- Kerangas forest
Sundaland heath forest, also known as "Kerangas"
forest , is a type of tropical moist forest found on the island ofBorneo , which is divided betweenBrunei ,Indonesia , andMalaysia , as well as on the Indonesian islands ofBelitung and Bangka, which lie to the west of Borneo.etting
The word "Kerangas", which means "land which cannot grow rice", came from the
Iban language .Heath forest s occur on acidic sandy soils that are the result of the area's siliceous parent rocks. Permanently waterlogged heath forests are known as "kerapah" forests. The sandy soil of the heath forest are often lacking in nutrients; it is generally considered thatnitrogen is the nutrient which is most lacking for plant growth in these forests. This is in contrast to many other lowland rain forests wherephosphorus is considered to be lacking.A more recent hypothesis, proposed by Proctor (1999), is that these forests are growing on soils which are highly acidic, such that hydrogen ion toxicity prevents the growth of non-adapted species.
Flora
The Sundaland heath forests are distinct from the surrounding
Borneo lowland rain forests in species composition, structure, texture, and color. The heath forests have a low, uniform canopy, with thick underbrush and rich growth of moss andepiphyte s.Many tree and plant species in the nutrient-deprived heath forests have developed unconventional ways to get their nutrients. Some tree species ("
Gymnostoma nobile", for example) utiliserhizobia (nitrogen fixing bacteria ) in their root nodules.Myrmecophyte s, including "Myrmecodia " spp. and "Hydnophytum " spp., are tree species that develop symbiotic associations with ants to get their nutrients. Other plants, includingpitcher plant s "(Nepenthes " spp.),sundew s "(Drosera " ssp.), andbladderwort "(Utricularia" ssp.), are carnivorous, trapping and digesting insects.The heath forests are characterized by many plants of Australasian origin, including trees of families families
Myrtaceae andCasuarinaceae and the southern hemisphereconifer s "Agathis ", "Podocarpus ", and "Dacrydium ".References
*Proctor, J. (1999) "Heath forests and acid soils". "Botanical Journal of Scotland" 51, 1-14.
*Wikramanayake, Eric; Eric Dinerstein; Colby J. Loucks; et al. (2002). "Terrestrial Ecoregions of the Indo-Pacific: a Conservation Assessment." Island Press;Washington, DC .External links
* [http://www.worldwildlife.org/wildworld/profiles/terrestrial/im/im0161_full.html Sundaland heath forest (World Wildlife Fund)]
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