Unit 5 - Land & Water Use

5.1 - Tragedy of the Commons

Learning Objectives

• Explain the tragedy of the commons: individuals prioritize personal gain over common resources leading to depletion.

• Suggested Skill: Concept Explanation (Explain environmental concepts and processes).

Key Concepts

• Tragedy of the Commons: A situation where individuals exploit shared resources, leading to degradation.

• Essential Knowledge (EIN-2.A):

  • The concept revolves around shared resources like groundwater and fisheries being overused.

Examples of Tragedy of the Commons

• Overuse of groundwater

• Water and air pollution

• Overfishing

• Overgrazing

Causes of the Tragedy

• Lack of ownership leads to no immediate responsibility.

• Assumption that others will exploit resources if not used personally.

• No repercussions for overuse or pollution.

Problems Resulting from Mismanagement

• Overfishing consequences: fishery collapse, loss of income, and starvation.

• Air pollution leading to health issues: bronchitis and asthma.

• Pesticide runoff contaminating drinking water.

Solutions to the Tragedy of the Commons

• Implement private land ownership or government control.

• Introduce fees or taxes for resource usage (e.g., permits for grazing/logging).

• Enforce laws like Clean Air Act and Clean Water Act.

• Bureau of Land Management (BLM) manages land by collecting grazing fees and restoring overgrazed areas.

5.2 - Clearcutting

Learning Objectives

• Describe the effects of clearcutting on forests.

Key Concepts

• Clearcutting provides economic benefits but leads to environmental degradation, including:

  • Soil erosion

  • Increases in soil and water temperatures leading to flooding.

• Forests play a role in pollutant absorption and carbon storage.

• Removing trees releases CO2, contributing to climate change.

Direct Effects of Clearcutting

• Soil erosion due to loss of root structure.

• Increased turbidity in streams due to sedimentation.

• Loss of tree shade affecting local habitat temperatures.

Biodiversity Impacts

• Replaces biodiverse forests with monoculture plantations.

• Lowers species resilience and habitat diversity.

Forest Benefits

• Air pollution filtering

• CO2 storage and O2 release

• Provides habitats for diverse organisms.

Deforestation Consequences

• Reduction in air filtering and carbon storage.

• CO2 release from both decomposition and slash-and-burn agriculture.

5.3 - The Green Revolution

Learning Objectives

• Describe changes in agricultural strategies to increase production.

Key Concepts

• The Green Revolution led to:

  • Mechanized farming

  • Use of GMOs, fertilizers, and irrigation.

• Positive outcomes include increased food production.

• Negative consequences: soil erosion and biodiversity loss.

Mechanization Impact

• Increases farming efficiency but raises fossil fuel dependency.

• Heavy machinery leads to soil compaction.

Importance of High-Yield Crops

• Hybrid and genetically modified varieties improve yields, especially in famine-prone areas.

Synthetic Fertilizers

• Transition from organic to synthetic fertilizers enhances soil nutrients but causes eutrophication in waters.

Pesticides Usage

• Increases crop yields but risks contamination to non-target species (e.g., bees).

5.4 - Impact of Agricultural Practices

Learning Objectives

• Describe agricultural practices causing environmental damage.

Key Concepts

• Soil erosion, pesticide runoff, and monocrop farming lead to habitat destruction, biodiversity loss, and increased pollutants in air/water.

5.5 - Irrigation

Learning Objectives

• Describe different methods of irrigation and their environmental impacts.

Key Concepts

• Spray, furrow, and flood irrigation vary in efficiency and environmental consequence:

  • Spray irrigation reduces evaporation loss, but is costlier.

  • Furrow irrigation is inexpensive but can lead to waterlogging.

  • Flood irrigation can be inefficient and cause runoff issues.

Groundwater Concerns

• Overuse can deplete aquifers and cause salinization affecting plant roots.

5.7 - Meat Production Methods

Learning Objectives

• Identify and describe methods of meat production.

Key Concepts

• Free-range vs CAFO methods:

  • CAFOs are efficient but generate waste affecting water bodies.

  • Free-range farming has less environmental impact but is costly.

5.8 - Impacts of Overfishing

Learning Objectives

• Describe causes and problems related to overfishing.

Key Concepts

• Fishery collapse occurs due to unsustainable practices, leading to economic impacts and biodiversity loss.

• Responses include regulatory meaning of Total Allowable Catch and Individual Transferable Quotas (ITQs).

5.10 - Urbanization

Learning Objectives

• Describe urbanization impacts on the environment.

Key Concepts

• Urban sprawl leads to resource depletion, carbon emissions, and impervious surfaces causing flooding.

• Solutions include urban growth boundaries and public transportation for sustainable city planning.