unit 5 environmental

• Unit 5 Land Use exam.

  <|>Tragedy of the Commons:

  • Shared public resource degraded when used in self-interest
  • Examples: overgrazing on unowned fields, overfishing in unowned oceans, water and air pollution
  • Solutions: privatize, give fees for overuse, legislation approach like clean air act
• Clear-cutting forests:

  • Results in soil erosion, less shade for streams, increased stream temperatures, less dissolved oxygen, higher turbidity, flooding, landslides
  • Replacing with non-native tree plantations lowers biodiversity and ecosystem resilience
• Green Revolution:

  • Industrialization of food production with mechanization, GMOs, new irrigation, fertilization, and pesticide methods
  • Benefits: increased efficiency, food yields, decreased world hunger
  • Consequences: more fossil fuels, soil compaction, less biodiversity, eutrophication, climate change
• Agricultural practices:

  • Monocropping decreases biodiversity and soil fertility
  • Tilling loosens soil but increases erosion and releases CO2
  • Slash and burn leads to deforestation and greenhouse gas emissions
  • Synthetic fertilizers cause eutrophication of water bodies
• Irrigation:

  • Types: furrow, flood, spray, drip (most efficient)
  • Overwatering leads to water logging, soil salinization
  • Groundwater depletion can cause saltwater intrusion and cone of depression
• Pest control:

  • Chemicals like rodenticides, fungicides, insecticides, herbicides
  • Pesticide treadmill: resistance leads to more chemical use
  • Alternatives: GMOs with resistance genes, organic farming
• Meat production:

  • Confined animal feeding operations (CAFOs) maximize land use and profit
  • Downsides: antibiotic use, water contamination, greenhouse gas emissions
  • Manure lagoons can overflow and contaminate surface waters
  • Free-range grazing and rotational grazing are more sustainable alternatives
• Overfishing can lead to fishery collapse, resulting in decreased tourism, decline in ocean ecosystems, and economic consequences for fishermen and consumers
• Tragedy of the commons is when fishing to the point where the population cannot recover
• Bottom trolling is a destructive fishing method that can harm bottom habitats, destroy structures like coral reefs, and result in bycatch of unintended species
• Mining involves removing overburden to access ore reserves, extracting the mineral of interest through smelting, and leaving behind waste materials like tailings or slag
• Surface mining disrupts habitats more than subsurface mining, leading to habitat loss, erosion into streams, and environmental impacts like acid mine drainage
• Urbanization disrupts habitats, changes the water cycle, and can lead to urban blight as suburbs expand and cities decline in population
• Ways to reduce urban runoff include using permeable pavement, rain gardens, green roofs, and cisterns to increase infiltration and decrease pollution in runoff
• Integrated pest management involves using various methods like bio controls, attracting beneficial insects, rotating crops, and monitoring to reduce the need for pesticides
• Sustainable agriculture practices include conserving soil through methods like contour plowing, planting cover crops, using windbreaks, and rotating crops to increase soil fertility and reduce erosion
• Aquaculture reduces pressure on wild fish populations but can lead to antibiotic use, escape of farmed species, and disease transmission to wild fish populations
• Ecologically sustainable forestry practices include selectively cutting trees, replanting native species, using recycled wood, and promoting prescribed burns to reduce biomass buildup and promote nutrient cycling