Chapter 49 Biosphere

Overview: The Scope of Ecology Ecology:

These interactions determine both the ________________________________ and their abundance Ecology is an enormously complex and exciting area of biology reveals the richness of

the________________________ Concept 50.1: Ecology is the study of interactions between organisms and the environment Ecology has a long history as a descriptive science is also a rigorous ___________________________

Ecology and Evolutionary Biology

Events that occur in _________________________________ affect life on the scale of __________________________

Organisms and the Environment

The environment of any organism includes Abiotic, : Biotic,: All the organisms living in the environment, the__________________________- Environmental components affect the __________________________ and ______________________________ of

organisms

Ecologists use __________________________ and _____________________________to test explanations for the

distribution and abundance of species

Subfields of Ecology

Organismal ecology

Kangaroos/km2

> 2010–205–101–50.1–1< 0.1Limits of

distribution

Climate in northern Australiais hot and wet, with seasonaldrought.

Red kangaroosoccur in mostsemiarid and aridregions of theinterior, whereprecipitation isrelatively low andvariable fromyear to year.

Southeastern Australiahas a wet, cool climate.Southern Australia has

cool, moist winters andwarm, dry summers. Tasmania

Population Ecology:

Community Ecology:

Ecosystem Ecology:

(a) Organismal ecology. How do humpback whales select their calving areas?

Population ecology.What environmentalfactors affect thereproductive rate ofdeer mice?

Community ecology.What factors influencethe diversity of speciesthat make up aparticular forest?

Landscape Ecology:

Biosphere:

Ecology and Environmental Issues

Ecology provides the scientific understanding underlying _______________________________ _______________________________ is credited with starting the modern environmental movement Most ecologists follow the __________________________________ regarding environmental issues The precautionary principle

Concept 50.2: Interactions between organisms and the environment limit the distribution of species Ecologists have long recognized ______________________________ patterns of distribution of organisms within the

biosphere Many naturalists began to identify broad patterns of distribution by naming

_____________________________realms

(e) Landscape ecology. To what extent do the trees lining the drainage channels in this landscape serve as corridors of dispersal for forest animals?

Ecosystem ecology. Whatfactors control photosyntheticproductivity in a temperategrassland ecosystem?

________________________________ provides a good starting point for understanding what limits the geographic

distribution of species

Dispersal and Distribution

Dispersal:

Contributes to the ________________________________ of organisms

Natural Range Expansion

________________________________________ show the influence of dispersal on distribution

Tropicof Cancer(23.5N)Equator

Nearctic

Neotropical

Ethiopian

Oriental

Australian

Palearctic

(23.5S)Tropic ofCapricorn

Species absentbecause

Yes

No

Dispersallimits

distribution?Behavior

limitsdistribution?

Biotic factors(other species)

limitdistribution?

Abiotic factorslimit

distribution?

Yes

No

Yes

No

Area inaccessibleor insufficient time Habitat selection Predation, parasitism,

competition, diseaseWaterOxygenSalinitypHSoil nutrients, etc.TemperatureLightSoil structureFireMoisture, etc.

Chemicalfactors

Physicalfactors

New areasoccupied Year1996

19891974

Species Transplant

_______________________________________ include organisms that are intentionally or accidentally relocated from their original distribution can often disrupt the __________________________________________ to which they

Behavior and Habitat Selection

Some organisms do not occupy all of their ____________________________________________ Species distribution may be limited by _______________________________________ behavior

Biotic Factors

Biotic factors that affect the distribution of organisms may include

A specific case of an ___________________________________- limiting distribution of a food species

Abiotic Factors

Abiotic factors that affect the distribution of organisms may include

Temperature

W. J. Fletcher tested the effects of two algae-eating animals, sea urchins and limpets, on seaweed abundance near Sydney, Australia. In areas adjacent to a control site, either the urchins, the limpets, or both were removed.

EXPERIMENT

RESULTSFletcher observed a large difference in seaweed growth between areas with and without sea urchins.

100

80

60

40

20

0

Limpet

Seaurchin Both limpets

and urchinsremoved

Onlyurchinsremoved

Only limpets removed

August1982

February1983

August1983

February1984

Control (bothurchins andlimpets present)

Sea

wee

d co

ver (

%)

Removing bothlimpets andurchins orremoving onlyurchins increasedseaweed coverdramatically.Almost noseaweed grewin areas whereboth urchins andlimpets werepresent, or whereonly limpets wereremoved.

Removing both limpets and urchins resulted in the greatest increase of seaweed cover, indicating that bothspecies have some influence on seaweed distribution. But since removing only urchins greatly increased seaweed growth whileremoving only limpets had little effect, Fletcher concluded that sea urchins have a much greater effect than limpets in limitingseaweed distribution.

