1. Chapter 5 Page 98
Trophic Levels

2. All ecosystems do 2 things:
1. Transfer Energy
2. Cycle matter

3. Transfer Energy
(Most ecosystems use Sunlight as its source, but some use inorganic molecules)
Moves from:
Sun – it’s source – into organisms – then into space as heat.

4. Transfer of Matter
Recycled
Carbon, oxygen, and other elements

5. 4.1 Roles of Living Things
Each living thing in the environment plays a different role in the flow of energy and matter.

6. Producers
“organisms that make their own food from inorganic molecules and energy”
PLANTS!
Create sugars thru PHOTOSYNTHESIS

7. Ways to gather food…
Producers
Consumers
Decomposers

8. TYPES OF PRODUCERS TERRESTRIAL Plants are the most important producers
AQUATIC
Small photosynthetic protists and bacteria are the main producers
Few nonphotosynthetic producers like bacteria that live in harsh envt’s

9. CONSUMERS “organisms that cannot make their own food”
Ex - Animals, fungi, protists, bacteria
Obtain energy by eating other organisms

10. HERBIVORE “eats only producers” Insects, cows, etc
4 TYPES OF CONSUMERS
HERBIVORE “eats only producers” Insects, cows, etc
CARNIVORE “capture and eat herbivores or other carnivores Secondary consumers, etc. Adapting to hunting, capturing, and eating prey
OMNIVORE “eats both producers and consumers” Humans Primary consumer, 2ndary consumer
SCAVENGERS “don’t hunt living prey, but feed on dead orgs.” Dead plants, animals,etc Begin the return of nutrients

11. Decomposers
“Consume the bodies of dead organisms and other organic wastes”
Ex – bacteria, fungi
Recycle nutrients back to the soil
Complete the cycle of matter

12. TROPHIC LEVELS
“layer in the structure of feeding relationships in an ecosystem”

13. Levels First layer = Largest layer Producers Autotrophs
2nd + layers= Heterotrophs
Herbivores = (Primary consumers)
Carnivores = (2ndary consumers,etc)

14. 4.2 Ecosystem Structure
“the interactions between trophic levels form a chain that links the organisms in an ecosystem.”

15. Food Chains
“A series of different organisms that transfer food between the trophic levels of an ecosystem”

16. Levels of Consumers Producers always on bottom 1st level of consumers
2nd level of consumers, etc

17. Food Chains
ALWAYS begins with PRODUCERS on the bottom (usually plants)
Next layer would contain the HERBIVORES
Next layer(s) would contain CARNIVORES

18. FOOD WEB
“Network of food chains representing the feeding relationships among the organisms in an ecosystem”

19. FOOD WEB Includes all the food chains in an ecosystem
Webs don’t usually show the decomposers at the top of the web.
Changes in the population of one organism can affect many other populations.

20. Diversity and Stability
Some biologists think that a food web with MORE links can withstand changes/instability better than one with only a few links.

21. Biological Magnification
“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.

22. 4.3 Energy in the Ecosystem
Energy is limited and affects the structure and function of the food web.

23. ENERGY AND FOOD Energy comes from the sun
Some energy reflected back, and some absorbed.
Plants receive less than 1% of energy that reaches earth.
30% of this energy is stored in organic matter from photosynthesis
This makes 170 billion tons of organic matter a year.

24. Biomass
“TOTAL AMOUNT OF ORGANIC MATTER PRESENT IN A TROPHIC LEVEL”

25. BIOMASS
Basically, biomass is the potential food for the next trophic level.
Most energy is lost before it is passed to the next trophic level.
This loss of energy explains why there is a limit to the number of trophic levels an ecosystem can support.

26. Ecological Pyramid
“diagram that shows the relative amounts of energy in different trophic levels in an ecosystem”
Can show energy, biomass, or number of orgs.

27. 4.4 Cycles of Matter
Water Cycle
Carbon Cycle
Nitrogen Cycle

28. Water Cycle Moves between the ocean, atmosphere, and land
Evaporation = movt of water into the atmosphere as it changes from a liquid to a gas
Transpiration = evaporation of water from the leaves of plants
ex -Rainforest = amount affects its climate!
Precipitation = water in atm returns in rain, snow, sleet, or hail.

29. Reclaimed Water?

30. Carbon Cycle Early earth = 95% CO2
Now is only .04% thanks to photosynthesis
Present in 3 main sources:
1. living things
2. oceans = CO2 dissolves in water easily
3. rocks = fossil fuels

31. Nitrogen Cycle
Living things need Nitrogen to make Amino Acids = Proteins
Can’t use the N gases present, but in a different form.
Therefore Nitrogen Fixation must occur!

32. Nitrogen Fixation
Use the N gases to make ammonia(NH3) which plants can use
Nitrogen- fixing Bacteria
Some bacteria live on plant roots. These plants are called LEGUMES. (peanuts, beans)