APES UNIT 5

📖 Garrett Hardin's "The Tragedy of the Commons"

• Written in 1968.

• Parallels resource depletion & pollution worldwide.

• The commons (seas, air, water, animals, minerals) are for human use, but exploitation makes some people rich.

🌍 Environmental Issues Related to "The Tragedy of the Commons"

• Air pollution

• Burning fossil fuels causing global warming

• Logging of old-growth forests & slash-and-burn practices

• Habitat destruction & poaching

• Over-extraction of groundwater from excessive irrigation

• Overfishing

• Overpopulation

⚖ Limits to "The Tragedy of the Commons"

• Dividing the commons into privately owned parcels fragments policies.

• Different standards/practices on one parcel may or may not affect others.

• Environmental decisions are long-term, while economic decisions are short-term.

• Discount rates could encourage investors to pay a short-term price for a long-term gain.

• Market pressures affect privately owned land.

• Controlling some commons (air/oceans) is harder than others (land/lakes/forests).

🌳 Clear-cutting

All trees in an area are cut at the same time.

🌍 Environmental Impacts of Clear-cutting

• Habitat loss reduces biodiversity.

• Sunlight reaches the ground, making it warmer and drier, unsuitable for many forest plants.

• Temporary wood availability followed by long periods without wood.

• Reduces carbon sinks, increasing atmospheric CO2.

• Runoff increases, leading to soil erosion.

🌿 Edge Effect

• Local environment changes along boundaries (edges).

• Forest edges are created when trees are harvested (especially with clear-cutting).

• Tree canopies provide shade, maintaining a cooler and moister environment.

🌍 Deforestation

• The conversion of forested areas into non-forested areas for agriculture, mining, or urban development.

💥 Impacts of Deforestation

• Runoff into aquatic ecosystems, climate change, and erosion decrease soil fertility.

• Without shade, forest soils dry out quickly.

• Degraded environments with decreased biodiversity and ecological services.

• Forests house 80% of land animals and plants.

• Increases habitat fragmentation and CO2 emissions from burning and tree decay.

• Reduces habitats for migratory birds and butterflies.

• Endangers niche-specialized species.

🌱 Deforestation Mitigation

• Adopt uneven-aged forest management practices.

• Educate farmers about sustainable forest practices.

• Monitor and enforce timber-harvesting laws.

• Grow timber on longer rotations.

• Reduce fragmentation in large forests.

• Reduce road building in forests.

• Eliminate clear-cutting practices.

• Sustainable tree-cutting methods.

🌾 First Agricultural Revolution (2000+ B.C.E.)

• Transition from hunting and gathering to the domestication of plants and animals.

• Allowed people to settle in areas and create cities.

• Settled communities enabled people to observe and experiment with plants.

🚜 Second Agricultural Revolution (1700–1900 C.E.)

• Occurred alongside the Industrial Revolution, with mechanization playing a major role.

• Advances in livestock breeding increased agricultural output.

• Enabled large urban populations to be fed.

• Improved methods of soil preparation, fertilization, crop care, and harvesting.

• Banking and lending practices helped farmers afford new equipment.

• New crops arrived in Europe from trade with the Americas.

• Railroads facilitated product distribution.

• The seed drill prevented seed waste and allowed for row planting.

• Tractors and farm machinery improved efficiency.

🌱 Third Agricultural Revolution (1900 C.E.–present)

• Mechanization like tractors and combines requires less labor and lowers food prices.

• Scientific farming methods include biotechnology, genetic engineering, and pesticides, with a focus on sustainable methods.

🌾 First Green Revolution (1940s–1980s)

Introduction of inorganic fertilizers, synthetic pesticides, new irrigation methods, and disease-resistant, high-yielding crop seeds.

🌱 Second Green Revolution (1980s–Present)

• New engineering techniques and free-trade agreements shaped agricultural policies and food production.

• Development of genetically modified organisms (GMOs) with genes that don't exist in nature.

• Examples: BT corn (modified with bacterial insecticide genes) and Golden Rice (modified with daffodil genes to produce more beta-carotene, which converts to Vitamin A).

🌱 Agricultural Productivity

• Refers to producing greater output with less input.

• Increases efficiency on farms, stabilizes food prices, and provides more food availability, especially important for developing countries.

