1. Chapter 52
Section 1 & 2

2. What Does Ecology Do?
Ecology
Reveals the richness of the biosphere

3. What is Ecology?
Study of interactions between organisms and the environment
Ecology
Has a long history as a descriptive science & is a rigorous experimental science

4. Organisms and the Environment
The environment of any organism includes:
Abiotic
Nonliving components
Biotic
Living components
Biota
All the organisms living in the environment

5. What role does the Environment play for organisms?
Affects the distribution and abundance of organisms
Kangaroos/km2
> 20
10–20
5–10
1–5
0.1–1
< 0.1
Limits of distribution
Climate in northern Australia
is hot and wet, with seasonal
drought.
Red kangaroos
occur in most
semiarid and arid
regions of the
interior, where
precipitation is
relatively low and
variable from
year to year.
Southeastern Australia
has a wet, cool climate.
Southern Australia has
cool, moist winters and
warm, dry summers.
Tasmania

6. Ways Ecologists Study the Environment
Use:
Observations
Experiments

7. Subfields of Ecology Organismal Ecology
Studies how an organism’s structure, physiology, and behavior meet the challenges posed by the environment
(a) Organismal ecology. How do humpback whales select their calving areas?

8. Subfields of Ecology Cont’d
Population Ecology
Concentrates mainly on factors that affect how many individuals of a particular species live in an area
Population ecology.
What environmental
factors affect the
reproductive rate of
deer mice?
(b)

9. Subfields of Ecology Cont’d
Community Ecology
Deals with the whole array of interacting species in a community
(c) Community ecology. What factors influence the diversity of species that make up a particular forest?

10. Subfields of Ecology Cont’d
Ecosystem Ecology
Emphasizes energy flow and chemical cycling between biotic and abiotic components
(d) Ecosystem ecology. What factors control photosynthetic productivity in a temperate grassland ecosystem?

11. Subfields of Ecology Cont’d
Landscape Ecology
Deals with arrays of ecosystems and how they are arranged in a geographic region
(e) Landscape ecology. To what extent do the trees lining the drainage channels in this landscape serve as corridors of dispersal for forest animals?

12. Biosphere
Is the global ecosystem,
Sum of all the planet’s ecosystems

13. Ecology and Environmental Issues
Ecology provides the scientific understanding underlying environmental issues
Rachel Carson
Started the modern environmental movement

14. Ecologists follow the Precautionary Principle
Humans need to be concerned with how their actions affect the environment

15. Section 52.2
Concept 50.2: Interactions between organisms and the environment limit the distribution of species

16. Dispersion Patterns
Many naturalists have noticed a pattern of the ways plants and animals are distributed
Tropic
of Cancer
(23.5N)
Equator
Nearctic
Neotropical
Ethiopian
Oriental
Australian
Palearctic
(23.5S)
Tropic of
Capricorn

17. Dispersal and Distribution
Movement of individuals away from centers of high population density or from their area of origin
Leads to distribution of species

18. Species Transplants
Species Transplants
Organisms that are intentionally or accidentally relocated from original distribution
How does this effect an ecosystem?
Can disrupt the communities or ecosystems causing a change in food chain

19. Behavior and Habitat Selection
A Few Thoughts
Some Organisms
Do not occupy all of their potential range
Species distribution
May be limited by habitat selection behavior

20. Biotic Factors These affect the distribution of organisms
Interactions with other species
Predation
Competition

21. Abiotic Factors These affect the distribution of organisms Temperature
Water
Sunlight
Wind
Rocks and soil
Salinity

22. Temperature Environmental Temperature
How does this effect distribution of species?
It can change biological processes

23. Water
How is water a factor that could influence species distribution?

24. Sunlight
How is sunlight a factor that could influence species distribution?
Can influence photosynthesis
Development and behavior of organisms sensitive to the photoperiods can be altered

25. Wind How does wind effect different species?
Amplifies the effects of temperature on organisms

26. Rocks and Soil
How are rocks and soil a factor that could influence species distribution?
Limit the distribution of plants and thus the animals that feed upon them by:
Physical Structure pH
Mineral composition

