Ecology Unit
The student will investigate and understand
dynamic equilibria within populations,
communities,and ecosystems.
Key concepts include:
• interactions within and among
populations
• nutrient cycling with energy flow
through ecosystems;
• the effects of natural events and human
activities on ecosystems
IMPORTANT Vocabulary
1. Biome
2. Species
3. Population
4. Community
5. Ecosystem
6. Niche
7. Food Chain
8. Trophic Level
9. Food Web
10. Biosphere
What is ecology?
Ecology- the scientific study of
interactions between organisms
and their environments, focusing
on energy transfer
• It is a science of relationships.
What Factors Make up the
Environment?
What do you mean by environment?
The environment is made up of two
factors:
Biotic factors- all living organisms
inhabiting the Earth
Abiotic factors- nonliving parts of
the environment (i.e. temperature,
soil, light, moisture, air currents)
Organism- any unicellular or
multicellular form exhibiting all of the
characteristics of life, an individual.
•The lowest level of organization
Population-a group of organisms
of one species living in the same
place at the same time that
interbreed and compete with each
other for resources (ex. food,
mates, shelter)
Bait Ball Video
Community- several interacting
populations that inhabit a common
environment and are interdependent.
Ecosystem- populations in a
community and the abiotic factors
with which they interact (ex.
marine, terrestrial)
Biosphere- life supporting portions
of Earth composed of air, land,
fresh water, and salt water.
•The highest level of organization
Organism
Population
Community
Biosphere
Ecosystem
“The ecological niche of an
organism depends not only on
where it lives but also on what
it does. By analogy, it may be
said that the habitat is the
organism's ‘address’, and the
niche is its ‘profession’,
biologically speaking.”
Odum - Fundamentals of Ecology
Habitat vs. Niche
Niche - the role a species plays in
a community (job)
Habitat- the place in which an
organism lives out its life
(address)
Habitat vs. Niche
A niche is determined by the
tolerance limitations of an
organism, or a limiting factor.
Limiting factor- any biotic or
abiotic factor that restricts the
existence of organisms in a
specific environment.
Examples of limiting factors-
•Amount of water
•Amount of food
•Temperature
Habitat vs. Niche
Feeding Relationships
• There are 3 main types of feeding
relationships
1. Producer- Consumer
2. Predator- Prey
3. Parasite- Host
Feeding Relationships
Producer- all
autotrophs (plants),
they trap energy
from the sun
• Bottom of the food
chain
Feeding Relationships
Consumer- all heterotrophs: they
ingest food containing the sun’s
energy
• Herbivores
• Carnivores
• Omnivores
• Decomposers
Feeding Relationships
Consumer-
Herbivores
– Eat plants
• Primary
consumers
• Prey animals
Feeding Relationships
Consumer-Carnivores-eat meat
• Predators
– Hunt prey
animals for food.
Feeding Relationships
Consumer-
• Scavengers
– Feed on carrion,
dead animals
Feeding Relationships
Consumer- Omnivores -eat both plants
and animals
Feeding Relationships
Consumer-
Decomposers
• Breakdown the
complex compounds
of dead and
decaying plants and
animals into simpler
molecules that can
be absorbed
Symbiotic Relationships
Symbiosis- two species living together
3 Types of
symbiosis:
1. Commensalism
2. Parasitism
3. Mutualism
Symbiotic Relationships
Commensalism-
one species benefits
and the other is
neither harmed nor
helped
Ex. orchids on a tree
Epiphytes: A plant, such as a
tropical orchid or a bromeliad,
that grows on another plant
upon which it depends for
mechanical support but not for
nutrients. Also called
aerophyte, air plant.
Symbiotic Relationships
Commensalism-
one species benefits
and the other is
neither harmed nor
helped
Ex. polar bears and
cyanobacteria
Symbiotic Relationships
Parasitism-
one species benefits (parasite) and
the other is harmed (host)
• Parasite-Host relationship
Symbiotic Relationships
Parasitism- parasite-host
Ex. lampreys,
leeches, fleas,
ticks,tapeworm
Symbiotic Relationships
Mutualism-
beneficial to
both species
Ex. cleaning birds
and cleaner
shrimp
Symbiotic Relationships
Mutualism-
beneficial to both species
Ex. lichen
Type of
relationship
Species
harmed
Species
benefits
Species
neutral
Commensalism
Parasitism
Mutualism
= 1 species
Trophic Levels
• Each link in a food chain is known
as a trophic level.
