environment life_01

7/29/2019 environment life_01

1/97

Chapter 4

Environments

and Life


2/97

What is your current classification?

A. Freshman

B. Sophomore

C. Junior

D. Senior


3/97

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 ofaquatic life?


4/97

Environmental Differences

Tropical vs Polar - Terrestrial and Marine

Low vs High Elevation

Shallow vs Deep

Wet vs Dry


5/97

Hypsometric Curve

Curve showing the proportions of the

Earths surface above and below sea level


6/97

Hypsometric Curve


7/97

QuickTime and a TIFF (Uncompressed) decompressor are needed to see this p icture.


8/97

Climate

Climate

Controls distribution of species globally

Has changed through time

Plate tectonics and other changes affect

climate


9/97

Ecology

Ecology

Study of the factors that govern the distribution andabundance of organisms in natural environments

Habitats

Environments on or close to Earths surface inhabitedby life

Terrestrial

Aquatic Marine

Freshwater


10/97

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


11/97

Competition

Arises because organisms share space

Predation also comes in here by possibly

limiting or preventing another species

from inhabiting a particular

environment.


12/97

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


13/97

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


14/97

Ecosystem

Biota Fauna: animals and protozoans of an ecosystem

Flora: plants and plantlike protists

Food chain

Sequence of consumption for producers to consumers


15/97

Food Web

Food web

More complex than simple food chain

More common

Several species occupy each level


16/97

Ecosystem

Parasites

Feed on living

organisms

Scavengers

Feed on organisms that

are already dead


17/97

Ecology

The movement of materials through an ecosystem.

Components within ovals are consumers.


18/97

Figure 4-35

(p. 134)Interdependenceof photosynthesis

and respiration.


19/97

Figure 4-38 (p. 136)

Simple pyramid of ocean life.


20/97

Biogeography

The distribution and abundance of

organisms on a broad geographicscale.


21/97

Biogeography

Temperature

Moisture

Nutrients


22/97

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


23/97

Biogeography

Distribution and

abundance of

organisms on a broadgeographic scale

Limiting factors

Diversity increases

toward equator

Barriers can affect

dispersal


24/97

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 deep4. Benthic vs. Planktonic


25/97


26/97


27/97

Atmosphere

Regulates Earths

temperature (-18C w/o

atmosphere)

Composition

N2, O2, CO2

Tilt of the Earth affectssolar insulation,

temperature, and climate


28/97

In our present atmosphere,

concentrations of O2 and CO2 are:

A. O2 > CO2

B. O2 < CO2

C. O2

= CO2


29/97

The Atmosphere

Nitrogen -78%

Oxygen - 21%

Carbon dioxide (CO2

) - 0.037% or 370 ppm

Methane (CH4) - 0.00018% or 1800 ppb


30/97

Solar Radiation

Daylight

Which receives more hours of daylight?

Equator vs Poles

The amount of daylight (# of hours) averagedover a year is the same at the poles as at the

equator


31/97

SolarRadiation


32/97

Solar Radiation

Temperature difference is due to the angleof the sunlight and the albedo

In the high latitudes, the sun hits at a lowangle and therefore the unit energy ofsunlight is spread over a large cross-sectional area of the earths surface. In the

tropics, the sun hits directly and therefore ismuch more concentrated


33/97

Solar Radiation


34/97

Solar Radiation

Qui ckTime and a TIFF (Uncompress ed) decomp ressor are needed to see this pic tu

Albedo refers to thereflectivity of the Earthssurface

1. Snow and ice is veryreflective - much of the solarradiation is reflected by tothe solar system

2. Water has a low albedo andabsorbs a lot of the solarradiation


35/97

Solar Radiation

QuickTime and a TIFF (Uncompressed) decompressor are needed to see this picture.


36/97

Solar Radiation


37/97

Solar Radiation

When do we have summers?

