Mangrove forests, dominated by stands of Bruguiera gymnorrhiza, typically occur in protected coastal bays and estuaries where fresh waters enter the ocean. These habitats are inundated by saline or brackish water at high tide and are often flooded by fresh water. The closed canopy allows only Bruguiera sp. seedlings in the understory, but the swamp fern Acrostichum aureum and trees of the species Rhizophora samoensis occupy openings. Often fronting mangrove forest is a mangrove scrub community dominated by small to medium-sized trees of Rhizophora samoensis. Where Rhizophora sp. competes with the larger Bruguiera gymnorrhiza, the former is shaded out. Mangrove scrub is found, particularly, on the south-central coast of Tutuila.
Cole, T.G., Whitesell, C.D., Whistler, W.A., McKay, N. & Ambacher, A.H. 1988. Vegetation survey and forest inventory, American Samoa. Pac. Southwest Forest and Range Exp. Sta. Resource Bull. USDA Forest Service, Berkeley, CA.
Mueller-Dombois, D. & F. R. Fosberg. 1998. Vegetation of the tropical Pacific islands. Springer-Verlag, New York. 733 pp.
Year |
Area |
Source |
Trend |
Methodology/Comments |
1976 |
52 |
Whistler, A.W. 1976. Inventory and Mapping of Wetland Vegetation in the Territory of American Samoa. U.S. Army Corps of Engineers. Fort Shafter, Hawaii. 94 pp. |
X |
Aerial photos. Scale 1:10 000. Cited in: Idechong, N., Ellison, J. and R. Jaensch. 1995. Regional Wetlands Action Plan for the Pacific Islands. (Draft prepared for SPREP). |
No significant changes appear to have occurred in the mangrove area extent over the last twenty years. Estimates for 1980, 1990 and 2000 have been slightly rounded.
