Suarez baobab (Adansonia suarezensis)
|Also known as:||Bozy|
|Size||Height: up to 25 m (2)|
Classified as Endangered (EN) on the IUCN Red List (1).
The bizarre and impressive baobabs are instantly recognisable with their massive, smooth trunks and compact, almost comical crowns, resembling exposed roots more than branches (2) (3). Eight species comprise this genus of deciduous trees, and the Suarez baobab is one of six endemic to the ecologically rich island of Madagascar (3). The Suarez baobab has a tall, cylindrical greyish-brown trunk with a yellowish-green photosynthetic layer faintly visible underneath the outer bark (2). Its short, thick branches are held horizontally in a flat-topped crown, and its leaves are yellowish-green and palmate (2) (3). During the leafless dry season, the tree produces large, sour smelling, white flowers, followed by large, elongated fruit (weighing up to 1 kilogram) that stay attached to the bare crown for up to four months (2) (3).
The Suarez baobab is restricted to the north of Madagascar, around the Baie d'Antsiranana and in Mahory Forest between the Ankarana and Analamera Reserves (1).
Typically occurs in deciduous forests on limestone, but young trees will also grow in disturbed coastal scrub (1) (2).
In April, at the end of the wet season, the Suarez baobab drops its leaves in preparation for flowering. The ephemeral flowers open an hour before dusk, from late May through to September and are reproductively receptive for only a single night, usually withering and falling from the branch within 24 hours of opening (2) (4). In addition to being large, pale and strong smelling, the flowers produce copious nectar during the night. While moths, bees and sunbirds have all been observed visiting the flowers, none are large enough to consistently make crucial contact with the stigma whilst accessing the available nectar. Instead, it is the fruit bat, Eidolon dupraenum, by virtue of its size, that is the primary pollinator of the Suarez baobab (3) (4). Following flowering, the fruit develop over an extended period, eventually becoming ripe in November. Whilst the fruit, which contain a nutritious pulp around numerous seeds, would be a rich reward for foraging animals, there are no known Madagascan animals that disperse the seed of the Suarez baobab, or indeed any Madagascan baobab (2). There is some speculation that several animal species that became extinct during human colonisation of Madagascar, such as two baboon-like primates and the enormous elephant bird, may have been original dispersers of baobab seed (2) (3). Needless to say, eventually the fruit fall from the crown, and when the first rains come, heralding the beginning of the wet season, the new leaves emerge (2).
While there are no extant wild animals that appear particularly partial to the nutritious pulp of the Suarez baobab fruit, humans have for a long time harvested the fruit as a source of food (5). Excessive harvesting of fruit is just one explanation, along with increased predation by burgeoning wild pig and rat populations and the absence of seed dispersal agents, for the lack of regeneration at all but one locality (2) (5). Unfortunately, all the localities where the Suarez baobab is found are being rapidly degraded by deforestation for timber, firewood and charcoal, including the only remaining regenerating population, which is under increasing threat from a growing mining town (5).
Despite being one of the most endangered of Madagascan baobabs, the Suarez baobab is the only species that is not protected within a reserve (5). In recent years, the Madagascan government has pledged to triple the size of protected areas within the country, including increasing the amount of forest under protection by five million hectares (6). It is hoped that this initiative will see the endangered Suarez baobab finally come under the formal protection it so desperately needs (7).
For further information on the Suarez baobab and conservation in Madagascar see:
- Wickens, G.E. (2008) The Baobabs: The Pachycauls of Africa, Madagascar and Australia. Springer, London.
Authenticated (23/02/09) by Professor David Baum, Department of Botany, University of Wisconsin.
- Deciduous: a plant that sheds its leaves at the end of the growing season.
- Endemic: a species or taxonomic group that is only found in one particular country or geographic area.
- Palmate: having three or more veins, leaflets or lobes radiating from one point; like the palm of a hand with outstretched fingers.
- Photosynthetic: plant tissue capable of photosynthesis; the metabolic process in which carbon dioxide is broken down, using energy from sunlight absorbed by the green pigment chlorophyll. Organic compounds are made and oxygen is given off as a by-product.
- Pollinator: animal that in the act of visiting a plant’s flowers transfer pollen grains from the stamen (male part of a flower) to the stigma (female part of a flower) of a flowering plant. This usually leads to fertilisation, the development of seeds and, eventually, a new plant
- Stigma: the receptive part of the female reproductive organ of a flower. Pollen germinates on the stigma.
IUCN Red List (December, 2009)