Download Ecological Succession

ECOLOGICAL SUCCESSION
How do events and processes that occur
during ecological succession change
populations and species diversity?
Notes
Population Growth Patterns:
Populations grow in predictable patterns.
Changes in a population’s size.
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The size of a population
is always changing.
Four factors affect the
size of a population.
immigration
 births
 emigration
 deaths

Population growth is based on available
resources.

Exponential growth is a rapid population increase due to
an abundance of resources.

Logistic growth is due to a population facing limited
resources.

Carrying capacity is the maximum number of individuals in
a population that the environment can support.
 A population crash is a dramatic decline in the size of a population over a short
period of time.
Ecological factors limit population growth.

A limiting factor is something that keeps the size of a
population down.
 Density-dependent limiting factors are affected by the number of individuals
in a given area.

Density-dependent limiting factors are affected by the
number of individuals in a given area.
– predation
– competition
– parasitism and
disease

Density-independent limiting factors limit a population’s
growth regardless of the density.
– unusual weather
– natural disasters
– human activities
Ecological Succession:
Ecological succession is a process of change in the species that make
up a community. Short term or long term and depends on the
ecosystem.
Succession occurs following a disturbance
in an ecosystem.

Succession regenerates after a disturbance or creates a
community.
a sequence of biotic changes
 damaged communities are regenerated
 new communities arise in previously uninhabited areas

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There are two types of succession:
– primary succession — where no life excited before--started by pioneer
species

There are two types of succession:
– secondary succession — started by remaining species after a catastrophe.
Regenerates a community.
Pond Succession
Succession in a pond
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Never reaches climax communities
Water plants begin to grow
sediment falls into the pond and the plant’s roots
anchor the soil
Sediment will continue to fall in until the pond if
filled in with soil which will eventually lead to
grasses and trees
Succession lab hand out!