Land Impacts On Flora example essay topic

ABSTRACT Environmental impact is clearly evident in Australia. By using the concept of an ecosystem, the term environment is defined as being composed of six interconnected areas. Although Aboriginals modified their landscape, particularly through their use of fire, the impacts they made did not substantially damage the environment. In contrast, the white settlers quite deliberately set out to tame, civilize, and exploit the land. The native flora was affected by clearing, grazing, and introduction of foreign plants.

Likewise, the fauna has had serious competition from introduced animals. Over half of Australia's wetlands have been destroyed in various ways, and our seas also fail to escape human impact. The land itself suffers from erosion, salinity, and desertification, as well as considerable change in the terrain. Industrial centres and the nation's cars affect the atmosphere. Each of these issues are closely inter-related. The seriousness of the impacts of 207 years of white settlement make it clear that the supporting ideologies are no longer sustainable.

INTRODUCTION "In the last one hundred years man has reshaped the earth more than he did in all the preceding generations, and today he changes land, sea and sky more rapidly and radically than he ever did in the past. The sheer scale of our present impact on the environment confronts us... ". 1 Indeed it does! And here in Australia no less than elsewhere. In fact David Attenborough estimates that eighty percent of Australia has been damaged since white settlement.

2 What have been the actions and ideologies behind the environmental impacts? What have the impacts been? Can the Australian environment continue to sustain the impacts? In answering the first question Aboriginal and white environmental ideologies are discussed; to illustrate the different land management approaches; to provide a baseline for the state of the environment before settlement; and to understand why the settlers interacted with the Australian environment as they did. The various impacts made upon the environment are then looked at to cover the second question. Finally, relationships between the topics, and implications for the environment's future, are mentioned.

Prior to discussing these issues it is necessary to define what is meant by the term environment. DEFINITIONS A general definition of environment is, "conditions under which any person or thing lives or is developed; the sum total of the influences which modify and determine the development of life or character". 3 Environment is also equated with 'surroundings'. It is possible to have a variety of environments, political, social, economic, etc.

But the one that comes most readily to mind is the physical environment. A definition of the physical environment is encompassed well by describing an ecosystem. An ecosystem is all of "the organisms that comprise a community and the physical environment [surroundings] with which they interact - including soil, water, atmosphere, terrain, etc"4 All components of the environment are interdependent, no one component of the system can experience change or human impact without far-reaching effects. For the purposes of this essay, environment, will be defined as a complex interaction of: flora; fauna; wetlands (including rivers, lakes, underground water, etc) and oceans; land; and atmosphere. ABORIGINAL IDEOLOGY Aboriginals have been living in Australia for at least 60,000 years, and not surprisingly have a thorough understanding of the world they live in. In Bell's words, "they explain to their children the significance of the land and its bounty, they impress upon children the integration of person, place and the Dreamtime heritage as one living complex whole"5 Evidence of Aboriginal land management is apparent in many areas, for example, yams were collected in a fashion that allowed them to grow again, waterholes were regularly cleared and care taken not to foul an essential supply, and most importantly, their use of fire to 'clean up the country'.

Regular low-density fires were used to produce grasslands (both for grain and animal pasture); to protect already productive areas by burning fire-breaks; and to control food yields. Regular burning increased cycad kernel production up to seven times and ensured that the crop ripened at the same time. 6 The fact that they "kept their own population in balance with their environment "7 is another example of understanding the limits of their land". [M] uch of the vegetation encountered by early white settlers in Australia was not natural but artificial: an Aboriginal artefact... ". 8, It was an environment that had been managed in a way that didn't cause ongoing damage.

The emphasis was on maintenance and stability of the country. WHITE IDEOLOGY In contrast to the Aboriginal ideology of maintenance, the dominant white Australian ideology was (and still is) one of development, particularly economic development. 9 Australia was set up as a colony and was expected to support itself and contribute to the 'progress' of England. This was to be achieved by providing raw materials for England's industries.

Along with this desire to exploit and develop the new country came quite definite ideas of how to go about it. In eighteenth century England views of "nature and human society based on 'scientific principles' "10, had developed, in fact Francis Bacon had gone as far as defining science as "aimed at mastery of nature, to subdue natural order"11 Thus colonists believed that they had every right and even a duty to 'improve' and 'tame' nature. A perfect example of this is Bennetts comment in 1843. "I could scarcely imagine a more interesting scene than to observe a country in the course of being rescued from a state of nature". 12, The ideal landscape was the English park 13, and they had every intention of creating this in Australia.

14 Conservation ideas were rejected by the working class as a relic of the poaching laws of England and by landowners as an infringement on their exclusive rights. 15 It didn't seem to occur to anyone that the environment would need to be investigated. It was assumed that white techniques were superior and would improve the land here. FLORA What impact have white settlers and their beliefs had on each of the six areas identified above as constituting environment?

