Environmental Management and Rehabilitation

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Questions and Answers

What are the first steps involved in the rehabilitation of a mined area?

The first steps involve clearing, stockpiling, and caring for vegetation, seeds, and seedlings.

How does ploughing contribute to soil erosion in agricultural practices?

Ploughing exposes the surface soil to rain and wind, leading to the removal of fine soil particles and nutrients.

What are two methodologies for decreasing agricultural erosion?

Minimising ploughing and re-planting vegetation are two effective methodologies.

What is bioaccumulation and how does it relate to top predators in a food chain?

Bioaccumulation refers to the process where substances like toxins accumulate in an organism over time, and it significantly impacts top predators who consume other organisms higher in the food chain. Signup and view all the answers

What measures are required by law on Australian construction sites to prevent sediment contamination in waterways?

Construction sites must implement effective temporary silt traps to catch sediment flow. Signup and view all the answers

Why is the use of native vegetation important in urban environments during development?

Native vegetation provides wildlife corridors, food, and aids in the rehabilitation process. Signup and view all the answers

Why are abiotic factors crucial in determining the distribution of organisms in an ecosystem?

Abiotic factors like temperature, soil quality, and water availability significantly influence the habitat suitability and survival of organisms within an ecosystem. Signup and view all the answers

How do biotic factors affect population dynamics within an ecosystem?

Biotic factors such as predation, competition, and symbiosis directly influence birth and death rates, which in turn affect the population dynamics of the interacting species. Signup and view all the answers

Explain the role of producers in an ecosystem's food web.

Producers, like plants and photosynthetic organisms, form the base of the food web by converting sunlight or chemical energy into food, which supports all other trophic levels. Signup and view all the answers

What can lead to changes in predator and prey population sizes over time?

Fluctuations in numbers of predators and prey can result from factors such as food availability, reproduction rates, and environmental changes within their habitats. Signup and view all the answers

Discuss the importance of decomposers in an ecosystem.

Decomposers, including fungi and microbes, break down dead organic material, recycling nutrients and thus maintaining soil health and ecosystem stability. Signup and view all the answers

How does symbiosis affect the organisms involved in an ecosystem?

Symbiosis involves interactions between different species that can benefit at least one participant, influencing their survival, reproduction, and resource utilization. Signup and view all the answers

What is the significance of having more prey than predators in a balanced ecosystem?

Having more prey than predators is essential for population stability, as it ensures that predator populations have enough food resources to survive and reproduce. Signup and view all the answers

What effect does salinisation have on soil fertility?

Salinisation reduces soil fertility by increasing the salinity levels, which damages soil microbes and plants. Signup and view all the answers

How do pesticides contribute to biomagnification in food webs?

Pesticides accumulate in the tissues of plants and animals, increasing in concentration as they move up the food chain. Signup and view all the answers

In what ways can introduced species disrupt local ecosystems?

Introduced species can out-compete native species for resources, disrupting the balance of the ecosystem. Signup and view all the answers

What are potential consequences of climate change on ecosystems?

Consequences include rising sea levels, ocean warming, and increased frequency of extreme weather events. Signup and view all the answers

How does overpopulation contribute to human-induced selection pressures?

Overpopulation leads to increased resource exploitation, habitat destruction, and the introduction of pollutants. Signup and view all the answers

What role does land clearing play in the competition among species?

Land clearing removes habitats, forcing surviving organisms into smaller areas where competition for resources intensifies. Signup and view all the answers

Explain how eutrophication affects aquatic environments.

Eutrophication leads to an overgrowth of algae, which can smother and suffocate other aquatic life. Signup and view all the answers

What measures can be taken to mitigate the negative impacts of mining?

Rehabilitation plans should be implemented to restore land after mining activities cease. Signup and view all the answers

How does human-induced climate change differ from natural climate changes?

Human-induced climate change is primarily driven by increased carbon dioxide emissions from fossil fuel consumption. Signup and view all the answers

What implications does human exploitation of resources have on biodiversity?

Over-exploitation can lead to habitat degradation and species extinction, disrupting ecological relationships. Signup and view all the answers

Discuss the impact of irrigation on salinity levels in arid regions.

Irrigation can cause water tables to rise, leading to salinisation as dissolved salts are brought to the surface. Signup and view all the answers

What consequences can arise from disrupted ecological relationships due to human activities?

Disruption can alter food webs, leading to changes in species populations and potentially mass extinctions. Signup and view all the answers

Why is it important to apply models based on past extinction events?

Models help predict future impacts on biodiversity by identifying potential threats from human-induced pressures. Signup and view all the answers

How do agricultural practices impact the salinity of soils?

Agricultural land clearing and excessive irrigation can lead to increased salinity, ultimately reducing soil fertility. Signup and view all the answers

What are the two types of competition that can occur between organisms?

Intraspecific and interspecific competition. Signup and view all the answers

How do Acacia trees warn other trees about grazing giraffes?

Acacia trees release allelochemicals when eaten, signaling nearby trees to cut off water flow to their leaves and become bitter. Signup and view all the answers

Define symbiosis and its types.

