1. Aquatic and Terrestrial Pollution

1.1 Sources of Pollution

1.1.1 Point vs. non-point sources

1.1.2 Agricultural runoff and industrial discharge

1.2 Eutrophication

1.2.1 Process and consequences for aquatic ecosystems

1.3 Waste Management

1.3.1 Landfills, incineration, and recycling methods

1.4 Human Health and Pollution

1.4.1 Bioaccumulation and biomagnification

1.4.2 Dose-response curves and LD50

2. The Living World: Biodiversity

2.1 Natural Ecosystem Disruptions

2.1.1 Short-term disruptions

2.1.2 Long-term disruptions

2.2 Ecological Succession

2.2.1 Primary vs. secondary succession

2.2.2 Climax communities and ecosystem stability

2.3 Introduction to Biodiversity

2.3.1 Levels of biodiversity

2.3.2 Importance of biodiversity to ecosystem resilience

2.4 Ecosystem Services

2.4.1 Provisioning, regulating, cultural, supporting services

2.4.2 Economic and ecological value

2.5 Island Biogeography

2.5.1 Species-area relationship

2.5.2 Factors affecting colonization and extinction

3. Populations

3.1 Population Dynamics

3.1.1 K-selected vs. r-selected species

3.1.2 Survivorship curves (Type I, II, III)

3.2 Human Population

3.2.1 Total fertility rate

3.2.2 Age structure diagrams and population pyramids

3.3 Carrying Capacity and Resource Use

3.3.1 Limiting factors

3.3.2 Impacts of exceeding carrying capacity

3.4 Demographic Transition

3.4.1 Stages of demographic transition

3.4.2 Social and economic implications

4. Global Change

4.1 Climate Change

4.1.1 Greenhouse effect and global warming

4.1.2 Mitigation strategies

4.2 Ocean Changes

4.2.1 Ocean warming and acidification

4.2.2 Coral bleaching and biodiversity loss

4.3 Biodiversity Loss

4.3.1 Habitat destruction

4.3.2 Invasive species and extinction risks

4.4 Ozone Depletion

4.4.1 Causes of stratospheric ozone depletion

4.4.2 Role of international treaties

5. Earth Systems and Resources

5.1 Plate Tectonics

5.1.1 Structure of Earth

5.1.2 Types of plate boundaries

5.1.3 Earthquakes, volcanoes, and mountain formation

5.2 Soil Systems

5.2.1 Soil formation processes

5.2.2 Soil horizons and profiles

5.2.3 Impacts of erosion and salinization

5.3 Atmospheric Systems

5.3.1 Composition and structure of Earth's atmosphere

5.3.2 Role of the ozone layer

5.4 Weather and Climate

5.4.1 Global wind patterns and the Coriolis effect

5.4.2 Solar radiation and seasons

5.5 Watersheds and Aquifers

5.5.1 Structure and function of watersheds

5.5.2 Human impacts on aquifers

6. The Living World: Ecosystems

6.1 Introduction to Ecosystems

6.1.1 Biotic and abiotic components of ecosystems

6.1.2 Relationships: predator-prey, mutualism, parasitism, commensalism

6.1.3 Niche concept and competitive exclusion principle

6.2 Terrestrial Biomes

6.2.1 Characteristics of major terrestrial biomes

6.2.2 Climate and vegetation patterns

6.2.3 Human impacts on terrestrial biomes

6.3 Aquatic Biomes

6.3.1 Freshwater biomes

6.3.2 Marine biomes

6.3.3 Ecosystem services provided by aquatic biomes

6.4 Biogeochemical Cycles

6.4.1 Carbon Cycle

6.4.2 Nitrogen Cycle

6.4.3 Phosphorus Cycle

6.4.4 Hydrologic (Water) Cycle

6.5 Energy Flow in Ecosystems

6.5.1 Primary Productivity

6.5.2 Trophic Levels

6.5.3 Energy Flow and the 10% Rule

7. Land and Water Use

7.1 Tragedy of the Commons

7.1.1 Concept and real-world examples

7.1.2 Strategies for sustainable use

7.2 Agricultural Practices

7.2.1 Green Revolution technologies

7.2.2 Irrigation, fertilizers, and pesticides

7.3 Urbanization and Land Use

7.3.1 Urban sprawl

7.3.2 Heat islands and transportation impacts

7.4 Sustainable Land Use

7.4.1 Integrated pest management

7.4.2 Sustainable forestry and agriculture practices

8. Energy Resources and Consumption

8.1 Renewable vs. Nonrenewable Energy

8.1.1 Definitions and examples of each

8.1.2 Global patterns of energy consumption

8.2 Fossil Fuels

8.2.1 Types of fossil fuels

8.2.2 Extraction methods and environmental impacts

8.3 Alternative Energy Sources

8.3.1 Solar, wind, hydroelectric, geothermal, and nuclear power

8.3.2 Advantages and disadvantages

8.4 Energy Conservation

8.4.1 Energy efficiency in homes, industries, and transportation

9. Atmospheric Pollution

