Transcript Cycles of Matter - RRMS 8th Grade Science

13.1 Ecologists Study Relationships
Get warm up
off table by
phone
Ecosystem
“Cycles”
Write everything
that is underlined
13.5 Cycling of Matter
Cycling of
Materials in
Ecosystems
13.5 Cycling of Matter
KEY CONCEPT:
Matter cycles in and out of an
ecosystem.
All materials that cycle through living
organisms are important in maintaining
the health of ecosystems; but four
elements are particularly important:
water, carbon, nitrogen and phosphorus.
13.5 Cycling of Matter
• Earth system has four parts
– Atmosphere
– Hydrosphere
- Lithosphere
- Biosphere
 chemical elements are required by life
from the living and nonliving parts of the
environment.
• Abiotic and biotic processes drive these
cycles between the different parts of the
Earth.
• Each compound (water, carbon,
nitrogen) typically exists in all four parts
of the Earth System
13.5 Cycling of Matter
13.5 Cycling of Matter
Biogeochemical Cycles
The paths of water, carbon,
nitrogen, and phosphorus
pass from the nonliving
environment to living
organisms; such as trees,
and than back to the
nonliving environment.
•These paths form
closed circuits, or
cycles, called
biogeochemical cycles.
13.5 Cycling of Matter
I. The Water Cycle
1. The hydrologic, or water cycle is the
circular pathway of water on Earth.
precipitation
condensation
transpiration
evaporation
surface
runoff
lake
groundwater
water storage
in ocean
13.5 Cycling of Matter
salt water = 97.5%
freshwater = 2.5%
oceans
ice caps
and
glaciers
1.97%
ground- lakes, atmosphere
rivers,
0.001%
water
0.5% and soil
0.03%
13.5 Cycling of Matter
Water Cycle
Water has the greatest influence
on the ecosystem’s inhabitants.
In this cycle water vapor in the
atmosphere condenses and falls
to Earth’s surface as
precipitation (snow or rain).
Some of this water seeps into
Earth’s surface (infiltration) and
becomes part of groundwater,
which is water retained beneath
the surface of the Earth.
13.5 Cycling of Matter
Water Cycle
Most of the remaining water that
falls to Earth does not stay on the
surface.
Instead, heated by the sun, it
reenters the atmosphere by
evaporation.
Much he of water is taken up by
the roots of plants.
After passing through a plant,
the water moves into the
atmosphere by evaporating from
the leaves, a process called
transpiration.
13.5 Cycling of Matter
Water Cycle
Most of the remaining water that
falls to Earth does not stay on the
surface.
Instead, heated by the sun, it
reenters the atmosphere by
evaporation.
Much he of water is taken up by
the roots of plants.
After passing through a plant,
the water moves into the
atmosphere by evaporating from
the leaves, a process called
transpiration.
13.5 Cycling of Matter
13.5 Cycling of Matter
2. Key terms for the water cycle:
a. Precipitation: moisture that falls to the
ground (rain, snow, sleet, hail)
b. Evaporation: changing from liquid to
gas (water to water vapor)
c. Transpiration: plants give off water
vapor from their leaves to the air
d. Condensation: changing from gas to a
liquid (little water droplets form on the
outside of a cold glass of lemonade - that’s
condensation)
13.5 Cycling of Matter
Carbon Cycle: Remember photosynthesis and
respiration both involve CO2 (now we’re looking
at the C for carbon)
carbon
dioxide
in air combustion
respiration
photosynthesis
respiration
decomposition
of organisms
fossil fuels
photosynthesis
carbon dioxide
dissolved in water
13.5 Cycling of Matter
Carbon Cycle
Carbon is the building block of life.
Carbon like water also
cycles between the biotic
and abiotic factors.
This cycle moves carbon
from the atmosphere,
through the food web,
and then returns it to the
atmosphere.
13.5 Cycling of Matter
Carbon dioxide in the air
or dissolved in water is
used by photosynthesizing
plants, algae, and bacteria
as a raw material to build
organic molecules.
Carbon atoms may return to
the pool of carbon dioxide in
the air and water in four ways
–
–
–
–
Respiration
Combustion
Decomposition
Erosion
Carbon Cycle
13.5 Cycling of Matter
Respiration - Organisms
use oxygen to oxidize
organic molecules
(glucose) during cellular
respiration. Carbon
dioxide is a product of
this reaction.
