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Environments

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Food Web. Food web. More complex than simple food chain ... the tropical rainforest. ... between 4 and 10 N and is termed the Inter-Tropical Convergence Zone (ITCZ) ... – PowerPoint PPT presentation

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Title: Environments


1
Chapter 4
  • Environments
  • and Life

2
What is your current classification?
  • Freshman
  • Sophomore
  • Junior
  • Senior

3
Guiding Questions
  • What factors determine the ecological niches of
    species, and by what means do species obtain
    nutrition?
  • What factors govern the geographic distribution
    of species?
  • What factors govern the distribution of aquatic
    life?

4
Environmental Differences
  • Tropical vs Polar - Terrestrial and Marine
  • Low vs High Elevation
  • Shallow vs Deep
  • Wet vs Dry

5
Hypsometric Curve
  • Curve showing the proportions of the Earths
    surface above and below sea level

6
Hypsometric Curve
7
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8
Climate
  • Climate
  • Controls distribution of species globally
  • Has changed through time
  • Plate tectonics and other changes affect climate

9
Ecology
  • Ecology
  • Study of the factors that govern the distribution
    and abundance of organisms in natural
    environments
  • Habitats
  • Environments on or close to Earths surface
    inhabited by life
  • Terrestrial
  • Aquatic
  • Marine
  • Freshwater

10
Ecology
  • Ecologic niche
  • The way a species relates to its environment,
    including food, nutrients, physical and chemical
    conditions
  • Life habit
  • The way a species lives within its niche
  • Limiting factors
  • Naturally occurring, restricting condition
    (physical and chemical)
  • Competition
  • Shared drive for limited resources
  • Predation

11
Competition
  • Arises because organisms share space
  • Predation also comes in here by possibly limiting
    or preventing another species from inhabiting a
    particular environment.

12
Ecosystem
  • Ecosystem
  • Organisms of a community and the physical
    environment they occupy
  • Population
  • Group of individuals that belong to a single
    species and live together in a particular area

13
Ecosystem
  • Ecologic community
  • Populations of several species living in a
    habitat
  • Producers
  • Photosynthesizing organisms foundation of
    community
  • Consumers
  • Herbivores feed on producers
  • Carnivores feed on other consumers

14
Ecosystem
  • Biota
  • Fauna animals and protozoans of an ecosystem
  • Flora plants and plantlike protists
  • Food chain
  • Sequence of consumption for producers to consumers

15
Food Web
  • Food web
  • More complex than simple food chain
  • More common
  • Several species occupy each level

16
Ecosystem
  • Parasites
  • Feed on living organisms
  • Scavengers
  • Feed on organisms that are already dead

17
Ecology
The movement of materials through an ecosystem.
Components within ovals are consumers.
18
Figure 4-35 (p. 134)Interdependence of
photosynthesis and respiration.
19
Figure 4-38 (p. 136)Simple pyramid of ocean
life.
20
Biogeography
  • The distribution and abundance of organisms on a
    broad geographic scale.

21
Biogeography
  • Temperature
  • Moisture
  • Nutrients

22
Ecosystem
  • Diversity
  • The variety of species that live together within
    a community
  • Lower in more difficult habitats
  • Predation influences diversity
  • Heavy can reduce diversity
  • Moderate can increase diversity by reducing
    competition
  • Opportunistic species
  • Species that specialize in invading newly vacated
    habitats

23
Biogeography
  • Distribution and abundance of organisms on a
    broad geographic scale
  • Limiting factors
  • Diversity increases toward equator
  • Barriers can affect dispersal

24
Life Habitats
  • The mode by which an organism lives, feeds in an
    environment
  • 1. Tropical vs. Polar
  • 2. Low vs high altitude
  • 3. Shallow vs deep
  • 4. Benthic vs. Planktonic

25
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26
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27
Atmosphere
  • Regulates Earths temperature (-18C w/o
    atmosphere)
  • Composition
  • N2, O2, CO2
  • Tilt of the Earth affects solar insulation,
    temperature, and climate

28
In our present atmosphere, concentrations of O2
and CO2 are
  • O2 gt CO2
  • O2 lt CO2
  • O2 CO2

29
The Atmosphere
  • Nitrogen -78
  • Oxygen - 21
  • Carbon dioxide (CO2 ) - 0.037 or 370 ppm
  • Methane (CH4) - 0.00018 or 1800 ppb

30
Solar Radiation
  • Daylight
  • Which receives more hours of daylight?
  • Equator vs Poles
  • The amount of daylight ( of hours) averaged over
    a year is the same at the poles as at the equator

31
Solar Radiation
32
Solar Radiation
  • Temperature difference is due to the angle of the
    sunlight and the albedo
  • In the high latitudes, the sun hits at a low
    angle and therefore the unit energy of sunlight
    is spread over a large cross-sectional area of
    the earths surface. In the tropics, the sun
    hits directly and therefore is much more
    concentrated

33
Solar Radiation
34
Solar Radiation
  • Albedo refers to the reflectivity of the Earths
    surface
  • 1. Snow and ice is very reflective - much of the
    solar radiation is reflected by to the solar
    system
  • 2. Water has a low albedo and absorbs a lot of
    the solar radiation

