HUMAN EFFECTS ON ECOSYSTEMS

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HUMAN EFFECTS ON ECOSYSTEMS
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Humans and Biodiversity

• Human use of ecosystems
• Humans have decreased biodiversity of ecosystems
  at a very fast rate

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Factors Affecting Biodiversity

• 5 factors affecting biodiversity
• 1. Habitat change
• Humans alter a habitat enough that the native
  species can no longer live there
• The species either die or move to another habitat
• We change habitats for agriculture, forestry, and
  urban development
• Sometimes habitats are only changed slightly
  which forces species to live among houses,
  buildings, and small forest areas

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Factors Affecting Biodiversity

• 2. Overexploitation
• We use resources faster than they can be replaced
• Can lead to extinction
• ex. Over fishing has reduced the number of fish
  in the worlds ocean

Shark Alert Species Struggle!
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Factors Affecting Biodiversity

• 3. Climate change
• Average temperature, rainfall, and wind increase
  or decrease
• Individuals need to adapt to new conditions in
  order to survive
• Major cause of loss of biodiversity around the
  world
• Global warming is an increase in the earths
  average temperature
• Mainly caused by carbon dioxide emissions

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Climate Change means Habitat Change
Climate Change
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Factors Affecting Biodiversity

• 4. Invasive species
• Introduction of non-native species to all parts
  of the globe
• This species can cause harm to an ecosystem
  because they compete with native species
• They would also have no predators in a new
  ecosystem
• Ex. Asian long horn beetle in this area has
  damaged trees and caused them to be removed

Zebra and Quagga Mussels
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Factors Affecting Biodiversity

• 5. Pollution
• Any substance added to the environment that
  produces a condition that is harmful to organisms
• ex. solid waste that cant be recycled
• - CO2 gas in the air produced from
  cars, air planes, power plants, and
  factories
• - fertilizer run-off from farms
• - salt run-off from roads

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Impact of Pollution on Ecosystems

• In Canada, pollutants come from mining and
  refining metals, electric power generators, oil
  and gas operations, and cars
• Nitrogen and sulphur are the most common
  pollutants in those emissions
• The emissions combine with water vapour in the
  air to form acids (this forms acid rain)
• Affects soil, vegetation, lakes, rivers, and
  terrestrial and aquatic animals
• Acid rain can damage the waxy coating that
  protects leaves and it can seep into the soil and
  burn the skin of earthworms

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Formation of Acid Rain
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Assessing Effects on Soil

• Soil Profile
• 1. topsoil
• Uppermost layer in soil
• Contains decaying organic matter, rock particles,
  bacteria, fungi, insects, worms
• 2. subsoil
• Layer below topsoil
• Has roots from trees and bacteria
• 3. bedrock
• Bottom of the soil
• Is solid rock and water cant pass through it
• Therefore, acid rain would affect the topsoil and
  subsoil

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The pH Scale

• Acidity is an abiotic factor that is connected to
  the chemical environment of soil
• Acids are very common in our life, for example,
  in orange juice we drink
• pH scale is a measurement of the acidity of
  substances
• ex. Sour taste in lemons
• - water is said to be neutral, pH 7
• Low pH means substance is very acidic, ex. pH 2
• Acidic soil can damage plant growth

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