The Biogeomorphology of Mangroves and Their Role in Natural Hazards Mitigation

Abstract

Along low‐relief coasts in tropical regions, mangroves occupy the biogeographical landscape usually occupied by salt‐marsh or cypress ecosystems in more temperate regions. Over 50 species of mangroves are found worldwide. In tropical regions, mangroves are the prevalent coastal wetland ecosystem, overshadowed in the public mind by tropical rainforests and coral reefs. Mangroves exist on the tropical rims of all continents except Antarctica. Numerous species of mangroves exist; collectively they create large ecosystems such as the Sundarbans in Bangladesh and India that provide habitats for endangered species, including the Bengal Tiger. As biogeomorphological agents, mangroves interact with tidal flows to entrap and stabilize sediment, create humus, and alter tropical coastal environments. Mangrove sediments and pollen entrapped therein record substantial sea‐level rises and falls during the Holocene, including a mid‐Holocene highstand, and a regression associated with the Little Ice Age. Mangroves provide habitats for a variety of coastal creatures, including crabs, juvenile fish, and sponges. Worldwide, the mangrove ecosystem is threatened by anthropogenic activities such as aquaculture, urban development, and forestry. Removal of mangroves not only endangers sensitive ecosystems, but also reduces the protection from natural hazards that mangroves offer. Tsunami and storm surges from tropical cyclones are dissipated by the intertwined root systems of the mangroves, limiting the destructive potential of the surging water, although the extent of protection offered by mangroves is controversial. The natural protection of the mangroves has proven superior to man‐made objects to deflect tsunami and storm surge. Mangrove revegetation efforts are underway in numerous countries, most notably Bangladesh, Vietnam, Thailand, and Tanzania. A variety of remote‐sensing platforms provide the ability to monitor mangrove recovery or decline around the world. The ultimate results of anthropogenic influences on mangroves remain to be seen.

Mangroves in the global climate and environmental mix

“…Costanza et al () noted that in 2007, mangrove ecosystem services value to humanity was approximately 193, 843 US$/ha/year. Throughout the 123 countries that host mangrove ecosystems, people depend on them for fuelwood, timber, fiber and non‐woody products (Blanco et al, ; Rajpar & Zakaria, ), protection from storm surges (Badola & Hussain, ; Barbier, ; Barbier, Koch, Silliman, Perillo, & Reed, ; FAO, ; Marois & Mitsch, ; Ostling, Butler, & Dixon, ), and food (e.g., mangrove crab, fish, shellfish, reptiles, and honey; Kelleway et al, ). Similarly, mangroves are associated with a number of tangible and non‐tangible cultural ecosystem services (see for example Farley, Batker, de la Torre, & Hudspeth, ; Friess, ; Kelleway et al, ; Mukherjee et al, ; Owuor et al, ; Sandilyan & Kathiresan, ; Spalding et al, ; Queiroz et al, ).…”

Green Infrastructures in Megacity Jakarta: Current Status and Possibilities of Mangroves for Flood Damage Mitigation

“…Mangroves may protect coastal areas from tsunamis, tidal surges, floods, and cyclones (or typhoons, hurricanes) by mitigating waves and winds and minimize damage to property and human life (e.g., Danielsen et al 2005;Kathiresan 2012; Unnikrishnan et al 2013;Sandilyan and Kathiresan 2015). Some types of mangroves have prop roots or pneumatophores, which strengthen their durability against winds and facilitate the accretion of sediment, resulting in wave attenuation (Alongi 2008;Ostling et al 2009). Accumulation of sediment preserves or even expands the coastline (Marois and Mitsch 2015).…”

Klasifikasi Mangrove Berbasis Objek Dan Piksel Menggunakan Citra Sentinel-2b Di Sungai Liong, Bengkalis, Provinsi Riau

“…Mangrove merupakan salah satu sumberdaya pesisir yang memiliki fungsi sebagai sistem ekologis seperti: proteksi pantai dari gangguan badai, tsunami, angin, dan gelombang; tempat pemijahan ikan dan organisme lainnya; sumber nutrisi (Abu dan Ibrahim, 2014;Cannicci et al, 2008;Carrasquilla-henao et al, 2013;Mazda et al, 2002;Nagelkerken et al, 2008;Ostling et al, 2009;Ronnbaack, 1999;Thampanya et al, 2006) dan sumber ekonomi seperti: tempat rekreasi; sumber bahan kayu; obatobatan tradisional (Datta et al, 2012;Illukpitiya dan Yanagida, 2010).…”