Flora was one of the first things to be affected by the new comers. The Aboriginal inhabitants had over time cultivated a landscape that consisted of the "finest grasses and richest herbage" and resembled a "wildflower garden. 16 This landscape appealed not only because of the similarity to English country parks but also due to its apparent suitability as grazing land. But Australian grasses were not accustomed to trampling by cattle and sheep hoofs nor to grazing without respite.

According to Dovers the native pasture "lasted about six years in most districts". 17 As the soil became compacted from grazing new grasses couldn't regenerate and foreign weeds, (introduced largely by accident) which were used to harder soils, thrived and took over. Another major impact on Australian vegetation was timber felling. It took very little time for the colonists to realize the economic worth of Australian trees.

In 1847 an official enquiry announced that the "Richmond river cedar country could not be cleared for five or six centuries"18 In reality it took a bare thirty years. What started with the loggers was continued by settlers. So overzealous were the settlers in removing vegetation that Governor King had to forbid the felling of riverside trees in 1803 due to the dangers of flooding and erosion that it caused. 19 The warning went unheeded and by 1892 it was estimated that 9.5 million hectares (just over a quarter of N.S.W.) of forest had been cleared.

20 This did not include the vast amounts of timber that had been, and would continue to be, used as fuel for gold, coal, and copper mines. The implications of this mass clearing, such as erosion, salinity, and extinctions, would not be realized for some time to come. FAUNA As the native grasses and the wooded areas disappeared, so too did the fauna dependent on them. Native animals now had to compete with introduced animals for food. Extinction now threatens approximately one third of our mammals.

21 Although the introduction of foreign species - Australia has the largest population of introduced species in the world 22 - is not the only contributing factor, it has had a considerable impact. Native animals not only have to contend with sheep and cattle, but also: rabbits; goats; buffalo; horse and donkeys; camels; pigs; dogs; cats; and foxes. These last three don't destroy the indigenous animals habitat so much as prey on the animals themselves. Unlike the introduction of foreign plants, the introduction of animals was quite deliberate. In some cases it was as a food supply, in others it was simply to provide a target for hunting. The varied problems caused by introduced animals in Australia include; degradation of soil, vegetation and terrain, competition for native animals, and increased risk of disease.

All are exacerbated by the fact that they are not native and so have no natural population control. Dovers' comment impresses the situation. "In the Centre they turned the Mul ga scrub into barren plains and they " ve kept them barren ever since". 23 Since white settlement in Australia, 15.4% of the animal species known to live here have become extinct - a level that is three times higher than Canada's extinction rate.

24 WETLANDS The term wetlands includes rivers, lakes, swamps, soaks, tidal mudflats, the water tables, in fact all types of water catchments. Sadly "over half of Australia's wetlands have vanished since European settlement and those that remain... are some of our most threatened natural areas"25 Many of Australia's wetlands have been drained, filled, and used as dumps. Rivers have been regulated by dams, and runoff from salt-affected, urban, or agricultural areas also cause damage. 26 Many wetlands contained extensive reed beds which acted as filters for silt, stopped soils from flowing out to sea, and recycled nutrients in the process.

These have largely been destroyed by sheep and cattle. Perhaps one of Australia's biggest problems is rising water-tables and the resulting salinity. As vegetation is removed, the tree roots no longer control the underground water levels, irrigation also contributes higher levels. As the water gets closer to the surface it evaporates and a salt residue is left behind. Dovers illustrates the problem with a photo taken in 1920, of a dead orchard surrounded by what appears to be snow but is in fact salt.

27 Goudie provides statistics for changing water levels that were as deep as 9 meters and are now less than a metre below the surface. He also states that once the area is replanted the water table and the corresponding salinity levels quickly fall. 28 Another problem that has received considerable attention in recent years is blue-green algae. Caused by an increase of nutrients in the water (resulting from agricultural fertiliser runoff), and exacerbated by hot weather, blue-green algae outbreaks render the water toxic.

The problem is not new, the first time it came to public attention was 1878 29, but very little investigation has been done on it. In fact water quality and availability does not seem to be high on the public or governmental agenda - in 1990 no-one on the National Health and Medical Research Council worked on water issues. 30 Oceans, like other types of wetlands, have suffered impact from white settlement. Sailors in the first fleets noticed the abundance of marine life off Australia's coasts, particularly whales and seals. Sealing was a brutal trade requiring the men to club their victims to death and rarely was any consideration paid to whether it was mating season, the seals were pregnant, nursing, or still cubs. The result of such indiscriminate hunting was the exhaustion of the Bass Strait sealing grounds by 1810.

