Download Ecosystems

Ecosystems
A division of the biome through
which energy flows and materials
cycle
Biogeochemical Cycles
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The pattern of movement of
the elements through living
organisms
Dependent upon the
characteristics of the
element and the need of the
organism for the element
SPONCH elements
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Sulfur
Phosphorous
Oxygen
Nitrogen
Carbon
Hydrogen
Carbon
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Carbon is taken in as CO2 in the
gaseous form or
As Bicarbonate ion in water(
HCO3-1)
Atmospheric CO2 has increased
in the past 100 years due to the
burning of fossil fuels
Greenhouse gases are CH4 –
methane and
CO( carbon monoxide) as well as
CO2
Levels of Carbon
Dioxide
Carbon Dioxide levels
Oceans and CO2 levels
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The CO2 in the ocean is
related to the amount of
photosynthesis in the
plankton in the surface
waters of the ocean
Carbonates are stored in the
shells of the ocean
CO2 is dispersed throughout
the ocean by a conveyer like
belt that distributes water
from the top to the bottom
Carbon Levels
Photoautotrophs
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Organism that convert light
energy to chemical energy
and utilize CO2 to build the
basic molecules of life(
molecular skeletons)
The organisms are classified
as producers
Cyanobacteria
Primary consumers
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Small larvae and
invertebrates eat the
plankton and algaes and pass
the energy along
These are
organoheterotrophs
Zooplankton
Secondary Consumers
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Eat primary consumers .
Energy transferred from
one organism to another
Secondary Consumers
Higher level
consumers
Predatory fish eyes
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Swordfishes, which hunt in
water as cold as 3°C (about
37°F), can maintain their brain
and eye temperatures 10°C15°C
(18°F 27°F) above ambient
temperatures by using a specially
adapted heating organ in muscle
next to their eyes. The biological
significance of this has been a
mystery. Now, however,
innovative research has shown
that warm eyes allow
swordfishes to process visual
information more than 10 times
more quickly than eyes cooled to
Trophic level
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The level for the capture of
energy
Producer, primary consumer,
secondary consumer,
tertiary consumer,
decomposers
Basic food chain
Food web
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Shows all of the organisms
at each trophic level
Connects the organisms to
each other on the basis of
nutritional dependency
Food webs show
relationships between
trophic level
Energy
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Sunlight is absorbed by
pigments in producers
Chlorophyll a, chlorophyll b,
carotene, xanthophyll,
Sunlight
Transformation of light
energy to chemical
energy
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Light dependent reaction
Light absorbed by pigments
to generate
Pigments arranged in
photosystems
Photosystem II produces
ATP
Photosystem I produced
NADPH
Wavelengths of light
Antenna Complex
Chlorophyll molecule
http://www.uphs.upenn.edu/biocbiop/local_pages/dutton_
Chlorophylls and the
absorption of light
Carotenoids compared to
chlorophylls
Arrangement of light
capturing structures in
chloroplasts
Thylakoids
Photosystem II on the
thylakoids
Photosystems
Photosystem II
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http://www.bio.ic.ac.uk/research/barbe
r/psIIimages/PSII.html
Stomates on leavesuptake CO2
Stomates
Carbon fixation
http://www.science.smith.edu/departments/Biolog
y/Bio231/calvin.html
Calvin cycle
Decomposers
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Bacteria and fungi
Recycle carbon from dead
and decaying organisms
Carbon stored in the earth
in the form of hydrocarbons
Coal - Carbon
The Sulfur Cycle
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Sulfur is apparently always abundant
enough to meet the needs of living
organisms.
Volcanoes and fumaroles emit sulfur
dioxide (SO2) and hydrogen sulfide
(H2S). These are the natural
nonbiological fluxes of sulfur, but they
are rare events.
Certain marine algae produce dimethyl
sulfide (CH3SCH3), which accounts for
half of the biotic component of the
sulfur cycle.
Sulfur plays an important role in global
climate.
Dimethyl sulfide is the major component
of particles in the air, which allow clouds
to form.
The Sulfur Cycle
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Humans have altered the sulfur cycle by
burning fossil fuels.
Acid precipitation is caused by sulfuric
and nitric acids derived largely from the
burning of fossil fuels.
Acidification of lakes in the Adirondack
region of New York has reduced fish
species richness there.
The Clean Air Act Amendments of 1990
have helped reduce acid precipitation in
the Eastern United States.
Canadian ecologists have shown that
lakes can recover from acid conditions if
the amount of sulfuric acid is reduced.
Figure 58.11 Acidification of Lakes Exterminates Fish Species
Figure 58.12 Acid Precipitation Is Decreasing in the Eastern United
States
The Phosphorus
Cycle
Phosphorus, a key component
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of DNA and ATP, is essential
for life.
Phosphorus does not have a
gaseous phase like the other
elements.
The global phosphorus cycle is
very slow (taking millions of
years to complete) because
the processes of rock
formation on the ocean
bottom, subsequent uplifting,
and weathering of rock into
soil all occur slowly.
Figure 58.13 The Phosphorus Cycle
The Phosphorus
Cycle
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Human activity has affected the
phosphorus cycle. About 90 percent
of the phosphorus that is mined is
used to produce fertilizers and
animal feeds.
Phosphorus is accumulating in soils at
a rapid rate due to fertilizer use.
Eutrophication of lakes with
phosphorus allows algae and bacteria
to multiply, forming blooms.
Decomposition of the dead cells
occurs after the bloom consumes all
oxygen in the lake and anaerobic
bacteria take over.
Figure 58.14 Phosphorus Is Accumulating in Agricultural Soils
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The Phosphorus
Cycle
Lake Erie is a eutrophic lake today,
although improved municipal waste
handling has reduced the phosphorus
level in the lake by 80% from its
maximum level.
The potential for recovery and
recycling of phosphorus is high. The
amount of phosphorus contained in
sewage and animal wastes could
supply major industrial needs.
Careful application of fertilizers on
agricultural lands can reduce the
rate of phosphorus accumulation
without reducing crop yields.
Interactions among
Biogeochemical Cycles
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Biogeochemical cycles are strongly
interrelated. Humans have altered
biogeochemical cycles on Earth.
Winter typically kills 99 percent of
pathogenic organisms. However, global
warming is causing warmer winter conditions,
which can lead to increased outbreaks of
disease.
The 1996 assessment report of the
Intergovernmental Panel on Climate Change
expressed concern about the effects of
climate change on human health.