Land Use of the Li-Speaking People in a Mountainous Area of Hainan Island, China: Impact of National Nature Reserve Established in 1986
The people claimed that the vegetation type of secondary growth differ by the type of former land use. On the sites that were used as grasslands for buffalo fodders and roofing materials, Haname lidacea will dominate the secondary growth (Fig 1, right). This is deciduous broad-leaved tree. It often stands collectively and the usually light-green leaves turn yellow or red in December to January. The leaves will fall before long. New leaves bud in February to March. The IKONOS data used in this study was taken on 24 March 2001 when Haname lidacea trees had vivid light-green leaves. This can work as an advantage for the classification process. On the other hand, on the sites that were used as slush-and-burn gardens in the past, two species of trees (Alchornea liukiuensis Hayata, and, Mallotus japonicus) can be found (Fig 1, left). Though these trees do not stand collectively, the color of leaves is brighter than those of trees in matured forest and is different from that of Haname lidacea trees. The people
could identify, on the basis of type of vegetation in the secondary grouth, whether the site was grassland for buffaloes fodders or slush-and-burn gardens. This folk knowledge for the secondary growth was used in the present study to estimate the spatial distribution of grassland and slush and burn gardens before the national reserve was established in 1986.
Fig. 1 Alchornea liukiuensis Hayata , the index trees of past slush-and-burn garden sites (left); collective stands of Haname lidacea, the index trees of past grasslands (right).
Methods
Fieldwork was conducted in September to November 2000, July to September 2001, March 2002, and June 2002. Ground control points were collected using two GPS equipments (Trimble, GeoExplorer III) that enabled us to apply differential correction using Pathfinder Office software (Trimble). The IKONOS image on 24 March 2001 was corrected geometrically with these ground control points.
