Developing a mapping method for selecting biodiversity conservation priority area and for invasive species measures in the oceanic islands

为了保护东京海洋岛屿上的濒危植物物种，我们研究了Viburnum物种个体的精确生物地理分布、群落结构和光环境。短枝V.brachyandrum分布在大岛岛(北界)至八岛，V.Japan onicum分布在Toshima岛至Hachjojima，而V.Japan var.Boninsimense仅限于小川群岛。栖息地位于典型的大气湿度较高的原生林中，且环境相对明亮(RPPFD&GT；13%)。然而，由于人类居住后土地的集约利用和植被的变化，这种环境已经减少。赤岛岛野生山羊对树苗的食草性很严重，母鸡标本的历史证据表明，在过去的几十年里，由于其他原因，Hahajima岛上的V.J.boninsimense当地种群已经灭绝。东岛大面积的山茶种植园和大岛岛外来鹿的入侵也很严重，我们发现，尽管一些濒危物种位于国家公园内，但在划定新的保护区时，不仅要考虑它们现在的分布格局，还要考虑它们过去的分布。

To conserve endangered plant species in oceanic islands of Tokyo, we studied precise biogeographic distribution, community structures, and light environment of individuals of Viburnum species. V. brachyandrum is distributed from Oshima Island(northern limit) to Hachijojima Island, V. japonicum is from Toshima Island to Hachjojima, and V. japonicum var. boninsimense is limited to the Ogasawara Islands. The habitat was in the primary forests with typically high atmospheric moisture, and in relatively bright environment(RPPFD> 13%). However, such environment has decreased due to intensive land-use and vegetation changes after human inhabitation. Herbivory on saplings by feral goats in Chichijima Island is severe, hens the historical evidence of specimens showed that the local population of V. j. boninsimense has become extinct from Hahajima Island due to alternative reasons in the past few decades. Extensive plantations of Camellia japonica in Toshima and invasion of an exotic deer, Muntiacus reevesi in Oshima Island are also serious, and we found out that even though some of the endangered species are located in the National Parks, not only their present distribution pattern, but also their past distribution must be considered when delineating the new protected areas.