Download 15.1 Life in the Earth System

15.1 Life in the Earth System
KEY CONCEPT
The biosphere is one of Earth’s four interconnected
systems.
15.1 Life in the Earth System
The biosphere is the portion of Earth that is inhabited by
life.
• The biosphere includes all ecosystems.
– one of Earth’s systems
– includes the biota, all the living things in the biosphere
15.1 Life in the Earth System
• There are three other Earth
systems.
– hydrosphere—water, ice,
and water vapor
– atmosphere—air
blanketing Earth’s solid
and liquid surface
– geosphere—geologic
features above and
below Earth’s surface
15.1 Life in the Earth System
Biotic and abiotic factors interact in the biosphere.
• All four Earth systems
are interconnected.
• The Gaia hypothesis
considers Earth as a
kind of living organism.
– Earth systems
interact to yield a
biosphere capable
of supporting life.
– It was developed by
James Lovelock
and Lynn Margulis.
15.2 Climate
KEY CONCEPT
Climate is a key abiotic factor that affects the
biosphere.
15.2 Climate
Climate is the prevailing weather of a region.
• Climate is the long-term
pattern of weather
conditions.
– average temperature
– precipitation
– relative humidity
• Key factors shape an area’s
climate.
– temperature
– sunlight
– water
– wind
15.2 Climate
• A microclimate is the climate of a small specific place
within a larger area.
15.2 Climate
Earth has three main climate zones.
• The three main zones are the polar, tropical, and
temperate climates.
– polar climate: the far northern
and southern regions of
Earth
– tropical zone: surrounds
the equator
– temperate zone: the
wide area in between
the polar and tropical zones
15.2 Climate
• The angle of the Sun’s rays help determine an area’s
climate.
90 N
polar
polar
temperate
temperate
tropical
tropical
temperate
temperate
polar
polar
15.2 Climate
• Earth’s tilt on its axis plays a role in seasonal change.
• Solar heating causes movements in both water and air.
– wind
– ocean currents
• Earth’s rotation also has effects on the winds and currents
15.2 Climate
• Landmasses shape inland
climates.
– larger changes in
temperatures
– less precipitation
• Oceans shape coastal
climates.
– smaller changes in
temperatures
– higher humidity
– more precipitation
15.2 Climate
• Mountains have an effect on climate.
– Precipitation occurs on the side of the mountain
facing the wind.
– On the downwind side, drier and cooler air produce
a rain shadow.
– A rain shadow is an area of decreased precipitation.
western slope
eastern slope
15.2 Climate
• Many organisms survive in a specific climate due to their
adaptations.
15.3 Biomes
KEY CONCEPT
Biomes are land-based, global communities of
organisms.
15.3 Biomes
Earth has six major biomes.
• A biome is a major community of organisms.
15.3 Biomes
• Tropical rain forest
biomes produce lush
forests.
– warm temperature
– abundant
precipitation all year
Source: World Meteorological Organization
15.3 Biomes
• Grassland biomes are where the primary plant life is
grass.
Rapid City, South Dakota
Source: National Oceanic Atmospheric Administration
15.3 Biomes
• Grassland biomes are where the primary plant life is
grass.
– Temperate grasslands are dry and warm during the
summer; most precipitation falls as snow.
– Tropical grasslands are warm through the year, with
definite dry and rainy seasons.
15.3 Biomes
• Desert biomes are
characterized by a very arid
climate.
– very low amount of
precipitation
– four types: hot, semiarid, coastal, and cold
Tucson, Arizona
Source: National Oceanic Atmospheric Administration
15.3 Biomes
• Temperate forest biomes include deciduous forests and
rain forests.
– Temperate deciduous forests have hot summers and
cold winters.
– Deciduous trees are the dominant plant species.
Burlington, Vermont
Source: National Oceanic Atmospheric Administration
15.3 Biomes
• Temperate forest biomes include deciduous forests and
rain forests.
– Temperate deciduous forests have hot summers and
cold winters.
– Deciduous trees are the dominant plant species.
– The temperate rain forests have a long wet season and
relatively dry summer.
– Ferns and moss
cover the forest
floor.
15.3 Biomes
• The taiga biome is located
in cooler northern climates.
– boreal forest
– long winters and short
summers
– small amount of
precipitation
Banff, Canada
Source: Environment Canada
15.3 Biomes
• The tundra biome is found
in the far northern latitudes
with long winters.
– winter lasts 10 months
– limited precipitation
– permafrost
Barrow, Alaska
Source: National Oceanic Atmospheric Administration
15.3 Biomes
• Minor biomes, such as chaparral, occur globally on a
smaller scale.
15.3 Biomes
Polar ice caps and mountains are not considered biomes.
• Polar ice caps have no soil, therefore no plant community.
• The climate and organisms found on mountains change as
the elevation changes.
15.4 Marine Ecosystems
KEY CONCEPT
Marine ecosystems are global.
15.4 Marine Ecosystems
The ocean can be divided into zones.
• Ocean zones can be determined by their distance from
shoreline and water depths.
– intertidal zone—between low and high tide
– neritic zone—from intertidal zone
neritic zone
intertidal zone to
continental shelf
bathmat
zone
– bathyal zone—
from neritic zone to
base of continental
abyssal
shelf
zone
– abyssal zone –lies
below 2000 m
15.4 Marine Ecosystems
• The neritic zone harbors more biomass than any other
zone.
• Plankton make up most of the biomass.
– zooplankton
– phytoplankton
15.4 Marine Ecosystems
Coastal waters contain unique habitats.
• Coral reefs are found in warm waters.
– tropical climate zone
– great amount of biomass
15.4 Marine Ecosystems
• Kelp forests are found in
cold, nutrient-rich waters.
– large communities of
seaweed
– great amount of
biomass
15.5 Estuaries and Freshwater Ecosystems
KEY CONCEPT
Freshwater ecosystems include estuaries as well
as flowing and standing water.
15.5 Estuaries and Freshwater Ecosystems
Estuaries are dynamic environments where rivers flow
into the ocean.
• An estuary is a partially enclosed body of water.
– mixture of fresh water with salt water
– Chesapeake Bay
– Louisiana bayous
15.5 Estuaries and Freshwater Ecosystems
• Estuaries are highly productive ecosystems.
• Estuaries provide a protected refuge for many species.
– birds migration
– spawning grounds
• Estuaries are primarily threatened by land development.
15.5 Estuaries and Freshwater Ecosystems
Freshwater ecosystems include moving and standing
water.
• A watershed is a region of land that drains into a body of
water.
• Ecosystems may be different along a river’s course
15.5 Estuaries and Freshwater Ecosystems
• Wetlands are among the most productive ecosystems.
– provide a home for many species
– filter dirty water
– renew underground water supply
• Some animals have adaptations suited to the freshwater
they inhabit.
15.5 Estuaries and Freshwater Ecosystems
Ponds and lakes share common features.
• Freshwater bodies are divided into three zones.
– littoral zone
– limnetic zone
– benthic zone
15.5 Estuaries and Freshwater Ecosystems
• All lakes “turn over” periodically.
– Turn over happens due to changes in density.
– In both autumn and spring, surface water flows
downward and bottom water flows upward.
– The upwelling brings up nutrients.