1. Unit 5
ECOLOGY

2. Introduction to ecology
Chapter 18
Introduction to ecology

3. Section 1 Introduction to ecology

4. Section 1

5. Introduction to ecology
Study of the interactions between ____________________________________________________________________________________________________________
Organisms depend on each other
Broad science seeking to explain __________________________________

6. Interdependence: a key theme in ecology
In the past, human survival depended on ____________________________________
Even today humans interact with the environment and other organisms daily

7. Organisms and their environments
All orgs interact with other orgs and nonliving portion of environment
Survival depends on these interactions
This is called _________________________ ______________________________
Example: ____________________________ ____________________________________

8. Effects of interdependence
Any change in environment can spread through the network of interactions

9. Ecological models Ecology is complex and difficult to study
________________represent and describe components of an ecological system
Helps us understand environmental interactions and _____________________ ___________________________________
Helps _______________________________ ____________________________________
Not always accurate due to too many variables

10. Levels of organization
Hierarchy of organization

11. The biosphere Broadest, _____________________level
________________________________
All orgs are in the biosphere
_______________________________

12. ecosystems
_____________________________________________________________________

13. Communities, populations, and organisms
Community: _________________________ (excluding nonliving factors)
Ecologists study interactions, very complex
Population: _________________________ ___________________________________
Organism: individual
Research focuses on __________

14. Communities, populations, and organisms

15. Homework section 1

16. Section 2 ecology of organisms

17. Section 2

18. Ecology of organisms
Habitat: _____________________________ _______________________________________________________________________

19. Ecosystem components
Two types of environmental factors that influence an org:
Biotic: ______________________________
Abiotic: ________________________________ ____________________________________________________________________________

20. Biotic and abiotic factors
Importance of each factor varies between environments
Not constant
Example: ___________________ __________________________________________________________________________________

21. Organisms in a changing environment
Organisms can survive in a _____________ _____________________________________
Example: can survive in limited range of temperatures
Determine this range by measuring ________________________________
Graph of performance vs environmental variable = _____________________________

22. Organisms in a changing environment
Organism can survive outside optimum range, but performance is _____________
Cannot survive outside tolerance limits
Optimum: ___________________________
Tolerance: ___________________________

23. acclimation __________________________________________________
Only some spp can do this
Not to be confused with adaptation.
____________________________________________________________________________________________________

24. Control of internal conditions
Abiotic factors fluctuate (__________________________________)
Two ways orgs deal with this
Conformers: ____________________________ ____________________(cold blooded animals)
Regulators: ___________________________ _______________________________________(mammals and birds)

25. Escape from unsuitable conditions
Survival by escaping temporarily
_________________________________
____________________________________
___________________________________

26. The niche
A niche refers to ______________________ ________________________________________________________________________
Includes range of conditions org can tolerate, resources, methods to obtain resources, number of offspring, time of reproduction
Generalist: __________________________ ___________________________________
Specialist: __________________________ ___________________________________

27. Homework section 2

28. Section 3 energy transfer

29. Section 3

30. Energy transfer All orgs need energy to carry out essential functions
In ecosystem, ________________________ ____________________________________________________________________________________________________________

31. producers Autotrophs ___________________________
Most are photosynthetic, _________________
Some bacteria uses chemosynthesis: ____________________________________________________________________________
In terrestrial ecosystems, _________________ _____________________________________
In aquatic ecosystems, ___________________ ___________________________________________________________________________

32. Measuring productivity
Gross primary productivity: ______________ ________________________________________________________________________
Biomass: ____________________________ ____________________________________
Only energy stored in biomass is available for other orgs
Net primary productivity: _______________ ____________________________________
_______________________________________

33. Measuring productivity
Light, temp, precipitation accounts for most variation in productivity

34. consumers
Heterotrophs: __________________________ ____________________________________________________________________________
Obtain energy by _______________________ ___________________________________________________________________________

35. consumers Grouped according to type of food eaten:
Herbivores _______________________
Carnivores ____________________________
Omnivores _____________________________
Detritivores feed on ______________________ ______________________________________
Some detritivores are decomposers, _____________ ______________________________________________________________________________________

36. consumers

37. Energy flow
When one org eats another, _____________ ___________________________________
Energy flows through an ecosystem from ________________________________
Trophic levels indicate the orgs position in a sequence of energy transfers
All ______________in first trophic level
____________________ in second trophic level
_______________belong to third trophic level
Terrestrial ecosystems have 3 or 4 levels, marine ecosystems have more

38. Food chains and food webs

39. Food chains and food webs
Feeding relationships are more complicated than just one chain.
________________________________________________
Food chains interlink
Food web: ___________________________________________________________________________

40. Energy transfer
Low % of energy transfer from one trophic level to the next, why?
_____________________________________
______________________________________

41. Energy transfer

42. Limitations of trophic levels
Low rate of energy transfer is why only a few levels exist
________________________________________________________________________
____________________________________

43. Homework section 3

44. Section 4 ecosystem recycling

45. Section 3

46. Ecosystem recycling Matter must be recycled and reused
_________________________________________________________________________________________________________________________________________

47. The water cycle Cells contain 70-90% water
Environment for chemical reactions
Very little of water on Earth is available for use
Water can be found in:
____________________________________
_____________________________________

48. The water cycle

49. The water cycle Important processes
Evaporation: ____________________________ ______________________________________________________________________________
Transpiration: ___________________________ ______________________________________________________________________________
Precipitation: ____________________________ _______________________________________

50. The carbon cycle
Photosynthesis: ______________________ ____________________________________
Cellular respiration: ____________________ ____________________________________
By-products are CO2 and H2O
Decomposers ________________________ ____________________________________

51. The carbon cycle

52. Human influence on the carbon cycle
[CO2] in atmosphere has risen over 30%
Humans burn fossil fuels and other organic matter
Fossil fuels: __________________________ ____________________________________
Deforestation causes __________________ ___________________________________

53. Nitrogen cycle ____________________________________
N2 (_____) makes up 78% of atmosphere
______________________________________
Converting N2 to nitrate = _________________

54. Nitrogen cycle Nitrogen fixing:
_______________________________________
______________________________________

55. Nitrogen cycle

56. Recycling nitrogen Dead bodies of orgs, urine and dung contain N
Decomposers break down these materials and release N as ammonia NH3 = _____________
Soil bacteria oxidizes this into nitrate = ________________
Erosion of rocks release _________________
N is returned to atmosphere through ______________________

57. Recycling nitrogen
Denitrification: ________________________ ____________________________________
Plants absorb nitrates from soil, animals cannot
________________________________________________________________________

58. Phosphorous cycle Essential element to form _______________
Plants get P from ____________________
Animals get P by _____________________
P cycle: _____________________________ ____________________________________
Slow cycle

59. Phosphorous cycle
Rocks erode, _________________________ ____________________________________
Plants absorb P through ___________
P added to soil through ________________ ___________________________________
Fertilizer adds P to soil, ________________ _________________________________

60. Phosphorous cycle

61. Homework section 4