Chapter 52

Ecology & Biosphere

Fig. 52-2Organismalecology

Populationecology

Communityecology

Ecosystemecology

Landscapeecology

Globalecology

Studies in Ecology

The Biosphere

Ecology = the study of the interaction of organisms with their environments.

The word "ecology" coined from Greek word "oikos", which means "house" or "place to live”.

It involves understanding biotic and abiotic factors influencing the distribution and abundance of living things.

Biotic Factors• Competitors

• Disease

• Predators

• Food availability

• Habitat availability

• Symbiotic relationships

Abiotic Factors• pH

• Temperature

• Weather conditions

• Water availability

• Chemical composition of environment

• nitrates, phosphates, ammonia, O2, pollution

• population growth

• competition between species

• symbiotic relationships

• trophic (=feeding) relationships

• origin of biological diversity

• interaction with the physical environment

• The entire proportion of the earth that is inhabited by life.

• Includes communities and ecosystems.

The BiosphereThe Biosphere

What are Biomes?

Biomes are regions in the world that share similar plant structures, plant spacing, animals, climate and weather.

How are Biomes Classified?

Terrestrial or aquatic.

Climate- long term weather patterns

Weather- momentary conditions of the atmosphere; created by the unequal heating & cooling of the earth’s surface.

I. Climate

Temperature & Precipitation- major factors that determine an areas climate.

Humidity- the amount of water vapor air holds, which is dependent upon temperature.

Fig. 52-10c

March equinox

60ºN30ºN

0º (equator)

30ºSJune solstice

Constant tiltof 23.5º

September equinox

December solstice

Fig. 52-10b

Low angle of incoming sunlight

Sun directly overhead at equinoxes

Low angle of incoming sunlight

Atmosphere

90ºS (South Pole)60ºS

30ºS

23.5ºS (Tropic ofCapricorn)

0º (equator)

30ºN

60ºN

23.5ºN (Tropic ofCancer)

90ºN (North Pole)

Climate

Convection cell model

Non-rotating Earth

Add rotation and add landmasses unequal heating and cooling of the Earth

Fig. 52-10f

0º(equator)

30ºS

60ºS66.5ºS(Antarctic Circle)

30ºN

66.5ºN(Arctic Circle)

60ºNWesterlies

Northeast trades

Doldrums

Southeast trades

Westerlies

Tradewinds

Fig. 52-11

Labradorcurrent

Gulfstream

Equator

Cold water

Warm water

Thermohaline Circulation

Fig. 52-13

Winddirection

Mountainrange

Leeward sideof mountain

Ocean

Rain Shadow Effect

Biomes

Species composition is not the same in different areasSpecies composition is not the same in different areas

Plant & animal communities

Occupy large regions

Function & structure similar to those in similar environments elsewhere

    tundra

grassland

taiga

chaparral

desert scrub

desert

deciduous forest

savannah

rainforest

alpine

Biomes of the World

Tundra

Taiga

Grasslands

Deserts

Deciduous Forests

Tropical Rainforests

Biomes

• Chaparral• Savanna• Tropical Deciduous

Rain Forest• Marine• Antarctic

Primary BiomesOther Biomes

Arctic Circle

Tropic of Cancer

Tropic of Capricorn

Antarctic Circle

Tropical

Temperate

Temperate

Arctic

Antarctic

Deciduous Forest Biome

• Moderate climate• Temperatures range between –30oC and 30oC• Averages from 75 to 150 cm of precipitation• Broadleaf plants; seasonal

• Complex biome

• Good canopy & understory

• Fairly rich soils; productive

• US: early ag. - abandoned

Deciduous Forest Biome

Temperate deciduous forest

• Deciduous trees lose their leaves each fall and remain dormant during winter

• Mid-latitude forests in Europe, East China, Eastern North America

• Fertile soils• Forests: oak, beech,

maple

deer

black bear

Grasslands Biome

Temperate grasslands• More extreme temperature

difference between winter and summer

• Less precipitation• Also called steppe or prairie

– Once widespread throughout parts of North and South America and much of central Asia

– Much was converted for agriculture

– Bison, prairie dogs, antelope, and ground-nesting birds

groundhogs

bison

Savanna

• Tropical grassland interspersed with trees

• Africa, South America, Australia, India

• Precipitation only during rainy season

• Water holes

• Zebras, gazelles, giraffes, lions, hyenas

giraffes

Temperate rainforest

• Coastal Pacific Northwest region

• Great deal of precipitation

• Coniferous trees: cedar, spruce, hemlock, fir

• Moisture-loving animals– Banana slug

• The fertile soil is susceptible to erosion and landslides.

