ECOSYSTEMS

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ECOSYSTEMS

• An ECOSYSTEM is made of all the living
  nonliving things that interact in a particular
  area
• Ecosystems can be
• large or small

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FACTORS THAT AFFECT THE GROWTH OF A POPULATION
When conditions are good, a population will
generally increase. But a population does not
keep growing forever. Eventually some factor in
its environment causes the population to stop
growing.
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LIMITING FACTORS

• LIMITING FACTORS Biotic and abiotic factors that
  prevents a population from increasing.
• Food
• Water
• Living space
• Temperature
• Predation
• Competition

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Limiting Factors

• Environmental abiotic and biotic factors can also
  be termed "Limiting Factors."
• They are limiting in that they tend to have the
  least affect on those organisms which have the
  best tolerance, or adaptation to the factor.
• At different times of the year, some abiotic
  factors take on more importance than others.
  These factors help to keep a population at or
  below carrying capacity.

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LIMITING FACTORS
FOOD WATER -When food is scarce, the
population numbers will decrease from starvation
or low birth numbers. -When food if plentiful,
numbers increase because of low death rates and
high birth rates.
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LIMITING FACTORS
SPACE -If the plant or animal does not have
enough room to reproduce and grow, the numbers
will decrease. -When space is plentiful, the
pop- ulation will increase.
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LIMITING FACTORS
CLIMATE -Conditions such as drought and
temperature changes can limit the population
growth. -Too cold, too hot, too wet, too dry all
affect population growth. Early frost can kill
many insects and plants. -Favorable weather
conditions such as seasonable temps, rainfall
etc, can increase populations.
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Predation

• Predation is the type of feeding relationship in
  which one animal captures and eats another animal
  for its food.
• Prey is eaten
• Predator captures and eats prey.

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LIMITING FACTORS
Predator/Prey Relationship Predation has a huge
effect on the size and growth of a population.
-If there are more predators or they are more
efficient at hunting techniques, then the prey
species goes down.
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Predator/Prey Continued

• -Predators affect prey species numbers and prey
  species affect predators numbers.
• As predator numbers decrease, the prey species
  numbers will increase due to less predators in
  the
• area.

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PREDATOR/PREY RELATIONSHIP
Predators directly affect the population of their
prey and the prey directly affect the population
of the predator.
How is this possible?
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PREDATOR/PREY RELATIONSHIP
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What is the carrying capacity of this ecosystem
for the rabbits? Fox?
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Name the carrying capacity of this environment
for the wolves and the moose.
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PREDATOR/PREY RELATIONSHIP
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PREDATOR/PREY RELATIONSHIP
Remember, when the prey species goes up, the
predator goes up SHORTLY THEREAFTER.
When the prey species goes down, the predators go
down, SHORTLY THEREAFTER.
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LIMITING FACTORS
COMPETITION -When two or more individuals or
populations try to use the same resources. Can
occur within populations or between populations
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Limiting Factors

• When competition for resources is high (many
  organisms fighting for the same one), populations
  will decrease.
• When competition for resources is low,
  populations will increase.

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Competition

• Competition occurs whenever more than one
  individual or populations tries to make use of
  the same limited resources.

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LIMITING FACTORS
DISEASE -When disease (fungal, parasitic,
bacterial, viral) is introduced to a population,
population numbers are affected. Only the
strongest individuals overcome the disease and
survive.-
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Limiting Factors

• Introduced Species
• Humans sometimes move organisms to a location
  where they do not belong. Sometimes they die, but
  often they prosper. If the organism has no
  predators, then its population will grow.
• An example of this occurring is the kudzu plant.
  It was transplanted to America and nothing eats
  it here.
• So, it grows out of control. This causes native
  plants to loose the space, sunlight and water
  supply they need to survive.

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Brown Tree Snake

• Shortly after World War II, and before 1952, the
  brown Treesnake was accidentally transported from
  its native range in the South Pacific to Guam,
  probably as a stowaway in ship cargo.  As a
  result of abundant prey to eat on Guam and the
  absence of natural predators and other population
  controls, brown Treesnake populations grew.
  Snakes caused the loss of most of the native
  forest vertebrate species thousands of power
  outages affecting private, commercial, and
  military activities widespread loss of domestic
  birds and pets. Most songbirds of Guam have gone
  extinct.

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Brown Tree Snake Cane Toad
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Cane Toad

• Cane toads, introduced into Australia to control
  beetles that were destroying sugarcane crops, are
  still spreading across Australia. They failed to
  control the cane beetles, and became a major pest
  themselves. Cane toads can harm native wildlife
  by eating small animals and poisoning larger
  predators that try to eat them. Household pets
  are also at risk from poisoning. So far, there is
  no known way to control cane toads across large
  areas, but scientists are searching for a
  biological control agent that is specific to the
  toads.

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Name the limiting factors in the pictures below
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CARRYING CAPACITY

• The maximum number of organisms an ecosystem can
  successfully support.

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Symbiosis

• Any close relationship between species.
  Individuals in the relationship are either
• 1. Helped 2. Unaffected 3. Harmed

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Mutualism

• A relationship in which both species benefit

Zebra oxpecker
Lichens algae fungus
Cleaner fish
www.orn.mpg.de
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Commensalism

• A relationship in which one species benefits and
  the other is neither helped nor harmed

Barnacles on whale
Shark remora
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Parasitism

• A relationship in which one organisms benefits
  and the other is harmed. The individual that
  benefits is called the parasite, the one harmed
  is called the host.

Mistletoe
Tick
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Coevolution

• The evolution of two species totally dependent on
• each other. Coevolution is an extreme example of
• mutualism.

Yucca flowers are a certain shape so only that
tiny moth can pollinate them. The moths lay their
eggs in the yucca flowers and the larvae
(caterpillars) live in the developing ovary and
eat yucca seeds.
Yucca moths and yucca plants
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Acacias are small, trees that have large, hollow
thorns. The acacia ants live in the thorns. On
the tips of its leaflets, the plant makes a
substance used by the ants as food. The ants
defend the tree from herbivores by
attacking/stinging any animal that even
accidentally brushes up against the plant. The
ants also prune off seedlings of any other plants
that sprout under their tree
Acacia ants and acacia trees
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The pollinator gets a reward such as nectar for
pollinating the plant. Insects (beetles) on the
plant found this protein/sugar mix and used it as
food. Insects became dependent on this food
source and started carrying pollen from plant to
plant. Beetle-pollination must have been more
efficient than wind for some species, so there
was natural selection for plants that attracted
insects.
Coevolution is often seen in a number of species
of flowering plants that coevolved with specific
pollinators (insects, bats, etc).
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Examples of Symbiosis
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Examples of Symbiosis
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Examples of Symbiosis
Tapeworm
Dustmite
Botfly
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Limiting Factors ORQ Proficient

• 1. 900
• 2. Food, water, space, disease, competition,
  predators, intro. New species, climate, natural
  disaster. You must DECSRIBE how the factors
  affected the population. NOT list.
• 3.The adding of a new species would decrease the
  squirrel population because they would use all of
  the resources.
• 4. Yes the Earth has a carrying capacity because
  the Earth has a limited number of resources

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Limiting Factors ORQ App. Or Novice

• 1. Got the number wrong makes it a 1 or 2.
• 2. If they just listed food, water, disease,
  climate, intro new species, disaster, space.
• If they just listed with no discussion or only
  listed one or incorrect. 1 or a 2.
• They did not say it went down. If they said it
  went up or blank, it is a 1.
• If they said the Earth had not capacity 1
• If they did not explain why - 2