Plant resources studies on the natural forest in subtropical Okinawa [Japan], 6: Distribution of the economically important plant in Miyako Island
2001
Aramoto, M. (Ryukyu Univ., Nishihara, Okinawa (Japan)) | Ishigaki, C. | Hirata, E. | Shinzato, T. | Asato, I.
Within the frame work of a series of plant resource studies on the natural forests in the subtropical Okinawa Islands, the present study was undertaken to investigate the distribution of resource plants (focusing primarily on the forest plants in Miyako Island), and to classify the plants by their application and use, with the goal of collecting basic data to be used in collection, preservation, cultivation, development and utilization of plant resources for the future. The following results were obtained. Twenty-eight plant species were confirmed in the forest inventory survey. The most frequent species found in the total forest area were distributed as follows : Casuarina equisetifolia 38%, Cinnamomum pseudo-pedunculatum 17%, Pinus luchuensis 11%, Acacia confusa 6%, Eurya emargionata 5%, Pongamia pinnata 4%, Diospyros maritima 3%, Hibiscus tiliaceus 3%, and Melanolepis multiglandulosa 3%. The number of tree species in Miyako Island was smaller than that on other majors islands constituting the Okinawa Islands (Okinawa Island, Ishigaki Island, Iriomote Island). Thus, the tree species were relatively mono tonous on Miyako Island. In this forest inventory survey, the sampling error is estimated to be 16.4% for the mean diameter at breast height, 11.7% for the mean tree height, 26.1% for the number of trees per hectare. 19.1% for the basal area per hectare, and 25.3% for the volume per hectare. The mean diameter at breast height was 11.0cm. The mean tree height was 6.4m. The number of trees per hectare was 2,077.
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