Niche, Community Interactions and Succession

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Niche, Community Interactions and Succession
IN Headings Vocabulary Important words/phrases
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Niche

• A niche is the range of physical and biological
  conditions in which a species lives and the way
  the species obtains what it needs to survive and
  reproduce.

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Tolerance

• Every species has its own range of tolerance, the
  ability to survive and reproduce under a range of
  environmental circumstances.

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Tolerance

• Organisms have an upper and lower limit of
  tolerance for every environmental factor. Beyond
  those limits, the organism cannot survive.

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Tolerance

• When an environmental condition, such as
  temperature, extends in either direction beyond
  an organisms optimum range, the organism
  experiences stress.
• The organism must expend more energy to maintain
  homeostasis, and so has less energy left for
  growth and reproduction.

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Habitat

• A species tolerance for environmental
  conditions, then, helps determine its habitatthe
  general place where an organism lives.

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Niche and Resources

• The term resource can refer to any necessity of
  life, such as water, nutrients, light, food, or
  space.
• For plants, resources can include sunlight,
  water, and soil nutrients.
• For animals, resources can include nesting space,
  shelter, types of food, and places to feed.

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Physical Aspects and Niche

• Part of an organisms niche involves the abiotic
  factors it requires for survival.
• Most amphibians, for example, lose and absorb
  water through their skin, so they must live in
  moist places.

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Biological Factors and Niche

• Biological aspects of an organisms niche involve
  the biotic factors it requires for survival.
• Birds on Christmas Island all live in the same
  habitat but they prey on fish of different sizes
  and feed in different places.

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• Polar bears live in the arctic. The arctic is
  their
• a. niche.
• b. habitat.
• c. tolerance.
• d. microclimate.

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• Which of the following is a biological aspect of
  an organisms niche?
• a. the water in the area
• b. the way it gets food
• c. amount of sunlight
• d. composition of soil

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Competition

• How one organism interacts with other organisms
  is an important part of defining its niche.
• Competition occurs when organisms attempt to use
  the same limited ecological resource in the same
  place at the same time.

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Intraspecific Competition

• Competition between members of the same species.

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Interspecific Competition

• Competition between members of different species.

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Competitive Exclusion Principle

• Direct competition between different species
  almost always produces a winner and a loserand
  the losing species dies out.
• Dotted line grown separately
• Solid line grown together

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Competitive Exclusion Principle

• The competitive exclusion principle states that
  no two species can occupy exactly the same niche
  in exactly the same habitat at exactly the same
  time.

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Dividing Resources

• Instead of competing for similar resources,
  species usually divide them.

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Dividing Resources

• The resources utilized by these species are
  similar yet different. Therefore, each species
  has its own niche and competition is minimized.

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• No two species can occupy the same niche in the
  same habitat at the same time
• a. because of the interactions that shape the
  ecosystem.
• b. unless the species require different abiotic
  factors.
• c. because of the competitive exclusion
  principle.
• d. unless the species require different biotic
  factors.

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• Several species of warblers can live in the same
  spruce tree ONLY because they
• a. have different habitats within the tree.
• b. dont eat food from the tree.
• c. occupy different niches within the tree.
• d. can find different temperatures within the
  tree.

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Predator-Prey Relationships

• An interaction in which one animal (the predator)
  captures and feeds on another animal (the prey)
  is called predation.

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Predator Prey Relationships

• Predators can affect the size of prey populations
  in a community and determine the places prey can
  live and feed.
• Idealized computer model

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Herbivore Plant Relationship

• An interaction in which one animal (the
  herbivore) feeds on producers (such as plants) is
  called herbivory.

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Herbivore Plant Relationship

• Herbivores, like a ring-tailed lemur, can affect
  both the size and distribution of plant
  populations in a community and determine the
  places that certain plants can survive and grow.

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Keystone Species

• A keystone species is one whose impact on its
  community or ecosystem is disproportionately
  large relative to its abundance .

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Keystone Species

• A species whose very presence contributes to the
  diversity of life and whose extinction would
  result in the extinction of species dependant on
  it.

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Symbiosis

• The close and often long-term interactions
  between biological species.
• Mutualism
• Parasitism
• Commensalism

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Mutualism

• Also known as cooperation.
• Both organisms gain a fitness benefit.
• Ex, clown fish and anemone

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Parasitism

• Relationships in which one organism lives inside
  or on another organism and harms it.
• Generally, parasites weaken but do not kill their
  host, which is usually larger than the parasite.

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Commensalism

• A relationship in which one organism benefits and
  the other is neither helped nor harmed.
• Ex, barnacles on whale

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Succession

• Ecosystems change over time, especially after
  disturbances, as some species die out and new
  species move in.
• Ecological succession is a series of more-or-less
  predictable changes that occur in a community
  over time.

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• A symbiotic relationship in which both species
  benefit is
• a. commensalism.
• b. mutualism.
• c. predation.
• d. parasitism.

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• A symbiotic relationship in which one organism is
  harmed and the other benefits is
• a. mutualism.
• b. parasitism.
• c. commensalism.
• d. predation.

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Primary Succession

• Volcanic explosions can create new land or
  sterilize existing areas.
• Retreating glaciers can have the same effect,
  leaving only exposed bare rock behind them.

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Primary Succession

• Succession that begins in an area with no
  remnants of an older community is called primary
  succession.

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Primary Succession

• The first species to colonize barren areas are
  called pioneer species.
• One ecological pioneer that grows on bare rock is
  lichena mutualistic symbiosis between a fungus
  and an alga.

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Secondary Succession

• Sometimes, existing communities are not
  completely destroyed by disturbances. In these
  situations, secondary succession occurs.

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Secondary Succession

• Secondary succession proceeds faster than primary
  succession, in part because soil survives the
  disturbance. As a result, new and surviving
  vegetation can regrow rapidly.

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Why Does Succession Occur?

• Every organism changes the environment it lives
  in.
• One model of succession suggests that as one
  species alters its environment, other species
  find it easier to compete for resources and
  survive.

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Succession after Disturbance

• Healthy coral reefs and tropical rain forests
  often recover from storms, and healthy temperate
  forests and grasslands recover from wildfires.

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Succession after Human-Disturbance

• Ecosystems may or may not recover from extensive
  human-caused disturbances.
• Clearing and farming of tropical rain forests,
  for example, can change the microclimate and soil
  enough to prevent regrowth of the original
  community.

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• Primary succession would most likely occur after
• a. a forest fire.
• b. a lava flow.
• c. farm land is abandoned.
• d. a severe storm.

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• An example of a human-caused disturbance is
• a. a hurricane.
• b. forest-clearing.
• c. wildfires.
• d. growing lichens.

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• What is one difference between primary and
  secondary succession?
• a. Primary succession is rapid and secondary
  succession is slow.
• b. Secondary succession begins on soil and
  primary succession begins on newly exposed
  surfaces.
• c. Primary succession modifies the environment
  and secondary succession does not.
• d. Secondary succession begins with lichens and
  primary succession begins with trees.