Essay Plans For HSC Geography Syllabus (Ecosystems, Urban Places, E.t.c) PDF

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Plans for HSC Geo syllabus including ecosystems at risk, urban places, people and economic activity. Notes and simplified plan for each essay question on the document. Good plans for your HSC endeavours...

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ECOSYSTEMS AT RISK Biophysical Interactions that lead to Diverse Ecosystems Introduction: Ecosystem - dynamic complex of plant, animal and micro organism communities and their non living environment as a functional unit Characterised by complex interactions b/w abiotic and biological environments and interactions b/w 4 spheres allowing ES to be diverse Action of one sphere determines the action of another = interdependent relationship creates diverse ES Body: 1. The Atmosphere’s role in facilitating climatic interactions including factors such as the movement of air masses and orographic rainfall are instrumental to the creation of diverse ES. o The large scale movement of air masses and formation of pressure systems are atmospheric processes o However, these processes also involve interactions with the hydrosphere and lithosphere leading to an array of diverse ES o Air masses are large bodies of air and are either Maritime Air Masses if formed over water (Hydro.) or Continental Air Masses (Litho) o Important factors in determining global climatic patterns and therefore impact the distribution of biomes o Tropical maritime/continental air masses are likely to be located in similar locations to ES requiring tropical weather e.g. tropical rainforest ES demonstrating diversity o Orographic Rainfall is a process which involves interaction b/w atmosphere with lithosphere and hydrosphere o Mountain ranges (litho) interrupt the movement of prevailing winds (atmo) and moisture laden air o As moist air rises it cools and is lost as rain or snow (hydro) on windward side of mountain range o As air passes over mountain it loses its moisture content and as a result it is common that areas on leeward side are desert or arid area o Functioning – process demonstrates interconnectedness of spheres + ES requiring heavy rainfall are located on windward side while little rainfall leeward side o Distribution of some ES can be determined by a process of atmo 2. The Hydrosphere’s interactions with other biophysical elements creates diverse ES through dependency on water. o The water cycle demonstrates interaction b/w all 4 spheres but particularly hydrosphere and atmosphere o Water is evaporated from oceans/land into atmosphere o Rate of evaporation depends on a number of atmospheric conditions (temperature, humidity)

o Water is also lost from plants (bio) through transpiration o Condensation is the process where moisture in air is changed from gaseous state into liquid state o When atmosphere can no longer support amount of moisture in air precipitation occurs – when reaches the ground it infiltrates (interaction b/w hydro, atmo, litho) o Water cycle mos immediate process determining the availability of water for ES thus ability to function 3. Interactions between the lithosphere and hydrosphere lead to diverse functioning ES by determining which ES are able to function effectively in a particular area o Processes of hydraulic action, abrasion and corrosion the lithosphere can be changed beyond recognition o Processes can be exacerbated in periods of heavy rainfall o Features e.g. meanders, flood plains can be shaped by water erosion o As a result, these features of the litho can cause further interactions with other spheres producing a specific microclimate (atmo) which encourage plant/animals (bio) o Wavers also powerful erosional forces (forming cliffs, beaches) Vulnerability and Resilience of ES Introduction: ES exist in state of dynamic equilibrium (constantly changing while maintain balance) If a significant change occurs, an ES can be permanently changed This is dependent on its vulnerability to changes – either natural or human ES have a level of resilience meaning they can withstand stresses and recover An ES biodiversity, extent, location and linkages are controlling factors Body: 1. The location of an ES can make it vulnerable and determine its resilience o Some ecosystems are located in environments considered extreme e.g. Antarctica (Polar ES) – organisms capable of living in such environment are highly specialised o The greater the degree of specialisation to environmental conditions, the more vulnerable an organism is e.g. Coral thrives in temperatures between 25-29 degrees, an increase in temperature sees coral polyp die leaving only white calcium carbonate skeleton known as coral bleaching o Another locational factor is proximity large populations of people – as populations grow so does demand for land. Urban and industrial land uses destroy ES e.g. runoff polluted by sewage and rivers are a source of excess nutrients 2. An ES extent affects vulnerability and resilience o The boundaries of ES overlap each other e.g. River ES extend beyond river channel into entire drainage system therefore human activity even if far away can affect river

