1. Ch 5 Energy Flow through Ecosystems
Food Chains
Food Webs
Trophic levels
Energy loss as it’s passed from trophic levels
Bioaccumulation/biomagnification

2. Food Chains are direct transfers of energy through an ecosystem

3. Where do I label decomposers?
You
don’t!

4. Food Webs – interconnections between all food chains.

5. HETEROTROPHS Organisms that consume their food. Aka - CONSUMERS
AUTOTROPHS Organisms that produce their own food Aka PRODUCERS
HETEROTROPHS Organisms that consume their food. Aka - CONSUMERS

6. Types of consumers Herbivore : eats only producers
Carnivore: eats other consumers.
Detrivore: eats dead consumers
Omnivore: eats both producers and consumers
Decomposer: breaks down nutrients and recycles them

8. 10% is the magic number!
Only 10% of the energy is the trophic level is passed up.
Most food webs rarely have more than 6 steps/trophic levels in the ecosystem due to the loss of energy.

9. Energy is lost from each species

11. BIOMASS
The term "biomass" refers to organic matter that has stored energy through the process of photosynthesis. It exists in one form as plants and may be transferred through the food chain to animals' bodies and their wastes, all of which can be converted for everyday human use through processes such as combustion, which releases the carbon dioxide stored in the plant material.

12. How much energy is lost to respiration?

13. Wait? So I just ÷ by 10 as I go up?

14. Energy decreases by 10% each level!!!

15. Food Webs

16. Bioaccumulation
Is a process resulting in the concentration of substances in living tissues.
Used to reference chemical contaminants that may do harm to organims like pesticides or heavy metals.

17. Biological Magnification (On page 312)
“the increasing concentration of a pollutant in organisms at higher trophic levels in a food web”
Pollutants become concentrated in the bodies of consumers the higher up the chain it goes SINCE THEY EAT MORE!
Therefore intake of a few organism can affect the whole food web.

18. Bioaccumulation vs. Biomagnification
Bioaccumulation is increasing the concentration of a substance in one organism whereas biomagnification is increasing the level as you go up in a food chain.
Bioaccumulation occurs within a tropic level and biomagnification occurs between tropic levels.

19. FUN VIDEO CLIP

20. Humans and DDT Now complete the Humans and DDT ws.

21. 5.2 Cycling of materials Carbon Nitrogen Phosphorus Just as water is
Recycled, so are the
elements in food chains!

22. Carbon Cycle
“process by which carbon is cycled between the atmosphere, land, water, and organisms.”

23. Wait? How would a plant get Carbon?
From carbon in our CO2 that is absorbed for photosynthesis?

24. How would that carbon get out of a plant to help others?
Eat the plant!!! or
Plants dies and the Carbon is returned to the ground or water , and then recycled.

25. Crash Course – Carbon Cycle
Start at 5:10 

26. Carbon Cycle Early earth = 95% CO2
Now is only .04% thanks to photosynthesis
Present in 3 main sources:
(aka: CARBON SINKS)
1. living things
oceans = CO2 dissolves in
water easily
3. fossil fuels

27. Short Term VS. Long Term SINKs
Cycles through a lifetime through the food web
Long Term
Millions of years
Ex – fossil fuels

28. Problems with sinks…
Humans are using these sinks and releasing the Carbon back into the ecosystems – upsetting its balance
Ex – burning FF
6 billion metric tons of carbon are released into the atmosphere each year!
Some remains in the atmosphere, some dissolves into oceans, some absorbed by plants

29. Crash Course – Nitrogen and Phosphorus

30. Nitrogen Cycle - All organisms need nitrogen to build PROTEINS.
78% percent of atmosphere
But must be FIXED before it can be used
Nitrogen- fixing bacteria to the rescue!!!

31. Nitrogen Fixing Bacteria
Plays a CRUCIAL part of the nitrogen cycle
Live in nodules on the roots of plants called LEGUMES – beans, peas, clover
They produce nitrogen-containing compounds called nitrates that and put excess back into the soil.
When an organisms eats the plant they get the converted nitrogen.
This keeps the nitrogen cycling between the atmosphere and living things.

32. Decomposers and Nitrogen 
Decomposers return Nitrogen in living things to the soil.
Some will be converted to gases released back to the atmosphere, but most of the Nitrogen will be cycled between soil and living things and

33. Phosphorus Cycle
“movement of phosphorus from the environment to organisms and then back to the environment.
Not typically in the atmosphere.
Enters from dissolved rocks which enters soil and water.
Excretions from animals, dead/decomposed animals

34. Two Sources of P Natural Sources
Enters from dissolved rocks which enters soil and water.
Excretions from animals, dead animals

35. Phosphorus Cycle

36. Effects of additional Nitrogen &Phosphorus
Fertilizers: Runoff enters aquatic and terrestrial ecosystems.
Causes ALGAL BLOOMS

38. Effects of additional Nitrogen &Phosphorus

39. Effects of additional Nitrogen &Phosphorus
Acid Precipitation - Affects the N cycle when we burn fuel since it releases Nitric Oxide into atmosphere.

40. 5.3 SUCCESSION
Ecological succession is the observed process of change in the species structure of an ecological community over time

41. SUCCESSION THAT BEGINS WHERE NO LIFE PREVIOUSLY EXISTED
TWO TYPES:
SECONDARY
SUCCESSION THAT BEGINS WHERE LIFE PREVIOUSLY
EXISTED
Ex - soil
PRIMARY
SUCCESSION THAT BEGINS WHERE NO LIFE PREVIOUSLY EXISTED
Ex – bare rocks

42. Fun Video Claymation

43. Primary Succession(#1) = “Starting from square #1”
This means the ecosystem has had no previous life.
Nothing, nope, nada.
Nothing here but barren rocks.
Ex – volcano forms a new island, glaciers slowly moves and leaves behind rocks.

44. How does it begin succession?
Rock is colonized by pioneer species
Pioneer species = Lichens and Mosses
These will break down the rock and turn it into SOIL! Yay!
Now smaller plants will begin to grow which adds to the soil content & nutrients so bigger plants can grow, etc.

45. PRIMARY SUCCESSION no soil initially exists
(such as caused by a lava flow following volcanic eruption or severe landslide that covered the land).
The primary succession is important in pioneering the area to create conditions favorable for the growth of other forms of plants and animals.

46. Secondary Succession = “begins with SOIL!”
If an ecosystem is disturbed, it will leave behind not much but SOIL.
This soil will serve as a basis for small pioneer plants to grow, then bigger plants, and so on as in Primary succession.
Ex – forest fires, man building structures, tsunamis, etc.

47. SECONDARY SUCCESSION
This process of regrowth that an ecosystem undergoes after a destructive event such as a fire, avalanche, agricultural clearing, deforestation, or disease
one thing is important to keep in mind: for secondary succession to occur, there must already be, you guessed it, dirt!

48. Secondary Succession

49. Both types of Succesion are attempting to reach…
A MATURE ecosystem is known as the climax community for that area.
(most complex community it can have)
Ex - large hardwood trees.
Most ecosystems do not mature to this ideal community, because disaster strikes again too soon, leading to more succession…

50. Another Fun Succession Clip

51. Old Field Succession
The form of ecological succession which occurs on abandoned farmland is referred to as old field succession. When a plowed field is abandoned, it represents a new habitat for plant and animal species to colonize, but because it is basically bare soil, it is a stressful habitat for many plants.

52. VIDEO CLIP