Human Effects

Ecosystem Services - Benefits that people obtain from the ecosystem

provisioning services - natural resources (food, raw material, energy

regulating services - affect the abundance of resources that people obtain from Ecosystems

cultural services - tourism and natural health benefits

supporting services - indirect effects (nutrient cycling, photosynthesis)

Extinctions:

  • 0.1-1 extinction happen per million species per year

Mass Extinction - a short period of time when high numbers of species go extinct

  • 5 mass extinctions have been recorded, as was during the dinosaurs

Human Population Growth:

  • Humans are greatest threat to biodiversity

  • major cause of habitat destruction, overusing resources, pollution, and excess waste

Ecological footprint - estimate of Earth’s surface required to produce the resources that we use and absorb

  • 2010, record that 4.2 acres are available per person

Biodiversity and Ecosystem Function

  • Ecosystems with higher biodiversity have high productivity (energy flow, nutrient cycle)

  • Keystone Species - species that are crucial to ecosystems function

    • Wolves, Bees, Elephants, Grizzly Bears, Sea Otters, Sugar Maple Trees

  • Habitat Destruction is the biggest human caused threat to biodiversity

    • deforestation, draining the wetlands, and urbanization

  • Habitat Fragmation - when a natural ecosystem isn’t completely destroyed, but it becomes broken or separated

    • Highways, roads

Overexploitation - Hunting or harvesting natural populations at an exceed rate faster than they can reproduce

  • Overfishing, poaching, large-scale mining, extraction of fossil fuels at a high rate

Pollution:

Microplastics (>5mm) huge threat to oceans and their biodiversity

Euthopication - Excess nutrients introduced to bodies of water causing dense plant growth and death of animals due to lack of oxygen (creates dead zones)

  • oil spills, acid rain, water contamination

  • plastic can take 500 years to bio degrade in the ocean

Fast Fashion: Business model of replicating recent designers and high fashion designs, mass producing and selling them for a low cost while demand is high

Air Pollution and the Ozone:

  • Chlorofluorocarbons - caused thinning of the ozone layer

    • 1987 Montreal protocol called for phaseout of 99% ozone depleting substances

  • Over production of greenhouse gasses increases heat trapping and overall heating of Earth’s atmosphere


Results:

  • colder biomes wiped out due to climate warming

  • deserts becoming hotter and dryer

  • migration from warm weather climates to cooler

  • melting ice caps and rising sea level

  • coral bleaching from warmer waters

  • more extreme weather: Hurricanes, Tsunamis, Volcanic Eruptions, Earthquakes