Levels of Organization
0 An ecologist is a scientist that studies the interactions of living
things with other living things and their surroundings
0 When ecologists study organisms in their environment they look at
the levels of organization
0 When studying nature, scientists recognize 6 levels of organization
Levels of Organization
0 Levels of Organization:
0 Species – a group of organisms so similar to one another that they can
breed and produce fertile offspring
0 Population – a group of the same species that live in the same area
0 Community – groups of different living species that live together in the
same area
0 Ecosystem – the community and all of the non-living components such
as water, soil, mountains, etc.
0 Biome – groups of ecosystems that have the same climate and similar
dominant communities
0 Biosphere – the highest level of organization that ecologists can study
Levels of Organization
Factors in an Ecosystem
0 All ecosystems are made up of
living and nonliving
components
0 Biotic factors – are all of the
living parts of an ecosystem
such as plants, animals, fungi,
and bacteria
0 Abiotic factors – are the
nonliving components such as
temperature, water, wind,
sunlight, and Earth’s
landmasses
Factors in an Ecosystem
ECOSYSTEM
Abiotic Factors
Biotic Factors
Habitat & Niche
0The habitat of an
Leopards are graceful and powerful
big cats closely related to lions, tigers,
and jaguars. They live in sub-Saharan
Africa, northeast Africa, Central Asia,
India, and China. However, many of
their populations are endangered,
especially outside of Africa. (National
Geographic)
organism is considered
all of the biotic and
abiotic factors where an
organism lives
Habitat & Niche
0The ecological niche of
a species is made up of
all the physical, chemical,
and biological factors
that
a
species
needs
to
Native to the Central Asian mountains,
the snow leopard is a rare sight, with survive, stay healthy, and
only about 6,000 left in the wild. They
are hunted for their beautiful, warm reproduce
fur and for their organs, which are
used in traditional Chinese medicine.
(National Geographic)
Habitat & Niche
0 Think of a habitat as where a species lives and the niche as how it
lives within its habitat
0 A niche includes:
0 Food – type of food, how it competes for food, and where it finds its
food
0 Abiotic conditions – air temp., amount of water, etc.
0 Behavior – the time of day a species is active as well as where and
when a species reproduces
Habitat & Competition
0 When two species live in the same habitat it is
possible that they may require the same resources
0 One species will always be better adapted to obtain a
resource over another
0 The competitive exclusion principle states that
when two species compete for the same resources,
one will “win” and the other will be ‘forced’ into a
new niche or become extinct
Habitat & Competition
0 When two or more species compete for resources
(competitive exclusion) it can have 3 Effects:
0 Extinction – one species puts so much pressure on the other
that it dies out
0 Niche partitioning – the two species could occupy different
niches near each other not overlapping
0 Evolutionary response – one species may evolve or be ‘selected
for’ different traits and evolve away from the original form
Habitat & Competition
0 An ecological equivalent would be a
case where two species occupy the same
niche in different parts of the world
Community Interactions
0 Competition happens when two
organisms fight for similar resources such
as food, space, or water
0 Interspecific competition – happens when
two different species compete
0 Intraspecific competition – occurs when the
same species compete
Community Interactions
0 Predation – the process by which
one organism captures and eats
another organism
Community Interactions
0 Symbiosis – an interaction between two or more organisms
that live in direct contact with one another
0 (Sym = same) (Bio = life) (Sis = together)
0 There are 3 Types of Symbiosis:
0 Mutualism
0 Commensalism
0 Parasitism
Mutualism
0 Mutualism – a symbiotic
relationship where both species
benefit from the interaction
A cleaner shrimp reaches into a moray eel's mouth.
The shrimp uses its claws to pick stuff off the eel's
body. That can include dead skin, tiny pieces of
food, and even little creatures that can hurt the fish.
(National Geographic)
Commensalism
0 Commensalism – an interaction
between organisms where one
species benefits and the other does
not benefit nor is it harmed
The clown fish swims among the stinging
tentacles of the sea anemone for protection
and safety. The sea anemone does not
benefit from this relationship nor is it
harmed. The clown fish is safe in its
anemone home!