CONCLUSION

____________________________________ is an important factor in the distribution of organisms because of its effects on biological processes

Water

____________________________________among habitats is another important factor in species distribution

Sunlight

Light intensity and quality can affect __________________________ in ecosystems Light is also important to the _____________________________________ of organisms sensitive to the

photoperiod

Wind

Wind amplifies the effects of temperature on organisms by increasing heat loss due to _____________________ and ____________________________ can change the __________________________of plants

Rocks and Soil

Many characteristics of soil limit the distribution of plants and thus the animals that feed upon them

Climate

Four major abiotic components make up climate __________________________________ ___________________________ is the prevailing weather conditions in a particular area Climate patterns can be described on two scales ____________________________, patterns on the global, regional, and local level __________________________, very fine patterns, such as those encountered by the community of organisms

underneath a fallen log

Global Climate Patterns

Earth’s global ____________________ patterns are determined largely by the input of ___________________ and the planet’s movement in space

_____________________________ plays a major part in determining the Earth’s climate patterns

_______________________ and wind patterns play major parts in determining the Earth’s climate patterns

Figure 50.10

Low angle of incoming sunlight

Sunlight directly overhead

Low angle of incoming sunlight

North Pole60N

30NTropic ofCancer0 (equator)

30S

60S

Atmosphere

LALITUDINAL VARIATION IN SUNLIGHT INTENSITY

Tropic ofCapricorn

South pole

June solstice: NorthernHemisphere tilts toward sun; summer begins in Northern Hemisphere; winter begins inSouthern Hemisphere.

March equinox: Equator faces sun directly;neither pole tilts toward sun; all regions on Earthexperience 12 hours of daylight and 12 hours ofdarkness.

60N30N0 (equator)30S

Constant tiltof 23.5September equinox: Equator faces sun

directly; neither pole tilts toward sun; all regions on Earth experience 12 hours ofdaylight and 12 hours of darkness.

December solstice: NorthernHemisphere tilts away from sun; winter begins in Northern Hemisphere; summer begins in Southern Hemisphere.

SEASONAL VARIATION IN SUNLIGHT INTENSITY

Descendingdry airabsorbsmoisture

Ascendingmoist airreleasesmoisture

Descendingdry airabsorbsmoisture

0Aridzone Tropics

Aridzone

60N

30N

0 (equator)

30S

60S

GLOBAL AIR CIRCULATION AND PRECIPITATION PATTERNS

Regional , Local, and Seasonal Effects on Climate

Various features of the ___________________________ contribute to local variations in climate

Bodies of Water

_____________________ and their currents, and large lakes moderate the climate of nearby terrestrial environments

Mountains

Mountains have a significant effect on the amount of sunlight reaching an area local _____________________ and ____________________. This is known as Rain Shadow Effect

GLOBAL WIND PATTERNS

Westerlies

Northeast tradesDoldrums

Southeast trades

WesterliesAntarcticCircle

60S

30S

0(equator)

30N

60NArcticCircle

Figure 50.10

Coolerair sinksover water.

3

Air cools athigh elevation.

2 1 Warm airover land rises.

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

Seasonality

The ____________________________ leads to many seasonal changes in local environments

Lakes

Lakes are sensitive to ____________________________ change experience __________________________

Microclimate

_________________________ is determined by fine-scale differences in abiotic factors

Long Term Climate Change

One way to predict future _____________________________ is to look back at the changes that occurred previously

Concept 50.3: Abiotic and biotic factors influence the structure and dynamics of aquatic biomes Varying combinations of both___________________ and__________________ factors determine the nature of

Earth’s many biomes Biomes:

Farther inland, precipitationincreases again as the airmoves up and over highermountains. Some of the world’sdeepest snow packs occur here.

Figure 50.12

3 On the eastern side of theSierra Nevada, there is littleprecipitation. As a result ofthis rain shadow, much ofcentral Nevada is desert.

As moist air moves inoff the Pacific Ocean andencounters the westernmostmountains, it flows upward,cools at higher altitudes,and drops a large amountof water. The world’s tallesttrees, the coastal redwoods,thrive here.

1 2

EastPacificOcean

Winddirection

CoastRange

SierraNevada

In spring, as the sun melts the ice, the surface water warms to 4°Cand sinks below the cooler layers immediately below, eliminating thethermal stratification. Spring winds mix the water to great depth, bringing oxygen (O2) to the bottom waters (see graphs) andnutrients to the surface.

2In winter, the coldest water in the lake (0°C) lies justbelow the surface ice; water is progressively warmer atdeeper levels of the lake, typically 4–5°C at the bottom.

1

In autumn, as surface water cools rapidly, it sinks below theunderlying layers, remixing the water until the surface beginsto freeze and the winter temperature profile is reestablished.

4 In summer, the lake regains a distinctive thermal profile, with warm surface water separated from cold bottom water by a narrowvertical zone of rapid temperature change, called a thermocline.

