Transcript SAES CH6x

Do Now
What is Biosphere 2?
How is it related to the
Biosphere on Earth?
CHAPTER 6 ECOSYSTEMS AND NUTRIENT CYCLING
ENGINEERING EARTH
A desert experiment gone awry
WHAT IS THE BIOSPHERE?
The total area on Earth where
living things are found.
Clicker Question
The biosphere is basically the sum of all
____________ in a given area, representing all
the organisms in that area as well as the
physical environment in which they interact.
A.
B.
C.
D.
habitats
ecosystems
biomes
communities
HOW IS LIFE IN THE
BIOSPHERE ORGANIZED?
HOW DOES THE
BIOSPHERE FUNCTION?
The biosphere functions through
two fundamental processes: energy
flow and nutrient cycling.
The Earth is energetically open
but materially closed.
WHAT IS A BIOME?
A biome is a distinctive type of
ecosystem determined by climate
and identified by the
predominant vegetation and
organisms that have adapted to
live there.
HOW MANY DIFFERENT
BIOMES ARE THERE?
Biomes can be divided into
three main types —
terrestrial, marine, and
freshwater.
Within these categories are
several subgroups.
How was Biosphere
2 designed to mimic
the biosphere?
Do Now
• How was the Biosphere 2 designed to
mimic Earths biosphere?
• What did the study accomplish?
• What went wrong, and what lessons can
be learned for future similar experiments?
BIOSPHERE
The biosphere is a
large and complex
system with many
different biomes
and ecosystems
that all contribute
to overall function.
BIOSPHERE 2
Biosphere 2 also has
several biomes
contributing to
overall function. But
being approximately
3 acres in area, the
challenge was
including a variety of
biomes in such close
proximity.
WHY ARE BIOMES
FUNCTIONALLY SIMILAR
BUT DIFFERENT IN THEIR
SPECIES MEMBERSHIP?
Species within each biome are
specifically adapted to the
particular environmental
conditions of that biome.
Range of tolerance: The range of a limiting factor
within which a species can survive and reproduce.
Limiting factor: The critical resource whose
availability determines species population size
distribution.
WHY DID
BIOSPHERE 2 FAIL?
The likely culprit: the failure
of nutrient cycles.
WHAT ARE NUTRIENT
CYCLES?
The movement of nutrients such
as carbon, nitrogen, and
phosphorous through the
abiotic and biotic components
of ecosystems.
Producers
Biotic
Consumers
Reservoirs
Decomposers
Atmosphere
Abiotic
Hydrosphere
Reservoirs
Lithosphere
Lower than
normal ozone
levels in the
atmosphere
CFCs might be
causing the
ozone to
disappear
Processes that cycle carbon
Do Now
• How are the biogeochemical nutrient
cycles different from one another? How
are they similar?
• In what ways do human activities affect
the nutrient cycling process?
Carbon Cycle
Nitrogen Cycle
Phosphorous Cycle
How nutrient cycling failed in Biosphere 2
How human activities interfere with
nutrient cycling in the biosphere
Reduces
carbon
uptake from
atmosphere
into biotic
reservoirs
Releases
carbon, and
nitrogen from
fossil fuel
sinks into the
atmosphere
Adds phosphorous and
nitrogen to the hydrosphere,
where it is a limiting factor
So what can we learn from Biosphere 2?
Ecosystems
are
complicated
But learning how they
function can help us
restore degraded ones.
The
biosphere is
irreplaceable
But learning how our
actions affect it can help
us change course.
“Isolating small pieces of large
biomes and juxtaposing them in
an artificial enclosure changed
their functioning and
interactions, rather than creating
a small working earth as originally
intended.”
–Science magazine