The effects of selective logging on streamwater quality
and solute budget s were investigated using three small
catchments: C1, C2 and C3. After a three-year calibration
period,Cl and C3 were logged using" unsupervised" and
"supervised" logging methods respectively, whereas C2 was left
as control. Several control measures were imposed in the
supervised C3 but none in the unsupervised C1.
During the calibration period the levels for most of the
streamwater quality parameters measured were within the
standards for potable water. The exceptions were colour,
turbidity and iron.Significant increases in pH, specific
electrical conductivity, hardness, suspended solids,
alkalinity, turbidity, dissolved solids, silicate, calcium,
iron,and sodium were recorded in the unsupervised C1. The
levels for colour and nitrate were also elevated initially but recovered to background values within a year. In contrast, in
the supervised C3, significant changes were detected only for
hardness, magnesium and iron. The impact of logging was
enhanced during the wet months especially for suspended solids,
turbidity and iron