35
Solar Radiation
36
Solar Radiation
37
Solar Radiation
  • When do we have summers?
  • True or False
  • Summers on Earth occur when it passes closest to
    the Sun

38
Solar Radiation
  • Obliquity or Tilt (23.5) of the to Earths
    rotational axis
  • This tilt gives us seasons. Summer is when the
    northern or southern hemisphere is point towards
    the Sun

39
Atmosphere
  • Regulates Earths temperature
  • Composition
  • N2, O2, CO2
  • Tilt of the Earth affects solar insulation,
    temperature, and climate

40
Solar RadiationHeat Capacity
41
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42
Movement of Air mass
  • Rises at Eq. and sinks near Poles
  • The high solar radiation at the equator heats the
    air masses, causing them to rise (buoyant).
  • As the air rises, the temperature of the air mass
    decreases

43
Atmospheric Circulation
  • Net transport
  • Air sinks at the poles, rises at the equator
  • Simplified model
  • No tilt
  • No Coriolis effect

44
Rising Air
  • As the air rises, the temperature of the air mass
    decreases (adiabatic lapse rate 5C/km)
  • Cold air holds less water vapor. Voila, rain and
    the tropical rainforest. Low pressure systems
    usually have rain because the rising air drop
    water as the air ascends and cools

45
Rising Air
46
Atmospheric Circulation
  • Coriolis effect
  • Earths rotation causes air and water masses to
    be defected to the right (clockwise) in the
    northern hemisphere
  • Counterclockwise for southern hemisphere

47
Atmospheric Circulation
  • If we reverse the direction and launch a rocket
    from Panama towards Washington DC, which way will
    it curve?
  • A Right
  • B Left
  • C Not at all because Panama is close to the Eq.

48
Coriolis force
  • Deflection of moving objects to the right in the
    No. Hemisphere and left in the So. Hemisphere

49
Coriolis Force
50
Atmospheric Circulation
  • Actual pattern is more complex
  • Three circulation cells
  • Trade winds, westerlies, easterlies
  • Intertropical convergence zone
  • Northern, southern trade winds converge near
    equator
  • Changes seasonally

51
Temperature Variations
  • Atmosphere retains heat
  • Solar radiation
  • Absorbed and turned into heat energy
  • Reflected
  • 6-10 ocean
  • 5-30 forest
  • 45-95 ice and snow

52
Trade winds
  • As the dry air descending around 30 begins to
    flow back towards the Eq. it is deflected to the
    right.

53
Trade windsAs the dry air descending around 30
begins to flow back towards the Eq. it is
deflected to the right.
54
Trade windsThe NE and SE trades converge on the
latitude where the maximum in convection (rising
air) is occurring. This is the warmest location.
Today, this is between 4 and 10N and is termed
the Inter-Tropical Convergence Zone (ITCZ)
55
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56
The Terrestrial Realm
  • Latitudinal Zones and Vegetation
  • Rain forests
  • Deserts
  • Savannah Grasslands
  • Temperate Forest
  • Conifer or Evergreen Forest
  • Tundra

57
Terrestrial Realm
  • Vegetation follows climatic zone
  • Tropical rain forest
  • Desert savannahs
  • Temperate forests
  • Polar tundra

58
Terrestrial Realm
  • Tropical Climates
  • 1820 C (6468 F)
  • 030 latitude
  • Tropical Rain Forest
  • Dense vegetation

59
Rain forests
  • develop under the tropical low pressure systems.
    Rising air dumps lots of rain. Found within a few
    degrees near the equator

60
Terrestrial Realm
  • Deserts
  • Dry trade winds remove moisture
  • 2030 north and south of the equator
  • lt 25 cm rain/year
  • Little vegetation
  • Savannah, grasslands
  • Too dry to support forests

61
Deserts
  • (lt10 inches of water per year) develop under the
    sinking dry air masses and under the dry Trade
    Winds. Usually found around 30 latitude.

62
Savannah Grasslands
  • found between Rain forest and Desert and receive
    seasonal rain falls. Not enough rain throughout
    the year to support woodland

63
Tundra
  • - Arctic ecosystem where layer beneath soil
    remains frozen throughout the year.

64
Terrestrial Realm
  • Poles
  • Defined by ice sheets and glaciers today
  • Absent or reduced at times in the past

65
Terrestrial Realm
  • Glaciers
  • Ice in motion
  • Glide and spread
  • Present at high latitudes and high elevations
    near equator

66
Terrestrial Realm
  • Tundra
  • Limited water
  • Grasses, sedges, lichens, shrubs dominate
  • Cannot support tall trees
  • Evergreen coniferous forests
  • South of tundra
  • Spruce, pine, fir

67
Terrestrial Realm
  • Temperate forests
  • Longer summers, slightly warmer
  • Deciduous trees
  • Maples, oaks, beeches
  • Mediterranean climate
  • Dry summers, wet winters
  • Common 40 N and S of equator
  • Californian, Mediterranean region

