Ecology

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Ecology
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The Biosphere

• What is Ecology?

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Ecology

• Definition - the study of interactions among
  organisms and between organisms in their
  environment

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Levels of organization

• A single member of a species is known as an
  individual
• Populations are groups of individuals
• Communities are grouping of different populations
• An ecosystem includes a community and its
  surroundings
• A biome is a group of ecosystems with the same
  type of climate
• A biosphere would be the entire planet

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The Biosphere

• Energy Flow

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Producers

• Q What do we call organisms that make their own
  food?
• A Autotrophs
• Q What process do plants undergo to make their
  own food?
• A Photosynthesis
• Q Whats the equation for photosynthesis?
• A 6CO2 6H2O sunlight ? C6H12O6 6O2

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Consumers

• Q What do we call an organism that consumes its
  food?
• A Heterotroph
• There are four types of heterotrophs, depending
  on where the organisms energy (i.e. food) comes
  from
• Carnivores
• Herbivores
• Omnivores
• Decomposers

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Consumers

• Q Where does a carnivore get its energy?
• A From meat only
• Q What are some examples of carnivores?
• A Lion, cheetah, jaguar, leopard

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Consumers

• Q Where does an herbivore get its energy?
• A Only vegetables/grains/fruits, etc (i.e.
  non-meat eater)
• Q What are some examples of herbivores?
• A Deer, rabbits, horses, zebra

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Consumers

• Q Where does an omnivore get its energy?
• A From both meat and vegetables/grains/fruit,
  etc
• Q What are some examples of omnivores?
• A Bears, chimpanzees, pigs, various birds

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Consumers

• Q Where does a decomposer get its energy?
• A From breaking down dead organic matter
• Q What are some examples of decomposers?
• A Bacteria, fungi (mushrooms), earthworms

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Food Chains

• The levels of a food chain include
• First level producer autotroph that makes
  food
• Second level primary consumer herbivore that
  eats producer
• Third level secondary consumer carnivore that
  eats herbivore
• Fourth level tertiary consumer carnivore that
  eats secondary consumer

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Food Chains

• Ex
• Producer grass that photosynthesizes
• Primary consumer rabbit that eats the grass
• Secondary consumer fox that eats the rabbit
• Tertiary consumer wolf that eats the fox

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Food Chains

• Energy flows through an ecosystem in one
  direction, from the sun or inorganic compounds to
  autotrophs (producers) and then to various
  heterotrophs (consumers)
• Energy is transferred by organisms eating and
  being eaten
• Energy transfer is represented by arrows going in
  the direction of the energys movement

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Food webs

• A food web links all the food chains in a
  ecosystem together
• More complex interactions than unidirectional
  flow of food chains
• In reality, the interactions between predators
  and prey in an ecosystems exists as a food web
  instead of a food chain

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Tertiary Consumer
Secondary Consumer
Primary Consumer
Producer
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Energy Pyramids

• Each step in the food chain is called a trophic
  level
• Producers are the first trophic level
• Consumers make up the second, third or higher
  trophic level

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Energy Pyramid
Amount of energy available in this tropic level

• Energy pyramid only 10 of energy is
  transferred from one trophic level to the next
• Energy is used up by the organisms metabolism
  and/or released as heat

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Please do Ecology Vocabulary Crossword,
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Ecosystems and Communities

• The Role of Climate

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Biotic vs. Abiotic factors

• Biotic factor influences/interactions of living
  organisms
• Abiotic factor physical, non-living influence
  that affect an ecosystem
• Q What are some biotic factors that affect a
  forest?
• A Birds, insects, deer, grass, trees
• Q What are some abiotic factors that affect a
  forest?
• A Temperature, precipitation, wind, soil type

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Biotic vs. Abiotic Factors
Abiotic Factors
Biotic Factors
Biotic Abiotic Factors Together Ecosystem
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Community Interactions

• Competition
• Predation
• Symbiosis
• Mutualism
• Commensalism
• Parasitism

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Competition

• Definition organisms of the same or different
  species attempt to use the same ecological
  resource
• Competitive exclusion principle no two species
  can occupy the same niche in the same habitat at
  the same time one species will outcompete the
  other
• Niche range of physical and biological
  conditions in which an organism lives and the way
  in which the organism uses those conditions

