2020 Volume 25 Issue 2 Article ID: 1905
Mangroves are salt-tolerant terrestrial plants that grow in tropical and subtropical estuary areas. In a mangrove ecosystem, the trees provide food resources and habitat for various species. Benthic animals may contribute to this ecosystem’s materials cycle, because most are thought to consume organic material produced by mangroves. In this study, the food web structure of benthic animals in mangrove forests was investigated using stable isotopes and compared between Kiire mangroves in Kagoshima City and Sumiyo mangroves on Amami-Oshima Island. The former were replanted in the 1700s and are located in a temperate area that is almost at the northern limit of mangroves, while the latter comprise a natural stand in a subtropical area. We found that benthic consumers, mainly gastropods and crustaceans, consumed mangrove materials in Sumiyo, whereas in Kiire they consumed algae or phytoplankton. The food web structure in Kiire did not change after simultaneous defoliation caused by a cold wave in January 2016, when the constant supply of mangrove leaves disappeared. These results imply that the Kiire mangrove trees do not function as the basis of a food web but rather as a habitat provider.