🏜 Desertification

The conversion of marginal rangeland or cropland into more desert-like land types.

🐮 Overgrazing

• Occurs when plants are re-grazed before their roots recover, reducing root growth by up to 90%.

🌾 Fertilizers

• Provide plants with the nutrients they need to grow healthy and strong.

⚗ Inorganic Fertilizers

Fertilizers mined from mineral deposits or manufactured from synthetic compounds.

🌱 Organic Fertilizers

• Fertilizers from organic sources like bone meal, compost, fish extracts, manure, or seaweed.

🥗 Genetically Modified Foods

• Foods produced from organisms (plants or animals) that have had changes introduced into their DNA.

🧬 Genetic Engineering Techniques

Allow for the introduction of new traits and greater control over them compared to previous methods.

🌿 Rangelands

• Native grasslands, woodlands, wetlands, and deserts grazed by livestock or wild animals.

• Managed through livestock grazing and prescribed fire, not intensive agricultural practices like seeding, irrigation, or fertilizers.

🔥 Slash-and-Burn Agriculture

A method where wild or forested land is clear-cut, and any remaining vegetation is burned to clear land for farming.

🌬 Soil Erosion

The movement of weathered rock or soil components from one place to another due to flowing water, wind, and human activity.

💧 Soil Degradation

• Decline in soil condition caused by improper use or poor management, typically for agricultural, industrial, or urban purposes.

🏜 Salinization

• Occurs when water evaporates from the soil, leaving behind dissolved salts in the topsoil.

💦 Waterlogging

• Occurs when soil becomes saturated with water, causing a rise in the water table.

🌾 Tillage

An agricultural method where the surface is plowed and broken up to expose the soil, which is then smoothed and planted.

💧 Irrigation

• The controlled application of water to plants at needed intervals.

• Has been essential for agriculture for over 5,000 years.

🚜 Ditch Irrigation

• Ditches are dug, and seedlings are planted in rows.

• Water is moved through canals or furrows between the rows using siphon tubes to bring water from the main ditch.

🌱 Drip Irrigation

• Water is delivered directly to the root zone of plants through small tubes.

• Water is dispensed at a measured rate, minimizing waste.

🌊 Flood Irrigation

• Water is pumped or brought to the fields and allowed to flow across the ground among the crops.

• Simple, inexpensive, and commonly used in less-developed countries.

📏 Furrow Irrigation (Channel)

• Small parallel channels are dug along the field length, usually along the slope.

• Water is applied to the top of each furrow and flows down the field, infiltrating more at the start and less at the end.

🌧 Spray Irrigation

Uses overhead sprinklers, sprays, or guns to spray water onto crops, mimicking natural rainfall.

💥 Pesticides

Used to control pests, but their use has drawbacks such as toxicity and environmental accumulation.

🌱 Integrated Pest Management (IPM)

• An ecologically based approach to pest control.

• Combines biological, chemical, and physical methods to manage pests, requiring an understanding of pest ecology and life cycle.

🦠 Types of Pesticides

• Biological Pesticides: Living organisms used to control pests.

• Carbamates (Urethanes): Affect the nervous system of pests, causing tissue swelling.

• Fumigants: Used to sterilize soil and prevent pest infestation of stored grain.

• Inorganic Pesticides: Highly toxic substances (e.g., arsenic, copper, lead, mercury) that accumulate in the environment.

• Organic Pesticides: Natural poisons derived from plants, such as tobacco or chrysanthemum.

• Organophosphates: Extremely toxic but break down quickly in the environment.

🔬 Persistent Organic Pollutants (POPs)

• Organic compounds that don’t break down chemically or biologically, so they accumulate in organisms' fatty tissues.

• Biomagnification occurs in food webs.

🚫 The Pesticide Treadmill

• Pesticide Resistance: Pest populations evolve resistance to pesticides, making them less effective.

• Pesticide Treadmill: Farmers must use increasingly toxic chemicals to control resistant pests.

🌍 Integrated Pest Management (IPM) Methods

• Mechanical controls, such as traps.

• Genetically modified crops that are pest-resistant.

• Intercropping: Planting multiple crops on the same land.

• Natural insect predators: Encouraging beneficial insects.

