1. Energy Transfer & Nutrient Cycling

2. How is energy transferred in an ecosystem?
Organisms in a community survive by either producing or consuming food

3. How is energy transferred in an ecosystem?
Trophic levels - levels of feeding in a community

4. How is energy transferred in an ecosystem?
Producers - produce food for themselves (ex. plants),
Other organisms may eat producers.

5. How is energy transferred in an ecosystem?
Consumers - must take in food (ex. fungi)
Primary Consumers - also called herbivores (ex. cow)

6. Energy Flow
Consumers- organism that relies on other organisms for its energy and food supply (Heterotrophs)
Herbivores- eat only plants
Carnivores- eat animals
Omnivores- eat both plants and animals
Detritivores- feed on plant and animal remains and other dead matter (mites, earthworms)
Decomposers- breaks down organic matter (bacteria and fungi)

7. What is it?

8. What is it?

9. What is it?

10. What is it?

11. What is it?

12. How is energy transferred in an ecosystem?
Secondary and Tertiary Consumers - may be carnivores (ex. lion) or omnivores (ex. bear)

13. How is energy transferred in an ecosystem?
Decomposers - as they consume, they break down wastes and dead organisms and return nutrients to the soil.

14. Food Webs
Made up of overlapping food chains.

15. Food Webs Shows feeding connections; arrows illustrate energy transfer
Ex:

16. Food Web
A network of complex interactions that links all the food chains in an ecosystem together

17. Fill It In … Answer using the food web: Organisms that eat grass.
Food sources for the fox.
An “omnivore”.
An “herbivore”.
A “carnivore”.

18. Ecological Efficiency
Producers have the most available energy (sun).
Energy is lost as it moves up through the food web; 10% rule - only 10% of the available energy is passed to the next trophic level.

19. Biomass Pyramid
Biomass- the total amount of living tissue within a given trophic level
Pyramid represents the amount of potential food available at each trophic level

20. Pyramid of Numbers B. Energy is lost from level to level as:
1. Heat (due to cellular respiration conversions)
2. Unused material
3. Waste
Based on the number of organisms at each level
Could this pyramid look any differently?

21. Ecological Efficiency
The “lost” energy is used to catch, eat, and digest food

22. Fill It In … 10% Rule: Carnivores (_____ cal) Herbivores (_____ cal)
Plants (1000 cal)

23. Bioaccumulation in NC
Bioaccumulation: the build up in higher trophic levels of certain chemicals like mercury and pesticides.
Almost all samples of fish taken from NC rivers contain some level of mercury.
Large mouth bass has been placed on a consumption advisory.

25. Check Yourself! What is a trophic level?
What is the difference between an omnivore and a carnivore?
From the food web above, write out a food chain that includes the rat.
Which level in a food web has the most energy?

26. Check Yourself!
What is a trophic level? LEVELS OF FEEDING IN A COMMUNITY
What is the difference between an omnivore and a carnivore?
From the food web above, write out a food chain that includes the rat.
Which level in a food web has the most energy?

27. Check Yourself!
What is a trophic level? LEVELS OF FEEDING IN A COMMUNITY
What is the difference between an omnivore and a carnivore? OMNIVORE EATS PLANTS AND MEAT, CARNIVORE EATS ONLY MEAT
From the food web above, write out a food chain that includes the rat.
Which level in a food web has the most energy?

28. Check Yourself!
What is a trophic level? LEVELS OF FEEDING IN A COMMUNITY
What is the difference between an omnivore and a carnivore? OMNIVORE EATS PLANTS AND MEAT, CARNIVORE EATS ONLY MEAT
From the food web above, write out a food chain that includes the rat. (ANSWERS WILL VARY)
Which level in a food web has the most energy?

29. Check Yourself!
What is a trophic level? LEVELS OF FEEDING IN A COMMUNITY
What is the difference between an omnivore and a carnivore? OMNIVORE EATS PLANTS AND MEAT, CARNIVORE EATS ONLY MEAT
From the food web above, write out a food chain that includes the rat. (ANSWERS WILL VARY)
Which level in a food web has the most energy? PRODUCER

30. How is matter reused in an ecosystem?
Role of decomposers
Decomposers break down wastes and dead organisms
Decomposition allows nutrients to be returned to the soil and atmosphere; this allows nutrients to be reused.
Decomposers include fungi, bacteria, and invertebrates

31. How is matter reused in an ecosystem?
Biogeochemical Cycles - the pathway through which a substance is recycled
Water cycle
Enters ecosystem by precipitation; may infiltrate the soil (be absorbed) or run-off into surface water