Combustion- Carbon is
released when wood or
fossil fuel is burned
Decomposition –Organic
tissue and waste are
broken down by
decomposer and
releases carbon in the
soil
Carbon Cycle
CO2 in
atmosphere
Plants,
algae,
bacteria
Cellular respiration
Burning
Photosynthesis
Higher
level
consumers
Wood
and
fossil fuels
Primary
consumers
Decomposition
Detritivores
(soil microbes
and others)
Decomposers
TheCycling
Carbon Cycle:
13.5
of Matter
Erosion:
• Marine organisms use carbon
dioxide dissolved in sea water
to make calcium carbonate
shells.
• Over millions of years, the
shells of dead organisms
form sediments, which form
limestone.
• As the limestone becomes
exposed and erodes, the
carbon becomes available to
other organisms.
Carbon cycle
13.5 Cycling of Matter
13.5 Cycling of Matter
Nitrogen (N) is an
essential constituent of
protein, DNA, RNA,
and chlorophyll.
Nitrogen is the most
abundant gas in the
atmosphere.
Nitrogen must be fixed
or converted into a
usable form.
Nitrogen cycle
13.5 Cycling of Matter
• Nitrogen is plentiful in
the atmosphere as N2
– But plants and animals
cannot use N2
• Some bacteria in soil and
legume root nodules
convert N2 to
compounds that plants
can use:
ammonium (NH4+) and
nitrate (NO3–)
• hydrogen to form
ammonia.
Nitrogen cycle
13.5 Cycling of Matter
Shoot
• Legumes and
certain other
plants have
nodules in their
roots that
contain nitrogenfixing bacteria
Nodules
Roots
Figure 32.14A
13.5 Cycling of Matter
ATMOSPHERE
N2
Amino
acids
Nitrogen-fixing
bacteria
N2
NH4+
NH4+
(ammonium)
Soil
Ammonifying
bacteria
Organic
material
Nitrifying
bacteria
NO3–
(nitrate)
Root
Figure 32.13
13.5 Cycling of Matter
Nitrogen cycle
1. The nitrogen cycle mostly takes place
underground.
2. Some bacteria convert gaseous nitrogen into
ammonia through a process called nitrogen
fixation.
– Some nitrogenfixing bacteria
live in
nodules on the
roots of plants;
others live
freely in
the soil.
nitrogen in
atmosphere
animals
plant
nitrates
nitrogen-fixing
bacteria in
decomposers
nitrifying
roots
bacteria
ammonification
nitrites
nitrogen-fixing
ammonium
bacteria in soil
nitrifying
denitrifying
bacteria
bacteria
13.5 Cycling of Matter
3. Ammonia released into the soil is transformed
into ammonium.
4. Nitrifying bacteria change the ammonium
into nitrate.
– Nitrogen moves
through the
food
web and
returns
to the soil
during
decomposition.
nitrogen in
atmosphere
animals
plant
nitrogen-fixing
bacteria in
decomposers
roots
ammonification
nitrogen-fixing
ammonium
bacteria in soil
nitrifying
bacteria
nitrates
nitrifying
bacteria
nitrites
denitrifying
bacteria
13.5 Cycling of Matter
V. Phosphate Cycle
1. Phosphate is released by the
weathering of rocks.
Phosphorus leaches
into groundwater
from the soil and
is locked in
plants
sediments.
b. Both mining and
agriculture add
phosphorus into
the environment.
a.
rain
geologic uplifting
weathering of
phosphate from rocks
runoff
animalsphosphate
phosphate in solution
in soil
leaching
decomposers
sedimentation
forms new rocks
13.5 Cycling of Matter
13.5 Cycling of Matter
Activity
• Draw, label, color, and explain the Carbon and
Nitrogen cycles on a sheet of paper.
• Page 414-115 figure 13.14 & 13.15
• Due tomorrow
13.5 Cycling of Matter
II. Oxygen Cycle:
1. Plants make food by photosynthesis
–They use carbon dioxide (CO2) to
make oxygen (O2)
2. Animals breathe out carbon by
respiration
–They use oxygen (O2) and breathe
out carbon dioxide (CO2)
–By the way … humans are animals
too
13.5 Cycling of Matter
Example: Oxygen Cycle:
oxygen
photosynthesis
respiration
carbon
dioxide
13.5 Cycling of Matter
Review Questions 13.5 Cycling of Matter
1. What is the key concept of this unit?
2. Define the key terms for the water cycle.
3. What do plants take in and then give out. What do
animals take in and give out?
4. How does the carbon cycle move carbon?
5. Where is carbon emitted?
6. Where does the nitrogen cycle take place
7. What are phosphates released by?