Ecosystems

1
Ecosystems

• Matter and Energy in the Ecosystem

2
Objectives

• Identify the roles of producers, consumers, and
  decomposers
• Explain the concept of the trophic level.
• Describe food chains and food webs.
• Examine how ecosystem structure is related to
  population changes and the transfer of
  pollutants.
• Investigate movement of energy through an
  ecosystem.

3
Objectives

• Define ecological pyramid, and explain its
  relationship to energy in an ecosystem.
• Describe the chemical composition of the human
  body.
• Explain the water cycle, the carbon cycle, and
  the nitrogen cycle.

4
Producers

• Organisms that make their own food from inorganic
  molecules and energy.
• Plants are most familiar
• Obtain energy through photosynthesis or
  chemosynthesis

5
Consumers

• Cannot make their own food
• Include all animals, fungi, many protists, and
  bacteria
• Obtain E by eating other organisms
• 4 types herbivores, carnivores, omnivores,
  scavengers

6
Decomposers

• Bacteria and fungi that consume bodies of dead
  organisms or other organic wastes
• Crucial to environment by recycling nutrients
  from organisms back to environment

7
Trophic Levels

• Different feeding levels of organisms in an
  ecosystem
• A layer in the structure of feeding relationships
  in an ecosystem

8
Food Chain

• A series of different organisms that transfer
  food between the trophic levels of and ecosystem

9
Food Web

• A Network of food chains representing the feeding
  relationships among the organisms in one
  ecosystem
• Includes all food chains in an ecosystem

10
Biological Magnification

• Increasing concentration of a pollutant in
  organisms at higher trophic levels in a food web
• Shows how pollutants taken in by a few organisms
  can affect the whole food web

11
Biomass

• Total amount of organic matter present in a
  trophic level
• Potentially food for next trophic level

12
Ecological Pyramid

• Diagram that shows the relative amounts of energy
  in different trophic levels in an ecosystem
• 3 Types Energy pyramids, biomass pyramids, and
  numbers pyramids

13
Energy Pyramid

• Represent different trophic levels in an
  ecosystem
• Size of each level represents amount of energy
  remaining at that trophic level

14
Think about it.

• Humans are omnivores and can eat both producers
  and consumers. Some people think that humans
  should eat only producers, so that the worlds
  food supply will stretch farther.
• What is the reasoning behind this?

15
Biomass Pyramid

• Show the mass of organic mater at each trophic
  level at each trophic level
• Combined mass of all producers at base masses
  of consumers above it

16
Numbers Pyramid

• Number of organisms by be different at each
  trophic level

17
Elements of Life

• 96 of your body is made of 4 elements Oxygen,
  Carbon, Hydrogen, and Nitrogen
• 78 of Earths atmosphere is Nitrogen, 21 is
  oxygen, Carbon is also present in atmosphere as
  well as in rocks and in biomass

18
Water Cycle

• Movement of water b/t ocean, atmosphere, and land
• Process includes evaporation, transpiration,
  precipitation, and runoff

19
Carbon Cycle

• Living things are most important source
• 2 other sources ocean and rocks
• Photosynthesis/Respiration could not occur w/out
  carbon

20
Nitrogen Cycle

• Organisms require nitrogen to make amino acids,
  building block of proteins
• Organisms need chemically reactive nitrogen