Download Chapter 6: Ecosystems and the Physical Environment

Chapter 5: Ecosystems and the
Physical Environment
The Atmosphere
http://mediatheek.thinkquest.nl/~ll125/en/atmos.htm
The Atmosphere
Hypothesis

Gaea= Greek “goddess
of Earth” or “mother”
Earth.
1970’s; This
theory proposed
global selfregulation.
Hypothesis
Example: Earth’s temperature has
remained stable due to organisms fixing
CO2 into Calcium Carbonate CaCO3 of
shells. Corals, Crustacea…
Planetary Temperature as a
Negative Feedback loop?
Example: A thermostat only turns on
when the temperature drops below the
desirable temp. Once it reaches the
correct temperature the heat turns off.
Energy and Matter
Do Now: Biogeochemical cycles
 Identify
the five Biogeochemical
cycles.
 Identify
some major reactions that
occur for each.
 Discuss their importance, be sure to
include the interaction between biotic
& abiotic factors.
Biogeochemical cycles

Interaction between biotic & abiotic.
 Transpiration,
decomposition, Photosynthesis
and respiration

The recycling of materials to be used over
& over again.

5 examples are:
1. Phosphorus cycle
2. Nitrogen cycle
3. Hydrologic cycle
4. Carbon cycle
Do Now:

Draw a simple carbon for your bioregion.
Include all the relevant processes as well as the
local / regional geographical features that are
part of the cycle.
The Carbon-Cycle


Carbon, hydrogen, and oxygen are recycled
through the environment by the processes of
respiration and photosynthesis.
Carbon makes up0.038% of our atmosphere
(CO2)

Oceanic Carbon
 Carbonate (CO3 2− )
−
 Bicarbonate HCO3 )


Dissolved organics from decay
Sedimentary Rock

Limestone: Calcium carbonate CaCO3
The Carbon-Cycle

Atmospheric Carbon
0.038% of our atmosphere carbon dioxide CO2
 Carbonic Acid (H2CO3)


Oceanic Carbon
Carbonate (CO3 2− )
 Bicarbonate (HCO3 − )
 Dissolved organics from decay


Sedimentary Rock
 Limestone: AKA Calcium carbonate: (CaCO3)
The Carbon-Cycle
CO2 + H20 Carbonic Acid (H2CO3)
(combines in rainwater)
2. H2CO3-  HCO3 − and H+
(dissociates in soil)
3. H+ (acidic) breaks down feldspar Ca2+
1.
4. H2CO3- + Ca2+  CaCO3
(in runoff combines)
forming
5. CaCO3 in runoff up taken and used by oceanic organisms
6. Organisms die, sedimentation occurs forming Limestone
Carbon Cycle
The Carbon-Cycle
The Carbon cycle
The Carbon-Cycle
C6H12O6 + 6O2 +6H2O  6CO2 + 12H2O + 36ATP’s
6CO2 + 12H2O + light  C6H12O6 + 6O2 +6H2O
Remember Photosynthesis ??
Respiration
 The
transfer of stored energy in food
molecules to a form usable by the
organism.
 Involves the exchange of gases between
the organism and the environment.
Process
 Through
the process of respiration,
the organism produces adenosine
triphosphate (ATP) which will be
used for energy.
Respiration

Respiration- is an organisms’ ability to create
energy. (ATP)
Respiration
Aerobic Respiration
Anaerobic
Respiration
Alcoholic
Lactic Acid
Fermentation
Fermentation
1. Cellular Respiration
 Involves
a series of enzymecontrolled reactions in which
energy in food is broken down
into energy that the organism
can use (ATP)
a) When ATP is broken down,
energy is released and ADP is
formed
ADP = adenosine diphosphate
H2O + ATP  ADP + P + energy

This is the energy used by the body to carry
out the functions of life
Types of Respiration
Aerobic Respiration
-involves the use of oxygen
2. Anaerobic Respiration
-oxygen is not used
1.
Anaerobic Respiration
Also known as Fermentation
 Does not require oxygen
 Takes place in the cytoplasm of cell
 Glucose is either broken down into
lactic acid or alcohol and CO2
 As a result of anaerobic respiration,
there is a net gain of 2 ATP’s

Equations for
Anaerobic Respiration
glucose  2 lactic acids + 2 ATP’s
glucose  2 alcohol + 2 CO2 + 2 ATP’s

In each equation, enzymes are used and a net
gain of 2 ATP’s are produced
Aerobic Respiration
Requires oxygen
 Takes place in the mitochondria
 When we say that glucose is oxidized, we
say that it is broken down with the help of
oxygen molecules

http://www.biosci.ohio-state.edu/~dcp/bio113a/ch910comp.html
Summary

Anaerobic Respiration = 2 ATP’s

Aerobic Respiration = 36 ATP’s

Therefore, Aerobic respiration is more efficient
than anaerobic respiration
The Carbon-Cycle
Glycolysis
Mitochondrion
An oval membrane
enclosed organelle in
which most of the
reactions of cellular
respiration occur.
Aerobic Respiration (Net gain of ATP)
1)Glycolysis (2 ATP’s)
2)Krebs Cycle (2 ATP’s)
3)Electron Transport Chain (ETC) (32
ATP’s)
Nitrogen Cycle
http://www.biology.ualberta.ca/facilities/multimedia/index.php?Page=280

Nitrogen is needed by all living things because it
is part of the structure of amino acids and
proteins.

