Chapter 6:
Biomes and Aquatic
Ecosystems
1. Explain how biomes are characterized
2. Describe how net primary production varies among biomes
3. Explain how organisms are adapted to the conditions of their
biomes
4. Describe the criteria ecologist use to classify aquatic systems
5. List the major categories of freshwater ecosystems
6. Explain the ecological importance of estuaries
7. List the three major zones of the ocean
8. Define the following terms: biome, climate, weather,
climatograph, net primary production, canopy, emergent
layer, understory, epiphyte, deciduous, estivation, coniferous,
hibernation, permafrost, salinity, photic zone, aphotic zone,
benthic zone, littoral zone, limnetic zone, wetland, flood
plain, estuary, upwelling,
Chapter 6: 164-195
Do Now Turn IN
1.Explain in words and or a
diagram the transition
between winter and spring on
the earth
2.and what it means for us in
the Northern Hemisphere.
3.Do you know exactly what
time spring starts?
On March 20, there are twelve hours of daylight and
twelve hours of darkness at all points on the earth's
surface. Sunrise is at 6 a.m. and sunset is at 6 p.m. local
(solar) time for most points on the earth's surface. (This
varies, of course, based on time zones, which are much
broader regions than local solar time.)
Equinoxes occur when the axis of rotation of the earth
(i.e. the line form the N to S poles) is exactly parallel to
the direction of motion of the earth around the sun. This
happens on just two days of the year, the spring and
autumn equinoxes. This means that day length is exactly
the same (12 hours) at all points on the earth's surface on
these days (except right at each pole, where it will be
about to change from permanent light to dark, or vice
versa).
During an equinox, the Earth's North and South poles are not
tilted toward or away from the Sun and the length of the day is
the same at all points on Earth's surface
Do Now
1.What is FOG?
2.What causes Fog?
Do Now
1.What is FOG?
a thick cloud of tiny water droplets suspended
in the atmosphere at or near the earth's
surface that obscures or restricts visibility –
basically it is a ground level CLOUD
2.What causes Fog?
2 types of fog:
Advection
Radiation
Do Now
Advection Fog
Advection fog occurs when
moist air passes over a cool
surface by advection (wind) and
is cooled.
It is most common at sea when
moist air encounters cooler
waters.
Do Now
Radiation Fog?
The cool ground produces
condensation in the nearby air by
heat conduction.
Radiation fogs occur at night, and
usually do not last long after
sunrise, though can persist all day
in the winter months
What are the differences?
Climate, Biology, Limiting Factors, Adaptations?
Things Change?
• Fossil evidence suggests that the
frozen continent of Antarctica was
once covered in temperate forest.
Earth’s Biomes
• Groups of terrestrial ecosystems that
share biotic and abiotic conditions
• 10 primary biomes:
– tropical rain forest
– dry forest savanna
– Savanna
– desert
– temperate rain forest
– temperate forest
– temperate grassland
– chaparral
– boreal forest
– tundra
La Mesa, CA
Philadelphia
• Climate: Average conditions,
including temperature and
precipitation, over long periods
of time in a given area
• Weather: Day-to-day conditions
in Earth’s atmosphere
• Climatographs: Diagrams that summarize an
area’s average monthly temperature and
precipitation
• Each biome has a set of characteristic
organisms adapted to its particular
climate conditions.
Across the U.S.
Productivity
• Net primary production: The
amount of organic matter
(biomass) that remains after
primary producers use some to
carry out cellular respiration
• Ecosystems vary in their net
primary productivity, the rate
at which primary producers
convert energy to biomass.
• Warm, wet biomes generally
have higher net primary
productivity than cold, dry
biomes.
Earth’s productivity: On land forests are highly productive in
dark green, deserts least in brown. At sea, red indicates high
productivity and deep oceans dark blue.
Aquatic Ecosystems (Wet Biomes)
• 75% of Earth’s surface
is covered by water.
• Salinity: the amount of dissolved salt
present in water. Ecosystems are
classified as salt water, fresh water,
or brackish depending on salinity.
• Photosynthesis tends to be limited
by light availability, which is a
function of depth and water clarity.
• Aquatic ecosystems are either
flowing or standing.
• Aquatic ecosystem zones: photic,
aphotic, benthic
Aquatic Ecosystem Limiting Factors
• Limiting factors may
include:
• Salinity
• Ph
• Sunlight
• Dissolved oxygen
• Temperature
Freshwater Ecosystems: Ponds,
Lakes, Inland Seas
Salinity is less than 0.5 ppt (parts per thousand)
Diagram is in book on page 183
Freshwater Ecosystems:
Wetlands
• Areas of land flooded with water at least part
of the year
• Include freshwater marshes, swamps, bogs,
and fens
Freshwater Ecosystems:
Rivers and Streams
Bodies of surface water that flow downhill,
eventually reaching an ocean or inland sea
Delaware
Water Gap
Estuaries
• Occur where a river flows
into the ocean or an inland
sea
• Coastal estuaries are
brackish ecosystems;
organisms must tolerate
wide salinity and
temperature ranges.
• Coastal estuaries are home
to salt marshes and
mangrove forests.
Oceans
• Intertidal Areas
• Neritic Zones
• Open Ocean
•
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•
•
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Review
Explained how biomes are characterized
Described how net primary production varies
among biomes
Explained how organisms are adapted to the
conditions of their biomes
Described the criteria ecologist use to classify
aquatic systems
Listed the major categories of freshwater
ecosystems
Explained the ecological importance of estuaries
Listed the three major zones of the ocean
Chapter 6 Review
• Explain what biomes and aquatic ecosystems
are
• Explain how biomes are characterized.
• Describe how net primary productivity varies
among biomes.