|| 要旨トップ | 目次 |||日本生態学会第68回全国大会 (2021年3月、岡山) 講演要旨
一般講演（ポスター発表） P2-020 （Poster presentation）
Coral reefs in the Ryukyu islands in Japan have been exposed to various acute disturbance events, such as heatwaves, typhoons, and outbreaks of coral predators. However, impacts of these disturbance events on coral cover and factors which affect the impacts remain unclear. We detected three kinds of disturbance events; heatwave, typhoons, and crown-of-thorns starfish (COTs) in 20 areas in 8 regions in the Ryukyus Island and quantified impacts of 84 events of those on coral cover by using long term coral cover data from 2005 to 2017. In addition, we evaluated impacts of 27 multiple disturbances, more than one kind of disturbance occurred in the same year, by comparing with their single impacts on coral cover. Results showed that the frequency of disturbance events, the number of areas where they occurred, the frequency of multiple disturbance events were increasing. Impacts of single disturbance events were affected by intensity of events, kinds of events, regions, and years they occurred. Although disturbance events mostly did not have significant impact on coral cover in regions around large islands, heat and COTS events had large negative impact in regions around Sekisei lagoon. Joint impacts of all multiple disturbance events acted additively on coral cover.