True or False

Summers on Earth occur when it passes

closest to the Sun


38/97

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


39/97

Atmosphere

Regulates Earthstemperature

Composition

N2, O2, CO2

Tilt of the Earthaffects solarinsulation,

temperature, andclimate


40/97

Solar Radiation

Heat Capacity


41/97


42/97

Movement of Air mass

Rises at Eq. and sinks near Poles

The high solar radiation at the equator heatsthe air masses, causing them to rise(buoyant).

As the air rises, the temperature of the airmass decreases


43/97

Atmospheric Circulation

Net transport

Air sinks at the poles,

rises at the equator

Simplified model

No tilt

No Coriolis effect


44/97

Rising Air QuickTime and a TIFF ( Uncompressed) decompressor are needed to see this picture.

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 thetropical rainforest. Low pressure systems

usually have rain because the rising air drop water

as the air ascends and cools


45/97

Rising Air



46/97


Coriolis effect

Earths rotation causes

air and water massesto be defected to the

right (clockwise) in

the northern

hemisphere Counterclockwise for

southern hemisphere


47/97


If we reverse the direction

and launch a rocket from

Panama towards

Washington DC, whichway will it curve?

A = Right

B = Left

C = Not at all because

Panama is close to the Eq.


48/97

Coriolis force

Deflection of moving objects to the right in

the No. Hemisphere and left in the So.

Hemisphere


49/97

Coriolis

Force


50/97


Actual pattern is more

complex

Three circulation cells

Trade winds, westerlies,

easterlies

Intertropical convergence

zone

Northern, southern trade

winds converge nearequator

Changes seasonally


51/97

Temperature Variations

Atmosphere retainsheat

Solar radiation

Absorbed and turnedinto heat energy

Reflected

6-10% ocean

5-30% forest 45-95% ice and snow


52/97

Trade winds

QuickTime and a TIFF (Uncompressed) decompress or are needed to see this picture.

As the dry airdescending

around 30begins to flowback towards

the Eq. it isdeflected tothe right.

T d i d


53/97

Trade windsAs the dry air descending around 30 begins to flow back

towards the Eq. it is deflected to the right.



54/97

Trade winds

The NE and SE trades converge on thelatitude where the maximum in

convection (rising air) is occurring. This

is the warmest location. Today, this isbetween 4 and 10N and is termed the

Inter-Tropical Convergence Zone

(ITCZ)


55/97


56/97

The Terrestrial Realm

Latitudinal Zones and Vegetation

Rain forests

Deserts

Savannah Grasslands

Temperate Forest

Conifer or Evergreen Forest

Tundra


57/97

Terrestrial Realm

Vegetation follows

climatic zone

Tropical rain forest

Desert savannahs

Temperate forests

Polar tundra


58/97

Terrestrial Realm

Tropical Climates

1820 C (6468 F)

030 latitude

Tropical Rain Forest

Dense vegetation


59/97

Rain forests

develop under the

tropical low pressure

systems. Rising airdumps lots of rain.

Found within a few

degrees near theequator

QuickTime and a TIFF (Uncompressed) decompressor are need ed to see this picture.


60/97

Terrestrial Realm

Deserts

Dry trade winds

remove moisture

2030 north and south

of the equator

< 25 cm rain/year

Little vegetation Savannah, grasslands Too dry to support

forests


61/97

Deserts (


62/97

Savannah Grasslands

found between Rain forest

and Desert and receive

seasonal rain falls. Not

enough rain throughout the

year to support woodland

QuickTime and aT IFF (Uncompressed) decompressor are needed to see this picture.

QuickTime and aT IFF (Uncompressed) decompressor are needed to see this picture.


63/97

Tundra

- Arctic ecosystem where

layer beneath soil remains

frozen throughout the year.

QuickTi me and a TIFF (Uncomp ress ed) decompress or are needed to see this picture.

QuickTime and a TIFF (Uncompressed) decompressor are nee ded to see this picture.