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Predation

• Definition one organism captures and feeds on
  another
• Predator benefits, prey does not

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Symbiosis

• Definition close, long-term relationship
  between two organisms
• There are 3 kinds
• Mutualism
• Commensalism
• Parasitism
• Notes on chart
• Examples PowerPoint

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Mutualism

• Definition both species benefit, neither
  species is harmed
• Ex flowers and pollinating insects
• Q How do flowers benefit?
• A Insects carry pollen to another plant
• Q How to insects benefit?
• A Consume nectar of flower

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Commensalism

• Definition one member benefits, the other is
  neither helped nor harmed
• Ex barnacles on whales
• Q How do the barnacles benefit?
• A They get a place to live!
• The whale is neither helped nor harmed by the
  barnacles

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Parasitism

• Definition one organism benefits, the other
  organism is harmed
• The parasite normally lives on (tick) or in
  (tapeworm) the host
• Ex mosquito on human
• Q How does the mosquito benefit?
• A Sucks the blood from human
• Human is harmed transmission of disease

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Populations

• How Populations Grow

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Characteristics of Populations
Population Growth
can be
represented by
characterized by
characterized by
represented by
which cause a
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Population Growth

• Three factors affect population size
• 1. Number of births
• 2. Number of deaths
• 3. Number of individuals that enter or leave pop.
• Immigration into area
• Emigration out of area

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Exponential Growth

• Under ideal conditions with unlimited resources,
  a population will grow exponentially
• Population increases indefinitely without
  stopping

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Logistic Growth

• As resources become limited, the growth of a
  population slows or stops
• Carrying capacity (K) largest number of
  individuals a given environment can support
• Once the population reaches its carrying
  capacity, the population size stays the same

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Practice Problem

• Q What type of growth is depicted in this graph?
• A Logistic
• Q Whats a carrying capacity?
• A Maximum number of organisms an environment can
  support

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Practice Problem

• Q Whats the carrying capacity of this
  population?
• A Around 65 rabbits
• Q When did this population reach its carrying
  capacity?
• A Around August 1

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Practice Problem

• Q What should be the title for the x-axis?
• A Months
• Q What might be a good title for this graph?
• A Logistic growth of a population of rabbits
  over 5 months

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Practice Problem

• Q Do you see a problem with the scale on the
  x-axis?
• A July isnt included!

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Populations

• Limits to Growth

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• Imagine a small island that has a population of
  five rabbits. Does how the factor affects the
  rabbits depend on the size of the population, or
  will the factor affect the rabbits in the same
  way, regardless of the population size?
• a. climate
• b. food supply
• c. predation
• Now imagine another small island that has a
  population of 500 rabbits. How would the same
  factors affect this population?
• Which of the factors depend on population size?
  Which factors do not depend on population size?

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Limiting Factors

• Limits to Growth
• Density-Dependent Factors limiting factor that
  depends on the populations size
• Predation (predator-prey relationships), food
  supply
• Disease
• Density-Independent Factors limiting factor
  that affects all populations in a similar way,
  regardless of the population size
• Weather, natural disaster
• Seasonal cycles

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Please do Deer Predation or Starvation Lab
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Density-Dependent Factor

• Predator-prey relationship
• Q What happens to the wolf population
  (predators) with an increase in deer population
  (prey)? Why?
• A Wolf population increases because their food
  source, deer, increased
• Q What happens to the deer population in
  response to an increase in wolf population? Why?
• A Deer population decreases because there are
  more wolves to hunt the deer

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Density-Dependent Factor

• Predator-prey relationship
• Q What happens when the deer population
  decreases?
• A The wolf population decreases because they
  dont have as much food (deer)
• Q What happens when the wolf population
  decreases?
• A The deer population increases because they
  dont have as many predators (wolves)
• Cycle/relationship between predator (wolf) and
  prey (deer)

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Density Independent

• Affect all populations in similar ways regardless
  of the population size
• Unusual weather, natural disasters, seasonal
  cycles
• Some human activities cutting down forests,
  damming rivers etc.

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Coevolution

• Definition- a long term change that takes place
  in two species because of their close
  interactions with one another.
• Examples
• Acacia tree and ants
• Flowers and pollinators (e.g., hummingbirds long
  beak and nectar)
• Newts and garter snakes- see videos
• Newt humor
• Newt versus garter snake