Parasitism
0 Parasitism – a relationship
where one organism benefits
while the other is harmed
0 Parasites keep their host
alive for days or even years
while predation kills
immediately
Organism Population
0 One of the main goals of all living things is to reproduce
0 Studying organism population distribution and growth is an
important part of Ecology
0 Population density – is a measurement of the number of
individuals living in a defined space
Organism Population
0 Organism populations have varying types of
population dispersion (aka) distribution
0 Clumped – living close together
0 Uniform – living at regular intervals in relation to
one another
0 Random – living in random places and distances
from one another
0 Each of these types has its own advantages and
disadvantages
Organism Population
0Population Growth and the Four Factors:
0 Migration (two types)
0Immigration – moving “in to” an area
0Emigration – moving “out of” an area
0 Birth & Death
0Birth rates – new organisms born cause an increase in
population
0Death rates – organisms dying cause a population to
decrease
Organism Population
Population
Change
=
Births
+
Immigration
–
Deaths
+
Emigration
0 To calculate an overall population increase or decrease, you
must know all four factors
Population Growth
0 There are Two Main Types:
0 Exponential – a population increases
quickly over a short period of time
0 Logistic – a population begins with slow
growth followed by rapid growth
before leveling off or slower growth
0 A carrying capacity occurs here
Limits to Growth
0 Most populations have a limit to
Carrying capacity
how large they can get
0 A limiting factor is any factor that
causes population growth to
decrease or stop
0 A carrying capacity is the maximum
number of individuals a given area
can support
Limits to Growth
0 There are Two Types of Limiting Factors:
0 Density-dependent – affects a population differently depending on
the size of the population
0 Example: a disease can have a greater effect on a larger population versus a
small population that is spread out (diseases, predation, competition, &
parasitism)
0 Density-independent – affects a population in similar ways
regardless of its size
0 Example: an earthquake will happen regardless of the size of the
population of groundhogs in a certain area (natural disasters, seasons, &
unusual weather)
Energy Flow in an Ecosystem
0 There are only TWO types of biotic
organisms on the planet
Producers
Consumers
Energy Flow in an Ecosystem
0 Producers are plants that “produce” or make
food for themselves and others
0 An autotroph is an organism that is capable of
making its own food (like a tree)
0 The suffix –troph refers to “food” usually in an
ecosystem
Energy Flow in an Ecosystem
0 Consumers are any organism that relies upon
another organism for food (this can be animals,
fungi, bacteria, protists, and even some plants)
0 The term heterotroph is used to describe this
organism
0 The prefix –hetero means “different”
Energy Flow in an Ecosystem
0 There are 5 types of Consumers/Heterotrophs:
0 Herbivores – eat only plant material
0 Carnivores – eat only animals
0 Omnivores – eat both plant and animals
0 Detritivores – eat dead organic matter
0 Decomposers – are detritivores that break down organic matter into
simpler compounds
Types of Consumers
Detritivores as Decomposers
0 Decomposers are responsible for returning nutrients
back to the soil to enrich the soil for more plants to
grow
Energy Flow
0 In any ecosystem the flow of energy is a one way path
that begins with the sun and producers
0 A food chain is a diagram that shows feeding relationships
and how energy flows through an ecosystem
0 Each “step” in the food chain is called a trophic level
0 There are 4 trophic levels shown below
Energy Flow
0 The first level of organisms (producers) feeds itself as well as the
primary consumer
0 The secondary consumer is next then tertiary and then quaternary
0 A food web is a
Food Webs
model showing the
complex network of
feeding relationships
through trophic
levels
0 The “arrow” points
to the organism
‘receiving’ the energy
Food Webs
0 Identify the
producers and all of
the levels of
consumers in the
food web shown
Energy in an Ecosystem
0 All ecosystems on Earth begin
with energy from the sun
0 Each step in a food chain loses a
certain amount of energy from
the system
0 Most energy loss is in the form of
heat loss from the ‘system’
Energy in an Ecosystem
0 When you eat food the energy rich molecules in the food are
used for growth, maintenance, and movement
0 The majority of the energy in foods is used to keep the body at a
healthy temperature
0 The body is not perfect at using everything that you eat so you
must get rid of the unused portion as waste
0 An energy pyramid is a diagram that compares energy used by
producers and consumers
Energy in an Ecosystem
0 In any ecosystem there is biomass
0 Biomass – is the measure of the total dry mass of organisms in a
given area
0 In an energy pyramid it shows that only 10% of the energy is
actually available to be transferred from one organism to the next
Energy in an Ecosystem
0 A biomass pyramid is a
diagram showing the amount
of biomass found at each
trophic level in an ecosystem
0 A pyramid of numbers
shows the actual numbers of
individual organisms at each
trophic level in an ecosystem
0 In most cases both pyramids
must have a much larger lower
trophic level to support the ones
above them
Cycling of Matter
0 Elements, chemical compounds, and other forms of matter
are passed from one organism to the next on our planet
0 The biogeochemical cycle is the cycle that describes how
nutrients and water are recycled in the biosphere
0 The four we will cover: Water, Carbon, Nitrogen, and
Phosphorous
The Water Cycle
aka the “Hydrologic Cycle”
0 Terms you should know for the Water Cycle:
0 Evaporation – process by which liquid water is changed into a gas
0 Transpiration – water evaporation through the leaves of plants
The Water Cycle
aka the “Hydrologic Cycle”
0 Terms you should know for the Water Cycle:
0 Condensation – process by which gaseous water forms liquid
water
0 Precipitation – the return of water back to the Earth (aka rainfall)
0 Seepage – process where liquid water soaks or seeps into the soil
or ground becoming groundwater
0 Runoff – when liquid water flows down a hillside, mountain or
slope to sea level
The Water Cycle
Where do we get our Water?
