Unit 5: Land and water use

5.1 Tragedy of the Commons

Learning Objective

  • EIN-2.A: Explain the concept of the tragedy of the commons.

Essential Knowledge

  • EIN-2.A.1: The tragedy of the commons suggests that individuals will use shared resources in their own self-interest rather than in keeping with the common good, thereby depleting the resources.

Suggested Skill

  • 1.B: Concept Explanation: Explain environmental concepts and processes.

Introduction

  • Engage common experience with public restrooms:

    • Discussion on the cleanliness levels of public restrooms compared to personal bathrooms.

Examples of the Tragedy of the Commons

  • Individuals exploit shared/public resources leading to degradation.

    • Overuse of groundwater: Commonly exploited public resource.

    • Pollution: Water and air pollution from various activities.

    • Overfishing: Leading to depletion of fish stocks.

    • Overgrazing: Excessive grazing leading to land degradation.

Conditions for the Tragedy to Occur

  1. No Ownership: Lack of individual ownership leads to neglect of the resource.

  2. Assumptive Behavior: Individuals assume others will exploit the resource.

  3. Lack of Immediate Penalty: Absence of immediate negative consequences for exploitation, as seen in some industries, e.g., hat factories.

Problems Arising from the Tragedy

  • Overfishing: Can result in fishery collapse and loss of income and food sources.

  • Air Pollution: Causes health issues such as bronchitis and asthma, and increases healthcare costs.

  • Pesticide Runoff: Contaminates drinking water, creating serious health risks.

Solutions to the Tragedy of the Commons

  1. Private Land Ownership: Establishing ownership can lead to better management of resources.

  2. Fees or Taxes for Use: Implementation of permit systems for activities like grazing, logging, or hiking.

  3. Regulatory Measures: Laws and fines can be enacted to combat pollution.

    • Examples:

      • Clean Air Act

      • Clean Water Act

      • Safe Drinking Water Act

  4. Management by Agencies: E.g., Bureau of Land Management (BLM) manages rangelands by collecting grazing fees from ranchers and assessing land deterioration.

Practice FRQ 5.1

  • Task: Identify one commons (other than oceans) and explain human impacts and management solutions.

5.2 Clearcutting & Sustainable Forestry

Learning Objectives

  • EIN-2.B: Describe the effect of clearcutting on forests.

Essential Knowledge

  • EIN-2.B.1: Clearcutting can be economically beneficial but leads to soil erosion, increased soil and stream temperatures, and flooding.

  • EIN-2.B.2: Forests absorb pollutants and store CO2; cutting and burning release CO2 contributing to climate change.

Suggested Skill

  • STB-1.G: Describe methods for mitigating human impact on forests.

Forest Benefits

  1. Filtration of Air Pollutants: Trees filter dust from the air and improve air quality.

  2. Carbon Storage: Trees store CO2 and release O2, critical for climate regulation.

  3. Habitat: Provide space and resources for diverse organisms, promoting biodiversity and ecotourism.

Definitions

  • Deforestation: Permanent removal of forest for agriculture and urban development, leading to various ecological issues.

  • Clearcutting: Temporary removal where every tree is cut down for timber sales, leading to uniform growth in tree farming.

Impact of Clearcutting

  • Biodiversity Loss: Replacement of diverse forests with single-species plantations lowers resilience.

  • Age Uniformity: Leads to similar aged trees, causing simultaneous harvesting and minimizing habitat variety.

Negative Effects of Clearcutting

  1. Soil Erosion

  2. Increased Soil/Stream Temperatures

  3. Flooding, Landslides, Desertification

  4. Increased Atmospheric CO2: Reduced tree cover results in higher CO2 levels due to less photosynthesis.

Sustainable Forestry Practices

  • Ecologically Sustainable Forestry: Minimizes ecological damage with practices like selective and strip cutting.

  • Benefits of Sustainable Practices:

    • Preserves habitat and biodiversity.

    • Maintains soil integrity and protects water quality.

    • Promotes long-term land productivity.

Fire Management

  1. Fire Suppression: Prevents uncontrolled fire spread.

  2. Prescribed Burns: Controlled burning to manage dead vegetation, reducing fuel for wildfires.

  3. Promotion of Natural Fires: Allowing beneficial fires for ecosystem health.

Mitigating Deforestation Effects

  1. Reforestation: Planting trees in deforested areas to restore ecosystems.

  2. Wood Reuse: Encouraging recycling and repurposing of old timber and furniture.

  3. Sustainable Wood Purchases: Supporting ecologically responsible forestry.

Practice FRQ 5.2

  • Task: Identify characteristics of a forest adversely affected when fires are suppressed and how prescribed burns can remedy these conditions.