9.1 Types and Sources of Pollution

9.1.1 Outdoor air pollution

9.1.2 Photochemical smog and thermal inversions

9.2 Acid Deposition

9.2.1 Formation of acid rain

9.2.2 Environmental and health impacts

9.3 Indoor Air Pollution

9.3.1 Common indoor pollutants: radon, VOCs, asbestos

9.4 Noise Pollution

9.4.1 Causes and effects on humans and wildlife

Invasive species and extinction risks

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Invasive Species and Extinction Risks

Introduction

Invasive species pose a significant threat to global biodiversity, disrupting ecosystems and increasing extinction risks for native species. Understanding the dynamics of invasive species is crucial for environmental management and conservation efforts, particularly for students preparing for the Collegeboard AP Environmental Science exam.

Key Concepts

Definition of Invasive Species

Invasive species are non-native organisms that, when introduced to a new environment, cause harm to the ecosystem, economy, or human health. Unlike native species, invasive species lack natural predators in their new habitats, allowing their populations to grow rapidly and outcompete indigenous species.

Mechanisms of Introduction

Invasive species can be introduced through various pathways, including:

Human Activity: Global trade, travel, and transportation facilitate the accidental or intentional movement of species across regions.
Aquaculture and Agriculture: The release of non-native species for farming purposes can lead to unintended ecological consequences.
Pet Trade: Exotic pets may escape or be released into the wild, establishing invasive populations.

Ecological Impacts

The introduction of invasive species can lead to:

Competition: Invasive species compete with native species for resources such as food, habitat, and light.
Predation: Some invasive species are predators that can decimate native prey populations.
Disease Transmission: Invasive species can introduce new pathogens to which native species have no immunity.
Hybridization: Invasive species can interbreed with closely related native species, leading to genetic dilution.

Case Studies

Several case studies illustrate the profound impact of invasive species:

Brown Tree Snake in Guam: Introduced accidentally, this snake has caused the extinction of several native bird species.
European Starling in North America: Introduced for aesthetic reasons, it now competes with native birds for nesting sites.
Sea Lamprey in the Great Lakes: This parasitic fish has significantly reduced native fish populations.

Extinction Risks

Invasive species contribute to extinction risks in several ways:

Reduction of Genetic Diversity: By outcompeting native species, invasive organisms reduce the genetic pool, making ecosystems less resilient.
Habitat Alteration: Invasive species can change the physical environment, making it unsuitable for native species.
Trophic Cascade Effects: The removal or reduction of a key species can have cascading effects throughout the food web.

Management and Control

Effective management strategies are essential to control invasive species and mitigate their impacts:

Prevention: Implementing biosecurity measures to prevent the introduction of invasive species.
Early Detection and Rapid Response: Identifying and eradicating invasive species before they become established.
Mechanical Control: Physical removal of invasive species through methods like trapping and hunting.
Chemical Control: Use of pesticides or herbicides to manage invasive populations.
Biological Control: Introducing natural predators or competitors to suppress invasive species populations.

Economic and Social Implications

The presence of invasive species can have significant economic and social consequences:

Agricultural Losses: Invasive pests can damage crops, leading to reduced yields and increased costs for farmers.
Fisheries Decline: Invasive species can disrupt fishing industries by reducing native fish populations.
Recreational Impact: Tourism and recreational activities may suffer due to degraded natural environments.
Public Health Risks: Some invasive species can be vectors for diseases affecting humans and animals.

