Environmental Engineering Reference
In-Depth Information
deteriorating soil quality caused by depletion of nutrients,
acidification, and structural and biological decline
dryland and irrigation salinisation of rivers and land
water and wind erosion
changes in riverine processes and loss of essential environmental
flows
movement of nutrients, salts and pollutants to rivers, wetlands and
water bodies
contamination of groundwater with nutrients, salt and pollutants,
and
contamination of land with residues of agricultural chemicals.
The scale and some of the effects of different forms of degradation are
summarised in Table 5.1.
The effects of degradation are enduring, not easily reversed, and are
becoming increasingly expensive to correct. Such damage has:
reduced the productive capacity of lands (although in some areas
productive capacity has increased)
adversely affected biological diversity and water quality
put agricultural trade at risk through contamination and failure to
demonstrate production systems that do not damage the
environment, and
threatened human health.
If we fail to build sustainable farming systems in an integrated, inclusive
and adaptive way, we will see further losses of biodiversity and changes in
ecosystem processes, resulting in more land and water degradation and the
cessation of agricultural production in the worst affected areas.
How conserving native vegetation can prevent land and water
degradation
Arguably, Australia's most serious environmental problem is the loss of biodi-
versity - plants, animals, micro-organisms, the genes they contain, the ecosys-
tems of which they form part and the interactions between these life forms and
the environment. The most severe losses are in Australia's agricultural zones.
In many areas within these zones, less than 10 per cent of the original vegeta-
tion remains, with the cleared areas used for agricultural production. This
Search WWH ::




Custom Search