The Nitrogen cycle includes the following
reactions nitrogen-fixation, nitrification,
ammonification, and denitrification.

Humans have increased fixed nitrogen levels
(smog, and acid rain HNO3 = Nitric acid)
Nitrogen Cycle


In this cycle, nitrogenous wastes and the
remains of dead organisms are converted by
decomposers and soil bacteria into compounds
that can be used by autotrophs.
5 steps
1.
Nitrogen fixation N2NH3
2.
3.
4.
5.
Nitrification NH3  NO2-  NO3Assimilation N-based compounds into tissues
Ammonification waste  NH3, NH+4,
Denitrification (NH3, NO2-, NO3-)  N2
The Nitrogen Cycle
N2
Urea
NH3,
(NO2-, NO3-)
Nitrogen Cycle
Nitrogen Cycle
Nitrogen fixation Occurs in Legumes Roots (clover)
N2NH3
Ammonification:  NH3, NH+4, Ammonifying
bacteria use animal wastes (urea and uric acid)
Nitrification: bacteria convert NH3  NO2-  NO3Denitrification: Bacteria convert
(Anaerobic nitrifying Bacteria)
NH3  N2
NO2-  N2
NO3-  N2
Nitrogen Cycle
 The
Nitrogen cycle includes the
following reactions:
1. Nitrogen Fixation: the conversion of N2 to
NH3 (ammonia) by Nitrogen-fixing bacteria
(Rhizobium in legume root nodules) as well as
cyanobacteria (Anabaena & heterocysts).
Nitrogen is “fixed” into a form that can be used.
Bacteria use nitrogenase (shielded from O2) to
split N2.
Also lightning & volcanic activity.
Nitrogen Cycle



2. Nitrification: the conversion of ammonia NH3
or ammonium NH4+ to NO3-.(when water reacts
with ammonia).
Soil bacteria such as Nitrosomonas &
Nitrococcus start NH3 or ammonium NH4+ to
NO2Then Nitrobacter oxidizes NO2- to NO3-.
Nitrogen Cycle

3. Assimilation: the conversion of inorganic N
(NO3-, NH3, NH4+) to organic molecules (amino
acids & proteins).
Nitrogen Cycle
4. Ammonification: the conversion of organic N
(amino acids & proteins) to NH3 & NH4+,
performed by Ammonifying bacteria. (Creating
ammonia or ammonium)
Conversion of Nitrogenous wastes:
Nitrogen Cycle
Nitrogen Cycle
5. Denitrification: the conversion (reduction) of
NO3- to N2 performed by denitrifying bacteria.
The nitrogen cycle.

Nitrogen Cycle
The Nitrogen-Cycle
Do Now answer

Explain the meaning of “nitrogen fixation.”
Give a specific example of an organism capable
of this process and discuss the relationship this
organism has with plants.
Do Now answer

Nitrogen fixation is the conversion of gaseous
nitrogen to ammonia (NH3) by bacteria,
Rhizobium, that live inside special swellings, or
nodules on the roots of legumes such as beans
or peas. The relationship is mutualistic. The
bacteria receive carbohydrates from the plant,
and the plant receives nitrogen in a form it can
use.
The Phosphorus-Cycle
Nongaseous phosphorus cycles from land to
sediments in the ocean and then back to land.
Phosphorus (P) is an essential nutrient for all life
forms.
Phosphorus plays a role in deoxyribonucleic
acid (DNA), ribonucleic acid (RNA), adenosine
diphosphate (ADP), and adenosine triphosphate
(ATP).
The Phosphorus-Cycle
The Phosphorus-Cycle
The Phosphorus-Cycle

In freshwater and marine systems exists in
either a particulate phase or a dissolved
phase.
 Particulate
matter includes living and dead
plankton, precipitates of phosphorus,
phosphorus adsorbed to particulates, and
amorphous phosphorus.
 Dissolved phase includes inorganic phosphorus
(generally in the soluble orthophosphate form),
organic phosphorus excreted by organisms,
and macromolecular colloidal phosphorus.
The Phosphorus-Cycle
 In
freshwater and marine systems
exists in either a particulate phase or
a dissolved phase.
 Particulate matter includes living and
dead plankton & precipitates of
phosphorus.
The Phosphorus-Cycle
The Sulfur-Cycle
Hydrologic Cycle
Hydrologic Cycle
Hydrologic Cycle




