Tragedy of the Commons and Sustainable Practices

Tragedy of the Commons

• Commons: Shared resources accessible to all. Examples include air, oceans, and forests.
• Carrying Capacity: The maximum resource use an environment can support without degradation.
• Sustainable Use: Using resources in a way that allows for natural replenishment.
• Overexploitation: Using resources beyond their ability to regenerate.
• Tragedy of the Commons: Describes how individuals prioritizing personal gain from shared resources ignores the collective well-being. Analogy: Herdsmen increasing herd size on a shared pasture leading to overgrazing and resource depletion for everyone.
• 2019 US Government Shutdown: Showcased consequences of unregulated shared spaces through misuse of national parks.

Irrigation & Sustainable Agriculture

Soil Conservation Techniques

• Contour Plowing: Plowing along natural land contours to reduce runoff and soil erosion.
• Terracing: Converting slopes into flat steps to allow farming on inclines and reduce water runoff.
• Windbreaks: Planting trees or barriers to reduce wind erosion and protect crops.
• Strip Cropping: Planting alternating rows of different crops to prevent large-scale pest outbreaks and soil erosion.
• Intercropping: Growing multiple crops together as part of crop diversification and soil health.
• Cover Crops: Planting crops that cover the soil instead of for harvest, preventing erosion and maintaining nutrients.

Irrigation Types

• Flood Irrigation: Flooding a field with water, simple and suitable for water-loving crops. High water losses through evaporation, waterlogging, and salinization risks.
• Furrow Irrigation: Water delivered through small channels to crop rows. Inexpensive, better water control, yet 33% water loss to evaporation.
• Spray Irrigation: Water sprayed like rain using sprinklers or pivot systems. Can add fertilizers and time watering, but expensive, uses fossil fuels, and 25% evaporation loss.
• Drip Irrigation: Water delivered directly to plant roots via perforated hoses. Minimal water loss (2-5%), but expensive setup and prone to damage/clogs.

Issues with Over-Irrigation

• Waterlogging: Oversaturated soil creates oxygen-deprived conditions, weakening or killing plants from root rot.
• Salinization: Accumulation of salts in soil due to water evaporation leading to infertile soil.

Pest Control Methods & Integrated Pest Management (IPM)

• Pesticides: Chemicals used to kill or repel pests. (Herbicides, Fungicides, Rodenticides, Insecticides)
• Monocropping: Growing a single crop over large areas, increasing pest susceptibility.
• Pesticide Resistance: Pests develop immunity to pesticides leading to stronger pesticide use. (Pesticide Treadmill Effect).
• Broad-Spectrum Pesticides: Kill many pest species, leading to harming non-target species.
• Narrow-Spectrum Pesticides: Target specific pests.
• Problems with Pesticides: Pesticide resistance, persistent pesticides contaminating the environment, harm to non-target species, biomagnification affecting apex predators.

Integrated Pest Management (IPM):

• Goal: Reduce pesticide use and manage pest populations effectively.

1. Biological Controls: Introducing predators of pests.
2. Physical Controls: Traps, tilling, screens, or weed blockers.
3. Chemical Controls: selective use of pesticides.
4. Cultural Practices: Crop rotation, intercropping, pest-resistant crops, and habitat creation for predators.

Mining

• Ore: Material containing valuable minerals (e.g., coal, gold).
• Overburden: Rock and soil above the ore.
• Spoils: Overburden removed during mining.
• Tailings: Leftover material after ore refining.
• Mining Types:
  • Surface Mining: Open-pit, strip mining, mountaintop removal, increasing erosion, reducing albedo, disrupting habitats.
  • Subsurface Mining: Accessing deep minerals, but expensive and hazardous. Risks include black lung disease, mine collapses.
• Refining Methods:
  • Cyanide Heap Leaching: Gold extraction, generates toxic waste.
  • Acid Mine Drainage: Sulfuric acid from exposed pyrite contaminates waterways.
• Negative Effects of Abandoned Mines: Increased erosion, water contamination (acid mine drainage), and habitat disruption.
• Mine Remediation: Goal is to restore abandoned mines sustainably using methods like replanting native species for ecological recovery.

Sustainable Forestry

• Sustainable Forestry: Managing forests to balance ecological benefits, economic benefits, and social benefits.
• Clearcutting: Removing all trees in an area.
• Selective Cutting: Removing specific trees to minimize environmental impact.
• Prescribed Burns: Controlled fires to reduce brush and prevent destructive wildfires.
• Forest Services: Ecological services (carbon storage, oxygen production, soil protection, biodiversity support) and economic services (lumber, paper, jobs).
• Harvesting Methods:
  • Maximum Sustainable Yield: Harvesting trees at peak growth rate, but can limit mature forests and reduce biodiversity.
  • Clearcutting: High yields, efficient replanting, but habitat destruction, erosion, water pollution issues.
  • Selective Cutting: Less environmental harm, preserves habitats, more expensive and less efficient.
  • Strip/Stand Cutting: Harvest sections while leaving others for regrowth.
• Forest Management Laws: National Forest Management Act (1976): requires sustainable long-term plans for resource extraction, recreation, and habitat conservation.

Explore the concepts of the Tragedy of the Commons, carrying capacity, and sustainable agriculture practices. This quiz examines how shared resources can be mismanaged and the techniques for soil conservation that promote sustainability. Understand the balance between personal gain and collective well-being in resource management.