- Mangrove forests occupy only 1% of the total tropical forest area, and yet provide valuable ecosystems along the coastal line of the tropics. Mangroves provide unique environments linking land and the sea and sustain ecosystems containing a variety of plants, providing habitat for mammals, birds, fish, and insects. Information is provided on the distribution and current status of mangrove ecosystems.
- World distribution of mangroves is looked at in the Asia Pacific region.
- Mapping techniques (field survey, remote sensing) employed in distribution map are discussed.
- Some cases of mangrove monitoring and restoration attempts are introduced.
Mangroves Course Outline
2010-01-24
Geographical Distribution of Mangroves
- “Mangroves are largely confined to the regions between 30°north and south of the equator, with notable extensions beyond this to the north in Bermuda (32°20’N) and Japan (31°22’N) and to the south in Australia, New Zealand, and the east coast of South Africa.”
- The slide shows the distribution of mangroves in the Asia Pacific.
- “The widespread occurrence of mangrove vegetation and the floristic divergence between the ‘old’ and the ‘new’ world, can only be explained by geological events. … The present distribution of individual mangrove species must be seen against this background of plate tectonics and continental drift.”
- “Each of these various interpretations is based on the existence, during the early Cretaceous, of an extensive tropical sea, the Tethys Sea, separating the northern supercontinent of Lauraisa from the southern Gondwanaland. Mangroves evolved within the Tethys Sea and dispersed outwards. … Around 18 million years ago (mya), … the pantropical mangrove flora became disjunct and developed as two isolated floras (assuming that the southerly extensions of Africa and South America formed impassable barriers to mangrove dispersal). Around 3mya, the Panama gap closed: … Thus, today, there are three disjunct mangrove floras.
Source: Spangle, et al. eds., 1997
Definition of Mangroves
- “Mangroves are not a single genetic group but represent genetic adaptation of a large variety of plant families to a particular environment.”
- “The word ‘mangroves’ means tropical plants and their communities which grow in the intertidal zone. The intertidal zone is the area under tidal influence along the coast line, such as seashores, estuaries, lagoons and river banks. Generally mangroves are trees and bushes growing below the high-water level of spring tides.”
- The mangrove species are classified into 3 groups:
- Major components,
- Minor components, and
- Mangrove associates
Source: Field, Journey among Mangroves, 1995
- “There are approximately 70 species of true mangrove (major and minor components of mangroves). Forty of these species occur in South-East Asia; approximately 15 species occur in Africa; and approximately 10 species occur in the Americas.”
- “Some mangrove species develop systems suitable for high salinity conditions, such as special secreting organs called salt glands.”Source: Kitamura, et al., Handbook of Mangroves in Indonesia, 1997.
References
- Shigeyuki Baba, “Mangroves, Mangrove Ecosystems and their Roles as One of Important Coastal Ecosystems”, Presentation contributed to Asia Pacific Joint Lecture Series 2005.
- Shozo Kitamura, Chairil Anwar, Amayos Chaniago, and Shigeyuki Baba, Handbook of Mangroves in Indonesia – Bali & Lambok, Ministry of Forestry Indonesia and Japan International Cooperation Agency, 1997.
- Mark Spalding, Francois Blasco, and Colin Field, eds. World Mangrove Atlas, The International Society for Mangrove Ecosystems (ISME), The World Conservation Monitoring Centre, The International Tropical Timber Organization.
- Colin Field, Journey amongst Mangroves, The International Tropical Timber Organization and the International Society for Mangrove Ecosystems, 1995.
- Colin Field, ed., Restoration of Mangrove Ecosystems, The International Tropical Timber Organization and The International Society for Mangrove Ecosystems.
- Shozo Kitamura, Chairil Anwar, Amayos Chaniago, and Shigeyuki Baba, Handbook of Mangroves in Indonesia ? Bali and Lombok – , Ministry of Forestry of Indonesia, Japan International Cooperation Agency (JICA), and The International Society for Mangrove Ecosystem.
- Research Institute for Subtropics, A Summary of the Mangrove Study in Okinawa, 2000-2002, 2003, with CD-ROM.
- Tokyo Kaijo Kasai Hoken, Umino Mori Zukuri (Restoration of Coastal Forests) (Video) (in Japanese).