How much fresh water is there?
(approximately)
The Carbon Cycle
0 Carbon, element 6 on the Periodic Table, is considered the
“element of life”
0 Carbon is found in all living organisms on Earth
0 The most common exchange of Carbon is between plants and
animals though there are Four Main Ways Carbon is recycled in
the Biosphere
The Carbon Cycle
0 The Four ways Carbon is recycled:
0 Biological processes like photosynthesis & respiration
0 Geochemical processes such as volcanic activity
0 Mixed biogeochemical like dead organisms being compressed over
time forming fossil fuels
0 Human activities such as burning of fossil fuels, forests, and mining
The Carbon Cycle
The Carbon Cycle
The Nitrogen Cycle
0 Nitrogen gas is the most abundant gas in our atmosphere at
78%
0 It is a binary molecule consisting of two ‘bonded’ Nitrogen atoms
(N2)
0 Nitrogen is an essential element in the formation of proteins
0 Plants cannot absorb Nitrogen gas directly so they need help
The Nitrogen Cycle
0 Bacteria is the key to making Nitrogen available for plant use!
0 Bacteria in the soil convert Nitrogen gas into Ammonia (NH3)
through a process called nitrogen fixation
0 Different types of bacteria convert the Ammonia into nutrients for
plants (nitrates and nitrites)
0 Nitrates are taken into plants where they convert them into amino
acids and proteins
The Nitrogen Cycle
The Nitrogen Cycle
0 A third type of bacteria
converts the nitrates back
into atmospheric
Nitrogen (N2 gas) in a
process called
denitrification
The Phosphorus Cycle
0 Phosphorus, element # 15 on the Periodic Table, is an essential
element to living organisms
0 Phosphorus helps to form the important molecules DNA & RNA
that contain the genetic materials critical for all living things on
the planet
0 Phosphorus is unique in that it does not enter the atmosphere
0 It is found mainly in land sediments like rock and ocean
sediments
The Phosphorus Cycle
0 In rocks and minerals phosphorus exists as inorganic
phosphate and is gradually “released” after erosion of
sediments
0 Phosphates are absorbed by plants through their roots and the
plant binds it into organic compounds that are passed to
consumers when they eat the plants
0 This is the only way that Phosphorus can enter the biological
systems!
The Phosphorus Cycle
Ecological Succession
0 Occasionally an ecosystem suffers a
tragic event that kills all life
0 Succession – the sequence of
biotic changes that regenerate a
damaged community or a ‘new’
area
Ecological Succession
0 Primary succession occurs when a new area is available for
colonization of species
0 The pioneer species is the first species to colonize an area of primary
succession
0 Mosses, lichens, and other primitive plants take root into rock and break it
down over a long period of time into the first soil
Ecological Succession
0 Secondary succession – regenerates a
community quicker than primary and
usually follows a natural disaster
Sample Test Question
0 Many lakes in the U.S. have received large amounts of
nutrients, such as nitrogen and phosphorus, as a result of
pollution from farms and industry. This pollution causes
rapid and massive increases in some lakes’ algae population.
This gradually depletes oxygen supply, killing many
organisms. What is the most logical explanation for the rapid
growth of algae?
Sample Test Question (answers)
0 A) The increased nutrients led many organisms to
emigrate
0 B) The increased nutrients supported the
population growth of algae
0 C) The increased nutrients allowed algae to
outcompete other species
0 D) The increased nutrients caused algae to
immigrate
Human Impact
0 In the late 1700’s an economist by the name of
Thomas Malthus stated
0 “the human population is growing faster than the
Earth’s resources can support”
0 Naturally, the rest of the world didn’t believe these
claims
0 The world’s population was around 1 billion people
worldwide at this time
Human Impact
0 Scientists tried to predict human population growth and
vastly underestimated it!
0 Today we have gone past the predicted carrying capacity
with a world population of over 6 billion!
