1. ecology
a look at the basics

2. Ecology – The study of the interactions of the living and non-living world.

3. Ecology terms/groupings
Species—one kind of organism; similar in structure and able to pass these traits on to offspring.
Population—all the members of a species living in a given geographic area.
Community—all of the populations in an area; i.e., all of the living things.

4. Ecology terms/groupings
Ecosystem—the interaction of the community with the non-living environment
Biome—a group of ecosystems that have the same climate & similar biological communities; ex.—grassland, desert, wetland, tropical rainforest, &c.
Biosphere—all the parts of the planet in which life exists.

6. biosphere
Dynamic!!
Extends from about 6 mi below surface to 5 mi above (discontinuous)
About % of the Earth by volume
About % of the Earth by mass

7. the biosphere
= peel
Unique

8. Ecosystems Biotic factors – the living part of the ecosystem. Geese
Plankton
People
Trees
Fungi
bacteria

9. Ecosystems Air Sand Water Temperature Wind Sunlight pollutants
Abiotic factors – the non living parts of the ecosystem.
Air
Sand
Water
Temperature
Wind
Sunlight
pollutants

10. The main point is how energy moves through the ecosystem.
Ecology
The main point is how energy moves through the ecosystem.

11. Energy in Ecosystems
Energy from the Sun is the major source for all living things.
The process of photosynthesis traps it so it can be used by living organisms.
Energy is NOT recycled throughout the ecosystem

12. Ecology Organisms can be producers or consumers
Producers (autotrophs)—convert energy from the environment into carbon bonds such as those found in glucose
Plants
Algae
Cyanobacteria
Deep sea bacteria
photosynthesis
chemosynthesis
chemicals

13. Electromagnetic spectrum

14. Pigment absorption across the visible spectrum

15. PHOTOSYNTHESIS sunlight Carbon dioxide glucose water oxygen
Sunlight + 6 CO2 + H2O
C6H12O6 + 6 O2

16. photosynthesis
Sunlight energy used to form C-C bonds in the form of sugar (glucose)
The sugars can be used or can be converted to cellulose, starch, or other substances

17. CHEMOSYNTHESIS

18. So…why are producers important?
Ecology is all about energy flow
LIFE is all about energy flow
Our source of energy is…
Producers are…

19. Heterotrophs Obviously DO NOT photosynthesize…
Don’t make their own food; get it from eating other things
PROCESS of breaking down food to get the energy from the C-C bonds???
Done by plants & animals (& fungi, protists, &c)
=cellular respiration
(not breathing!!!)

20. Energy Review Energy Storing Molecules
ATP supplies most of the energy that drives metabolism in living things
ATP releases energy when converted into ADP

21. Cellular Respiration Overview
Living things get most of the energy they need from glucose.
Autrotrophs make glucose using photosynthesis
Heterotrophs get glucose from food they eat
Cellular Respiration
The process that releases energy by breaking down glucose and other food molecules in the presence of oxygen.

22. Cellular Respiration Overview
Cellular Respiration Overall Equation
6O2 + C6H12O6  6CO2 + 6H2O + Energy
Three Stages
Glycolysis
Kreb’s Cycle
Electron Transport Chain
The Main form of Energy produced = ATP

23. Consumers = heterotrophs
Get their energy from the carbon bonds made by producers… 4 types:
Consumer
Trophic level
Food source(s)
Herbivores
Primary
Plants
Carnivores
Secondary or higher
Animals
Omnivores
All levels
Plants, animals, and others
Detritivores
detritus

24. Herbivores
Heterotrophic organisms who eat primarily plant material

25. Carnivores Heterotrophic organisms who eat other animals
1st level carnivores
2nd level carnivores
etc.

26. Omnivores
Heterotrophs, like us, that eat both producers (plants) and other consumers

27. Detritivores
Heterotrophic organisms who ingest dead organic matter. (e.g. earthworms, woodlice, millipedes)
Earth worm
(Lumbricus terrestris)

28. (Cantherellus cibarius)
Saprotrophs
Heterotrophic organisms who secrete digestive enzymes onto dead organism matter and absorb the digested material. (e.g. fungi, bacteria)
Chanterelle
(Cantherellus cibarius)

29. Heterotroph specialists
Fruit-eating = fructivores
Insect-eating = insectivores
blood-eating = sanguivores
&c.

30. Consumers
Some animals do not specialize in their diets (called generalists)… they feed on multiple food sources.

31. Consumers
Most species are much more specific in their diets—these are called specialists.
Which one are we???

32. All the roles that an organism plays in its environment.
NICHE
All the roles that an organism plays in its environment.
what it eats
physical changes to habitat
what eats it
symbionts
parasites
what it takes from the habitat
what it puts into the habitat

33. Some Ecological Roles Prey Predator Symbiosis Commensalism + 0
Mutualism + +
Parasitism

34. Energy flow HEAT HEAT sun producers consumers Inorganic nutrients
decomposers
HEAT

35. Energy flow
Energy flows in the form of carbon-carbon bonds (in organic molecules)
Bonds = energy
1 glucose molecule = 686 kcal
1 ATP = 7.3 kcal
1 glucose  36 ATP
So…38% of energy from glucose yields ATPs—62% lost as heat

36. Energy flow
Photosynthesis = C-C bonds formed (glucose) from sunlight (energy), water and CO2
Respiration = C-C bonds broken to form CO2 & energy
All energy is, ultimately, lost—10% rule
ATP (used)
heat (lost)

37. Food Chain
Series of steps in an ecosystem in which organisms transfer energy by eating and by being eaten.
Energy flows in one direction from sun or inorganic compounds to autotrophs to various heterotrophs

38. Food Chain
Arrows show the direction the energy is flowing.

39. Food Webs Many food chains combined together. Hognose Snake Hawk
Garter Snake
Mouse
Toad
Rabbit
Spider
Preying Mantis
Grasshopper
Sparrow
This is a grazing food web. Producers are at the base of this type of food web.
Grasses

40. Food webs

41. Food Webs A detrital food web.
Detritus is the dead stuff that falls to the ground or substrate and feeds myriad critters. Decomposers are at the base of this type of food web.

