this study awaked an important entity for future carbon crediting programmes, which would be a win-win situation in forestry and farming aspects.