×

Species Details

Details of Black Mangrove will be displayed below

Black Mangrove   

Common Name: Black Mangrove, White-flowered Black Mangrove
Scientific Name: Lumnitzera racemosa
Local Name: Burevi
Dhivehi Name: ުބުރެވި
Plantae  (Kingdom)
Tracheophyta  (Plylum)
Magnoliopsida  (Class)
Myrtales  (Order)
Combretaceae  (Family)
Lumnitzera   (Genus)

Black Mangrove's description

Black mangrove is a much ramified shrub or evergreen tree, up to 8 m tall, even if, usually, it keeps lower, around the 2-4 m, with grey or reddish brown bark in the young branches, tending to blacken and to fissure with the age. It has simple, pale green, alternate and succulent leaves, grouped at the extremities of the branches, 4-7 cm long and 1-3 cm broad, obovate, oblanceolate or spatulate, with corrugated edges and rounded extremity with a small notch at the apex (“emarginated” leaf).

 

The inflorescences are axillar, long up to about 6 cm, usually carrying few hermaphrodite, perfumed flowers, with an about 1 cm long coralline tube, corolla with 5 petals each 5 mm long and of white colour and 5-10 stamina as long as the petals or little more.

 

The fruits are ovoid drupes slightly flattened laterally, fibrous, of blackish brown colour when ripe, 1-2 cm long and 6-8 mm broad, containing only one ovoid seed; the fruits can float and this facilitates their dispersion by means of the water.

 

Among the mangroves, it is one of the plants which better tolerate the highest rate of salinity in the soil, up to the 90 per mill after some researchers, but it stands also among the few bearing conditions of dry soil and therefore is capable to diffuse in environments differing from the typical ones of the mangroves; this versatility makes it a potential infester in the tropical and subtropical areas.

 

It is found on the eastern coast of Africa and other places in the western Indo-Pacific region.

 

Occurrence in Maldives: Mangroves areas of the Maldives.

Black Mangrove's Behavior & Ecology

It prefers relatively less moist, well drained, sandy soil mixed with clay for better performance. It also prefers relatively higher ground level than other mangrove plants. It is a non-viviparous mangrove species and seeds are similar to terrestrial plants. It is normally propagated by nursery-raised seedlings and wildlings. Mature fruits are brown in colour and can be easily collected from trees or gathered from ground. Fruits are normally used for planting instead of seeds. Fruits are sown in a slanting position in containers, keeping half of the fruit inside the mud. Fruits should be stored in wet condition for three to five days before sowing. Germination rate decreases with increasing salinity and no germination will be seen if the salinity increases beyond 25 ppt. Nursery-raised seedlings 20 to 30 cm, which can be obtained within a period of ten months, can be used for out planting.

Black Mangrove's Conservation

Mangroves in general are under threat from coastal development, and this species, which grows on the landward edge of the mangrove area, may be more threatened by rising sea levels than are other species because it may be unable to move further inland. There may be a decline in populations of this species due to habitat loss or harvesting, but it is a common species of mangrove with a very wide range, and is not declining at a sufficient rate to be included in any threatened category, so it is listed by the International Union for Conservation of Nature as being of "least concern".

Black Mangrove's Relationship with Humans

In its original locations, the wood of black mangrove, due to its resistance and duration, is utilized as structural material in constructions, as sleepers, fences, boats, etc.; moreover, it is excellent firewood.

 

Fluid substance made from incisions in the stem, mixed with coconut oil, used as anti-herpetic and as cure of itches.

Black Mangrove habitat

This back mangrove species is found most often in the upstream zones in the mid to high intertidal region. It can also be found along sandy beaches. It is a colonising species and grows relatively quickly, and is shade intolerant with a maximum porewater salinity of 78 ppt (Robertson and Alongi 1992).

Black Mangrove threats

This species is particularly sensitive to siltation from upstream, land use changes, and erosion. Although local estimates are uncertain due to differing legislative definitions of what is a 'mangrove' and to the imprecision in determining mangrove area, current consensus estimates of mangrove loss in the last quarter-century report an approximately 19% decline in mangrove areas in countries within this species range since 1980 (FAO 2007).

Sea level rise is a major threat, especially to back mangroves that have no area in which to expand. Mangrove species with a habitat on the landward margin may be particularly vulnerable to sea-level rise if owing to coastal development their movement inland is blocked. Species that occur at the landward edge, or upstream in tidal estuaries include Nypa fruticans, Heritiera littoralis, Xylocarpus granatum, Lumnitzera racemosa, Lumnitzera littorea, Sonneratia caseolaris, Sonneratia lanceolata, and Bruguiera sexangula.

All mangrove ecosystems occur within mean sea level and high tidal elevations, and have distinct species zonations that are controlled by the elevation of the substrate relative to mean sea level. This is because of associated variation in frequency of elevation, salinity and wave action (Duke et al. 1998). With rise in sea-level, the habitat requirements of each species will be disrupted, and species zones will suffer mortality at their present locations and re-establish at higher elevations in areas that were previously landward zones (Ellison 2005). If sea-level rise is a continued trend over this century, then there will be continued mortality and re-establishment of species zones. However, species that are easily dispersed and fast growing/fast producing will cope better than those which are slower growing and slower to reproduce.

In addition, mangrove area is declining globally due to a number of localized threats. The main threat is habitat destruction and removal of mangrove areas. Reasons for removal include cleared for shrimp farms, agriculture, fish ponds, rice production and salt pans, and for the development of urban and industrial areas, road construction, coconut plantations, ports, airports, and tourist resorts. Other threats include pollution from sewage effluents, solid wastes, siltation, oil, and agricultural and urban runoff. Climate change is also thought to be a threat, particularly at the edges of a species range. Natural threats include cyclones, hurricane and tsunamis.

Black Mangrove's status