Tropical Grasslands (2006) Volume 40, 1423
Pasture management in semi-arid tropical woodlands: effects on tree regrowth
JOHN G. McIVOR
CSIRO Sustainable Ecosystems, St Lucia, Queensland, Australia
The impact of pasture management on tree
regrowth (from seedlings and/or root suckers)
was measured from 1982 to 1992 at 'Hillgrove'
and 'Cardigan', near Charters Towers, north-east
Queensland. Oversowing introduced legumes and
grasses, applying superphosphate and cultivating
the soil before sowing had little impact. In contrast,
on plots where the trees were killed, the
number of stems, height and leaf area indices of
regrowth were much greater than on plots with
live trees. Heavy stocking rates (1 steer/ha) also
greatly reduced stem number and leaf area index
of regrowth but these stocking rates were not sustainable.
Clearing and killing trees can give large
herbage growth responses but the regrowth problems
reported here, and other potential negative
impacts, necessitate a cautious approach to
clearing and careful post-clearing management.