3

Winter Spring

HighMediumLow

O2 concentration

O2 (mg/L)

Lake

dep

th (m

)

0 4 8 12

81624

8

1624

Lake

dep

th (m

)

O2 (mg/L)

O2 (mg/L)

Lake

dep

th (m

)

0 4 8 12

816

24

O2 (mg/L)

Lake

dep

th (m

)

0 4 8 12

81624Autumn Summer

4C4444 4

4C4

44

20

4C4

4444

4C68182022

5Thermocline

0 4 8 12

The examination of biomes will begin with Earth’s ______________________________

________________________________ account for the largest part of the biosphere in terms of area Can contain fresh or salt water Oceans cover about ______________________ of Earth’s surface have an enormous impact on

the____________________ Many aquatic biomes are stratified into zones or layers defined by ___________________________________

_______________________________- Standing bodies of water range from ponds to lakes

30NTropic of CancerEquator

30S

Continentalshelf

LakesCoral reefs

RiversOceanic pelagiczone

EstuariesIntertidal zone

Abyssal zone(below oceanicpelagic zone)

Key

Tropic ofCapricorn

Marine zonation. Like lakes, the marine environment is generally classified on the basis of light penetration (photic and aphotic zones), distance from shore and water depth (intertidal, neritic, and oceanic zones), and whether it is open water (pelagic zone) or bottom (benthic and abyssal zones).

Zonation in a lake. The lake environment is generally classified on the basis of three physical criteria: light penetration (photic and aphotic zones), distance from shore and water depth (littoral and limnetic zones), and whether it is open water (pelagic zone) or bottom (benthic zone).

(a)

Littoralzone

Limneticzone

Photiczone

Benthiczone Aphotic

zone

Pelagiczone

Intertidal zoneNeritic zoneOceanic zone

0200 mContinental

shelf

Photic zonePelagic

zoneAphoticzone

Benthiczone

2,500–6,000 m Abyssal zone(deepest regions of ocean floor)

(b)

_________________________ covered long enough period to support aquatic plants

Streams and rivers Having a _____________________

An oligotrophic lake in Grand Teton, Wyoming

A eutrophic lake in Okavango delta, Botswana

LAKES

Figure 50.17

WETLANDS

Okefenokee National Wetland Reserve in Georgia

Nutrient Poor Nutrient Rich

__________________________ Transition between River and Sea Example: ______________________________ Largest Estuary in the USA

_____________________________________ Area of high and low tides

STREAMS AND RIVERS

Figure 50.17A headwater stream in theGreat Smoky Mountains

The Mississippi River farform its headwaters

Figure 50.17 An estuary in a low coastal plain of Georgia

ESTUARIES

Cold Current, Clear, Turbulent and Swift

Warmer Water

More Turbity

__________________________________ is a vast realm of _____________________ constantly mixed by wind-

driven oceanic currents

_______________________ Found in the photic zone (Tropical Latitude) Highly sensitive to _________________________________

Marine ____________________________ Seafloor community organisms have adapted to live with little or no light

Figure 50.17

INTERTIDAL ZONES

Rocky intertidal zone on the Oregon coast

Figure 50.17Open ocean off the island of Hawaii

OCEANIC PELAGIC BIOME

Figure 50.17A coral reef in the Red Sea

CORAL REEFS

Concept 50.4: Climate largely determines the distribution and structure of terrestrial biomes Climate is particularly important in determining why particular _____________________________ are found in

certain areas Climate has a great impact on the distribution of organisms, as seen on a ______________________________

The distribution of major _____________________________

Figure 50.17A deep-sea hydrothermal vent community

MARINE BENTHIC ZONE

Desert Temperate grassland Tropical forest

TemperatebroadleafforestConiferousforest

Arctic andalpinetundra

Annual mean precipitation (cm)

Ann

ual m

ean

tem

pera

ture

(ºC

)

100 200 300 400

30

15

0

15

30NTropic ofCancerEquatorTropic ofCapricorn30S

KeyTropical forestSavannaDesert

ChaparralTemperate grassland

Temperate broadleaf forestConiferous forest

TundraHigh mountainsPolar ice

Terrestrial biomes are often named for major physical or __________________________ and for their______________________________

Stratification is an important feature of terrestrial biomes layering of _____________________________________ (Example: Canopy found in the Tropical Rain Forest)

Tropical forest: tropical region large __________________________ Characterisitcs:

Desert (VERY DRY) Characteristics

Savanna: Equatorial and subequatorial (THE LION KING) Characteristics:

Chaparral Coastal regions around several continents (California) Characteristics:

Temperate Grassland Characterisitcs:

Coniferous Forest Characteristics:

Temperate Broadleaf Forest (State of Virginia) Characteristics:

Tundra: Frozen Desert—20% Earth Surface Characterisitcs: