*Ecological Succession

Ecological
Succession

Succession is a series of gradual changes that occur
in a community following a disturbance.
There are two types of succession.

PRIMARY SUCCESSION

Pioneer Species:
first organisms to
colonize an area
where there are no
other living things.
Ex. Lichen

Climax Community:
the final stage of
succession; the most
stable stage.

**takes more time to recover**

No soil is present
after the
disturbance.

Examples: glaciation, landslides, paved areas (abandonment), and volcanic eruptions (new
volcanic rock forms).

*Succession applies to animals too, not just to vegetation.*

SECONDARY SUCCESSION

**takes less time to recover**

Climax Community:
the final stage of
succession; the most
stable stage.

Soil is still present
even after the
disturbance.

Examples: fire, tornadoes, floods, windstorms, and volcanic
eruptions (no new volcanic rock forms).

*Succession applies to animals too, not just to vegetation.*

Multiple Choice

After a wheat field is cleared, wild grasses and weeds begin growing. This process is considered —

• primary succession because pioneer species appear

• primary succession because there are no large trees

• secondary succession because soil is already present

• secondary succession because the field contains inorganic matter

Multiple Choice

During secondary succession, which of these best describes why decomposing pioneer plants give way to larger, more complex plants species, such as hardwood trees?

• Increased amounts of sunlight are able to reach the ground while the pioneer species are decomposing.

• Increased soil temperatures from decomposing pioneer species help tree seeds germinate more quickly.

• Increased amounts of decomposing pioneer species remove nutrients that tree seedlings need to grow and mature.

• Increased amounts of soil from decomposing pioneer species allow plants with more extensive root systems to become established.

BIODIVERSITY: the variety of life in a particular
ecosystem.
Quadrat Sampling is often used for
estimating populations that have limited
or no movement.

Mark-Recapture Method is often used for
estimating populations that are mobile.

Species Diversity

Time (years)

Climax Community

Low Biodiversity

From Ants to Grizzlies: A General Rule for Saving

Biodiversity

Quadrat Sampling is often used for estimating populations that have limited or no movement.

Multiple Choice

Sand dunes along the coast are formed of bare sand. Eventually, grasses take root on the dunes. Over time, larger plants such as shrubs and trees are able to grow at the edge of the sand dune ecosystem. This gradual change in plant communities of a sand dune ecosystem can result in —

• reduced symbiotic relationships between producers and bacteria

• reduced energy absorption by consumers

• greater erosion rates

• greater species diversity

BIOMES

AQUATIC BIOMES & ADAPTATIONS

●Adaptations are traits that help an
organism survive in its environment.

●Different biomes require different
adaptations.

TERRESTRIAL BIOMES & ADAPTATIONS

●Adaptations are traits that help an
organism survive in its environment.

●Different biomes require different
adaptations.

Effects of Latitude and Altitude

THE END