Extinction risks and cofactors of amphibia

在规划过程中，生物多样性的保护取决于规模。首先，利用一个简单的生境模型，在国家或区域范围内广泛筛选优先领域。第二步是在景观尺度上设计保护区。1.在国家尺度和地理学研究中的风险评估。有无数据可供参考，包括云顶蝾螈、滋贺和大坂府。Logistic模型被用来估计这两个物种的潜在栖息地。栖息地的适宜性估计使用的物种，只有存在数据的生态位因子分析。通过将土地利用规划图与潜在栖息地图重叠，对这些动物的未来风险进行了评估。为了鉴定星云血吸虫的区域种群单位，在线粒体DNA控制区内测定了420个碱基对的序列 关于我们 .结果表明，大量的地理结构和强大的人口水平的分离。2.景观尺度的风险评估利用1/2,500植被图和10 m DEM，建立了1 km × 2 km范围内的云雾蝾螈景观尺度生境模型，并利用该模型评估了不同土地变化情景下云雾蝾螈的灭绝风险。集合种群的风险评估可以对复杂景观（如日本的里山）的环境影响进行详细的评估。3.小型水坝对日本大鲵迁移的影响。但可以预见的是，小水坝阻止了这一运动。我们调查过了。的季节性运动，并探讨了小型水坝对日本西部的穆科水系的哈图卡河运动的影响。在1523米的河段进行了调查，其中包括6个大坝，并标记了104个个体。每座大坝上都有10多人向上游移动。但在30 cm以上、倾角30°的堤坝下观察到的个体数量较多，说明如果没有旁路或立足点，雾状小鲵（Hynobius nebelosus）就无法越过堤坝。在我们的实验中，我们测试了捕食性蝾螈和小龙虾的影响，蝌蚪的非致命性影响和经验不足的鱼类的影响，发现H.nebulosus可以识别捕食者不是基于视觉线索，而是基于捕食者释放的利它素。对不栖息在临时池中的捕食性鱼类鲫鱼的利它素没有反应，说明云斑鲫对不栖息在同一生境中的捕食性鱼类没有回避反应。少

Conservation of biodiversity is the scale dependent in the planning process. At first, priority areas are screened extensively on the national or regional scale by using a simple habitat model. The second step is to design a conservation area in the landscape scale. We developed habitat models for amphibias in this two scales and discussed usefulness of the models in conservation1.Risk assessment in national scale and phylogeographic studyPresence and absence data were available for the clouded salamander and in Shiga and Osaka Prefecture. Logistic models were used to estimate the potential habitat for these two species. Habitat suitability was estimated using Ecological-Niche Factor Analysis for species in which only presence data are available. Future risks were evaluated for these animals by overlaying land use planning maps with the potential habitat maps. To identify regional population units of H.nebulosus, 420 base pairs were sequenced within the mitochondrial DNA control region … More . Results indicate substantial phylogeographic structuring and strong population-level separations. Four groups were detected among this species.2.Risk assessment in landscape scaleA habitat model in landscape scale (1 km x 2 km range) was built for the clouded salamander by using a result of ecological survey and a 1/2,500 vegetation map and 10 m DEM. This model was used to estimate extinction risk of the salamander in several scenarios of land change. The risk assessment of metapopulation allows a sophisticate evaluation of environmental impacts in complex landscapes such as Satoyama in Japan.3.Influence of small dams on the movements of Japanese giant salamander.A.japonicus move to up stream before their breeding season. But it is predictable that the movement is prevented by small dams. We surveyed. a seasonal movement of A.japonicus and examined the effect of small dams on the movement in Hatuka river of Muko river system in western Japan. We surveyed in 1523 m section of the river that include six dams, and marked 104 individuals. More than 10 individuals moved up stream over each of the dams. But the fact that many individuals were observed just under dams that are taller than 30 cm and 30° in the inclination suggests that A.japonicus cannot pass over those dams without a bypass or a foothold4.Avoidance responses of (Hynobius nebulosus mediated by predator chemical cue.We studied antipredator behavior of the clouded salamander (H.nebulosus)larvae. In our experiment, we tested the effects of predatory newt and crayfish, non-lethal effects of tadpole and effects of inexperience fish We found that H.nebulosus can recognize predators not based on visual cue but kairomones emitted by the predator. larvae did not respond to kairomones of predatory fish Carassius auratus which did not inhabit in temporary pool, therefore it suggested that H.nebulosus do not have avoidance response to predator not inhabit the same habitat. Less