43. Ecological Pyramid

44. Ecological Pyramid
That’s more like it!!!

45. Ecological Pyramid
Is a diagram that shows the relative amounts of energy or matter contained within each trophic level in a food chain or food web.
3 types:
biomass,
energy, or
numbers
What is a trophic level?

46. Ecological (biotic) pyramids
As written by Aldo Leopold, “The species of a layer are alike not in where they came from, or in what they look like, but rather in what they eat.”

47. Trophic levels First level = Second level = Third level =
Fourth level =

48. Biomass Pyramid The total mass of living tissue at each trophic level.
Represents the amount of potential food available for each trophic level in an ecosystem

49. Biomass Pyramid The first level includes producers.
Here we find the most abundant amount of biomass.

50. Biomass Pyramid
Generally, the further removed a trophic level is from its source (detritus or producer), the less biomass it will contain.
WHY?
Not everything in the lower levels gets eaten
Not everything that is eaten is digested
Energy is always being lost as heat

51. Biomass Pyramid A few exceptions… Aquatic ecosystems
Algae outnumbered & outweighed by critters that eat them
How does it work, then??????????
Algae can reproduce at least as quickly as they are eaten
Algae are mostly digestible (much more so than terrestrial plants)

52. Energy Pyramid
About 10% of the total energy is transferred to this level to be used by these consumers.
This is the 10% Rule
10 cal
100 cal
1000 cal
10,000 calories

53. Ecological pyramids
Numbers pyramid

54. Pyramid of numbers
The number of organisms at each trophic level.

55. Matter Energy flows through the ecosystem—it is transferred
Matter also moves through the ecosystem
While energy is NOT recycled (adding more all the time!), matter IS recycled

56. Biogeochemical Cycles
Elements, Chemical compounds and other forms of matter are passed from one organism to another and from one part of the biosphere to another.
Pass the same molecules around again and again within the biosphere.
Matter is always recycled!

57. Nutrient cycling
Ecosystems can be sources, sinks, or transformers of chemicals
Source = supplier of nutrients to other habitats
Sink = “holder” of nutrients from other habitats
Transformer = takes nutrients in one form and gives them up as another form

58. Water Cycle

59. Carbon cycle

60. Nitrogen Cycle

61. Phosphorus Cycle

62. Community interactions
Competition
Intra-species
Inter-species
Predation
Symbiosis
Mutualism
Commensalism
parasitism

63. Two organisms living together and both benefiting from each other.
Mutualism
Two organisms living together and both benefiting from each other.
Lichens are fungus and algae living together.
Algae produces the food and the fungus absorbs the nutrients.

64. More Mutualistic Relationships
Bee gets food and the flower gets pollinated.
The ant benefits by receiving honeydew from the aphid, while the aphid benefits by being protected by the ant.

65. Commensalism
The relationships between two kinds of organisms in which one benefits and the other is not affected.
Examples:
Bird nesting in a tree
Barnacles, ghost shrimp, &c. live on sea turtle shells

66. Parasitism
two organisms live together, one drawing its nourishment at the expense of the other
The lamprey eel gets energy from the fish. Parasites rarely kill the host but will leave wounds

67. What are some other Parasites?
Viruses
Flukes (liver parasites)
Tape worms (intestinal parasites)
Fungus (athletes foot)
Trypanasoma (malaria)
Bacteria

68. competition
Populations are going for the same resources (or at least some of the same resources)
Intraspecific
Interspecific
Populations inhibit each other
Gause’s Competitive Exclusion Principle

69. Anoles in Florida green anole (Anolis carolinensis)—native
brown anole (A. sagrei)—1960’s, Cuba
resource partitioning

70. THE COMPETITIVE EXCLUSION PRINCIPLE
G.F. Gause (1934) If two species, with the same niche, coexist in the same ecosystem, then one will be excluded from the community due to intense competition

71. The niche as a two-dimensional shape
Species A
Niche represented by a 2-dimensional area

72. Separate niches Species B Species A No overlap of niches.
So coexistence is possible

73. Overlapping niches Species B Species C
Interspecific competition occurs where the niches overlap

74. Specialization avoids competition
Species B
Species C
Evolution by natural selection towards separate niches
Species B’
Species C’
Specialization into two separate niches

75. This niche is not big enough for the both of us!
Species A Species D
Very heavy competition leads to competitive exclusion
One species must go

76. Total exclusion Species A has a bigger niche it is more generalist
Species E has a smaller niche it is more specialist
Specialists do tend to avoid competition

77. Example: Squirrels in Britain
The Red Squirrel (Sciurus vulgaris) is native to Britain
Its population has declined due to:
Competitive exclusion
Disease
Disappearance of hazel coppices and mature conifer forests in lowland Britain
Isle of Wight Tourist Guide
© 2008 Paul Billiet ODWS

78. The Alien The Grey Squirrel (Sciurus carolinensis) is an alien species
Introduced to Britain in about 30 sites between 1876 and 1929
It has easily adapted to parks and gardens replacing the red squirrel
© 2008 Paul Billiet ODWS

79. Today’s distribution Red squirrel Grey squirrel
© 2008 Paul Billiet ODWS