• Trophic levels represent a feeding
step in the transfer of energy
and matter in an ecosystem.
Trophic Levels
Biomass- the amount of organic matter
comprising a group of organisms in a
habitat.
• As you move up a food chain, both
available energy and biomass
decrease.
• Energy is transferred upwards but is
diminished with each transfer.
Trophic Levels
Producers- Autotrophs
Primary consumers- Herbivores
Secondary consumers-
small carnivores
Tertiary
consumers- top
carnivores
E
N
E
R
G
Y
LE 54-11
1,000,000 J of sunlight
10,000 J
1,000 J
100 J
10 JTertiary
consumers
Secondary
consumers
Primary
consumers
Primary
producers
Trophic
level
4
3
2
1
Feeding strategy
Secondary carnivore
Carnivore
Herbivore
Autotroph
Grazing food chain Decomposer food chain
Cricket
Maple tree leaves
Owl
Shrew
Earthworm
Dead maple leaves
Cooper’s
hawk
Robin
Figure 51.6a
Trophic levels
Ecological PyramidsPyramid of
Numbers:
Shows the relative
number of individual
organisms at each
trophic level.
Ecological Pyramids
0.1% Third-level
consumers
1% Second-level
consumers
10% First-level
consumers
100% Producers
Energy Pyramid:
Shows the relative
amount of energy
available at each
trophic level.
Only part of the
energy that is stored
in one trophic level is
passed on to the next
level.
Where does the other 90% go?
• Remember the law of conservation of
energy: energy cannot be created OR
destroyed.
• 90% of the energy stored in food is lost to
the consumer, but it hasn’t been destroyed.
• Some leaves the body as chemical energy in
bodily wastes, but most is radiated out into
the space around our bodies as heat
80.7% respiration
17.7% excretion1.6% growth and
reproduction
Energy derived
from plants
Figure 51.4
Trophic Levels
Food chain- simple model that
shows how matter and energy
move through an ecosystem
Trophic Levels
Food web- shows all possible
feeding relationships in a
community at each trophic level
• Represents a network of
interconnected food chains
Food chain Food web
(just 1 path of energy) (all possible energy paths)
Nutrient Cycles
Cycling maintains homeostasis
(balance) in the environment.
•3 cycles to investigate:
1. Water cycle
2. Carbon cycle
3. Nitrogen cycle
Water cycle-
•Evaporation, transpiration,
condensation, precipitation
Water cycle-
Carbon cycle-
•Photosynthesis and respiration
cycle carbon and oxygen through
the environment.
Carbon cycle-
Nitrogen cycle-
Atmospheric nitrogen (N2) makes up nearly
78%-80% of air.
Organisms can not use it in that form.
Lightning and bacteria convert nitrogen into
usable forms.
Nitrogen cycle-
Only in certain bacteria and industrial
technologies can fix nitrogen.
Nitrogen fixation-convert atmospheric
nitrogen (N2) into ammonium (NH4
+
)
which can be used to make organic
compounds like amino acids.
N2 NH4
+
Nitrogen cycle-
Nitrogen-fixing
bacteria:
Some live in a
symbiotic
relationship with
plants of the legume
family (e.g.,
soybeans, clover,
peanuts).
Nitrogen cycle-
•Some nitrogen-fixing bacteria live
free in the soil.
•Nitrogen-fixing cyanobacteria are
essential to maintaining the fertility
of semi-aquatic environments like rice
paddies.
Atmospheric
nitrogenLightning
Nitrogen
fixing bacteria
Ammonium
Nitrification
by bacteria
Nitrites Nitrates
Denitrification
by bacteria
Plants
Animals
Decomposers
Nitrogen Cycle
Toxins in food chains-
While energy decreases as it moves up
the food chain, toxins increase in
potency.
