Quantitatively characterizing the floristics and structure of a traditional homegarden in a village landscape, Sri Lanka

摘要

Our study examined the species composition and vegetative structure of traditional homegardens within the context of the surrounding land use mosaic typical of village lands in the southwest region of Sri Lanka. We conducted interviews and spatially mapped the land uses of a single traditional village comprising over thirty households. After mapping the different land uses for each household we selected ten households and conducted a census of the vegetation of their land use areas. Land use categories included homegarden, patio, rubber, tea plantation, and secondary forest and scrub. Land holdings varied in size between 0.18 and 1.34 hectares and comprised 39% tea land, 27% homegarden, 12% patio, 17% secondary forest and scrub land, and 4% rubber plantation. We identified a total of 268 plant species on the ten properties in a total of 216 genera and 84 families across all growth habits combined (trees, shrubs, herbs and climbers). Our results show three times the plant species richness in homegardens than for any similar research on tree gardens elsewhere, but a large proportion are exotic and almost all have some kind of utilitarian purpose. The top three tree species are palms in homegardens which represent over two-thirds of the stem density and half the basal area. The conservation activities within tree gardens emphasizes the crucial-but perhaps undervalued-role local livelihoods and land management activities play in retaining tree species diversity comparable but dramatically differing in taxa as compared to the original rain forest.