Runoff and the ameliorating effect of plant cover in the Mulga communities of South Western Queensland.

Level 1 General description


To determine how the frequency of runoff in mulga country varies with the quantity of rain, vegetation and topography.

Methods (brief)

Surface runoff was monitored in relation to a range of surface management practices, including:

  • Varying %  vegetation cover; and
  • Varying vegetation species.

Key findings (brief)

  • Runoff was positively correlated with soil bulk density, fine sand % and slope %. Runoff was negatively correlated with dry matter, litter other than wood, dry matter + other litter, dry matter + wood, basal area %, and the course sand fraction of the soil.
  • Plant tussock greatly decreased the number of runoff events;
  • Runoff greater in hard mulga and residue land zones than in the soft mulga zone; and
  • Perennial grass basal area > 2% is considered essential to reduce the loss of surface soil and nutrients.
  • Threshold values of runoff varied widely. Runoff was first noticed following 9.9 ± 1.1 mm of rain, but varied between 4.4 mm and 22.8 mm.


Mulga rangeland, Southwest QLD

Related studies



Level 2, level 3, level 4 and level 5