Ecosystems

1
Ecosystems

• Chapter 54
• By Nima Mehr
• Biology Ms.Walters

2
Ecosystem

• A ecosystem is a combination of biotic and
  abiotic components through which energy flows and
  material cycles.

http//starryskies.com/articles/2003/08/earth.fact
s.html
3
Solar Energy

• Life on earth powered by sun responsible for
  climate, wind, and weather.
• Because of the atmosphere only a fraction of the
  energy reaches the surface of the earth and its
  organisms

http//voyager.jpl.nasa.gov/multimedia/flash_html.
html
4
The Influence of the Atmosphere
http//encarta.msn.com/media_461517631/divisions_o
f_the_atmosphere_(illustration).html
5
The Influence of the Atmosphere

• 75 percent of all molecules in troposphere
• Ozone layer
• In stratosphere
• Reflects 30 percent of the solar energy, 20
  percent absorbed in the different layers, and 50
  percent reaches the earth
• Atmosphere delicate depending on supply of CO2,
  if the concentration was changed, the affects
  could change the entire system in response

6
The Influence of the Atmosphere
Picture Ozone Hole

• http//observe.arc.nasa.gov/nasa/exhibits/history/
  history_7.html

7
Climate, Wind, Water

• The energy to earth is not equal in all parts.
• The earths tilt causes this
• Air is warmest along equator because it is heated
  most intensely from the sun.
• Due to the different land formations, that land
  may have varying climate, for example a mountain
  which cold because it is so high up.

8
Climate, Wind, Water

• http//members.aol.com/pakulda/emmod.htm

9
The Flow Of Energy

• Trophic levels
• In a food chain animals are eaten at different
  levels each of these are a tropic level
• Food Web
• Producers
• Primary producer usually-plant/algae
• 99 percent of organic matter in plant and algae/1
  percent in all heterotrophs
• Gross productivity/Net Productivity
• Biomass
• Net Primary Production

10
The Flow Of Energy

• Consumers
• Energy thought to be lost through respiration for
  consumers
• Primary Consumers
• 2nd level of consumers made up of carnivores, and
  plants that eat other plants
• Some food chains have up to 4 or 5 links
• Detritivores
• Scavengers
• Decomposers
• Not much energy transferred to them-they are
  higher on the food chain

11
The Flow Of Energy
http//www.usoe.k12.ut.us/curr/science/sciber00/8t
h/energy/sciber/foodweb.htm
http//www.arcytech.org/java/population/facts_food
chain.html
12
The Flow Of Energy

• http//www.arcytech.org/java/population/facts_food
  chain.html

13
The Flow Of Energy

• Energy Transfer and Ecosystem Structure
• Most energy transfer pyramids are upright with
  producers on bottom

http//curriculum.calstatela.edu/courses/builders/
lessons/less/biomes/rainforest/temp_rain/temppy.ht
ml
14
Biogeochemical Cycles

• Movements of inorganic substances are referred to
  as biogeochemical cycles
• Components- producers, consumer, and detritivores
  (scavengers/decomposers)
• Nitrogen cycle
• Ammonification
• Nitrification
• Assimilation

15
Biogeochemical Cycles

• http//www.epa.gov/maia/html/nitrogen.html

16
Biogeochemical Cycles

• http//msucares.com/crops/soils/phosphorus.html

17
Biogeochemical Cycles

• Dentrification
• All organisms depened on nitrogen fixation for
  their energy
• Recycling in a Forest Ecosystem
• 1965-1966 all trees, saplings, and shrubs in one
  15.6-hectare area of the forest were completely
  cut down.

18
Biogeochemical Cycles

• Concentration of Elements
• Element concentrations around organisms
• DDT- Toxic substance
• Strontium-90- Another toxic substance that gets
  mixed up with the good minerals

http//www.environment.no/templates/PageWithRightL
isting____2806.aspx
19
Biogeochemical Cycles

• http//www.anselm.edu/homepage/jpitocch/genbios/ec
  ologybi04.html

20
Biogeochemical Cycles

• Chernobyl
• Nuclear reactor went out of control at high rates
  of concentration
• It exploded causing some radioactive particles to
  move way out of Chernobyl and affect other areas
• The biological concentration of elements is a
  dangerous phenomenon with severe consequences,
  especially for the top of the food chain.