0 Carrying capacity – the maximum number of individuals
that the environment can normally and consistently
support
Human Impact
0 Several human “advancements” have made it possible for
the human population growth explosion!
0 Technology
0 Agriculture
0 Transportation
0 Medical advancements
0 Sanitation
Human Impact
0 Oil and Coal
0 These natural resources are what humans
have relied upon for power for the last 258
years
0 Oil and coal are considered nonrenewable
resources
0 Nonrenewable resources – resources that are
used faster than they are replenished
Human Impact
0 If humans continue at the rate of 77 million
barrels of oil per day (and growing) we will
quickly approach or exceed our carrying
capacity!
0 We must make a choice to invest in
renewable energy technology if we wish to
survive and preserve a planet capable of
supporting life
0 Renewable energy – resources that cannot be
used up or replenish themselves regularly
Human Impact
0 Water is considered a renewable resource because of
annual rains and snow ‘returning’ water back to the earth
0 Humans are finding ways to make water a nonrenewable
resource by polluting water sources and overuse!
Human Impact
0 Humans need resources in order to survive
0 There is a problem when people need too much!
0 An ecological footprint is the amount of land and
resources necessary to maintain an individual
0 Maintenance includes: food, water, shelter, health,
energy, and waste
Human Impact
0 What is Global Warming?
0 The trend of an increasing global temperature
0 What contributes to Global Warming?
0 Our earth is protected by a thin layer of atmosphere from outer
space
0 Greenhouse gases are certain gases that become “trapped” by the
ozone around our planet
0 Gases like CO2, Methane CH4, and water vapor
Global Warming
ANIMAL BEHAVIOR
o Behavior is defined as anything an animal does in
response to stimuli in its environment.
o Examples:
o A squirrel gathering nuts and acorns in the
autumn is a behavior that is stimulated by
shorter days and colder weather.
o Gathering food for themselves and their
young, caring for their young, avoiding
predators, seeking shelter, and finding a mate
are important behaviors to the survival of
many animals.
INSTINCTIVE AND LEARNED
BEHAVIORS
o Instinctive Behaviors are those that are determined by
inheritance.
o This would be organisms expressing behavioral patterns
that are genetically controlled as opposed to behavior
that has been previously learned in the organisms
lifetime.
o Learned Behaviors are a result of previous experiences of
an animal that modifies their current behavior.
INSTINCTIVE BEHAVIOR
o
o
o
o
Inherited/Innate Behavior
Instinctive Behavior
Territorial Behavior
Migratory Behavior
INHERITED/INNATE
BEHAVIOR
o Inherited/Innate Behavior:
o Inheritance plays an important role in an animal’s
behavior.
o An animal’s genetic composition determines how it
responds to stimuli. (Reflexes)
o An animal’s hormonal balance, in combination with its
nervous system, affects how sensitive an animal is to
stimuli.
o Inherited behavior of animals is also known as innate
behavior.
o It includes both automatic responses and instinctive
behaviors.
INSTINCTIVE BEHAVIOR
o Instinctive Behavior:
o Instincts are a complex pattern of innate behaviors.
o Instinctive behaviors may take longer than reflexes and may be
a combination of behaviors.
o For example, an animal’s courtship behavior is instinctive.
Animals will recognize certain behaviors exhibited by
members of the same species. Each species has its own
specific courtship behaviors.
o The male and female black-headed gull dance in unison
side by side and turn their heads away from each other.
The female taps the male’s bill and he gives her a
regurgitated fish. Then the courtship is over and the pair
will mate.
o Different species of fireflies flash distinctive patterns of
light. The female will respond only to the male that
exhibits the species-correct flashes.
ANIMAL COURTSHIP
PATTERNS
TERRITORIAL BEHAVIOR
o Territorial Behavior:
o A territory is a physical space that contains the breeding grounds,
feeding area, shelter, or potential mates of an animal.
o Animals that have territories use different behaviors to defend
their space against an animal of the same or different species.
o This is a way to reduce conflict, control populations, and
decrease competition.
o Aggression is another behavior exhibited by animals to fend off
predators and competitors.
o It is a way to protect young and to protect food sources.
o Animals of the same species will not usually fight to the
death. Usually it will be the stronger animal that will stop the
fighting when the weaker animal shows signs of submission.
TERRITORIAL BEHAVIOR
MIGRATORY BEHAVIOR
o Migratory Behavior:
o Migration is the instinctive, seasonal movement of a
species.
o Over half of the birds that nest in the United States fly
south for the winter.
o Many head to South America where food is more
abundant during the winter months. Then they fly
north in the spring to breed.
o Animals use various environmental cues to navigate
during migration.
o Scientists believe that some species use
geographical clues such as mountain ranges.
o Other species use the Earth’s magnetic field.
