| |
|---|---|
 (317Kb)
|
30,531,000 Yen (FY1995 9,689,000 Yen)
Decomposition processes of wood and leaf litter were investigated as a source of nutrients for tree growth in lowland rain forests of penninsular Malaysia. By trapping plant litter in the forest for a few years, seasonal dynamics of plant litter supply to the decomposition process on forest floors were revealed. Amount of soil organic matter was also measured to estimate the amount of litter decomposed. The plant litter supply was almost doubled, but the amount of soil organic matter was low compared with temperate forests. So, the amount decomposed annualy was estimated to be twice as those of temperate forests. It is concluded that abundant supply and rapid decomposition of plant litter is a characteristic of tropical forest ecosystem.
Termites were predominant among soil animals involved in decomposition. On the other hand, collembolans, one of the minor fauna, reflected high activity of decomposing fungi in that they were composed of many fungivores. Termites involved in wood decay were mostly composed of those of Mactotermitinae. Previous studies also show that this group of termites play an important role in leaf-litter decay. It is suggested that they are worth focusing on in the study of decomposition process.
It was revealed that the degree of acceleration by termites in plant litter decomposition would amount to eight times. The immobilization phase of decomposition where nitrogen release is suppressed by fungal growth was terminated earlier in tropical forests compared with in temperate forests. It was also revealed that this earlier mobilization is due to the activity of termites. These findings suggest that termites play an important role in the decomposition process, without which soil formation would be retarded.
Decomposition, Plant litter, Termite, Soil formation