Questions and Answers
What was the primary reason for the introduction of Cane Toads in Queensland?
How do invasive species like Cane Toads primarily contribute to the decline of native species?
What economic impact do invasive species like Cane Toads have on Australia?
What is eutrophication primarily caused by?
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What is a serious effect of eutrophication on water supplies?
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What environmental problem is caused by the over-irrigation of farmland?
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How can salinity in impacted areas be rehabilitated?
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What is one of the main causes of soil erosion?
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Study Notes
Cane Toads Introduction and Impact
- Cane toads were introduced to Queensland to combat cane beetle populations in sugarcane farms.
- They emit toxins when ingested, representing a significant biotic threat to native predators.
- The spread of cane toads affects various ecosystems across Australia, disrupting native species.
- Human activities, such as agriculture and habitat alteration, have facilitated cane toad proliferation.
- Economic losses attributed to cane toads and other invasive species in Australia reach approximately 24.5 million dollars annually.
- Public opinion about cane toads is divided, with some viewing them as a pest while others see them as part of the ecosystem.
Decline of Native Species
- Invasive species lead to resource competition against native species, often depleting essential resources.
- Predatory behaviors from invasive species result in higher mortality rates among native populations.
- Hybridization occurs when invasive species breed with natives, diluting genetic diversity.
- Pathogen transmission by invasive species introduces diseases that native species may not withstand.
- Alteration of habitats by invasive species can lead to detrimental physical or chemical changes, making them unsuitable for native organisms.
Eutrophication Process
- Eutrophication occurs when nutrient concentration, particularly nitrogen and phosphorus, increases in water bodies.
- Excess nutrients cause blooms of microscopic algae and cyanobacteria, resulting in discolored water (algal blooms).
- Causes include agricultural fertilisers and untreated sewage runoff, contributing to nutrient overload.
- Eutrophication leads to decreased biodiversity, hypoxia (low oxygen levels), and tainted drinking water supplies, impacting both human health and recreational opportunities.
Dry Land Salinity Causes
- Accumulation of salt in the soil occurs from saline groundwater saturation or proximity.
- Salinity affects agricultural productivity and diminishes soil health.
Importance of River Flow
- Rivers supply essential resources such as food, drinking water, and waste management.
- Adequate river flow supports water purification processes, sustaining habitats and biodiversity.
Environmental Issues from Over-Irrigation
- Over-irrigation leads to waterlogged soil, which can poison plant roots through anaerobic decomposition.
- Poor soil conditions disrupt agricultural productivity and increase susceptibility to salinity.
Soil Erosion Causes
- Soil erosion is exacerbated when soil is left exposed to harsh weather conditions, including wind and rain.
- Human activities like farming and land clearing significantly increase soil vulnerability.
Rehabilitation of Salinity-Affected Areas
- Effective salinity management requires balancing water recharge and discharge within groundwater systems.
- Rehabilitating salt-affected soils through revegetation using specific shrubs can enhance biodiversity and aesthetics.
Reducing Soil Erosion in Agriculture
- Maintaining soil cover helps minimize both wind and water erosion incidents, preserving soil health.
Types and Causes of Soil Contamination
- Asbestos contamination arises from construction, demolition, and mining activities.
- Pesticide pollution stems from overuse, leaks, and spraying drift.
- Lead contamination can result from gasoline usage, lead-based paints, and industrial activities.
- Petroleum contamination frequently originates from leaks, spills, and accidents involving vehicles.
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Description
This quiz explores the ecological and economic impacts of the invasive cane toad species introduced in Australia. Learn about their biotic and abiotic effects, areas affected, human influences, and management strategies. Assess how this introduction has led to significant losses in tourism and fisheries.