5.3 The Green Revolution

Learning Objectives

  • EIN-2.C: Describe changes in agricultural practices due to the Green Revolution.

Essential Knowledge

  • EIN-2.C.1 - EIN-2.C.2: The shift to industrial agriculture increased food production but brought negative consequences like soil erosion and biodiversity loss.

Practice Examples of the Green Revolution

  • Transition from family farms to industrial-scale farming.

  • Use of mechanization, GMOs, fertilizers, and pesticides to maximize yields.

  • Resulting benefits include decreased world hunger and increased carrying capacity but led to environmental degradation.

Mechanization

  • Advantages: Increases crop yields and efficiency.

  • Dependence on Fossil Fuels: Increased greenhouse gas emissions from machinery and potential soil compaction.

High-Yield Variety (HYV) Crops

  • Cultivated to enhance crop yields, HYV crops include hybrids and genetically modified organisms.

Genetic Modification Offered

  1. Traits like drought tolerance and pest resistance enhancing yield stability in typically vulnerable regions.

Synthetic Fertilizers & Irrigation

  • Shift from organic to synthetic fertilizers, which can pollute waterways and require fossil fuel for production.

  • Irrigation expands agricultural possibilities but can deplete groundwater and lead to soil salinization.

Summary of the Green Revolution

  • Objective: Increase food production and agricultural profitability through advanced technologies.

  • Pros: Increased food supply and agricultural expansion in previously non-productive areas.

  • Cons: Environmental degradation including erosion, loss of biodiversity, and increased chemical contamination.

5.4 Agricultural Practices & Their Impact

Learning Objectives

  • EIN-2.D: Describe agricultural practices that can harm the environment.

Essential Knowledge

  • Agricultural methods like tilling, slash-and-burn farming, and chemical fertilizers can lead to extensive environmental damage.

Monocropping and Its Effects

  1. Monocropping: Growing one crop species significantly increases efficiency but decreases biodiversity and increases soil erosion.

  2. Historical Context: Bananas exemplify monocropping repercussions, as tropical crops like Gros Michel were devastated by disease due to lack of genetic diversity.

Tilling Impact

  • While it aids initial planting and root growth, over time, it contributes to erosion and degradation of organic matter and nutrients.

The Slash & Burn Method

  • Results in loss of habitat and biodiversity, and releases harmful greenhouse gases. Can be beneficial if controlled but has destructive long-term effects.

5.5 Irrigation Methods

Learning Objectives

  • EIN-2.E and EIN-2.F: Explain various irrigation methods and their efficiencies and drawbacks.

Essential Knowledge

  • Water Usage in Agriculture: 70% of freshwater is used for irrigation with several systems available, including drip, flood, and furrow irrigation.

  • Waterlogging and Salinization: Excessive irrigation practices can lead to waterlogged soils and detrimental salinity levels.

Irrigation Systems Overview

  • Furrow: Simple, effective but loses 33% of water.

  • Flood: Efficient but risks drowning plants and leads to waterlogging issues.

  • Spray: More efficient than previous methods, yet energy-intensive and costly.

  • Drip: Most efficient but expensive, maintaining high efficacy while conserving water.

5.6 Pest Control Methods & Integrated Pest Management (IPM)

Learning Objectives

  • EIN-2.G: Understand various pest control methods and their implications.

Essential Knowledge

  • Common pest control methods contribute to resistance and environmental health concerns.

Integrated Pest Management (IPM)

  • Definition: A methodology combining biological, physical, and selected chemical strategies to manage pest populations responsibly.

Benefits and Challenges of Using IPM

  • Reduces pesticide risks and minimizes environmental disruption but may involve complexity and higher costs.

5.7 Meat Production Methods

Learning Objectives

  • EIN-2.H and EIN-2.1: Understanding different meat production methods and their environmental impacts.

Methods of Meat Production

  1. Concentrated Animal Feeding Operations (CAFOs): Increase production efficiency but lead to significant environmental concerns.

  2. Free-Range Grazing: Promotes animal welfare and disperses waste but requires more land.

Overgrazing Considerations

  • Overgrazing leads to erosion and desertification, suggesting rotational grazing solutions.

Resource Inefficiency in Meat Production

  • Compared to plant agriculture, meat production is substantially less efficient regarding land, water, and energy use.

Practice FRQ 5.7

  • Task: Explain the environmental benefits of plant-based diets compared to meat-based diets.