o ES restricted to relatively small area or have already been disturbed are esp vulnerable e.g. tropical rainforests have small populations of a large number of species confined to small areas – loss of even small area can result in extinction of plant and animal species 3. Three levels of biodiversity; genetic diversity, species diversity and ES diversity – ES with low levels of biodiversity are more vulnerable than those with rich biodiversity o Genetic diversity is the variety of genetic information contained in all individual plants and animals o Favours survival of species as it increases chances that some members will have favourable characteristics o Species Diversity is the measure of the number of species at each trophic level of an ES – in simple terms, the greater the species diversity the more robust o When an ES is diverse, alternative pathways are used if the original one is destroyed – greater diversity, the higher the resilience and ability to adapt o ES Diversity refers to diversity in habitat differences and biotic communities 4. High levels of linkages b/w organisms within an ES increase the ES ability to absorb change thus being more resilient. o The loss of a primary consumer from a food web is unlikely to have a major impact on secondary consumers as there is an alternative o ES with low linkages are more vulnerable to change e.g. Krill are the dominant primary consumer organism and the main source of energy for a whale – any reduction in Krill will directly impact ES o Interdependence may be subtle e.g. some flowering plants can only be fertilised by one species of insect Natural and Human Induced Modifications that cause stress in ES Introduction: Define ES ES constantly changing and evolving in response to stress induced changes within the environment In nature, changes take place slowly however when human initiated changes are sudden and drastic resulting in loss of habitat Body: 1. ES exist in a state of dynamic equilibrium meaning a situation where stability is achieved in an ES o Product of interrelationship b/w four spheres o Changes constantly occur to maintain this stability as all ES have the ability to withstand stress o They will restore themselves back to their original condition if not disturbed too drastically o Therefore, if natural and human induced modifications are extreme they cause stress and irreversibly damage an ES 2. Natural modifications to ES gradually cause stress in ES

o Changes in response to availability of water, average temperature take place very slowly o Biome gradually adapts as animals and plant species that have characteristics unsuited to new environment remain alive and breed (natural selection) o However, natural stresses can be catastrophic e.g. eruption of Mt St Helens in Cascade Valley in USA in 1980 which destroyed forest ES and surrounding hinterland reducing it to rock o Although, scientists initially thought ES was vulnerable, it was resilient as pioneering flora and fauna colonised 3. The nature of human induced modifications significantly cause ES stress o Intentional ES change – sometimes unintended consequence of human activity over long term o E.g. Aboriginal Australians burnt bush to clear undergrowth (management) – unintended consequence is long term effect on Australia’s pattern of vegetation o Some are arguably intentional e.g. human conflict 1991 Gulf War inflicted severe environmental damage o Inadvertent ES change – meeting needs and wants of humans brings large scale environmental change o Humans ability to transfer resources from one region to another and modify ES to sustain continued population growth – such modification lead to changes o E.g. population sprawl in Sydney – need to house increasing urban population is inevitable consequence of ecological domination of humans 4. Human induced modifications are mostly catastrophic and insinuates natural stress o Large scale environmental change pushes ES out of state of dynamic equilibrium beyond limits o In Aus, more than 40 000 years of fire stick farming gradually changed the forest ES so that fire resistant species dominated o However, the cultivation of crops and the domestication of animals 10 000 years ago, induced large scale human impacts on biodiversity and ecological destruction o Ecosystems with low bio diversity are mores vulnerable to stress as their resilience is lower o Total reduction of ES have been the pattern of human induced modifications with 90% of NSW temperate woodland cleared for farming land o Changing balance of ES via introducing new species e.g. cane toad in Queensland which has reached epidemic levels Reasons for Protection of Ecosystems Introduction: Define ES Diversity of life on Earth is of inestimable value Provides basis for planetary processes and wellbeing of people – protection of ES central to intergenerational equity