Here water moves between the earth’s surface and the
atmosphere.
Evaporation, Condensation, aerobic respiration and
transpiration in plants.
Estuaries are areas where fresh water meets marine
areas.
Watersheds are large areas where runoff drains from
the terrestrial to the marine environments. These
areas filter the water as well.
Hydrologic Cycle
The Hydrologic-Cycle
The Effect of Aerosols?
DO NOW:
Pick any one cycle and describe it as
scientifically as possible….
DO NOW:

Bacteria are key participants in the sulfur and
nitrogen biogeochemical cycles. Briefly describe
the role of oxygen in the various bacteria’s
ability to process sulfur and nitrogen.
DO NOW: answers


Bacteria drive both the sulfur and nitrogen cycles. In freshwater
wetlands, tidal flats, and flooded soils, which are oxygendeficient, bacteria convert sulfates to hydrogen sulfide gas, which
is released into the atmosphere. Or the bacteria convert sulfates
to metallic sulfides, which are deposited as rock. In the absence
of oxygen, other bacteria perform an ancient type of
photosynthesis that uses hydrogen sulfide instead of water.
Where oxygen is present, different bacteria oxidize sulfur
compounds to sulfates.
Bacteria that reside in the root nodules of legume plants have
the ability to convert gaseous nitrogen to ammonia. These
nitrogen-fixing bacteria, including cyanobacteria and Rhizobium,
employ the enzyme nitrogenase to split diatomic atmospheric
nitrogen (N2) and combine the resulting single nitrogen atoms
with hydrogen. Nitrogenase functions only in the absence of
oxygen.
DO NOW:
List and briefly explain three ways
in which human activities are
impacting the biogeochemical
cycles
Some Human Effects on
Biochemical Cycles




The burning of fossil fuels such as coal, oil and natural gas release CO2 into
the atmosphere at a rate greater than the carbon cycle can handle. This
increase of carbon dioxide may contribute to global warming which could
result in a rise in sea level, changes in precipitation patterns, death of forests,
extinction of organisms and problems for agriculture.
In addition, humans more than doubled the amount of fixed nitrogen entering
the global nitrogen cycle in the 20th century through the use of chemical
fertilizers.
Precipitation washes nitrogen fertilizer into rivers, lakes and coastal waters
stimulating the growth of algae. These algae die and their decomposition by
bacteria robs the water of dissolved oxygen contributing to fish kills. The
nitrates from fertilizer can also leach through the soil and contaminate
groundwater used by many for drinking water.
Humans affect the phosphorus cycle by accelerating the long-term loss of
phosphorus from the land. For example, corn grown in Iowa (which contains
phosphate absorbed from the soil), fattens cattle in Illinois (some phosphate
ends up in feedlot wastes), which are eaten by humans in Texas (more
phosphate in human wastes ending up in sewer systems). Sewage treatment
rarely removes phosphorus and thus phosphorus washes into the ocean where
it remains for millions of years.
II. Solar Radiation
•Most of the energy produced by the sun never reaches th
Earth.
•30% reflected into outerspace.
•47% is absorbed by the atmoshpere.
•23% runs the hydrologic cycle.
•Less than 1% drives the wind and the ocean currents.
•0.02% is captured for photosynthesis.
•Energy then is lost as infrared radiation (reradiation).
The Sun
Albedo: The reflective property of the Earth’s surface.
Caption and image courtesy of the Snowball Earth Web site: Ice albedo is a critical
variable in snowball earth climate models: snow-covered ice has a high albedo (~0.9),
bubble-free (mature) marine ice has relatively low albedo (~0.4) and bubble-rich glacial ice
(compacted snow) has intermediate albedo (~0.65).
•Glaciers and ice sheets reflect 80 to 90%
of the sunlight that hits their surfaces.
•Asphalt and buildings have low Albedos
and reflect 10 –15%.
•Oceans and forests reflect only about 5%.
IIa. Temperature changes with
latitude
*Due to intensity
IIb. Temperature changes with
seasons (23.5 degrees)
Layers of the Atmosphere

Troposhere:







extends up to a height of
approximately 10km (6.2mi).
For every in the temperature6˚C
Weather occurs here
Stratosphere:
Mesosphere:
Thermosphere
Exosphere:
III. The Atmosphere


Layers of the Atmosphere
Atmospheric Circulation



Surface winds
Coriolis Effect
Prevailing winds




Patterns of Circulation in the ocean



Polar easterlies:
North pole blow Northeast, South pole southwest
Westerlies and trade wins
Gyres and Currents
Vertical Mixing of Ocean Water (density)
Ocean Interactions width the Atmosphere

