1'2 Ecosystems

1
1.2 Ecosystems

• Ecosystem a part of a biome in which abiotic
  (non-living) factors interact with biotic
  (living) components
• Can be many hectares of land, or the size of an
  old log.
• Within an ecosystem, there are many habitats.

The habitat of the red fox often includes the
edges of forests or marshlands
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Abiotic Interactions in Ecosystems

• It is the abiotic components that allow the
  biotic components to survive in an ecosystem.
• Abiotic factors include
• Oxygen - produced by green plants
  micro-organisms.
• Water - necessary for all life.
• Nutrients - for growth.
• Light - required for
• photosynthesis.
• Soil - contains water
• nutrients.

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Biotic Interactions in Ecosystems

• Community all organisms that interact within an
  ecosystem.
• Population all members of a certain species
  within an ecosystem.
• Species all organisms within an ecosystem that
  have the same structure who can
• reproduce with each other (and
• produce fertile offspring).

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• Species can have many types of relationships in a
  population.
• Symbiosis refers to the interaction between the
  members of two different species.
• Commensalism - one species benefits, one is not
  affected
• For example, the barnacles on a whale
• Mutualism - both species benefit
• For example, a bee gathering nectar from a
  flower
• Parasitism - one species benefits, the other is
  harmed
• For example, hookworm living in dogs

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Niches, Competition and Predation

• Niche the role an organism has within an
  ecosystem.
• also refers to the environment in which a species
  prospers
• Competition occurs when a limited resource is
  desired by 2
• or more individuals in a niche.
• this limits the size health of individual
• organisms, perhaps the population .
• Predation the relationship between the
• eaters the eaten.
• Predators have adaptations to help them catch
  prey.
• Prey have adaptations to help avoid predators.
• Eg. spines shells, camouflage and mimicry.

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Biodiversity in Ecosystems

• Biodiversity the variety number of different
  individuals species in an ecosystem.
• Healthy ecosystems generally have high
  biodiversity.
• Most biodiversity losses occur from the loss of
  habitat.
• Humans often have a negative
• impact on biodiversity.
• Ecological management
• programs try to balance
• human progress with
• maintaining biodiversity.

Take the Section 1.2 Quiz