Understanding River Landscapes

Naturally Forested Headwaters

Headwater streams across much of humid Australia are the common, small narrow streams that collect much of the runoff and feed it into the larger creeks and rivers. They are found throughout catchments, in the uplands around the edges of a catchment and along the lowlands, plains, and coast. They are naturally forested and wooded, but in cases where the vegetation has been cleared, they tend be highly degraded. The impact of agriculture and pastoral activities on headwater streams is significant, with only a few examples of these streams remaining intact in National Parks and other State Reserves. In situations where vegetation is cleared, the form of the river is fundamentally changed (bed and banks), as is the wildlife it supports and the balance of the processes controlling it. The diagram below explains some of the key processes at work in these streams and how the removal of vegetation significantly impacts upon river functioning:

See also Rivers as Ecological Systems Chapter 2.