•This is called biological magnification
Ex: DDT & Bald Eagles

Basic ecology notes

Editor's Notes

  • #3 What do you think about when I say ecology? Recycling? Acid rain?
  • #5 What do you think about when I say ecology? Recycling? Acid rain?
  • #7 When I say environment you think what—weather. Well Ok but it it much more than that
  • #8 The lowest level is the individual. The organism. Here we see a salmon and a bear as examples of organisms. REMINDER: organisms die, species go extint
  • #9 The next level is a population. A population consists of a single species living together and breeding. Give me an example of a population. Ex. large mouth bass living in Lake Meade. Beetles living under the same log. Here we have salmon spwning and two bears fishing.
  • #10 Next level is a community which is several populations living together and depending on each other. What does interdependent mean? An example of a community is shown here with the bear and the salmon. They both live in a common environment and the bear needs the fish for food? How does the salmon need the bear?
  • #12 Lets review. Organisms make up populations, populations make up communities, communities and abiotic factors make up ecosystems, and all of the ecosystems make up the biosphere. From one to many and each depending on the other.
  • #13 Just like with classification, ecology is hierarchal. Each level builds on itself and they fit together like nesting boxes.
  • #14 You don’t have to write this down!!
  • #15 Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.
  • #16 Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.
  • #17 Although several species may share a habitat they each have their own niche. A niche is a very narrow range where a species fits within a habitat.
  • #18 How do they trap the sun’s energy? Through what process? What is that process similar to in animal cells?
  • #19 How do they trap the sun’s energy? Through what process? What is that process similar to in animal cells?
  • #20 Energy moves up the food chain through the producer/consumer relationship.
  • #21 Herbivores are the 1 st step up the food chain, they eat the producers
  • #22 Scavengers are a type of carnivore that eat dead animals, or carrion. Vultures, hyenas, crabs, deep sea fish-talk about distance from the sun and must eat the dead things that sink to the bottom, bottom feeders
  • #23 Scavengers are a type of carnivore that eat dead animals, or carrion. Vultures, hyenas, crabs, deep sea fish-talk about distance from the sun and must eat the dead things that sink to the bottom, bottom feeders
  • #24 Humans and bears are omnivores but a large and important subset of omnivores are the decomposers. They breakdown dead producers and release the energy back into circulation.
  • #25 Humans and bears are omnivores but a large and important subset of omnivores are the decomposers. They breakdown dead producers and release the energy back into circulation.
  • #26 Cleaning shrimp
  • #28 You can see here that this polar bear is no longer white.
  • #31 The Egyptian plover takes insects from the backs of buffaloes, giraffes and rhinos. The plover has also been observed taking leeches from the open mouths of crocodiles! In this association the plover receives a supply of food and the other animal rids itself of unwelcome pests
  • #32 The Egyptian plover takes insects from the backs of buffaloes, giraffes and rhinos. The plover has also been observed taking leeches from the open mouths of crocodiles! In this association the plover receives a supply of food and the other animal rids itself of unwelcome pests
  • #39 Figure: 51.6a Caption: (a) Each trophic level in an ecosystem is defined by a distinct feeding strategy. The organisms illustrated in this table furnish an example for each trophic level in the grazing and decomposer food chains of a temperate-forest ecosystem. Many other species exist at each trophic level in this ecosystem.
  • #40 Ecological pyramids show the decreasing amounts of energy, living tissue, or number of organisms at successive feeding levels. The pyramid is divided into sections that represent each trophic level. Because each trophic level harvests only about one tenth of the energy from the level below, it can support only about one tenth the amount of living tissue.
  • #43 Ecological pyramids show the decreasing amounts of energy, living tissue, or number of organisms at successive feeding levels. The pyramid is divided into sections that represent each trophic level. Because each trophic level harvests only about one tenth of the energy from the level below, it can support only about one tenth the amount of living tissue.
  • #45 Figure: 51.4 Caption: Very little of the energy consumed by chipmunks, a primary consumer (herbivore), is used for secondary production. Most of the energy is used for cellular respiration.