Symbiosis is a close relationship between organisms, which can be parasitism, commensalism, or mutualism. Signup and view all the answers

What is the competitive exclusion principle?

The competitive exclusion principle states that no two species can occupy the same niche. Signup and view all the answers

Explain how ecological niches relate to biodiversity.

Ecological niches contribute to biodiversity by allowing various species to coexist and fulfill different roles in the ecosystem. Signup and view all the answers

What factors can lead to the spread of infectious diseases in wildlife populations?

Factors include environmental changes like deforestation, overcrowding, or continuous population contact. Signup and view all the answers

Describe the capture-recapture method used in population studies.

In the capture-recapture method, individuals are captured, marked, and released, then recaptured to estimate total population size. Signup and view all the answers

What was a major cause of the extinction of the Australian Megafauna?

The extinction was primarily caused by hunting pressures from humans and environmental changes. Signup and view all the answers

What role do decomposers play in an ecosystem?

Decomposers break down dead organic matter, recycling nutrients back into the ecosystem. Signup and view all the answers

Define allelopathy and give an example.

Allelopathy is the release of biochemicals by plants that affect the growth of other plants; for example, pine trees releasing acidic substances. Signup and view all the answers

How does mutualism benefit both organisms involved?

Mutualism provides advantages such as increased resources, protection, or support for reproduction for both organisms. Signup and view all the answers

What type of sampling technique would you use for highly mobile animals?

The capture-recapture method is suitable for sampling highly mobile animals. Signup and view all the answers

How do generalist species differ from specialist species in niche occupation?

Generalist species can adapt to various niches, while specialist species are tailored to specific niches. Signup and view all the answers

What is the effect of the Devil Facial Tumour Disease on Tasmanian devils?

The disease causes widespread fatality among Tasmanian devil populations, leading to severe population declines. Signup and view all the answers

Explain how different feeding and nesting strategies affect species occupation of ecological niches.

Different feeding and nesting strategies allow species to exploit different resources and coexist in the same area. Signup and view all the answers

What major factors contributed to the extinction of Australian megafauna?

Changes in climate and the arrival of humans are the major factors. Signup and view all the answers

How did climate change impact the availability of water for megafauna in Australia?

The continent dried out during the last ice age, reducing water supply vital for large animals. Signup and view all the answers

What evidence suggests that the arrival of Aboriginal people coincided with the end of megafauna?

Archaeological findings indicate that the timing of their arrival aligns with megafauna extinction. Signup and view all the answers

What role did Aboriginal rock paintings play in understanding past ecosystems?

They provide insights into the species present and environmental conditions of the time. Signup and view all the answers

How does ice core drilling contribute to our understanding of past atmospheric conditions?

Ice core drilling traps gas bubbles from the atmosphere, preserving evidence of past climate. Signup and view all the answers

What are iron banded formations and what do they signify about Earth's history?

They are geological formations made of alternating iron-rich sediments, indicating oxygen's increase in oceans. Signup and view all the answers

Explain the significance of radiometric dating in studying past life forms.

Radiometric dating allows determination of the age of fossils and rocks using radioactive isotopes. Signup and view all the answers

What led to the extinction of the Thylacine in Australia?

Bounties, habitat loss, competition from introduced species, and population fragmentation caused its extinction. Signup and view all the answers

How did palaeontological and geological studies combine to enhance our understanding of ancient ecosystems?

They provide evidence of changes in environments through fossil records and rock formations. Signup and view all the answers

Describe how Aboriginal rock paintings evolved over time in relation to climate changes.

The paintings show shifts from lush forests to scrub and grasslands as rainfall decreased. Signup and view all the answers

What are the main components of gas analysis in studying past climates?

Mass spectroscopy, chromatography, and ion microprobe are key techniques in gas composition analysis. Signup and view all the answers

What evidence supports the claim that present-day organisms evolved from past species in Australia?

Comparative analysis of fossils and living species indicates evolutionary adaptations over time. Signup and view all the answers

What impact did the most recent ice age have on Australia's flora and fauna?

The ice age led to habitat changes and the gradual depletion of water sources for large animals. Signup and view all the answers

How can the chemical composition of ice provide insight into historical climate changes?

Bubbles in ice contain gases that reflect the atmosphere's composition at the time of their entrapment. Signup and view all the answers

Discuss the relationship between human hunting practices and the decline of Australian megafauna.

Human hunters, including the introduction of Dingoes, may have increased predation pressure on megafauna. Signup and view all the answers

Study Notes

Biosphere and Ecosystems

The biosphere encompasses all life on Earth, integrating both biotic (living) and abiotic (non-living) components.
Ecosystems consist of communities of organisms interacting with their physical environment.

Abiotic Factors

Key abiotic components in ecosystems include:
- Terrestrial: light availability, soil quality, geology, climate, rainfall.
- Aquatic: temperature, depth, salinity, current, dissolved oxygen.

