The Picking and Transplanting of Rhododendron dilatatum and Rhododendron kiyosumense on the Boso Peninsula, Chiba

Abstract

The actual situation of both the wild and transplanted population of Rhododendron dilatatum and Rhododendron kiyosumense grown around Kimitsu city has been studied through fieldwork and interviews with local people. The results show that the geographical range of wild R. dilatatum and R. kiyosumense has become reduced. Those that have been transplanted from their native habitat are distributed widely throughout Kimitsu city. The number of people who are in possession of these two species becomes higher in the area closer to the native habitat. The collecting of these plants from their native habitat grew intensely during the period of 1970 to 1985. These plants have been used as garden plants, and they have rapidly spread out in the last 30 years. There are many means of obtaining these two species of Rhododendron. One of the means is by picking-plants. The closer the native ranges, the higher the percentage of these picking-plants. The other means are mainly through merchants and as gifts from acquaintances. A large number of individuals of the same species that were collected originally existed in low mountain areas in the Boso Peninsula. Almost all of the two species of Rhododendron close to the area of native habitat were found by picking-plants. It was a crucial time (1970-1985) when the picking-plants boomed, and great changes were made in the areas surrounding the native habitat. With the rapid industrialization of urban areas, the number of households has increased proportionally. These changes led to the transplanting of these two species of Rhododendron and brought about a decrease in their growing in the wild.