Intro to Ecology & the Biosphere

BIOL 101General Biology I

Chapter 52

Rob SwatskiAsst. Prof. Biology

HACC-York1Willy Volk http://flic.kr/p/2EML7W

2

Ecology

The study of interactions between

organisms & the environment

Interactions determine the distribution & abundance of

organisms

Ecologists work at ALL levels: individual

organisms entire planet!

Organismalecology

Populationecology

Communityecology

Ecosystemecology

Landscapeecology

Globalecology

3

Organismal Ecology

4

Population Ecology

5

6

Community Ecology

7

Ecosystem Ecology

8

Ecosystem Ecology

Studies energy flow & chemical

cycling

Biotic factors

Abiotic factors

9

Landscape Ecology

Landscape: a mosaic of connected ecosystems

Studies how ecosystems are arranged in a

geographic area

10

Global Ecology

Biosphere: the sum of all the

planet’s ecosystems

Studies the influence of

energy & chemicals on

organisms across the Earth

Kangaroos/km2

0–0.10.1–1

1–55–1010–20> 20Limits ofdistribution

Biogeography

11

Why is species X absentfrom an area?

Does dispersallimit its

distribution?Does behavior

limit itsdistribution?

Area inaccessibleor insufficient timeYes

No

No

No

Yes

YesHabitat selection

Do biotic factors(other species)

limit itsdistribution?

Predation, parasitism,competition, disease

Do abiotic factorslimit its

distribution?

Chemicalfactors

Physicalfactors

WaterOxygenSalinitypHSoil nutrients, etc.

TemperatureLightSoil structureFireMoisture, etc.

12

Ecology is COMPLEX!

Current

1966

1970

1965 1960

1961

1958

1951

1943

1937

1956

1970

Dispersal

Natural range expansions13

14

Biotic Factors

Interactions with other

species

Predation

Competition

15Does feeding by sea urchins limit seaweed distribution?

RESULTS

Sea urchin

100

80

60

40

20

0

Limpet

Seaw

ee

d C

ove

r (%

)Both limpets & urchinsremoved

Only urchinsremoved

Only limpets removed

Control (both urchins& limpets present)

August1982

August1983

February1983

February1984

16

17

Abiotic Factors

Temp. Water

Sunlight Salinity

WindRocks &

soil

18

Seven-Mile Bridge

19

Seven-Mile Bridge

20

Temperature

Major regulator of biological processes

Cells freeze & rupture below 0°C, while

proteins denatureabove 45°C

Thermoregulation by mammals & birds consumes energy!

21

Water

Availability in habitat is major limiting factor

Adaptations for water

conservation

Salinity: affects osmosis &

water balance22

Sunlight

Light intensity & quality affect photosynthesis

Water absorbs light

Most PSN occurs near

water’s surface

UV stress in deserts & mountains

23

24What major abiotic factors are at work here?

Rocks & Soil

Physical structure

Mineral composition

pH

25

Climate

Long-termprevailing weather

conditions in an area

Includes temperature,

water, sunlight, & wind

Macroclimate: patterns on the

global, regional, & local level

Microclimate: very fine patterns

26

Low angle of incoming sunlight

Sun directly overhead at equinoxes

Low angle of incoming sunlight

Atmosphere90ºS (South Pole)

60ºS

30ºS

23.5ºS (Tropic of Capricorn)

0º (equator)

30ºN

60ºN

23.5ºN (Tropic of Cancer)

90ºN (North Pole)

27

Global Climate Patterns

March equinox

60ºN

30ºN

0º (equator)

30ºSJune solstice

Constant tiltof 23.5º

September equinox

December solstice

28

Descendingdry air

absorbsmoisture

Descendingdry air

absorbsmoisture

Ascendingmoist airreleasesmoisture

Aridzone

Aridzone

Tropics

30º 23.5º 0º 23.5º 30º

60ºN

30ºN

0º(equator)

30ºS

60ºS

Global air circulation & precipitation patterns

29

0º(Equator)

30ºS

60ºS66.5ºS(Antarctic Circle)

30ºN

66.5ºN(Arctic Circle)

60ºNWesterlies

Northeast trades

Doldrums

Southeast trades

Westerlies

30

Labradorcurrent

Gulfstream

Equator

Cold water

31

Great Ocean Conveyor Belt

Warm airover land rises.

