Overview

 

Map of Australian Savannas (shaded area) [source:savanna.cdu.edu]

Historically prized for its massive open plains and incredible ecological diversity, the Australia Savanna is one of the few remaining on the entire Planet.  A part of the island covering more then 247 million acres, the Savanna of Northern Australia is know for its historically diverse ecosystem, containing 460 bird species, 110 mammals, and 225 freshwater fish. (The Nature Conservancy)  Some of the more notable Savanna dwellers include the Emu, and the Koala Bear. Many animals that once found shelter in the Savanna are being killed.  These animals have historically found their homes across the Savanna, but as of late many have become endangered due to the huge increase of human interaction and the development of both the farming and mining industries.  The Emu has recently come under attach from Farmers defending their crops, while others like the Koala are being killed in fires that have become an unnatural aspect of the Savanna. (Blue Planet)

Not only does it have a complex and diverse ecosystem, the Savanna is also home to a majority of Australia’s indigenous Aboriginal population who have deep historical roots to the region.  The Aboriginal peoples were the first people to begin cultivating the Savanna for the Pastoral, also known as ranching, and Mining Industries. (Savanna Explorer)  Over the 40,000 years that the Aboriginals have been rising live stock and mining the Savanna, sustainability was well maintained and the impacts on the environment were almost non-existent; however, more recently with the increase in foreign ranching and mining, the Savanna is in more danger then ever before of being greatly reduced. (The Nature Conservancy)  Many animals that once found shelter in the Savanna are being killed.  Farmers defending their crops are one cuprite, while others like the Koala are being killed in fires that have become an unnatural aspect of the Savanna.

Both indigenous peoples and animals of the Savanna that have once called the vast territory of Australia their home are steadily losing their ground.  The Savanna is under great pressure from the increasing population and the ever-growing threat of over industrialization.  From the death of innocent animals leading to higher rates of extinction, to the abusive tendencies of modern industry on the land and its inhabitants, Australia’s Savanna region is nearing a critical point in its preservation. 

Australian savanna [source:savanna.org]

Victoria River passing through the Northern savannas [source:nature.org]

Current Human Impact

Human impact on this ecosystem is generally good. We use the savannas of Australia for agriculture and ranching (Hurst 16441). Beef and wool are produced here with the use of the pastoral land (Burrows 503). The ecosystem is affected by the process of this production. Fires that occur here are often created by humans to “reduce the bulk of nutritionally poor herbage, and to stimulate the growth of higher protein grass shoots” (Holt 430). Although much of this bioregion is used as pastures, the burning and grazing of the lands don’t seem to have a great negative effect on this area. Studies have shown a strong correlation between grazing in this bioregion and the increase of plant and invertebrate species (Ludwig). The constant grazing of the lands prevents species from dominating the area. The change of the landscape promotes diversity in species that grow and live there. Fires aren’t inherently threatening to this ecosystem because it is essential to its existence. Fires are a natural occurrence in savannas and other grasslands. Without fire, or the suppression of fire, would allow scrubs and trees to grow and take over the area, turning the savanna into a scrubland. The vegetation that survives and populate the Australian savannas are adapted to fire. Grasses here are burned by fire but their roots survive underground. The fast growth rate of grasses keeps vegetation in the area at a healthy level, enough to sustain our use of the ecoregion as pastures. The soils of Australian savannas are generally poor in nutrients; however, fire is used to help the weak soil fuel the life of this ecosystem. By burning the biomass in the area, we are speeding up the process of the nutrient cycle. Nutrients are in the vegetation and are released by the burning of the vegetation. They nutrients then decompose in the soil, allowing rich vegetation to regrow in that area (Holt 430).

Grazing and fires have a great influence on the species which inhabit the area “As habitat heterogeneity shifted with the imposition of grazing on typical fire pattern, so too did the relative abundance of some species, and to the detriment or advantage of species tolerant or vulnerable to the shifting habitat states” (Kutt 104). So the species adaptation to fires dictate what will succeed the area. The variation of vertebrate species changes in the savannas, but this is not necessarily a bad thing because although species which aren’t well adapted to fire become less abundant in the area, other species which are adapted to fire will still grow and live there. One type of species is succeeding the less adaptive ones so there is still a healthy diversity of life in the savannas.

Fire history 1997-2003 [source:savanna.org]