Grade 11 equivalent Biology Ecology

1. Ecology Notes

2. What is ECOLOGY?
 Ecology is a study of
connections in nature.
 How organisms
interact with one
another and with their
nonliving
environment.
Figure 3-2

3. Levels of Organization

4. Organisms
 The different forms of life on earth
Species
 Organisms that can breed & produce fertile offspring

5. Population
 A group of individual organisms
that belong to the same species
and live in the same area.

6. Community
 Different populations that live &
interact in an area.

7. Ecosystem
 The community plus their non-living
environment.

8. Biotic & Abiotic Factors of Ecosystems
 Biotic (living)
 Ex. – bacteria, animals, plants
 Abiotic (non-living)
 Ex. – humidity, solar energy, rocks, clouds

9. Biome
 A group of ecosystems that have the same
climate
 Ex. – Tundra, Taiga, Desert, Tropical Rainforest

10. Biosphere
 All of the
combined portions
of the planet
where life exists,
including land,
water, and
atmosphere

11. Universe
Galaxies
Solar systems Biosphere
Planets
Earth
Biosphere
Ecosystems Ecosystems
Communities
Populations
Organisms Realm of ecology
Communities
Organ systems
Organs
Tissues
Cells
Protoplasm
Populations
Molecules
Atoms Organisms
Subatomic Particles
Fig. 3-2, p. 51

12. Energy Flow  Producers
 Autotrophs - use solar energy or
chemical energy to make their own food
Chemosynthesis
Photosynthesis

13. Energy Flow Consumers
 Heterotrophs - get energy from the
food they eat
 Herbivores – eats plants
 Carnivores – eats animals (includes insects)
 Omnivores – eats plants and animals
 Detritovores – feed on dead matter (scavengers)
 Decomposers – break down dead matter

14. Break it Down
 Auto – self  -vore – eat
 Herb – plant
 Troph – feeding
 Carni – meat
 Photo – light
 Omni – all
 Synthesis – make
 Hetero – different

15. Energy Flow 
Food Chains & Food Webs
 Show how
energy &
nutrients move
from one
organism to
another through
the ecosystem

16. Energy Pyramid
 Shows the amount of energy available at
each trophic level
0.1%
Tertiary Consumer
Secondary Consumer 1%
Primary Consumer 10%
Producer 100%

17. Energy Flow 
Losing Energy in Food Chains and Webs
 90% of the
energy at each
energy level is
lost because
the organism
uses the
energy. (heat)

18. Energy Flow  Other Pyramids
Biomass pyramid – total amount of
living tissue
- Amount of potential food for each trophic
level
Pyramid of Numbers – # of individuals
at each level
- Does not always resemble a pyramid
- Forest – fewer producers than consumers
1 tree = lots of insects / birds

19. Interactions in an Ecosystem
 Habitat – The area where an
organism or a population lives

20. Interactions in an Ecosystem
 Niche - the total role of a species in
an ecosystem
 All the physical and biological conditions a
species needs to live & reproduce in an ecosystem

21. Interactions in an Ecosystem 
Relationships
 Predation – one organism captures and
feeds on another

22. Predator – Prey Cycle
SOURCE: Isle Royale Wolf/Moose Study | GRAPHIC: By Patterson Clark, The Washington Post - July 21, 2008

23. Interactions in an Ecosystem 
Relationships
 Competition – organisms of the same or
different species attempt to use the same
resources at the same time

24. Interactions in an Ecosystem 
Relationships
 Symbiosis – any relationship in which 2
species live closely together
 Mutualism
 Commensalism
 Parasitism

25. Mutualism: Win-Win Relationship
 Both of them benefit
Pollination of flowers by
insects Oxpeckers and black rhinoceros

26. Commensalism: Using without harming
 One is helped and has little or no effect on
the other
Burrs are carried by
animals. This helps
scatter the seeds for
the parent plant.

27. Parasitism: Sponging Off of Others
 One benefits and the other is harmed
Mosquitos
Tapeworms

28. Carrying Capacity
 The maximum # of individuals
that a given habitat can support

29. What is the carrying capacity?

30. Lower limit of Upper limit of
tolerance tolerance
No Few Abundance of organisms Few No
organisms organisms organisms organisms
Population size
Zone of Zone of Optimum range Zone of Zone of
intolerance physiological physiological intolerance
stress stress
Low Temperature High
Fig. 3-11, p. 58

31. 4 Factors Determine Growth Rate
 1. Birth rate
 2. Immigration
 3. Death rate
 4. Emigration
Which increase and which decrease
the population?

32. Limiting Factors
 Bioticor abiotic resource that
limits size of population

33. Habitat Needs
 Cover – shelter; trees, shrubs,
etc.
 Water
 Nutrients

34. Population Growth
 Populations can grow until
competition for resources increases &
the carrying capacity is reached

35. Biosphere
Carbon Phosphorus Nitrogen Water Oxygen
cycle cycle cycle cycle cycle
Heat in the environment
Heat Heat Heat
Fig. 3-7, p. 55

36. CARBON CYCLE

37. Nitrogen Cycle

38. Nitrogen Fixation
 This is the first step of the nitrogen cycle
where specialized bacteria convert gaseous
nitrogen to ammonia that can be used by
plants. This is done by cyanobacteria or
bacteria living in the nodules on the root of
various plants.

