Ecological Niche

1
Ecological Niche
2
Ecological niche

• The ecological niche describes the role an
  organism plays in its environment. It consists
  of
• The species habitat.
• The organisms activity, the period of time it is
  active.
• The resources it obtains from the environment.
• Eg. A pukeko lives in marsh areas. It feeds of
  small insects and grasses.

3
Fundamental niche and realised niche

• The fundamental niche of a species includes the
  total range of environmental conditions that are
  suitable for existence without the influence of
  interspecific competition or predation from other
  species. The realized niche describes that part
  of the fundamental niche actually occupied by the
  species.

4
Niche differences

• Organisms can be identified as either
• Generalists
• Organisms with a broad niche
• Eat lots of types of food
• Live in many types of environments
• Eg. house mice
• Specialists
• Organisms with a narrow niche
• Eat a narrow range of food items
• Live in few, specific types of habitats
• Eg. panda bear

5
Law of tolerance

• The law of tolerance states that for every
  abiotic factor, an organism has a range of
  tolerance within which it can survive.

6
Habitat

• The habitat provides the organism with the
  following resources
• Mating sites
• Food and water
• Nesting sites
• Shelter from climate extremes
• Predator avoidance
• Organisms may or may nit have the adaptations to
  exploit all the available resources successfully.

7
What determines where species can live?

• All species have requirements for many
  factors/conditions.
• Abiotic factors non-living factors ex.
  temperature, precipitation, pH
• Biotic factors other species ex. prey species,
  competing species
• For each of these factors, species exhibit a
  range of tolerance.
• For example, a fish species may only be found
  within a pH range of 4.5 to 6 in lakes.

8
Competition

• When two species use the same resources, they are
  said to compete and their interaction
  competition.
• ex. lions and hyenas compete for food in Africa
• Competition does not necessarily involve contact
  interaction may be only by means of effects on
  the resources.
• No two organisms can occupy exactly the same
  niche at the same time