The objective of this study is twofold. First, to describe the species composition and structure of traditional tree garden systems in southwest Sri Lanka. Second, to record the use and cultivation techniques used in these systems.
The traditional Sri Lankan home garden system is a centuries-old agroforestry practice, with usage of some plants dating from 5,000 years before present. Rural communities have traditionally valued forests for a diversity of products and services, with timber serving a minor role. This diversity is particularly notable in southwest Sri Lanka, where 70% of the flora in the rain forest region is endemic. Little work has systematically set about to quantitatively describe the floristics and structures of these systems, and match this to human use and cultivation.
The study’s chosen field site is a village comprised of thirty households. The village is adjacent to the Sinharaja Man and the Biosphere Reserve, a UNESCO World Heritage Site comprising the last remaining unlogged rainforest in Sri Lanka. A head from each of the thirty households was interviewed regarding their land-use history, current plant uses (e.g. non-timber forest products like tea, rubber, cinnamon, and medicinal herbs), and the specific techniques of cultivating and maintaining their tree gardens. All home gardens were mapped using gps to delineate property boundaries and distinguish dominant cover types throughout the tree garden. Ten of the thirty houses were then selected for a more detailed total stem mapping. Every plant was mapped with gps, identified, and structure data (i.e. height, d.b.h., and, when applicable, area) was noted in order to describe tree garden diversity, floristic patterns (i.e. spatial patterns), and stand productivity.
Results from this study will identify common tree garden management practices, reveal specific plant associations (e.g. a black pepper vine climbing a leguminous shade tree over tea bushes), quantify their spatial relationships, and inform how these relationships may change over time.