空撮画像とＧＰＳ比高データによるマングローブ（フタバナヒルギ：Ｒｈｉｚｏｐｈｏｒａ ａｐｉｃｕｌａｔａ Ｂｌ．）に適した生育条件の推定

Abstract

Mangrove forest was once cut down on a large scale area to use for shrimp culture etc. But now, mangrove reforestation is advanced for the disaster prevention in the coastal area and for increase in production of marine resources. However, reforestation activities are not so going well. Although it is known that the ground level has affected the result of reforestation, the range of exact adaptation is not examined well. When a mangrove area is used for other purposes, the ground level is usually changed. In this paper, in order to estimate the suitable growth condition in Rhizophora apiculata, the relative height in the study area was measured by high precision GPS. Then, the biomass in the area as the index of productivity was calculated using the aerial-photograph taken by radiocontrolled helicopter. Fine satellite imagery is hard to be obtained in a tropical region, and the tidal level at the observation influences analysis for mangrove region. The radio controlled-helicopter can be applied at any time standing by. This is the reason why we used this platform. As a result of the analyzing optimum growth condition in Rhizophora apiculata based on the above-mentioned, it was found that the range of relative height suitable for growing is between 36cm and 95cm.