Why is Landscape Scale Research Important in Australia?
Understanding and managing Australian landscapes is a special challenge because of two key factors - variability and patchiness. Rainfall is highly variable and patchy, with frequent droughts lasting several seasons. South-east Australia has missed a whole year's worth of rain in the drought since 2002, while experiencing the hottest temperatures on record.
The continent covers such a large range of latitude and longitude that every type of climate can be found, from alpine to tropical to desert. The annual rainfall patterns show a major area in the middle of the continent which has average annual rainfall <400 mm, with most of the rain falling around the coasts and northern region. The four main factors that contribute to the dryness of the Australian landmass are the shape of the land mass, its lack of mountains, the dominance of high-pressure weather systems, and the effect of cold ocean currents close to the shoreline.
The European agricultural systems known by our immigrant forefathers are generally reliable and predictable especially in the temperate and humid environments of the northern hemisphere. Much of Europe relies on perennially flowing rivers and annual rainfall recharge of shallow groundwater reserves for water supplies. In contrast, Australia has highly variable and unreliable water supplies.
Australian ecosystems have developed a 'boom and bust' approach to recruitment, adapting to the highly variable cycles of flood and drought. The Australian population, on the other hand, wants regular and predictable supplies of food and water, creating conflicts between society's needs and Australia's highly evolved ecosystems. Managing this conflict is critical because the long term success of the economy is increasingly dependent on the provision of services from the environment such as basic food supplies, clean water, detoxification and fresh air.
The introduction of urban and agricultural development to our landscapes has led to significant problems which undermine the sustainability of ecosystem services. Loss of vegetation cover exposes soil to erosion, and diversions of water from rivers dries floodplains and river channels. Replacing perennial ever-green vegetation with short-lived annual crops alters water and salt balances, while changes in land management can reduce or increase run-off water and water quality.