• Pest-repellant crops: Planting crops that naturally repel pests.

• Polyculture: Raising multiple types of crops or animals together.

• Regular monitoring and traps.

• Releasing sterilized insects.

• Crop rotation to disrupt insect life cycles.

• Using mulch to control weeds.

• Pheromones and hormone interrupters to disrupt pest behavior.

• Pyrethroids or natural microorganisms for pest control.

🌱 Benefits of IPM

• Reduces bioaccumulation and biomagnification of pesticides.

• Prevents pests from becoming resistant to pesticides.

• Avoids destruction of beneficial organisms and non-target species.

🐮 Concentrated Animal Feeding Operations (CAFOs)

Intensive animal feeding operations where large numbers of animals are confined in feeding pens for over 45 days a year.

💩 Environmental Impact of CAFOs

• Large amounts of animal waste from CAFOs present a risk to water quality and aquatic ecosystems.

• States with high concentrations of CAFOs experience 20-30 serious water-quality problems annually due to manure management issues.

🌊 Water Pollution from CAFOs

• CAFO waste can negatively impact water quality through two main pollutants:

  1. Soluble nitrogen compounds

  2. Phosphorus

• Both can contaminate water sources, leading to pollution.

💨 Gas Emissions from CAFOs

• CAFOs release several types of harmful gases:

  • Ammonia

  • Hydrogen sulfide

  • Methane

  • Particulate matter

• Decomposition of animal manure stored in large quantities is the primary cause of these emissions.

🎣 Fishing Industry Pressures

• The fishing industry is under pressure from growing demand and falling supply.

• Both marine and terrestrial life depend on primary producers, like aquatic plants.

🌊 Importance of Coastal Waters

• Aquatic plants require sunlight and are restricted to shallow coastal waters.

• These waters make up less than 10% of the world's ocean area but contain 90% of all marine species.

🐟 Aquaculture

• Aquaculture (also known as mariculture or fish farming) involves commercially growing aquatic organisms for food.

• It includes stocking, feeding, protecting from predators, and harvesting.

💡 Key Factors for Profitable Aquaculture

For aquaculture to be profitable, the species must be:

1. Marketable

2. Inexpensive to raise

3. Efficient at converting feed into fish biomass

4. Disease-resistant

🌍 Methods to Manage Marine Fishing

• Eliminate government subsidies for commercial fishing.

• Increase the number of marine sanctuaries.

• Prevent fish imports from unsustainable fishing countries.

• Label fish products caught or raised sustainably.

• Require fishing licenses, open inspections, and trade sanctions if limits are exceeded.

🌱 Methods to Restore Freshwater Fish Food Webs

• Control erosion.

• Control invasive species.

• Create/restore fish passages.

• Enforce laws that protect coastal estuaries and wetlands.

• Plant native vegetation on stream banks.

⛏ Mining

• Mining is the process of removing mineral resources from the ground.

• It can involve various methods like underground mines, drilling, room-and-pillar mining, open pit, dredging, contour strip mining, and mountaintop removal.

🌍 Surface Mining Methods

• Contour mining: Removing overburden along a ridge or hillside to follow the contours of the land.

• Dredging: A method for mining below the water table, often used in gold mining. Small dredges use suction or scoops to bring material from the water’s bottom.

• In situ: Small holes are drilled into the Earth, and toxic chemical solvents are injected to extract the resource.

• Mountaintop removal: Removing the mountaintops to expose coal seams and disposing of overburden in adjacent valley fills.

• Open pit: Extracting rock or minerals from the Earth by removing material from an open pit.

• Strip mining: Removing soil above coal seams to expose the coal.

🏗 Underground Mining Methods

• Blast: Uses explosives to break up material, which is then loaded onto conveyors for transport.

• Longwall mining: A rotating drum with teeth pulls back and forth across a coal seam, breaking the material loose for transport.

• Room and pillar: Leaves pillars of coal to support the roof of the mine, which are later removed, causing the mine to collapse.

⚠ Environmental Damage from Mining

• Acid mine drainage

• Disruption of natural habitats

• Chemicals from in situ leaching entering the water table

• Disruption of soil microorganisms, impacting nutrient cycling

• Dust release, causing lung problems and health risks

• Land subsidence

• Large consumption and release of water

🏙 Urbanization

• Urbanization: The movement of people from rural areas to cities and the changes that come with it.