EL NIÑO, LA NIÑA
Atmospheric Circulation
Winds:
complex horizontal movements of the atmosphere.
Atmospheric Circulation
Atmospheric & Oceanic Circulation

Coriolis Effect: Earth’s
rotation from West to East
causes air/currents to swerve
to the right of the direction in
which its traveling in the
northern hemisphere and to
the left in the southern
hemisphere.
Human change of Earth’s rotation?
Surface Ocean Currents
Patterns of Circulation in the ocean
•Prevailing winds generate gyres (circular ocean patterns)


Caused largely by winds
and partly the coriolis
effect.
Main ocean currents
flow:


Northern Hemisphereclockwise
Southern Hemisphere –
counter clock wise
Landmasses affect ocean circulation.
Which is most unimpeded?
Southern Hemisphere
Northern Hemisphere
Vertical Mixing of Ocean Water.
•Ocean Conveyor Belt
•(Cold is denser then hot)
•Coriolis effect more pronounced at greater depths
•What happened 11000-12,000 years ago?
•Heat transfer issue???
•Unintentional link between global warming and ocean
conveyor belt
Vertical Mixing of Ocean Water.
•Ocean Conveyor Belt
Do Now:

What is an ENSO event and what causes it to
occur? (provide more then a decrease in trade
winds) Please include in your discussion:

Define ENSO?

What is oscillating?
What effects does an ENSO event have on marine
life?
 How does an ENSO even manage to have such farreaching impact?






Do Now Answer:
El Niño-Southern Oscillation (ENSO) is a periodic, large-scale
warming of surface waters of the eastern Pacific Ocean. This
warming temporarily alters both ocean and atmospheric circulation
patterns.
Normally, westward-blowing trade winds confine the warmest waters
to the western Pacific (near Australia). Every 3-7 years, however,
these trade winds weaken allowing the warm mass of water to
expand eastward to South America.
The increasing surface temperatures in the East Pacific cause ocean
currents, which normally flow westward in this area, to slow down,
stop altogether, or even reverse and go eastward. The warmer
surface ocean temperatures prevent upwelling of the nutrient-rich
deep water.
The lack of nutrients in the water results in a severe decrease in the
populations of marine fish.
ENSO has such a far-reaching impact because it alters global air
currents, directing unusual weather to areas far from the tropical
Pacific. ENSO have been responsible for torrential rains, droughts,
wildfires, heavy snows, deaths and property damage.
EL NIÑO (ENSO)

EL NIÑO Southern Oscillation event is a
periodic warming of surface waters of the
tropical East Pacific that alters both ocean &
atmospheric circulation.


Upwelling?
LA NIÑA: surface water in the eastern
Pacific becomes unusually cool.
EL NIÑO
Climate associated with ENSO
Coastal upwelling weakens during ENSO events.
Do Now:
How
does ENSO affect
local fisheries?

Animation Of An Idealized El Niño/La Niña Cycle in
the Pacific showing anomalies of sea-surface height
(the grid in the animation) and anomalies of sea-surface
temperature (the color of the grid). The weakening of
trades in the western equatorial Pacific causes warm
water in the upper layer of the equatorial region to
move eastward, leading to higher sea level and warmer
water in the eastern equatorial Pacific. The wave of
higher sea level (called a Kelvin wave) reflects off South
America, and returns to the west at latitudes north and
south of the equator.
Do Now answers:




Normally: Colder deep water is 40m (130ft) below
surface causes upwelling in response to trade winds.
ENSO: 152m (500ft) below surface
The warmer surface temperatures and weak trade winds
produce nutrient POOR waters devastating anchovies
and other marine fisheries.
Who now's who might be looking for food?????
ENSO flooding?
Climate: average weather conditions
DO NOW:

Explain what is a rain shadow and how does it
affect the local climate?
DO NOW:
ANSWER


The dry land on the side of a mountain, away from the
prevailing wind, is a rain shadow. Rain shadows are
formed because mountains force air to rise and remove
moisture from humid air. The air cools as it rises,
clouds form, and precipitation occurs.
As the air mass moves down the other side of the
mountain, it is warmed, thereby lessening the chance of
precipitation of any remaining moisture. Deserts,
characterized by lesser precipitation, tend form in this
rain shadow of mountains.
Westcoast of America Rainshadow
Westcoast of America Rainshadow
Earth’s Core
Divergent: Movement apart
The Richter Scale
Transform/Plate
boundary
Hotspo
t
Mt.
Pinatubo
Convergent/subduction
Transform Plate Boundary horizontally
in opposite but // directions.
Transform Plate
Boundary
horizontally in
opposite but //
directions.
Ex: San
Andreas fault