Five experiments were conducted to determine the impacts
of ground-based logging machines on soil physical properties
and on early gr01vth of Acacia mangium Willd. The experiments
are : (i) a survey of the areal extent of logging machine
disturbance, (ii) effects of logging machines on soil physical
properties, (iii) effects of travelling intensity with a
rubber-tired and track-type logging machine on some soil
physical properties, (iv) recovery rate of compacted soils, and
(v) measurement of growth responses of A. mangium on compacted
and non-compacted soils and their loosening treatments.
Areal disturbance on 10 logging blocks following logging
with crawler t ractors averaged 30(18), 28(27), and 42(55)
percent in 'undisturbed', 'moderate', and 'serious' class of
disturbance on clay loam soils in the dry (wet) season,
respectively. For sandy loam soils under dry (wet) season, the
areal extent of logging disturbance were 16(27), 44(22), and
40(48) percent, respectively. Average values for to
penetration, and soil temperature of prelogging soils, adjacent
undisturbed soil, secondary forest roads, secondary landings,
primary landings and skid trails were also determined
