Origin and Nature of Tropical Peat
Posted by dedenia72 on August 13, 2009
Peat in wet tropical regions (including Indonesia) formed from the woods of tropical rain forest trees. The peat, therefore, is not composed of only fine organic debris but also contains a significantly large amount of coarse woody material from roots, branches and trunks of trees, which have decayed by different degrees. Tropical peat does not form a continuous and compact mass but consists of different sizes of organic material with different sizes of voids or holes.
BD (Bulk Density) values at tropical peat (especially in Indonesia) are about 0.1 to 0.02 g/cc. This values got from new methods of BD measurement for tropical peat. This methods using larger ring sampler than ring sampler which used to for mineral soils. For result, the values from new methods is smaller than values from usual ring sampler. In addition, BD of tropical peat cannot be considered homogeneous throughout the depth; therefore it would be very difficult to get a single representing value, especially for thick peat of, for example thicker than 5 m, that is common for tropical peat. An additional measurement of BD, by calculating auger column volume and weight of the samples of depthwise boring, could contribute data of deeper layers that are too difficult to be taken by box sampler.
Apart from the characteristics of the peat material itself, the type of sediment underlying the peat layer is also of great important and should be considered. One big caution that should not be ignored is related to the presence of peat that has developed in a mangrove environment. Reclamation of this peat should carefully consider the depth of the mangrove sediment beneath the peat layer. It is well known that mangrove sediment have potential to produced pirit (FeS2). Exposing the mangrove sediment will be followed by development of acid sulphate soils, and once this stage is reached it will be very difficult to be overcome.