39. Nitrification
 Ammonia is converted to nitrite, then to
nitrate
Assimilation
Plant roots absorb ammonium ions and
nitrate ions for use in making molecules suc
as DNA, amino acids and proteins.

40. Ammonification
 After nitrogen has served its purpose in
living organisms, decomposing bacteria
convert the nitrogen-rich compounds,
wastes, and dead bodies into simpler
compounds such as ammonia.
Denitrification
•Nitrate ions and nitrite ions are converted into
nitrous oxide gas and nitrogen gas.
This happens when a soil nutrient is reduced
and released into the atmosphere as a gas.

41. Biomagnification
 Concentration
of toxin at
higher trophic
levels

42. Succession
 The process where plants & animals
of a particular area are replaced by
other more complex species over
time.

43. Stages of Succession
Land – rock  lichen  small shrubs 
large shrubs  small trees  large trees

44. Primary Succession
 When the starting
point is an ABIOTIC
environment
 Volcano
 Flood

45. Secondary Succession
 When an
EXISTING
ecosystem is
disturbed
 Fire/lightning
 Disease
 Hurricanes Credit: Jeff Schmaltz, NASA's MODIS Rapid Response Team
 Human activities

46. Fig 10.7 Diagram of bog
succession.
Wetland Succession 1
Wetland
Succession
Sedges and
floating plants
close over the 2
open water,
trapping
sediments in
their roots, and
gradually
drying out the 3
pond.
© 2003 John Wiley and Sons Publishers

47. CLIMATE: A BRIEF INTRO.
 Weather - local, short-term conditions such as
temperature and precipitation
 Climate - a region’s average weather
conditions over a long time
 Latitude and elevation help determine climate

48. BIOMES:
 Large terrestrial regions characterized
by similar climate, soil, plants, and
animals

49. Biomes Around the World

50. DESERT BIOMES
 The evaporation is greater than the
precipitation (usually less than 25
cm). Covers 30% of the earth.

51. DESERT BIOMES
 Variations in
annual
temperature (red)
and precipitation
(blue) in tropical,
temperate and
cold deserts.
Figure 5-12

52. FOREST BIOMES
 Forests have enough precipitation to support
stands of trees and are found in tropical,
temperate, and polar regions.

53. FOREST BIOMES
 Variations in
annual temperature
(red) and
precipitation (blue)
in
tropical, temperate,
and polar forests.
Figure 5-19

54. Taiga (evergreen coniferous forest)
 Just south of the tundra (northern part of N.
America), it covers 11% of earth’s land. Its
winters are long, dry & cold. Some places have
sunlight 6 to 8 hours a day. The summers are
short and mild, w/ sunlight 19 hours a day.

55. MOUNTAIN BIOMES (Taiga)
 High-elevation
islands of
biodiversity
 Often have snow-
covered peaks that
reflect solar
radiation and
gradually release
water to lower-
elevation streams
and ecosystems.

56. Evergreen Coniferous Forests
 Consist mostly of
cone-bearing
evergreen trees
that keep their
needles year-round
to help the trees
survive long and
cold winters.

57. Tropical Rainforest
 Near the equator. It has warm
temperatures, high humidity & heavy
rainfall.

58. Tropical Rain Forest
 Tropical rain
forests have heavy
rainfall and a rich
diversity of
species.
 Found near the
equator.
 Have year-round
uniformity warm
temperatures and
high humidity.

59. Tropical Rain Forest
 Filling such niches enables species to avoid
or minimize competition and coexist

60. Temperate Rain Forests
 Coastal areas support huge cone-bearing
evergreen trees such as redwoods and
Douglas fir in a cool moist environment.

61. Temperate Deciduous Forest
 It has moderate temperatures, long, warm
summers, cold winters &lots of rain. Trees
include oaks, hickory, maple, and beech.

62. Temperate Deciduous Forest
 Most of the trees
survive winter by
dropping their
leaves, which
decay and
produce a
nutrient-rich soil.

63. Grassland
 The rainfall is erratic & fires are
common. It has & shrubs that are
good for grazing animals.

64. GRASSLANDS AND CHAPARRAL
BIOMES
 Variations in
annual
temperature
(red) and
precipitation
(blue).
Figure 5-14

65. Savanna
 The tropical & subtropical grassland.
It is warm all year long with
alternating wet & dry seasons.

66. Chaparral (temperate grassland)
 These are coastal areas. Winters are mild
& wet, w/ summers being long, hot, &
dry.

67. Chaparral
 Chaparral has a
moderate
climate but its
dense thickets
of spiny shrubs
are subject to
periodic fires.

68. Temperate Grasslands
 The cold winters
and hot dry
summers have deep
and fertile soil that
make them ideal for
growing crops and
grazing cattle.

69. Tundra (polar grasslands)
 Covers 10% of earth’s land. Most of the year,
these treeless plains are bitterly cold with ice
& snow. It has a 6 to 8 week summer w/
sunlight nearly 24 hours a day.

70. Polar Grasslands
 Polar grasslands
are covered with
ice and snow
except during a
brief summer.