Studies on spatial distribution of two invasive alien species spreading and conservation of vegetational landscape in a warm-temperate evergreen forest of the Kasugayama Forest Reserve, a World Heritage of Ancient Nara, Japan

本文研究了日本特殊自然纪念物和联合国教科文组织世界文化遗产Kasugayama森林保护区（KFR）的两种外来物种Podocarpus nagi （podocarpacae）和Sapium sebiferum （Euphorbiaceae）的空间分布。利用地理信息系统（GIS）技术对2002-2004年的野外数据进行了野外调查和分布图绘制，确定了这些物种的分布和可能的入侵模式。利用全球定位系统（GPS）在约120公顷的土地上分别记录了约10000株sebiferum和约10000株p.a nagi（包括当年幼苗）的位置。大部分木门植物聚集在林隙中，而木门植物则集中在封闭林冠中。在KFR西部靠近三笠山的地方，长尾木密度较高，表明长尾木林分发育。在分布上没有明显的方向性倾向。两种外来种树苗的空间分布存在差异，但两种树种的空间分布差异不大。结果表明，这两个外来物种虽然在入侵历史和传播行为上存在很大差异，但由于它们对鹿群的不适口性，它们在KFR附近的三笠山和奈良公园大量扩张。此外，我们还在奈良公园的森林中调查了梅花鹿（Cervus nippon）剥树皮的情况，该公园有大约101200只梅花鹿居住。在1041棵高度为1.3 m的树木中，有33.8%的树木剥皮。在10个地区记录的39种树种中，有31种存在不同程度的剥皮现象。梅花鹿剥树皮取决于对树皮的偏好，而不是胸径。在每个样地中，随距离Kasugayama森林保护区和/或Wakakusayama山的距离增加，低电流率树种的比例增加。空间环境梯度与梅花鹿剥树皮的关系表明，区域保护是奈良公园植被和梅花鹿高密度种群管理的必要措施。少

We studied the spatial distribution of two alien species, Podocarpus nagi (Podocarpaceae) and Sapium sebiferum (Euphorbiaceae), in the Kasugayama (Mt.Kasuga) Forest Reserve (KFR), a warm-temperate evergreen forest designated a Special Natural Monument of Japan and a UNESCO World Heritage Site. We conducted field surveys and distribution mapping of these species with the aid of geographic information system (GIS) technology from 2002-2004 field data, to determine their distributions and characterize the likely invasion patterns. We recorded the locations of ca 10000 S.sebiferum plants and ca 10000 P.nagi plants (including current-year seedlings) at, respectively, using a global positioning system (GPS) in an approximately 120-ha site. Most S.sebiferum plants were aggregated in canopy gaps, whereas P.nagi tended to occur in closed canopies. High densities of P.nagi in the western part of KFR near Mt.Mikasa indicated the development of P.nagi stands. Sapium sebiferum showed no remarkable … More directional tendency in its distribution. The spatial distributions of saplings of these two alien species differed, but few differences were observed in the spatial distributions of these two species. Our results suggest that these two alien species, which originated from Mt.Mikasa and Nara Park adjacent to KFR, have expanded abundantly because of their unpalatability to deer, although they differ greatly in invasion history and spreading behavior.Additionally, we investigated bark-stripping by sika deer (Cervus nippon) in the forest at Nara Park, which is inhabited by >1200 deer. We found bark-stripping in 33.8% of 1041 trees >1.3 m in height. Among the 39 tree species recorded in 10 areas, 31 species were found to suffer various degrees of bark-stripping. Bark-stripping by sika deer depends on bark preference rather than DBH. In each plot, the proportion of tree species of low electivity increased with increasing distance from the Kasugayama Forest Reserve and/or Wakakusayama Hill. The relationship between the spatial environmental gradient and bark-stripping by sika deer suggests that regional conservation is necessary for the management of vegetation and the high-density sika deer population in Nara Park. Less