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Degradation of
the soil physicochemical properties resulting from
continuous logging of Gmelina arborea and Tectona
grandis plantations
O. O Awotoye1*, O. Ekanade2 and O. O.
Airouhudion1
1Institute
of Ecology and Environmental Studies, Obafemi Awolowo
University, Ile-Ife, Nigeria.
˛Department of Geography, Obafemi Awolowo University,
Ile-Ife, Nigeria.
*Corresponding author. E-mail:
segunawotoye@yahoo.co.uk.
Accepted 3 August, 2009 |
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This study assessed the changes in soil properties in
sites subjected to continuous logging in exotics plantation
sites of Gmelina arborea and Tectona grandis
with the aim to evaluate the deterioration level of the soil
productivity in respect to human disturbance. Thirty five
sampling plots, each measuring 40 m x 25 m were used for
soil sampling. Standard field and laboratory methods were
employed in the collection of data for 18 soil
characteristics (sand, silt, clay, water holding capacity,
electrical conductivity, bulk density, total porosity, pH,
organic matter , total nitrogen, available phosphorus,
exchangeable calcium, magnesium, potassium, sodium,
exchangeable acidity, cation exchange capacity and base
saturation) at depths of 0 - 15 cm and 15 - 30 cm. The
results indicated that values of soil and plant parameters
decreased with length of continuous logging (1, 5 and 10
years respectively). The soil deterioration indices of the
logged plots showed high deterioration of all the soil
properties except electrical conductivity, bulk density
exchangeable acidity and in exchangeable sodium, percent
silt and sand at both levels of soil depths. The two exotic
species were impacted differently on the soil properties on
the study area as a result of adverse logging. If these
plots area are left to fallow for a considerable period of
time, the lost soil nutrients may be replaced.
Key words:
Deterioration level, soil productivity, textural properties,
electrical conductivity, Gmelina species, Tectona
species, continuous logging and sustainable productivity. |