MIGRATORY BEHAVIOR
LEARNED BEHAVIOR
o
o
o
o
Habituation
Imprinting
Mechanical Defense
Chemical Defense
HABITUATION
o Habituation:
o Learned behavior that occurs when an animal is
repeatedly given a stimulus that is not harmful and
does not have a negative impact on the animal.
o Examples:
o Feral horses learn to allow people to ride them.
o Deer have learned to come into yards to feed with
no fear of people or barking dogs.
IMPRINTING
o Imprinting:
o A process whereby a young animal follows the
characteristics of his/her mother after hatching
o Examples:
o A young chick after hatching can follow his/her
mother and adapt to the environment where his/her
mother goes, and also the movement of his/her
mother. Is like doing what the mother does.
o A young goose after hatching can follow its future
mating partner and when gets matured it will start to
mate with its partner due to sexual behavior it
imprinted.
ADAPTATIONS FOR DEFENSE
o Most species of plants and animals have adaptations that
serve as a defense against a predator. They fall into two
categories:
o Mechanical Defense
o Chemical Defense
MECHANICAL DEFENSE
o Mechanical Defense:
o Incorporated into the physical structure of the organism
o Examples: claws, sharp ivory tusks, stingers, shells,
camouflage, disruptive coloration, and
countershading
CHEMICAL DEFENSE
o Chemical Defense:
o occurs when the animal produces stinging sensations,
paralysis, poisoning, or just a bad taste.
TROPISMS
0 Plants possess mechanisms that enable
them to respond to their environment. These
responses are known as tropisms
0 There are several types of tropisms:
Geotropism or gravitropism—a plant’s response to
gravity
Phototropism—a plant’s response to light
Thigmotropism—a plant’s response to touch
GEOTROPISM/GRAVITROPISM
o Geotropism or gravitropism is the response of seedlings to
the force of gravity.
o It is important when seeds are sprouting.
o Geotropism causes the roots to grow downward and the
stems to grow upward, no matter what the position of the
seed when it is planted.
PHOTOTROPISM
o Phototropism is the ability of the plant to respond to
light.
o If a plant is placed near a window or another light
source, the plant will grow in the direction of the light
source.
o A phototropic response can happen so quickly that even
a seedling will respond within a few hours.
THIGMOTROPISM
o Thigmotropism is the response of a plant to touch.
o Climbing plants, ivy, and vines use thigmotropism in
order to find their way up or around a solid object for
support.
o It is also used by some plants for protection.
TYPES OF HORMONES
o Auxins:
o Responsible for regulating phototropism in a plant by
stimulating the elongation of cells. The cells on the
auxin-rich shaded side of a stem will grow longer than
the cells on the other side, causing the stem to bend
toward the light. High concentrations of auxin help
promote the growth of fruit and minimize the falling off
of fruit from the plant. When auxin concentrations
decrease in the autumn, the ripened fruit will fall. The
plants will begin to lose their leaves
TYPES OF HORMONES
o Gibberelins:
o Growth hormones that cause plants to grow taller.
o They also increase the rate of seed germination and bud
development.
o There are certain tissues in the seeds that release large
amounts of gibberellins to signal that it is time to
sprout.
TYPES OF HORMONES
o Abscisic Acid :
o Inhibits plant growth and cell division during times of
stress, such as cold temperatures or drought.
o scientists have found that it is the balance of different
hormones that determines the plant growth, rather than
one hormone by itself.
EXAMPLES OF PLANT
ADAPTATIONS
o Adaptations help plants survive adverse conditions in their
environment
o Seeds of many plants will go dormant in unfavorable
conditions.
o The leaves of conifers such as pine trees have a waxy
coating over them to reduce evaporation and to
conserve water.
o The bark on conifers is thick, helping to insulate the
tissues from fire.
o The branches of the conifers are flexible, allowing for
them to bend instead of break under the weight of ice
and snow
EXAMPLES OF PLANT
ADAPTATIONS
o Adaptations for reproduction
o flowers can be pollinated in many ways including wind,
insects, birds, or other animals.
o Maple trees produce seeds that are shaped like
wings and are carried over long distances by the
wind.
o Some plants produce seeds that have hooks or barbs
on them that attach to the fur of passing animals.
o Many flowers are brightly colored and fragrant, to
draw attention of insects that aid in pollination.
Pollen will rub off on the insect and then is carried
to another flower.