Riparian vegetation and in-stream vegetation

Although shrubby vegetation along the reach is generally in good condition, riparian woodlands have been impacted by fire and land use. Riparian areas are generally also threatened by weeds, feral animals, overgrazing and bank disturbance, reduced occurrence of floods, and clearing. In-stream vegetation has been significantly affected by sediment deposition and sand slugs, as well as erosion, livestock access, altered flow regimes, reduced river flow, clearing, weeds and infrastructure.

Of the four dominant riparian associations, two are reduced or under pressure:

  • Vigor of the She-oak Tableland Riparian Woodland has decreased due to fires and low soil moisture with altered river flows.
  • Ribbon Gum Tableland Riparian Woodland once found on the alluvial floodplain terraces is now locally depleted;

A recent study showed that less than 10% of the likely original distribution of Ribbon Gum (E. viminalis ) woodland along the river remains and is in need of protection and rehabilitation.

Plants found in wet and moist areas of the gorges and the River Bottlebrush-Burgan Tableland Riparian Shrubland (Johnston et al, 2009) are in better condition. However the high level of weeds and lack of overbank flooding in riparian areas is a problem for recruitment of future generations of riparian vegetation communities. The river corridor is also a conduit for the downstream spread of weeds.