68
Climate
  • Altitude
  • Similar to latitudinal gradient
  • At base
  • Deciduous forest
  • On slopes
  • Evergreen forest
  • Tundra above tree-line
  • At top
  • Glaciers

69
Climate
  • Mountains
  • Rain shadow
  • Prevailing winds bring moisture
  • Precipitation on windward side
  • Aridity on leeward side
  • Rain shadows common on east side of North
    American mountain chains

70
Climate
  • Seasonal Change
  • High heat capacity of water
  • Less change in ocean temperatures than on land
  • Monsoon Circulation
  • Summer winds flow onshore bring rain
  • Winter winds offshore

71
Plants as Climate Indicators
  • Sensitive indicators of change
  • Cycads
  • Tropics and subtropics today
  • Fossil distribution allows reconstruction of
    climate patterns

72
Plants as Climate Indicators
  • Leaf Margins
  • Tropics
  • Smooth, waxy margins
  • Temperate climates
  • Jagged margins

73
Marine Realm
  • Ocean currents
  • Wind driven
  • Follow atmospheric patterns
  • Trade winds
  • Push waters west form equatorial currents
  • Equatorial countercurrents
  • Return flow
  • Gyres
  • Clockwise in Northern Hemisphere
  • Gulf Stream

74
Marine Realm
  • Circumpolar current
  • Circles Antarctica
  • Very cold

75
Marine Realm
  • Polar circulation
  • Sea ice leads to more saline water
  • Cold, dense waters sink
  • Antarctic waters
  • Flow north at depth
  • Arctic waters
  • Flow south at depth

76
Marine Realm
  • Ocean circulation
  • Waves
  • Surface waves
  • Wind driven
  • Break when seafloor interacts at shallow depths
  • Tides
  • Cause major movement of water in oceans
  • Due to rotation of solid Earth beneath bulges of
    water produced by gravitational attraction of the
    moon

77
Marine Realm
  • Continental Shelf
  • Submarine extension of continental landmass
  • Shelf break
  • Edge of shelf
  • 200 m w.d.
  • Continental Slope
  • Continental Rise
  • Abyssal Plain

78
Figure 4-31 (p. 131)Classification of marine
environments. (After Hedgspeth, UJ. W., ed.
1957. Treatise of Marine Ecology and
Paleoecology. Geological Society of America
Memoirs 67(1) 18.)
79
The Marine Realm
  • The depth of the Sea
  • Moving from the beach seaward, one crosses a
    consistent pattern of water depth changes. The
    continental shelf extends from the shoreline to
    the continental shelf break. Water depths over
    the shelf vary from 0 to 200 m. This
    environment is very important for benthic
    communities because the photic zone in the ocean
    extends only down to 200m. Consider the
    implications for primary production

80
The Marine Realm
  • The Shelf break marks the distal edge of the
    shelf where seaward of this point, water depths
    increase at a greater rate (3 to 5slope)
    compared with the shelf (1 to 2slope).

81
The Marine Realm
  • Continental Slope.
  • Typically, the slope extends down to 3000 to 3500
    m. Near the base of the slope is the transition
    from continental to oceanic crust.

82
The Marine Realm
  • The Slope gives way to the Continental Rise.
    This is a less steep surface that segways to the
    Abyssal Plain (the ocean floor). The Rise is
    created as sediments are transported down the
    slope in turbidity currents.

83
The Marine Realm
  • At the base of the slope and out on the abyssal
    plain, the slope decreases significantly and the
    sediments are dropped, forming the Rise

84
Figure 4-31 (p. 131)Classification of marine
environments. (After Hedgspeth, UJ. W., ed.
1957. Treatise of Marine Ecology and
Paleoecology. Geological Society of America
Memoirs 67(1) 18.)
85
Marine Realm
  • Near shore
  • Barrier islands
  • Marshes
  • Epicontinental seas

86
Marine Realm
  • Photic Zone
  • Region of ocean where enough light penetrates to
    permit photosynthesis
  • Pelagic life
  • Plankton
  • Phytoplankton
  • Zooplankton
  • Nekton
  • Benthic life
  • Suspension feeders
  • Deposit feeders

87
Marine Realm
  • Marine Biogeography
  • Tropical
  • Subtropical
  • Transitional
  • Subarctic

88
Figure 4-36 (p. 135)Major ocean surface
currents.
89
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90
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91
Marine Realm
  • Corals
  • Most require warm water
  • Common in tropics
  • Reef builders
  • Coral polyp
  • Builds coral cup
  • Connected to other polyps
  • Symbiotic relationship with algae

92
Marine Realm
  • Salinity
  • Limiting factor near shore
  • Oceanic
  • 35 ppt
  • Brackish
  • Lower than marine
  • Bays, lagoons
  • Hypersaline
  • Higher than marine
  • Hot arid climates

93
The portion of the temperature-depth curve in the
ocean that shows maximum change is the
thermocline.
94
Deep Water Circulation
95
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96
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97
Atmospheric Circulation
  • If we reverse the direction and launch a rocket
    from Panama towards Washington DC, which way will
    it curve?
  • A Right
  • B Left
  • C Not at all because Panama is close to the Eq.
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