Biotic Factors

Biotic factors encompass all living organisms and their interactions within an ecosystem:
- Producers: plants and photosynthetic microorganisms.
- Consumers: animals reliant on producers for food.
- Decomposers: fungi and microbes that recycle nutrients from dead organisms.

Predator-Prey Dynamics

Predator-prey relationships are essential, with predators such as orcas and seals demonstrating population fluctuations based on prey availability.
A sustainable ecosystem requires more prey than predators to ensure survival.

Competition

Competition occurs over limited resources: food, space, mates.
Intraspecific competition involves individuals of the same species, while interspecific competition involves different species.
Plants exhibit competition through allelopathy, where they release chemicals affecting surrounding vegetation.

Symbiosis

Symbiotic relationships can be mutually beneficial (mutualism), harmful (parasitism), or neutral (commensalism).
Coral reefs, for example, rely on mutualism between corals and symbiotic algae for structural complexity and diversity.

Disease in Ecosystems

Infectious diseases are significant threats, spreading through pathogens and potentially leading to population declines (e.g., Devil Facial Tumour Disease in Tasmanian devils).

Ecological Niche

An ecological niche is an organism's role within its ecosystem, influenced by both biotic and abiotic factors.
The competitive exclusion principle states that two species cannot occupy the same niche simultaneously.

Population Measurement Techniques

Sampling techniques include quadrats for plants, transects for distribution, and capture-recapture methods for mobile organisms.
Capture-recapture formula: (S1 x S2) / M2 estimates population size, where S1 is the initial captured number, S2 is total captured later, and M2 is the marked individuals in the second sample.

Extinction Events

The Australian Megafauna, including species like Diprotodon and the Thylacine, went extinct primarily due to climate changes and human influence.
Factors contributing to extinction involve habitat destruction, competition with introduced species, and direct hunting.

Evidence for Past Ecosystems

Palaeontology and geology reveal past ecosystems through fossil records and rock strata.
Aboriginal rock paintings provide insight into historical flora and fauna, reflecting ecosystem changes over time.

Technologies for Historical Change Analysis

Radiometric dating determines the age of materials through radioactive isotopes.
Gas analysis using different methodologies helps assess past atmospheric conditions.

Human Impact on Future Ecosystems

Human-induced selection pressures, such as habitat destruction, exploitation of resources, and pollution, significantly affect biodiversity.
Overpopulation leads to resource depletion and heightened competition among species.

Salinisation and Agriculture

Land clearing for agriculture disrupts natural water balance, leading to increased soil salinity and decreased fertility.
Sustained salinisation damages organisms and ecosystems, marking a critical environmental issue.

Pesticides and Ecosystem Health

Pesticides may eliminate both pests and beneficial organisms, leading to bioaccumulation and biomagnification along food webs.
This dynamic creates selection pressures that challenge species adaptability.

Eutrophication Process

Fertilizer runoff contributes to nutrient overload in waterways, resulting in algal blooms that disrupt aquatic life.
Adaptation or relocation becomes crucial for species under altered conditions.

Introduced Species Challenge

Non-native species disrupt ecosystems by outcompeting native species for resources, leading to biodiversity loss.

Climate Change Impact

Human-induced climate change leads to temperature increases, sea level rise, and frequency of extreme weather events, stressing ecosystems.
Mining activities also pose significant risks, often leading to habitat degradation and necessitating rehabilitation efforts post-mining.

Future Biodiversity Management Models

Historical extinction events inform models predicting future biodiversity impacts, emphasizing the need to address human environmental interactions proactively.### Mining Rehabilitation
Clearing and stockpiling vegetation, seeds, and seedlings is essential for future site rehabilitation after mining.
Tailings, which are waste materials generated from mining, require proper treatment to mitigate environmental impact.
Upon mining completion, the pit must be refilled either with landfill or water to create a dam.
Stockpiled soil is spread over the area to promote natural regrowth of vegetation in stages, facilitating a return of native plants and animals.

Agricultural Land Degradation

Soil is critical for sustainable agriculture in Australia, providing the foundation for food production globally.
Traditional ploughing increases erosion rates by exposing topsoil to rain and wind, resulting in loss of fine particles and nutrients.

Erosion Control Methods

Minimising ploughing through the use of environmentally friendly chemicals can effectively kill weeds without disturbing topsoil.
Re-planting vegetation with tree roots stabilizes soil, significantly reducing erosion risk.
In urban settings, clear land can lead to sediment wash-off into local waterways, necessitating protective measures.
Australian law mandates construction sites to implement temporary silt traps to prevent sediment pollution in waterways.

Vegetation Role in Erosion Prevention

Maintaining vegetation cover on road verges and around new developments helps prevent erosion.
Native vegetation not only stabilizes soil but also creates wildlife corridors, providing food and beginning the process of ecological rehabilitation.

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Description

This quiz explores essential concepts in environmental management, focusing on the rehabilitation of mined areas, the impact of agricultural practices on soil erosion, and the legal measures for construction sites in Australia. It also delves into ecological principles such as bioaccumulation and the significance of abiotic factors in ecosystems.