• Overharvesting has driven species to extinction and ruined human communities.

Tropical Rainforest Biome

Tropical Rainforest• Typically found near the equator• Receives more than 200 cm of

rain annually• Temperatures typically fall

between 20oC and 25oC for the entire year

• As many as 50% of all the world’s animal species may be found here

Tall, stratified tree canopy= dark on forest floor (seedlings?)

Good drainage

Rapid decomposition = nutrients in plants

Tropical Rainforest Biome

Tropical rainforest

• Central and South America, southeast Asia, west Africa

• Year-round rain and warm temperatures

• Dark and damp

• Lush vegetation

• Highly diverse species, but at low densities

• Very poor, acidic soils

• Nutrients contained in plants

Understory

Canopy layer

Emergent layer

Forest floor

Tropical dry forest• Tropical deciduous

forest

• India, Africa, South America, northern Australia

• Wet and dry seasons

• Warm, but less rainfall

• Converted to agriculture

• Erosion-prone soil

Desert Biome

Desert• Widely spaced plants

• Thorn bushes, succulents

• Many types of animals, well adapted

• Typically found between 25o and 40o latitude

• Receives less than 25 cm of rain each year

• Temperatures typically range between 20oC and 25oC but some extreme deserts can reach temperatures higher than 38oC and lower than –15oC

Desert Biome

Spade-foot ToadsSpade-foot Toads

playa (temporary lake)

Tundra Biome

Very short growing season

Mosses, lichens, sedges, no trees

Permafrost layer

Abundant water; sponge

Mammals, lemmings

Flies, mosquitoes, birds

Tundra Biome

Tundra• Canada, Scandinavia, Russia

• Minimal precipitation– Nearly as dry as a desert

• Seasonal variation in temperature– Extremely cold winters

• Permafrost: permanently frozen soil

• Few animals: polar bears, musk oxen, caribou

• Lichens and low vegetation with few trees

watervegetation

permafrost

soil

Structure of the Tundra

soil

caribou

snowyowl

Taiga Biome

• Evergreen conifers

• Typically found between 45o and 60o North latitude

• Cold climate with summer rains• Very few reptiles• Limited understory• Snow is primary form of precipitation (40 – 100

cm annually)• Seasonal cycle: migrations

• Abundant, open water

• Nutrient rich soils

Taiga (Boreal) Biome

Boreal forest (taiga)

• Canada, Alaska, Russia, Scandinavia

• Variation in temperature and precipitation

• Cool and dry climate– Long, cold winters – Short, cool summers

• Poor, acidic soil• Few evergreen tree species• Moose, wolves, bears,

migratory birds

Chaparral• Mediterranean Sea,

California, Chile, and southern Australia

• High seasonal– Mild, wet winters– Warm, dry summers

• Frequent fires• Densely thicketed,

evergreen shrubs

Marine Biome

• The ocean is the largest of all ecosystems.• Consists of oceans, coral reefs, and

estuaries, hydrothermal vents, salt marshes, coastal zones

• The ocean contains a diverse array of plants and animals at various depth zones.

The Water Planet

Fig. 52-16b

(b) Marine zonation

2,000–6,000 mAbyssal zone

Benthiczone

Aphoticzone

Pelagiczone

Continentalshelf

200 mPhotic zone

0

Oceanic zoneNeritic zone

Intertidal zone

Marine Biome

Questions

• The area used as the basis for defining a biome is:

• An important function of permafrost is to:

• In which biome would you expect to find the fewest trees?

• Limitations for primary production in the ocean include:

• The ocean is a desert because: