Download Section 3.3: Cycles of Matter

Ecology
What is Ecology?
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Ecology is the study of interactions among
organisms and between organisms and their
environment.
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There are many levels of organization
ecologists study…
Levels of Organization
Levels of Organization
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Species: can breed and produce fertile offspring
Population: same species in same area
Community: different populations in same area
Ecosystem: all organisms (biotic) in particular
place; includes nonliving (abiotic) surroundings
Biome: group of ecosystems with same climate
(temperature and precipitation) and similar
communities
Biosphere: all portions of the planet where life
exists (land, water, air, atmosphere)
Basic Terminology
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Ecosystem – All the biotic and abiotic factors
in an environment
Heat Energy – Form of “lost” energy, 90% of
available energy is lost in the form of heat.
Chemical Energy – Glucose transfer in the
food chain
Light Energy – Originating source of Energy
from the sun (Main source of energy)
Energy Flow Summary
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Energy flows in one direction through an
ecosystem, from the sun or inorganic
compounds to producers (organisms that
can make their own food) through various
levels to consumers (organisms that rely
on other organisms for food).
Energy Flow
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Producers: Autotrophs
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Photosynthesis Vs. Chemosynthesis
Consumers: Heterotrophs
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Herbivores
Carnivores
Omnivores
Detritivores
Decomposers
Scavenger
Trophic Levels
Feeding Relationships
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Food chain: series
of steps (linear)
Food web: links all
food chains
together
Trophic level: each
step in a chain or
web
Ecological Pyramids
Energy Pyramid
Shows the relative
amount of
energy available at
each trophic
level. Organisms
use about 90
percent of this
energy for
life processes.
Only 10% is
transferred.
Biomass Pyramid
Represents the amount
of living organic matter at
each trophic level.
Typically, the
greatest biomass
is at the base of
the pyramid.
Pyramid of
Numbers
Shows the relative
number of
individual
organisms at each
trophic level.
Cycling of Nutrient and Matter
Remember: Energy flows in
one direction and matter cycles.
Recycling in the Biosphere
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Unlike the one-way flow of energy, matter
is recycled.
Matter moves through an ecosystem in
biogeochemical cycles.
Matter is recycled because systems do not
use up matter, they transform it.
Four Main Cycles
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Water Cycle
Nutrient Cycles
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Carbon Cycle
Nitrogen Cycle
Phosphorus Cycle
Water Cycle
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1. When rain falls on the ground, it either soaks
into the soil or runs across the surface of the soil.
When rainwater runs across the land, what body
of water might collect the rain?
2. From here, where might the water flow?
3. After the rain, the sun comes out and the land
dries. Where does the water that had been on the
land go?
Water Cycle
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Water moves between the ocean, atmosphere, and
land.
Steps of the water cycle:
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Evaporation
Condensation
Precipitation
Runoff
Seepage
Groundwater
Transpiration
Water Cycle
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Sketch a simple diagram of the water cycle in your notes.
Nutrient Cycles
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Every organism needs nutrients to grow
and function. Like water, nutrients are also
transferred in cycles.
3 Nutrient Cycles:
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Carbon
Nitrogen
Phosphorus-mostly in rocks and soil minerals
Carbon Cycle
CO2 in
Atmosphere
CO2 in Ocean
Carbon Cycle
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Four main types of processes move carbon
through its cycle:
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Biological processes, such as photosynthesis,
respiration, and decomposition, take up and
release carbon and oxygen.
Geochemical processes, such as erosion and
volcanic activity, release carbon dioxide to
the atmosphere and oceans.
Carbon Cycle
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Mixed biogeochemical processes, such as the
burial and decomposition of dead organisms
and their conversion under pressure into coal
and petroleum (fossil fuels), store carbon
underground.
Human activities, such as mining, cutting and
burning forests, and burning fossil fuels,
release carbon dioxide into the atmosphere.
Nitrogen Cycle
N2 in Atmosphere
NH3
NO3and NO2-
Nitrogen Cycle
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Bacteria that live in the soil and on the
roots of legume plants convert nitrogen gas
to ammonia through nitrogen fixation.
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When organisms die, their ammonia can be
converted back to nitrogen gas through
denitrification.
Phosphorus Cycle
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Phosphorus is essential to living organisms because it forms part of
important life-sustaining molecules such as DNA and RNA.
Phosphorus remains mostly on land in rock and soil minerals, and in
ocean sediments.
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It is not very common in the biosphere
phosphorus exists in the form of inorganic phosphate.
As the rocks and sediments gradually wear down, phosphate is
released.
On land, some of the phosphate washes into rivers and streams, where
it dissolves.
The phosphate eventually makes its way to the oceans, where it is
used by marine organisms.
Phosphorus Cycle