Recognition of values and practices compatible with sustainable development Body: 1. An ES Utility Value refers to the living and non living components of Earths ecosphere having an existing or potential usefulness. o ES provide basis for all humanities resources – potential ES have to provide is seemingly limitless o Maximise humanities ability to adapt to change o Diversity of life present represents a vast store of genetic material  Earths plants, animals, micro organisms which constitute chemical compounds supplying medicine to cure human diseases e.g. Australian Corkwood Hyoscine for motion sickness o Highly competitive ES e.g. tropical rainforests organisms depend on chemically based mechanisms for survival o These naturally produced chemicals constitute a large part of pharmalogical resources e.g. Amazon Rainforest contains over 30% of Earth’s species and contains undiscovered species – loss of even a small area could result in loss of potential disease conquering compounds e.g. cancer or AIDS o Medical scientists have only examined 5000 of the 25 000 plants with pharmacological value emphasising need to manage and protect to benefit human existence 2. The existence of ES regardless of utility value and for inspirational, aesthetic and spiritual needs of humans is central to the notion of intrinsic value. o In an increasingly urbanised society, spiritual and emotional wellbeing humans can attain from environment suggests a reason for management and protection of ES o Interacting with biophysical environment, humans are reminded that they are part of the interdependent natural world o Combination of aesthetic and recreational values is maximised as individuals undertake activities e.g. bush walking, photography and trekking  contributes to growth of ecotourism as humans grow appreciation for environment o E.g. Scenic World in Blue Mountains demonstrates appreciation of aesthetic and ecological environmental qualities through scenic cableways o Strong relationship b/w Indigenous and environment accentuates ecocentric view in terms of management and protection o E.g. Australian Aboriginal and Torres Strait Islander People who regard themselves as apart of the biophysical environment – inextricable connection with land creating custodial relationship as they acknowledge responsibility for continuity of ES o Intrinsic management assists long term survival of ES due to minimal human use however in practical context successful ES protection involves acknowledgment for intrinsic value but managing with utility value for social, political and economic reasons

3. The protection of ES in accordance to heritage value allows for effective ES management o The World Heritage Conservation Council protects ES with ‘outstanding universal value from an aesthetic or scientific view point.’ o 206 natural WHS which protect biodiverse ES e.g. Galapagos and GBR o Powerful symbolic value of WHS relates closely to intrinsic value by protecting diverse ES, able to protect and manage ES from urban development and resource exploitation o World Heritage Committee can classify sites UNESCO ‘in danger’ as seen through GBR for 3 years o Despite this, GBR 2017 taken off ‘in danger’ list even through 2/3 reef subject to unprecedented coral bleaching o According to UNESCO, Reef 2050 plan is effectively managing GBR however fails to include adequate CC policies highlighting ineffectiveness o Increase support via education to develop heritage listing 4. ES rich in diversity generally have greater resilience and are able to recover more rapidly from natural induced stress. o When genetic diversity is diminished ES are made more vulnerable, hindering function o For this reason, P+M of ES for genetic diversity is important for species survival o Communities with high levels of genetic diversity often survive periods of stress as some organisms nots affected by change o Process of ‘natural selection’ demonstrates survival of organisms based on favourable characteristics which enable them to cope with stress o Survivors pass traits on to subsequent generations o Humanity’s lack of knowledge in relation to ecological processes is evident as Earth’s natural ES are increasingly utilised o Estimated 5 to 30 million species inhabit the planet yet only 1.4 million have been identified o Evolutionary extinction account for the loss of one species/year – actual rate is now 1/day reflects impact of humans on ES o Lack of genetic diversity in Platypus Population on King Island Tasmania due to small pop. Inbreeding occurs resulting in lack of genetic variation in MHC gene making platypus subject to epidemic diseases 5. The need to allow natural change to proceed encompasses the view that humans have an ethical responsibility to allow evolutionary processes to continue unhindered o Diversity of life is product of ongoing evolutionary processes o Evolution occurs when genetic diversity is high and leads to stronger genetic material which creates resilience and lowers vulnerability o To achieve this, areas need to be well managed and effectively resourced as well as large enough to protect and conserve

o E.g. Macquarie Marshes for irrigation consequently resulted in the loss of a breeding ground for birds – prior to irrigation 100 000 birds bred, now only 30 000 nesting pairs o Human land use interfered with natural change preventing it from continuing