64/97

Terrestrial Realm

Poles

Defined by ice sheets

and glaciers today

Absent or reduced at

times in the past


65/97

Terrestrial Realm

Glaciers

Ice in motion

Glide and spread

Present at high

latitudes and high

elevations near equator


66/97

Terrestrial Realm

Tundra

Limited water

Grasses, sedges, lichens,

shrubs dominate Cannot support tall trees

Evergreen coniferous

forests

South of tundra Spruce, pine, fir


67/97

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


68/97

Climate

Altitude

Similar to latitudinal

gradient

At base

Deciduous forest

On slopes

Evergreen forest

Tundra above tree-line

At top

Glaciers


69/97

Climate

Mountains

Rain shadow

Prevailing winds bring

moisture Precipitation on

windward side

Aridity on leeward side

Rain shadows common

on east side of NorthAmerican mountain

chains


70/97

Climate

Seasonal Change

High heat capacity of

water

Less change in oceantemperatures than on

land

Monsoon Circulation

Summer winds flowonshore; bring rain

Winter winds offshore


71/97

Plants as Climate Indicators

Sensitive indicators of

change

Cycads

Tropics and subtropics

today

Fossil distribution

allows reconstruction of

climate patterns


72/97

Plants as Climate Indicators

Leaf Margins

Tropics

Smooth, waxy margins

Temperate climates

Jagged margins


73/97

Marine Realm

Ocean currents

Wind driven

Follow atmospheric patterns

Trade winds

Push waters west; formequatorial currents

Equatorial countercurrents

Return flow

Gyres

Clockwise in Northern

Hemisphere Gulf Stream


74/97

Marine Realm

Circumpolar current

Circles Antarctica

Very cold


75/97

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


76/97

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 ofwater produced by gravitational attraction of the

moon


77/97

Marine Realm

Continental Shelf

Submarine extension of

continental landmass

Shelf break Edge of shelf

~200 m w.d.

Continental Slope

Continental Rise Abyssal Plain


78/97

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.)


79/97

The Marine Realm The depth of the Sea

Moving from the beach seaward, one crosses a

consistent pattern of water depth changes. The

continental shelfextends 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 to200m. Consider the implications for primary

production


80/97

The Marine Realm

The Shelf breakmarks the distal edge of

the shelf where seaward of this point, water

depths increase at a greater rate (3 to5slope) compared with the shelf (1 to

2slope).


81/97

The Marine Realm

Continental Slope.

Typically, the slope extends down to 3000

to 3500 m. Near the base of the slope is thetransition from continental to oceanic crust.


82/97

The Marine Realm

The Slope gives way to the Continental

Rise. This is a less steep surface that

segways to the Abyssal Plain (the oceanfloor). The Rise is created as sediments are

transported down the slope in turbidity

currents.


83/97

The Marine Realm

At the base of the slope and out on theabyssal plain, the slope decreasessignificantly and the sediments are dropped,forming the Rise


84/97

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.)


85/97

Marine Realm

Near shore

Barrier islands

Marshes

Epicontinental seas


86/97

Marine Realm

Photic Zone

Region of ocean where enoughlight penetrates to permitphotosynthesis

Pelagic life Plankton

Phytoplankton

Zooplankton

Nekton

Benthic life

Suspension feeders

Deposit feeders


87/97

Marine Realm

Marine Biogeography

Tropical

Subtropical

Transitional

Subarctic


88/97

Figure 4-36 (p. 135)Major ocean surface currents.


89/97


90/97


91/97

Marine Realm

Corals

Most require warm water

Common in tropics

Reef builders Coral polyp

Builds coral cup

Connected to other polyps

Symbiotic relationshipwith algae


92/97

Marine Realm

Salinity

Limiting factor near shore

Oceanic

35 ppt Brackish

Lower than marine

Bays, lagoons

Hypersaline Higher than marine

Hot arid climates


93/97

The portion of the temperature-depth curve in the

ocean that shows maximum change is the thermocline.


94/97

Deep Water Circulation


95/97


96/97


97/97


If we reverse the direction

and launch a rocket from

Panama towards

Washington DC, whichway will it curve?

A = Right

B = Left C = Not at all because

Panama is close to the Eq.

environment life_01

Documents

Transcript of environment life_01