Environmental Engineering Reference
In-Depth Information
suited to wet, fertile landscapes. The large-scale clearing and change of
hydrological regimes have raised watertables and leached salt in the upper
layers of the soil. This has resulted in loss of native species, changes in eco-
system processes and the consequent land and water damage is well docu-
mented. Much of the degradation is the consequence of agro-ecosystems
that leak carbon, water, nutrients and sediments.
Since about 1985, Australian society, as reflected in the emergence of
Landcare and the conservation movement, decided it would no longer toler-
ate the land management styles that resulted in losses of biodiversity and
land and water degradation. We now allocate considerable, but inadequate,
resources to fixing the problems. In the past 15 years, Landcare and other
institutions have produced significant changes in the attitudes and activities
of land managers, industries and the community. Land managers, however,
must now shift their focus from treating the symptoms to treating the causes
of the degradation.
This will not be easy, because the solutions lie in a nationwide revolution
in land use. We need to build ecologically sustainable landscapes consisting
of a mosaic of commercial land uses that can capture this leakage of carbon,
water, nutrients and sediments and turn these into wealth-creating food and
fibre products. To create and shape such a future we need to move from pro-
ducing the familiar commodities to producing new products for new
markets that demand goods produced in environmentally benign ways. We
need commercial land uses that do not cause further species losses or
impacts on ecosystem processes including damage to land and water.
These new products and land uses will need to be coupled with native
ecosystems that provide a suite of ecosystem services (such as the production
of clean water, maintenance of fresh air, and conservation of healthy soils)
that are valued and paid for by stakeholders and beneficiaries, public and
private. This will require innovative and inclusive approaches that permit
fair comparison of market and non-market values. Developing the concept
of valuing and marketing ecosystem services as part of this process will be
increasingly important.
Discovering and building new land use practices that meet these essential
criteria require solutions to scientific and technical problems that are many,
complex and difficult. For example, the deficiencies in our scientific under-
standing of the ecology of the rehabilitation process in Australian ecosystems
