Download Interactions in the Ecosystem Habitats and Niches

Interactions in the
Ecosystem
Habitats and Niches
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Habitat- The place within an ecosystem where an
organism lives. Ex. Forest, mountains, etc.
Niche- The role of an organism in the ecosystem
(what it does in the habitat, Ex. how it obtains food)
Competitive Exclusion

2 species that eat the same thing cannot share
the same area. 1 will exclude the other.
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Ex. If 2 lizard species eat the same size of insect,
they will compete for the insects of that size in
places where they live together. If one species is
better at catching the insects, the other species will
not get enough food and eventually die (or become
extinct).
Fundamental niche

Species A can survive in both higher and lower
areas of a cliff, but species B can only survive
in the lower area because it is at risk of drying
out and needs the water. If B is removed A will
move on down the cliff to where B was. A was
limited to an area by B. This is the niche it
could use. The niche it actually used is called
it’s realized niche.
Nich diversity
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Biotic factors-living parts of the environment
(plants, birds, insects, mushroom, and etc)
Abiotic factors-nonliving parts of the
environment (water, soil, air, temp, wind, and
sunlight)
Marsh not diverse
Desert more diverse- lots of different abiotic
factors.
Predator vs. Prey
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Hunter or Huntee
Predators increase diversity by decreaseing the
population size of the prey species, thus creating
another niche.
Specialized vs. Generalized Species
Carrying Capacity

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The # of individuals of a
species that can be
supported by an ecosystem
Reasoned that if the human
population continued to
grow unchecked, sooner or
later there would be
insufficient living space
and food for everyone
Malthus
Population Growth

Exponential growth of a population is
represented by an S-curve.
Limiting Factors
forces that slow the growth of a population
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Density-dependent: depends on population size;
food supply, predation, disease and are related to
competition and other interactions between
organisms Represented by an S-curve
Density-independent: does not matter about the
size of the population;
fires, hurricanes, tornados
Represented by a
boom-and-bust curve