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
Objectives
• Describe the interactions of the biosphere, hydrosphere,
and geosphere
• Describe the interactions of biotic and abiotic factors in
the biosphere
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.
15.1 Life in the Earth System
What is the relationship between the biota and the
biosphere?
• The biosphere contains the biota- all living things on
earth, as well as portions of the hydrosphere and,
atmosphere, and geosphere
15.1 Life in the Earth System
How does the Gaia hypothesis explain the interaction
explain the interaction between biotic and abiotic
factors in the biosphere
• According to the Gaia hypothesis, Earth itself is an
analogous to a living organism.
• The interactions between the atmosphere, geosphere,
biosphere, and hydrosphere are like the interactions of
an organisms vital organs
15.1 Life in the Earth System
How might a rise in global temperatures affect the
biosphere?
• A rise in global temperatures might affect the
DISTRIBUTION of living things in the biosphere.
• Some species might increase in #
• Some species could decrease or go extinct
15.1 Life in the Earth System
Explain how feedback loops, such as those described
by the Gaia hypothesis might appluy to predator prey
relationships
• When a prey population increases in size, the predator
population has more food to eat.
• As a result, the predator population increases in size.
• When the predator becomes so plentiful that the prey
population decreases, the predators have less food to
eat.
• As a result, the predator population decreases in size.
15.1 Life in the Earth System
KEY CONCEPT
Climate is a key abiotic factor that affects the
biosphere.
15.1 Life in the Earth System
Objectives
• Differentiate between weather, climate, and
microclimates
• Identify factors that determine Earths climate zones
15.1 Life in the Earth System
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
15.1 Life in the Earth System
• A microclimate is the climate of a small specific place
within a larger area.
15.1 Life in the Earth System
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
15.1 Life in the Earth System
• The angle of the Sun’s rays help determine an area’s
climate.
90 N
polar
temperate
tropical
temperate
polar
15.1 Life in the Earth System
• 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
15.1 Life in the Earth System
• Landmasses shape inland
climates.
– larger changes in
temperatures
– less precipitation
• Oceans shape coastal
climates.
– smaller changes in
temperatures
– higher humidity
– more precipitation
15.1 Life in the Earth System
• 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
15.1 Life in the Earth System
• Many organisms survive in a specific climate due to their
adaptations.
15.1 Life in the Earth System
What is the difference between climate and weather
• Weather is the day-to-day temperature, precipitation, and
wind conditions in a region
• Climate is the long term pattern of weather
15.1 Life in the Earth System
What are the 3 different climate zones, and where are
they located?
• The polar climate zones are found at the North and South
poles
• The tropical climate is located at the equator
• The temperate climate is found between the polar and
tropical climate zones
15.1 Life in the Earth System
Would areas along the shores of the Great Lakes have
warmer summers and colder winters than other inland
areas? Explain.
• NO, because of the buffering affects of the water,
shoreline areas have moderate seasonal temperature
changes compared to inland areas
15.1 Life in the Earth System
Would you expect an area with several microclimates to
have more or fewer ecological niches? Explain.
• An area with several microclimates would have more
ecological niches, allowing a wider variety of organisms
to find suitable habitats.
15.1 Life in the Earth System
KEY CONCEPT
Marine ecosystems are global.
15.1 Life in the Earth System
Objectives
• Identify the 4 major ocean zones and organisms unique
to each zone
• Describe the unique habitats of coastal waters
15.1 Life in the Earth System
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
15.1 Life in the Earth System
• The neritic zone harbors more biomass than any other
zone.
• Plankton make up most of the biomass.
– zooplankton
– phytoplankton
15.1 Life in the Earth System
Coastal waters contain unique habitats.
• Coral reefs are found in warm waters.
– tropical climate zone
– great amount of biomass
15.1 Life in the Earth System
• Kelp forests are found in
cold, nutrient-rich waters.
– large communities of
seaweed
– great amount of
biomass
15.1 Life in the Earth System
What criteria do scientists use to divide the ocean into
different zones?
• Open sea & ocean floor
• Presence of light
• Distance from shoreline
• Water depth
15.1 Life in the Earth System
What conditions account for the development of highly
diverse habitats in coastal waters?
•
•
•
•
•
•
•
Sunlight
Upwelling of nutrients
Temperature variations
Currents
Wind
Waves
Tides
15.1 Life in the Earth System
A red tide occurs when a bloom of plankton causes a
reddish discoloration of coastal ocean waters. What
might cause such an increase in plankton populations?
• Increased amounts of nutrients in the water
• Temperatures that are conducive to that type of species