Species Composition, Distribution and Management of Trees in Rice Paddy Fields in Central Lao, PDR

摘要

Presence of different types of trees dispersed singly or in small groups throughout the fields is a very common feature in the extensive rice paddies of Laos and Thailand. Factors such as land-settlement history, proximity to forest, and role of species in the local culture are known to influence the nature and distribution of tree species so retained. The extent of influence of these factors on tree-species composition and distribution in rice paddies was investigated in three villages in Central Laos: Dongmakngeo, a newly established village with an abundance of adjacent forest; Bak, an old village with adjacent forest; and Nakhou, an old village without any adjacent forest. At Dongmakngeo village, 23 species, mostly remnants from the original forest, were observed in paddy fields. At Bak village, few trees were found in the paddy fields because villagers had ample access to resources in the surrounding large forest. On the other hand, 119 species, 27 of which were planted, were recorded at the forest-deprived Nakhou village; the scarcity of forest resources at Nakhou was compensated for by the utilization and management of trees located among the fields, resulting in tree species changing from remnant to ruderal over time. Thus, our results demonstrate that the pattern of tree distribution and species composition in paddy landscapes is not uniform, but varies in relation to settlement history, topography, and human management. This has important implications for setting both landscape-level land-use management plans and local tree management policies for achieving sustainable tropical paddy-dominated agro-silvicultural systems.