Transcript Principles of Ecology

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AL COS
– 3, 6, 23, 24, 25, 38, 39, 41
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AHSGE
– Standard I Objective 1
 Analyze the methods of science used to identify and
solve problems.
– Standard II Objective 1
 Trace the transfer of matter and energy through
biological systems.
– Standard VI Objective 1
 Demonstrate an understanding of factors that affect
the dynamic equilibrium of populations and
ecosystems.
Principles of Ecology Outline
I.
II.
III.
IV.
Organisms and their environment
a. Ecology
1. Scientific fields
2. Methods used
b. Abiotic factors
c. Biotic factors
Levels of organization in ecology
a. Organisms
b. Populations
c. Communities
d. Ecosystems
e. Biosphere
Three major types of ecosystems
a. Terrestrial
b. Fresh water
c. Salt water
Additional notes
V.
VI.
VII.
VIII.
IX.
X.
XI.
Three main types of symbiosis
a. Commensalism
b. Mutualism
c. Parasitism
Nutrition and energy flow
a. The sun
b. Autotrophs
c. Heterotrophs
d. Decomposers
Food chain and trophic level
Food web
Ecological pyramid
Water cycle, Carbon cycle, Nitrogen
cycle, Phosphorus cycle
Teacher resources
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Organisms and Their Environment
Ecology is the scientific study of interactions among
organisms and their environment.
– The study of how living things relate to each other and to
their environment
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The biosphere is the portion of Earth that supports
life
– An ecosystems biotic and abiotic factors
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The nonliving parts of an organism’s environment
are the abiotic factors
– Ex. Air currents(wind), temperature, moisture, light, soil,
humidity, and rocks
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All the living organisms that inhabit an environment
are called biotic factors.
Levels of Organization(Classification) in Ecology
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Organisms
 Populations
– A group of organisms of one species that interbreed and live in the
same place at the same time.
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Competition may occur if resources(food, water, etc) are in short supply.
Communities
– Made up of several interacting populations.
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Ecosystems
– Made of the interactions among the populations in a community
and the abiotic factors
– Ecosystems are studied by ecologists
– Ecosystems are made up of organisms, populations, and
communities
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Biosphere
– Includes from high in the atmosphere to the bottom of the ocean.
Three major kinds of
ecosystems
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Terrestrial- on land
– Ex. Forests, meadows,
and desert scrub
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Fresh water
– Ex. Ponds, lakes, streams
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Salt water (Marine)
– 75% of the Earth’s
surface
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A habitat is the place where an organism
lives out its life.
 A niche is the role and position a species
has in its environment---how it meets its
need, how it reproduces, and how it
survives.
 Predators area animals that kill and eat
other animals.
– The animals that are eaten are called prey
– Predator-prey relationships
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The relationship in which there is a close
and permanent association among
organisms of different species is called
symbiosis.
3 Main types of symbiosis
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Commensalism- one
species benefits and the
other species is neither
harmed nor benefited.
– Ex. Spanish moss
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Mutualism- two species of
organisms benefit
– Ex. Ants and an acacia tree
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Parasitism- one organism
benefits at the expense of
another, but usually does
not kill the host.
– Ex. Ticks
Nutrition and energy flow
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The ultimate source of energy is the sun.
 Producers(Autotrophs)- make their own food.(use
energy from the sun or energy stored in chemical
compounds to manufacture their own nutrients
– Ex. Plants, some unicellular organisms
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Consumers(Heterotrophs)- consume other
organisms for their energy
– Obtain energy and nutrients from autotrophs
– Omnivores, carnivores, herbivores, scavengers, and
decomposers are all consumers
– Ex. Animals, humans
Three
types of heterotrophs
–Carnivores- kill and eat other animals
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Ex. Lions
–Scavengers- animals that eat animals that have
already died
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Ex. Black vultures
–Omnivores- eat both plant material and animals
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Ex. Humans, raccoons, opossums, bears
Decomposers-
organisms that break down and
absorb nutrients form dead organisms.
Before
plants can reuse many organic materials, the
materials must be broken down by decomposers
–Ex. Most fungi, some protozoans, many bacteria
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Food chain- a simple
model that scientists use
to show how matter and
energy move through an
ecosystem.
– Only shows one route for the
transfer of matter and energy.
– Usually has three links but no
more that five.
– At each link a portion of
energy is lost as heat,
therefore, the amount of
energy remaining in the 5th
link is low.
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Trophic level- a feeding
step in the passage of
energy and materials.
 Pg 50-51
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Food webexpresses all the
possible feeding
relationships at
each trophic level
in a community.
– Network of
interconnected food
chains
– Trophic level and
food chain are parts
of a food web
– A more realistic
model because
most organisms
depend on more
than one other
species for food.
Food chain and food web movie
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Ecological pyramid- shows
how energy flows through
an ecosystem.
– The base of the pyramid, or 1st
trophic level are the
autotrophs.
– The total transfer from one
level to the next is only about
10% because energy is lost
due to heat.
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A pyramid of biomass
expresses the weight of
living material at each
trophic level.
– How to calculate biomass:
 Find the average weight of
each species at that trophic
level and multiply by the
estimated number of
organisms in each
population.
The Water Cycle
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In the water cycle,
water is constantly
moving between the
atmosphere and Earth.
Pg 55
– Water is lost to the
abiotic parts of the
biosphere from the
biotic parts by the
process of transpiration
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Water, carbon, and
nitrogen are released
back into the
atmosphere during
decomposition
Water cycle movie
The Carbon
Cycle
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Carbon cycle begins
with autotrophs.
During
photosynthesis
carbon is converted
from carbon dioxide
gas.
Heterotrophs eat the
autotrophs and then
release carbon
dioxide gas.
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Plants use nitrogen
to make proteins.
Herbivores eat the
plants and convert
the proteins into
human proteins.
Nitrogen is
released to the
abiotic parts of the
biosphere from the
process of death
and decay by
bacteria.
Lightning and
certain bacteria
convert the
nitrogen in the air
into more usable
forms.
The Nitrogen Cycle
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The Phosphorus Cycle
The phosphorus cycle is different from other cycle because
phosphorus is found in sedimentary rock, not the
atmosphere.
Two cycles:
– Short term: phosphorus is in the soil and plant life
– Long term: phosphorus is washed into the sea
Teacher Activities/Labs
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Food web activity-Gar Gar Gator
SIM Lab: Owl pellet(SIM lab disc required)
SIM Lab: BioAssessment (SIM lab disc required)
SIM Lab: Water Quality (SIM lab disc required)
SIM Lab: Stream in a Bucket (SIM lab disc required)
SIM Lab Soil Testing: (SIM lab disc required)
AHSGE Pathways Lab: Grabbing for Grub(Teacher)
AHSGE Pathways Lab: Gone Fishing(Teacher)
AHSGE Pathways Lab: Producers-ConsumersDecomposers (Teacher)
AHSGE Pathways Lab: Pass The Energy Please(Teacher)
AHSGE Pathways Lab: Cycles of Nature(Teacher)
Food Webs in the Bay