1

23

4

Air cools athigh elevation.

Cool air over watermoves inland, replacingrising warm air over land.

Cooler air

sinks over

water.

32 Climate Moderation

33

Winddirection

Mountainrange

Leeward sideof mountain

Ocean

Rain Shadow

How Mountains Affect Rainfall

Biomes

Major ecological systems that occupy

large geographic regions of land or

water

Varying combinations of biotic & abiotic

factors determine biome structure

Aquatic & terrestrial biomes

34

Aquatic Biomes

Make up the largest part of the biosphere

in terms of area

Cover approx. 75% of the Earth’s surface

Fresh water or salt water (marine)

Have an enormous impact on the

biosphere35

Stratification of Aquatic

Biomes

Light penetration

Temperature

Depth

36

Littoralzone Limnetic

zone

Photiczone

PelagiczoneBenthic

zone

Aphoticzone

Lake Zonation

37

38 Phytoplankton & Zooplankton

2,000–6,000 m

Abyssal zone

Benthiczone

Aphoticzone

Pelagiczone

Continentalshelf

200 mPhotic zone

0

Oceanic zoneNeritic zone

Intertidal zone

detritus

39

Marine Zonation

0º2º

4º4º

4º

4ºC

40

Seasonal Turnover

Winter

4º4º

4º

4ºC

4º4º

turnover

O2

nutrients

41Spring

8º6º

5º4ºC

18º20º

Thermocline22º

42Summer

4º4º

4º

4ºC

4º4º

turnover

O2

nutrients

43Autumn

nutrients

O2

44

Oligotrophic Lake

45 Lake Bled, Slovenia

nutrients

O2

46

Eutrophic Lake New Jersey Pine Barrens

47

Wetlands

Any habitat that is inundated by water at least some of the

time

Supports plants adapted to water-

saturated soil

Among the most productive biomes

on Earth

48

Wetland Locations

Shallow basins

Flooded river banks

Along the coasts of large lakes & seas

49

50

Fresh Water Stream

headwaters

51Fresh Water River

Estuaries

Salt Marshes: influenced by tidal

flow

Variable salinity

Nutrient-rich

52

53

Barrier Island

Cumberland Island, GA

54

55

56

57

58

59

60

61

Rocky Intertidal Biome

62

63

64

65

Ocean Pelagic Biome

66

67

68

69

70

71

72

Tropical Coral Reef Biome

73

Sombrero Key, FL

74

75

76

77Deep Sea Hydrothermal Vent

78

79

80

81

Tropical forest

Savanna

Desert

Chaparral

Temperategrassland

Temperatebroadleaf forest

Northernconiferous forest

Tundra

High mountains

Polar ice

30ºN

Tropic ofCancer

Equator

Tropic ofCapricorn

30ºS

Distribution of Terrestrial Biomes

82

Tropical forestTemperate grasslandDesert

Temperatebroadleafforest

Northernconiferousforest

Arctic andalpinetundra

An

nu

al m

ean

te

mp

era

ture

(ºC

)

Annual mean precipitation (cm)

30

15

0

0–15

100 200 300 400

Climograph 83

Terrestrial Biomes

Distribution

Temperature & precipitation

Plants & animals

84

Tropical Rainforest

Vertical Layering

Canopy

Low-tree layer

Understory

Ground layer

Forest floor

Root layer

85

86 Desert

87 Savanna

88 Temperate Grassland

89

Coniferous Forest (Taiga)

90Temperate Broadleaf Forest

91Tundra

92

93

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