Within another ten years all southern seals were near extinction. 31 Whaling began in 1790 (predominantly by overseas companies) and lasted a bare fifty years. 32 Two decades of American whaling in South Australia saw them take some 150,000 Southern Right Whales. By 1978 the species was so depleted that they couldn't be accurately counted. 33 Another impact that we have on our oceans is the careless way we discharge substances into the sea. A variety of corporations dispose of waste directly or indirectly into the sea, the content of which, although controlled by standards, is not monitored closely enough.

The stresses that the accumulated wastes of industrial society put on marine life must be immense. Effluent in particular effects sea grasses, which hold sands in place, feed marine life and produce oxygen. Off Adelaide's coast 3500 hectares of sea grasses are dead and the same amount again are badly damaged 34- it's no wonder that local councils spend a fortune shifting sand from one beach to another. The additional nutrients also promote the growth of the red algae that has become a sadly familiar feature of our beaches during summer. LAND Impacts on flora, fauna and water obviously contribute to the impact made on the land.

One quite visible impact is erosion. Collins commented in 1804 that "rains washed the earth from steep hills cleared of timber and subjected to four or five years' cultivation. Eroded soil filled the valleys". 35 Erosion is a serious problem in the 1990's, as we lose valuable top soil in dust storms. As early as 1796 some people were recognizing that the reason for poor harvests lay in exhaustion of soil. 36 Australian soils are naturally low in both phosphorous and nitrogen which means that the land can not sustain the continuous cropping that farmers carry out.

By claiming large areas of land for intensive farming practises, such as wheat or cattle, the natural diversity of the environment is destroyed. The only things mono-cultures do support are increasing populations and the economy (although it fails both in the long term as this type of land use steadily reduces its viability). Erosion, salinity, and exhaustion of the soil all contribute to the problem called desertification. Areas that previously supported a variety of life have been so badly damaged that neither native plants, animals, or commercial crops can survive. Land so damaged becomes like desert in the sense of the Sahara (a legacy of environmental damage in the far distant past), rather than the Australian deserts which in their undisturbed state teem with life. I was surprised in a recent visit to Central Australia, at the amount of vegetation compared to the bare and dusty wheat belt of South Australia.

AIR Impacts on atmosphere are harder to gauge, but judging by the smog warnings that Melbourne issues on a regular basis during summer, the introduction of an industrial and motorized society in Australia has reduced air quality. Cars are a large contributor to air pollution - they produce 80% of the nitrogen oxides (one of the components of ozone pollution) released. 37 Unfortunately Australia has almost no air pollution controls 38, and what attempts are made are purely cosmetic. For example the Port Pirie Smelters, partly due to pressure from local residents regarding the lead levels in their children's blood, built a new stack to reduce the levels of fallout. This new stack, considerably taller and wider, simply moved the problem further afield. The smog now falls on the surrounding farms - visibly.

CONCLUSION The above paragraphs are not intended to be all-embracing. I have not mentioned the way the land has been ripped open by mining. I have also neglected the huge impacts of the sprawling urban centres along our coastlines. Damage done to areas such as coral reefs, mangrove swamps, the snow fields, the Mara linga area, or even human health, has also been passed-over. It should be evident though that white settlement has had a considerable impact on the flora, fauna, wetlands, oceans, land and atmosphere in Australia. No single impact can be looked at in isolation.

Not only do the intricate relationships within an ecosystem cause each impact to affect another, but the political, social and economic ideologies must also be considered. There is a close relationship between food prices and soil erosion, timber felling and housing requirements, consumption levels and pollution. It is not possible to not make an impact, every action having a reaction, but the question must be asked whether Australia can continue to sustain the types of impact made in the last 207 years. The dominant ideology of development is being challenged by the notion of sustainable land use. The phrase, ecologically sustainable development, has appeared and is defined as being "development that meets the needs of the present without compromising the ability of future generations to meet their own needs.

39 But David Suzuki claims that "no development in the usual sense is environmentally sustainable". 40 Sustainability should be equated with stability, while development is equated with progress. Meanwhile the situation is coming to a head. The United Nations has announced that world grain production has now fallen below world consumption rates. 41 The hole in the ozone layer is growing. The earth's ecosystems are increasingly less able to cope with the disruption.

Perhaps one of the biggest problems to tackle is the increasing population. Without population control we will experience "More frequent droughts, more damaged crops and famines, more dying forests, more smog, more international conflicts, more epidemics, more gridlock, more drugs, more crime, more sewerage swimming... ". 42, and more impact.

Even the N.S. W Premier agrees that Australia needs a low, stable population. "If you focus on the Murray-Darling river system and if your soils are blown across the Tasman when the weather turns bad and if our marginal farm land is collapsing, you just have got no alternative". 43 In summary, the ideologies and actions that have caused the impacts mentioned above are not sustainable. We must learn how to "Take not too much of a land, wear out not all the fatness, but leave in it some heart". 44

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