Traditional and Contemporary Management Strategies used to Protect ES Introduction: Define ES Natural and human induced modifications can significantly impact an ES by causing stress Although, ES exist in a state of dynamic equilibrium a push beyond this will cause irreversible damage Therefore, necessity to utilise traditional and contemporary management strategies to protect both terrestrial and aquatic ES Effective maintenance of ES is aligned with management in accordance to values Body: 1. Traditional management strategies involve native Indigenous land owners o The GBR 348 000km inhabits 1500 fish species, over 600 coral and 200 bird species o Over 35 Indigenous groups have traditional links to GBR o Traditional management included seasonal hunting – ecologically sustainable as Indigenous ensured marine life did not become extinct – did not disturb dynamic equilibrium o Aboriginals also had sacred animal totems to protect species like stingrays and sharks – marine environment important in Dreaming o Indigenous built relationship of stewardship as custodians protectors of land meaning sustainable protection 2. Contemporary management strategies utilise a modern and scientific approach o 1981 named UNESCO WHS – preserve for natural beauty o Tourism – subject to 2 million tourists each year o 5 key strategies to minimize environmental impact of humans are followed o Exclusion, Action, Education, Design, Legislation – works collaboratively to promote rehab., greater education and strict policies o Although, it is co management which is successful in managing GBR – 1995 Indigenous Partnerships Liaison Unit – traditional fishing allowed 3. Stockton Bight Sand Dunes emerge as an ES@R due to both natural and human induced stress o Located between Port Stephens and Newcastle, it contains unique flora and fauna o Traditionally, little is known about the ways Indigenous managed the SD – due to rising sea levels archaeological evidence does not exist beyond 6000 years o Maaiangal clan set size limits on sea food o Although, Captain Cook saw migrating dunes suggesting Indigenous used fire management destroying coastal vegetation allowing migrating dunes to develop 4. Successful contemporary management involves maintain the natural functions of the dune environment

o Fencing – protects dunes from trampling by beach users o Construction of fences around the fore dune area – stop people from trampling dune vegetation – constructed with wire and timber o Dune Reconstruction – timely and costly technique reduces ability of wind to carry away sand – artificially manipulates to become ideal for stabilisation o Unless dune is well vegetated it is unable to resist wind erosion and storm wave attack Nature and Rate of Change Introduction: Define ES The nature of an ES will determine its vulnerability; weaker ES more susceptible to changes Increases ‘at risk’ status bringing detrimental effects to biodiversity of ES GBR subject to both natural and human stresses impacting the nature + rate of change e.g. storm damage and coral bleaching Similarly, SD possess a high resilience to natural processes yet the nature of human induced modifications significantly hinder the functioning of SD Body: 1. The nature of TC significantly changes the GBR however this change is gradual due to its resilience. o GBR is a highly dynamic ES with over 1500 fish species and 600 corals spanning over 348 000km o The GBR is located in Aus. Cyclone region, meaning tropical cyclones shaped reef for years with negative impacts o TC generate large waves associated with LPS damaging coral o Large amounts of rain are also associated with TC, fresh water from coastal river systems alter the salinity of the reef increasing turbidity o Cyclone Larry 2006 o GBR has grown increasingly resilient to TC which are a result of the atmospheres functioning and TC even have positive impact by avoiding mass bleaching event 2. Similarly, SD located between Newcastle and Port Stephens experience storm damage. o SD are large amounts of sand that have built up over long periods located immediately behind active beach zone – provide foundation for F+F o Due to their location on the coast, subject to storm induced waves causing major structural damage in the form of washouts o Washouts are associated with breaching of sand barriers – isolating coastal lagoons from open sea following heavy rain o Occur when heavy rainfall result in accumulation of water in swales – if there are depressions in dunes water may be channelled through and overflow on beach o The nature of storm damage degrades the beach leaving little sediment for dune construction o Although storm damage is often sudden, SD are able to withstand stress 3. The nature of climate change will cause catastrophic damage to the reef at a fast rate o Ongoing CC will directly impact the terrestrial and aquatic F+F on the reef

o For this reason, the functioning of the reef will be significantly hindered o CC alters sea temperatures and Reefs are highly specialised as they thrive in temps of 25 – 27C, above this = bleaching o Colouration of healthy coral due to microscopic algae zooxanthellae which live within its tissue – when bleaching o...