Abstract:
Studies were carried out (Laboratory and field) during the dry and wet seasons of 2010 and 2011
at the Akanga Forest planted with Teak (Tectona grandis) for the production of timber and poles.
The area prior to use was an undisturbed forest and planting was carried out from 1966 at an
annual interval to the year 1982.The intent of these experiments was to compare the changes in
chemical properties of soils at the different age series and to determine the influence of passage
of seasons on these properties. Soil samples were collected from three plantation age series
1979, 1980, 1981 and control. The samples were analysed using standard procedures .pH
decreased under the plantations and was higher in the dry season. Exchangeable cations recorded
higher values under the older age series and were higher in the teak plantations as compared to
the natural forests (control). This study showed that rainfall seasons have great effect on the
parameters studied .It was concluded that monoculture teak plantations may lead to soil
deterioration and consequent reduction in site quality. Monitoring of fast growing exotic
monoculture species of younger ages in order to determine the trend of nutrient reduction and the
gradual nutrient build-up with increasing plantation age is required.Thus, for a plantation site to
be sustainable, there should be no significant negative changes in soil physical, chemical, or
biological conditions . In managed forests, the inherent site potential is largely determined by
soil characteristics and climatic factors |