27. Climate Climate Four major abiotic components make up climate:
Is the prevailing weather conditions in a particular area
Four major abiotic components make up climate:
Temperature
Water
Sunlight
Wind

28. Climate patterns can be described on two scales
Macroclimate
These are on the global, regional, and local level
Microclimate
In certain locations
Mountain Tops, under a fallen log etc…

29. Global Climate Patterns
Determined by the input of solar energy
Location of Earth in space

30. How Global Climate Is Determined (Input of Solar Energy)
Sunlight Intensity
Plays a major part in determining the Earth’s climate patterns
Figure 50.10
Low angle of incoming sunlight
Sunlight directly overhead
North Pole 60N
30N
Tropic of Cancer
0 (equator)
30S
60S
Atmosphere
LALITUDINAL VARIATION IN SUNLIGHT INTENSITY
Tropic of Capricorn
South pole

31. How Global Climate Is Determined Cont’d (Location In Space)
June solstice: Northern
Hemisphere tilts toward
sun; summer begins in
Northern Hemisphere;
winter begins in
Southern Hemisphere.
March equinox: Equator faces sun directly;
neither pole tilts toward sun; all regions on Earth
experience 12 hours of daylight and 12 hours of
darkness.
60N
30N
0 (equator)
30S
Constant tilt
of 23.5
September equinox: Equator faces sun
directly; neither pole tilts toward sun; all
regions on Earth experience 12 hours of
daylight and 12 hours of darkness.
December solstice: Northern
Hemisphere tilts away from sun;
winter begins in Northern
Hemisphere; summer begins
in Southern Hemisphere.
SEASONAL VARIATION IN SUNLIGHT INTENSITY

32. How Global Climate Is Determined Cont’d
GLOBAL WIND PATTERNS
Westerlies
Northeast trades
Doldrums
Southeast trades
Antarctic Circle
60S
30S 0
(equator)
30N
60N
Arctic Circle
Figure 50.10

33. Regional, Local, and Seasonal Effects on Climate
Various features of the landscape contribute to local variations in climate
What might be some of these?

34. Bodies of Water Oceans and their currents, and large lakes Cooler
air sinks
over water. 3
Air cools at
high elevation. 2 1
Warm air
over land rises. 4
Cool air over water
moves inland, replacing
rising warm air over land.

35. Mountains Mountains have a significant effect on
The amount of sunlight reaching an area
Local temperature
Rainfall

36. Mountain Effect Cont’d
Farther inland, precipitation
increases again as the air
moves up and over higher
mountains. Some of the world’s
deepest snow packs occur here. 3
On the eastern side of the
Sierra Nevada, there is little
precipitation. As a result of
this rain shadow, much of
central Nevada is desert.
As moist air moves in
off the Pacific Ocean and
encounters the westernmost
mountains, it flows upward,
cools at higher altitudes,
and drops a large amount
of water. The world’s tallest
trees, the coastal redwoods,
thrive here. 1 2
East
Pacific Ocean
Wind
direction
Coast Range
Sierra
Nevada

37. SEASONAL VARIATION IN SUNLIGHT INTENSITY
Seasonality
The angle of the sun
Leads to many seasonal changes in local environments
June solstice: Northern
Hemisphere tilts toward
sun; summer begins in
Northern Hemisphere;
winter begins in
Southern Hemisphere.
March equinox: Equator faces sun directly;
neither pole tilts toward sun; all regions on Earth
experience 12 hours of daylight and 12 hours of
darkness.
60N
30N
0 (equator)
30S
Constant tilt
of 23.5
September equinox: Equator faces sun
directly; neither pole tilts toward sun; all
regions on Earth experience 12 hours of
daylight and 12 hours of darkness.
December solstice: Northern
Hemisphere tilts away from sun;
winter begins in Northern
Hemisphere; summer begins
in Southern Hemisphere.
SEASONAL VARIATION IN SUNLIGHT INTENSITY