32. How is matter reused in an ecosystem?
Water cycle
Returned to atmosphere by evaporation or transpiration (the loss of water by plants)

34. Fill It In …
Diagram of water cycle:

35. How is matter reused in an ecosystem?
Carbon cycle
Powered by two main processes
Photosynthesis - plants and algae capture CO2 from the air and change it into sugar (which have carbon)

36. How is matter reused in an ecosystem?
Carbon cycle
Respiration - all living things break down sugars for energy, which returns CO2 to the atmosphere

37. How is matter reused in an ecosystem?
Carbon cycle
Other factors in the carbon cycle:
Decomposition returns carbon to the soil and atmosphere

38. How is matter reused in an ecosystem?
Carbon cycle
Humans burn fossil fuels which adds CO2 to the atmosphere
Deforestation removes tress which normally photosynthesis and remove CO2 from the atmosphere

39. How is matter reused in an ecosystem?

40. CARBON CYC LE

41. Fill It In … Factors that ADD carbon to atmosphere:
Factors that REMOVE carbon from atmosphere:

42. Using the Carbon Cycle diagram on page 77 of textbook:
What are the 4 sources/processes that ADD carbon to the atmosphere?
What are the 2 sources/processes that REMOVE carbon from the atmosphere?
What process do animals carry out that adds CO2 to the atmosphere?
What process do plants carry out that removes CO2 from the atmosphere?
The combustion of _______ by humans can add CO2 to the atmosphere.
______ of dead organisms may return carbon to the soil.
How is carbon stored in plants transferred to animals?

43. How is matter reused in an ecosystem?
Nitrogen Cycle
Nitrogen is essential for living organisms so that they can build proteins; nitrogen is plentiful in the atmosphere, but is not usable in this form.

44. How is matter reused in an ecosystem?
Nitrogen Cycle
Nitrogen fixation - bacteria living in the root nodules of bean plants (legumes) convert nitrogen from the air into a more usable form.

45. How is matter reused in an ecosystem?
Nitrogen Cycle
Nitrogen fixation is the first of many steps that involves bacteria and changing the form of nitrogen.

46. Nitrogen Cycle Questions
What are the main nitrogen containing nutrients in the biosphere?
ammonia, nitrate, nitrite
What controls the primary productivity of an ecosystem?
the amount of available nutrients
What is a limiting nutrient?
a single nutrient that is scarce or cycles very slowly
Why do algal blooms occur?
when more nutrients are available and producers can produce more than consumers can eat
What does “equilibrium” of an ecosystem mean?
equilibrium = balance

48. Check Yourself!
How do decomposers help with the recycling of nutrients?
How do plants return water to the atmosphere?
What two processes drive the carbon cycle?
What organisms are essential for the conversion of nitrogen?

49. Check Yourself!
How do decomposers help with the recycling of nutrients? BREAK DOWN WASTES & DEAD ORGANISMS TO ALLOW NUTRIENTS TO BE RETURNED TO THE SOIL OR ATMOSPHERE
How do plants return water to the atmosphere?
What two processes drive the carbon cycle?
What organisms are essential for the conversion of nitrogen?

50. Check Yourself!
How do decomposers help with the recycling of nutrients? BREAK DOWN WASTES & DEAD ORGANISMS TO ALLOW NUTRIENTS TO BE RETURNED TO THE SOIL OR ATMOSPHERE
How do plants return water to the atmosphere? TRANSPIRATION
What two processes drive the carbon cycle?
What organisms are essential for the conversion of nitrogen?

51. Check Yourself!
How do decomposers help with the recycling of nutrients? BREAK DOWN WASTES & DEAD ORGANISMS TO ALLOW NUTRIENTS TO BE RETURNED TO THE SOIL OR ATMOSPHERE
How do plants return water to the atmosphere? TRANSPIRATION
What two processes drive the carbon cycle? PHOTOSYNTHESIS & RESPIRATION
What organisms are essential for the conversion of nitrogen?

52. Check Yourself!
How do decomposers help with the recycling of nutrients? BREAK DOWN WASTES & DEAD ORGANISMS TO ALLOW NUTRIENTS TO BE RETURNED TO THE SOIL OR ATMOSPHERE
How do plants return water to the atmosphere? TRANSPIRATION
What two processes drive the carbon cycle? PHOTOSYNTHESIS & RESPIRATION
What organisms are essential for the conversion of nitrogen? BACTERIA