Abiotic Effects on an Ecosystem

1
Abiotic Effects on an Ecosystem

• The weather, soil, and such

2
Biotic or Abiotic?
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Biotic or Abiotic?

• Abiotic components non-living components
• Chemical, geological, physical factors
• Temperature
• Light
• Water
• Oxygen Supply
• Soil
• Biotic components living components
• Organisms and their relationships with other
  organisms

4
Role of the Abiotic Environment in Population
Growth

• Size and growth of population are affected by
  both biotic and abiotic factors
• Organisms are dependent on the abiotic factors of
  the environment
• They also modify these factors!
• Plants create shade, preserve water in the soil,
  consume carbon dioxide, and produce oxygen

5
Sunlight

• Source of energy for almost all organisms
• Green plants need sunlight for photosynthesis
• Adaptations occur to capture as much light as
  possible
• Water is divided into two zones
• Photic zone top layer where sunlight reaches
• Aphotic zone lower layer that sunlight does not
  penetrate

6
Oxygen Supply

• Air is composed of about 20 oxygen
• Easy for terrestrial organisms to obtain
• Oxygen is returned to the air through
  photosynthesis
• Water contains dissolved oxygen in parts per
  million
• Aquatic organisms extract this oxygen
• Pollution can lower oxygen content
• Benefits some, harms some

7
Substratum

• Soil or rock
• Acidity (pH)
• Acid rain can make soil pH too low for many
  plants
• Some plants like low pH (rhododenrons and pines)
• Texture of soil or clay content
• Determine the quantity of water the soil can hold
• Minerals
• Nitrates, phosphates, and other minerals
• Humus quantity
• Determined by the amount of decaying plant and
  animal life in soil

8
Chemical Cycles

• Within ecosystems, abiotic elements like
  nutrients are recycled and reused
• Nature has its own effective cycles of abiotic
  elements, and these cycles are crucial to every
  living organism on earth
• Carbon Cycle
• Nitrogen Cycle
• Water Cycle
• Phosphorus Cycle

9
Carbon Cycle
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Carbon Cycle

• Gaseous carbon dioxide enters the living world
  via plants
• Photosynthesis uses carbon dioxide to produce
  glucose
• Plants use glucose ot make starch, proteins, and
  fats
• Animals eat plants and use digested nutrients to
  form carbs, fats and proteins
• Organic compounds are used in cellular
  respiration in plants and animals and release
  carbon dioxide back into the air
• The other organic carbons remains in an organism
  until death then the decaying process returns
  it to the air

11
Nitrogen Cycle
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Nitrogen Cycle

• Free nitrogen cannot be used by most organism
• Free nitrogen is changed into usable, soluble
  nitrates by bacteria and lightning strikes
• Plants absorb the nitrates and synthesize nucleic
  acids and proteins
• Animals eat the plants and synthesize animal
  proteins
• Plants and animals give off wastes and eventually
  die
• Nitrogen in wastes and dead tissue is released
  through decay as ammonia
• Ammonia is converted into nitrites by
  chemosynthetic bacteria
• Nitrites are converted into nitrates by
  nitrifying bacteria
• Remaining ammonia is broken down to release free
  nitrogen

13
Water Cycle
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Water Cycle

• The sun heats up water in streams, lakes, oceans,
  etc
• The water turns to vapor and moves into the air
  (evaporation)
• Water vapor in the air cools and condenses into
  clouds
• Eventually, the air cannot hold any more moisture
  and water falls back to the Earth as
  precipitation
• Water is collected in streams, lakes, oceans or
  as groundwater

15
Phosphorus Cycle
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Phosphorous Cycle

• Phosphorus is present in compounds that dissolve
  in water
• Plants take in the phosphates from the water
• Animals eat the plants and excrete waste that
  contains phosphates, which are returned to soil
  or the ocean
• When plants and animals die, decay returns more
  phosphates to the soil or ocean