The Groundcover target in the Reef Water Quality Protection Plan 2009 (Reef Plan) was: “A minimum of 50 per cent late dry season groundcover on dry tropical grazing land by 2013.”
The groundcover target was consistently exceeded throughout the five years of Reef Plan 2009 with mean groundcover levels for the Great Barrier Reef catchment area above 80 per cent in all years. Annual rainfall was consistently above average during this time which contributed significantly to the growth and maintenance of groundcover on grazing lands.
It is important to note that averaging groundcover across whole catchments can mask localised areas of lower cover, particularly in large catchments with a strong rainfall gradient (e.g. Burdekin or Fitzroy). Mean groundcover is, therefore, indicative of general levels of cover within the reporting catchment. It is important to consider the spatial distribution of cover when accounting for its impact on sediment generation. Future reporting will focus on improved ways of representing spatial and temporal variability in groundcover.
Recent studies have shown that subsurface processes such as gullying and streambank erosion contribute large proportions of the sediment measured in the reef’s receiving waters. However, maintaining groundcover is still extremely important for reducing hillslope erosion, slowing runoff and increasing infiltration and water storage in the catchment areas of gullies and streambanks.
- Great Barrier Reef-wide
- Wet Tropics (Herbert catchment only)
- Mackay Whitsunday
- Burnett Mary