Policy and Legislation

Governments and international bodies have established policies to address invasive species:

National Invasive Species Councils: Coordinated efforts to manage invasive species at the national level.
International Agreements: Frameworks like the Convention on Biological Diversity to prevent the spread of invasive species.
Regulations and Permits: Control the import, export, and movement of potentially invasive species.

Public Awareness and Education

Educating the public about the risks associated with invasive species is crucial for prevention and management:

Community Engagement: Involving local communities in monitoring and controlling invasive species.
Educational Programs: Incorporating invasive species topics into school curricula to raise awareness.
Media Campaigns: Utilizing media platforms to disseminate information about invasive species risks.

Future Directions and Research

Ongoing research is essential to develop more effective strategies for managing invasive species:

Genetic Studies: Understanding the genetics of invasive species to develop targeted control methods.
Ecological Modeling: Predicting the spread and impact of invasive species under various scenarios.
Innovative Control Technologies: Developing new methods for the removal and suppression of invasive species.

Comparison Table

Aspect	Invasive Species	Native Species
Origin	Non-native to the ecosystem	Originated and evolved in the ecosystem
Impact on Ecosystem	Disrupts balance, often harmful	Maintains and supports ecosystem balance
Population Control	Lacks natural predators, can become overabundant	Regulated by natural predators and environmental factors
Biodiversity	Reduces native biodiversity	Contributes to native biodiversity
Economic Impact	Often negative, causing economic losses	Generally positive or neutral

Summary and Key Takeaways

Invasive species are non-native organisms that harm ecosystems and increase extinction risks.
They are introduced through human activities, aquaculture, and the pet trade.
Ecological impacts include competition, predation, disease transmission, and habitat alteration.
Effective management requires prevention, early detection, control measures, and public education.
Understanding invasive species is essential for conserving biodiversity and maintaining ecosystem health.

Examiner Tip

Tips

- **Mnemonic for Invasive Species Impacts:** CPHED - Competition, Predation, Hybridization, Ecological alteration, Disease transmission.
- **AP Exam Strategy:** When answering questions, first identify if the species is native or invasive, then consider its specific impacts on the ecosystem.
- **Stay Organized:** Create flashcards for different invasive species and their effects to enhance memorization and recall during exams.

Did You Know

1. The introduction of the cane toad in Australia was intended to control agricultural pests but ended up becoming a major invasive species, threatening native wildlife.
2. Zebra mussels, originally from Russia and Ukraine, have spread to over 20 U.S. states, causing billions in infrastructure damage by clogging water pipes.
3. The emerald ash borer, an invasive beetle, has killed millions of ash trees in North America, drastically altering forest ecosystems.

Common Mistakes

1. **Misidentifying Native vs. Invasive:** Students often confuse native and invasive species.
**Incorrect:** Assuming all non-native species are beneficial.
**Correct:** Recognizing that non-native species can disrupt ecosystems.

2. **Overlooking Prevention:** Focusing solely on control methods without emphasizing prevention strategies.
**Incorrect:** Ignoring biosecurity measures.
**Correct:** Implementing measures to prevent the introduction of invasive species.

3. **Simplifying Ecological Impacts:** Underestimating the complex consequences of invasive species on ecosystems.
**Incorrect:** Viewing impacts as limited to direct competition.
**Correct:** Understanding multifaceted effects like trophic cascades and habitat alteration.

FAQ

What defines an invasive species?

An invasive species is a non-native organism that causes harm to the environment, economy, or human health after being introduced to a new habitat.

How are invasive species introduced to new environments?

They are commonly introduced through human activities such as global trade, travel, transportation, aquaculture, agriculture, and the pet trade.

What are some effective methods for controlling invasive species?

Effective methods include prevention, early detection and rapid response, mechanical and chemical control, biological control, and public education initiatives.

Why are invasive species a threat to biodiversity?

They compete with native species for resources, predation, disease transmission, and can alter habitats, leading to reduced native biodiversity and increased extinction risks.

Can invasive species ever be beneficial?

While some invasive species may provide temporary benefits, such as aesthetic value or pest control, their long-term impacts are usually detrimental to ecosystems and native species.

How do policies and legislation help manage invasive species?

Policies and legislation establish regulations and frameworks for prevention, control, and management of invasive species, including biosecurity measures, permits, and international agreements.