• The greatest urbanization growth is occurring in Asia and Africa.

✅ Pros of Urbanization

• Better educational delivery system

• Better sanitation systems

• High tax revenues from large populations

• Mass transit reduces fossil fuel reliance

• Point-source pollution is easier to manage

• Efficient recycling systems

• Urban areas attract industries due to resources, distribution, and labor

❌ Cons of Urbanization

• Overcrowded schools

• Sanitation systems struggle with high waste volumes

• High demand for social services due to poverty

• Infrastructure struggles to keep up with growth

• High pollution levels in dense populations

• Solid-waste buildup and landfill shortages

• Higher crime rates and job shortages due to population increase

🏡 Urban Sprawl

• Urban Sprawl: Expansion of low-density, car-dependent communities outward from city centers.

• Job Sprawl: Spread-out employment centers outside city centers.

• Impacts:

  • Loss of agricultural land

  • Single-family homes dominate, separated by roads and lawns

  • Single-use development: Separates living, work, and recreation, requiring more car use

🌿 Smart Growth

• Smart Growth: Encourages compact, walkable, transit-oriented communities to limit urban sprawl.

• Strategies:

  • Mixed-use planning (residential, commercial, cultural, industrial in one area)

  • Greenbelts & undeveloped land around cities

  • Tax incentives for urban-centered businesses

  • Subsidies for mass transit

  • Converting abandoned buildings into green spaces

🏗 Urban Development

• Urban Development: Designing cities for functionality, sustainability, and attractiveness.

• Strategies:

  • Recycled materials & waste-minimizing designs

  • Energy conservation (solar, clean energy incentives)

  • Indoor air quality improvements

  • Public transit-focused building locations

  • Preserving community history & culture

  • Water-efficient landscaping (xeriscaping)

🌊 Urban Runoff

• Urban Runoff: Rainwater runoff from cities, causing flooding & pollution.

• Effects:

  • Erosion & sedimentation, reducing water quality

  • Warmer urban water harming aquatic life

  • Pollution from gasoline, oil, metals, fertilizers, pesticides, and trash

💡 Solutions for Urban Runoff

• Construct wetlands to filter water before it enters larger bodies

• Retention basins to absorb stormwater into groundwater

• Street-sweeping vacuums to remove trash & debris

• Urban parks & green spaces to increase infiltration

🌍 Ecological Footprint

• A measure of human demand on Earth's ecosystems.

• Standardized to compare natural resource use vs. Earth’s ability to regenerate.

📏 What It Represents

The amount of biologically productive land & sea needed to:
✅ Supply resources a population consumes
✅ Absorb and process the waste produced

♻ Why It Matters

• Helps determine sustainability of human activities.

• Larger footprints indicate greater resource consumption & environmental impact.

• Can be reduced by:
  ✅ Using renewable energy
  ✅ Reducing waste & pollution
  ✅ Sustainable agriculture & fishing

🌱 Sustainability

• The ability of human civilization & the biosphere to coexist by balancing resource use.

• Ensures that resources are not depleted faster than they can be replaced.

🔢 IPAT Formula

I = P × A × T

• I = Environmental Impact

• P = Population

• A = Affluence (Consumption per person)

• T = Technology (Impact per unit of consumption)

⚠ Threats to Sustainability

🌾 Sustainable Agriculture

• Focuses on long-term solutions for food production, environment, and energy efficiency.

✅ Practices Include:

• Ecological pest management

• Diversifying farms to reduce risks

• Increasing energy efficiency

• Crop rotation for better yields & pest control

• Water conservation & quality protection

• Cover crops & manure for soil fertility

🌍 Soil Conservation Techniques

1⃣ Contour Plowing – Plowing along land contours to reduce erosion
2⃣ No-Till Agriculture – Leaving soil undisturbed, preserving nutrients
3⃣ Perennial Crops – Long-living plants (e.g., fruit trees)
4⃣ Strip Cropping – Alternating strips of different crops
5⃣ Terracing – Creating step-like levels on slopes to reduce runoff
6⃣ Windbreaks – Rows of trees to protect against wind erosion