Savannas, a main terrestrial biome comprises of a dynamic mix of trees and grasses that encompasses open woodlands and grassland. Savannas are frequently seen as a transitional zone, between forest regions and desert regions and are also much threatened regions around the world.
Yet the last great pristine wilderness zones, covering an area larger than Western Europe can be found in Northern Australia and it might face degradation due to climate change induced drought that has hit Australian farmers hard.
The country’s tropics, stretching 2,000 kilometers (1,250 miles) across the continent, account for more than a quarter of the world’s remaining savanna after the decline of grasslands that once spread over South America, Africa and Asia.
Australia’s northern rivers and forests remained largely untouched by small Aboriginal communities amidst World Heritage-listed parks. Their importance can be judged from the fact that of scientists from the WildCountry Science Council have ranked them with Antarctica and South America’s Amazon rainforests in environmental importance.
Threats to savannas around the world
The trees in these regions are sufficiently small or widely spaced so that the canopy does not close characterize savannas. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of C4 grasses. These grasses are commonly used for grazing domestic livestock. As a result, much of the world’s savannas have undergone substantial change and degradation because of grazing by sheep, goats and cattle, ranging form changes in pasture composition to woody weed encroachment and severe soil erosion.
Next threat is felling the spaced out trees, for wood or to increase pastureland, which totally changes the ecology of the region. Artificial clearing, particularly pulling, mimics the effects of fire, and we all know the disastrous effects of fire on savanna.
The introduction of invasive plant species have altered the structure and composition of savannas worldwide. Greenhouse induced climate change is also said to have been responsible for woody encroachments on savanna forests.
Australia is suffering the worst drought in 1000 years. Relentless droughts, shortage of drinking water, crop failures and agitated farmers have made headlines though out the year. No, wonder a government-ordered inquiry into whether Australian farmers should consider moving from the drought-hit south to the more fragile north to take advantage of heavy seasonal monsoon rains for crop growing, has come up.
The countries savannas will be able to sustain some economic development, but once started, human greed for short-term benefits knows no end. Exploiting a part of this region might trigger the path to its deterioration.
The Intergovernmental Panel on Climate Change predicted dire consequences for Australia: Water inflows to the Murray-Darling river basin, Australia’s main agricultural region, are likely to fall by 10 and 25 percent by 2050, Barrier Reef of Australia would become ‘functionally extinct, ‘ Snow would disappear from Australia’s southeast alps. Keeping that in mind it should move very cautiously in terms of trying to exploit its great savanna.
Source: Reuters
