Black Mangrove

Taxonomy
Scientific Name
Bruguiera gymnorrhiza (L.) Lam.
Higher Classification
Dicotyledons
Family
RHIZOPHORACEAE
Common Names
Black Mangrove (e), Cigar-tree (e), Mangrove (e), Red Mangrove (e), Seebasboom (a)
National Status
Status and Criteria
Least Concern
Assessment Date
2016/06/02
Assessor(s)
J. Adams, A. Rajkaran & D. van der Colff
Justification
A widespread and common species, in spite of ongoing habitat loss and degradation. It is able to regenerate after disturbance, mitigating some population decline, and it is therefore not considered to be in danger of extinction.
Distribution
Endemism
Not endemic to South Africa
Provincial distribution
Eastern Cape, KwaZulu-Natal
Range
Widespread along the east coast of South Africa from the Nahoon to Kosi Bay. It is also globally widespread along the western shores of the Pacific Ocean, Ryukyu Islands, Micronesia, Australia, Polynesia and in the Indian Ocean and along the East African shores from South Africa to Ethiopia.
Habitat and Ecology
Major system
Terrestrial
Major habitats
Albany Thicket, Indian Ocean Coastal Belt
Description
Evergreen woodlands and thickets along the intertidal mud-flats of sheltered shores, estuaries and inlets, mainly towards the seaward side of mangrove formation.
Threats
Habitat loss and degradation as a result of urban and industrial development, and road and airport construction in coastal areas are the most severe threats to this species. Ten mangrove forests have been lost due to bridge construction, which led to such severe downstream habitat degradation that the mangroves could not persist. Since these forests occur in very low densities, it is more vulnerable to these extreme changes in habitat condition (Ward and Steinke, 1982). Canalization of rivers lead to changes in flow regimes as well as siltation, which has resulted in mangrove swamps becoming inundated, causing tree death. Mhlangakulu estuary experienced a flood event in 1977, and in a 2006 survey no mangrove species were detected (Rajkaran 2011). When conditions return to normal, mangroves are however able to recolonise formerly occupied sites, and some of the forests previously lost to inundation have recovered. Wood harvesting has been recorded in the Isipingo estuary as well of some other nearby estuaries, which may lead to long term population decline if harvesting is not managed sustainably. Invasive alien plants are also impacting in some estuaries where they compete with mangrove species for space.
Population
Population trend
Stable
Assessment History
Taxon assessed
Status and Criteria
Citation/Red List version
Bruguiera gymnorrhiza (L.) Lam.Least Concern Raimondo et al. (2009)
Bruguiera gymnorrhiza (L.) Lam.Lower Risk - Conservation Dependent Scott-Shaw (1999)
Bibliography

Adams, J., Colloty, B. and Bate, G. 2004. The distribution and state of mangroves along the coast of Transkei, Eastern Cape Province, South Africa. Wetlands Ecology and Management 12(5):531-541.


Adams, J.B., Veldkornet, D. and Tabot, P. In press. Distribution of macrophyte species and habitats in South African estuaries. South African Journal of Botany.


Boon, R. 2010. Pooley's Trees of eastern South Africa. Flora and Fauna Publications Trust, Durban.


Hoppe-Speer, S.C., Adams, J.B. and Rajkaran, A. 2015. Mangrove expansion and population structure at a planted site, East London, South Africa. Southern Forests: a Journal of Forest Science 77(2):131-139.


Raimondo, D., von Staden, L., Foden, W., Victor, J.E., Helme, N.A., Turner, R.C., Kamundi, D.A. and Manyama, P.A. 2009. Red List of South African Plants. Strelitzia 25. South African National Biodiversity Institute, Pretoria.


Rajkaran, A. 2011. A status assessment of mangrove forests in South Africa and the utilization of mangroves at Mngazana Estuary. Unpublished Ph.D., Nelson Mandela Metropolitan University, Port Elizabeth.


Scott-Shaw, C.R. 1999. Rare and threatened plants of KwaZulu-Natal and neighbouring regions. KwaZulu-Natal Nature Conservation Service, Pietermaritzburg.


Torre, A.R. and Goncalves, A.E. 1978. Rhizophoraceae. In: E. Launert (ed). Flora Zambesiaca 4:81-99. Flora Zambesiaca Managing Committee, London.


Ward, C. and Steinke, T.D. 1982. A note on the distribution and approximate areas of mangroves in South Africa. South African Journal of Botany 1(3):51-53.


Citation
Adams, J., Rajkaran, A. & van der Colff, D. 2016. Bruguiera gymnorrhiza (L.) Lam. National Assessment: Red List of South African Plants version 2017.1. Accessed on 2019/03/21

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Distribution map


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