Species in VARIABLE ENVIRONMENTS Flashcards
the gradual and
fairly predictable change in species
composition of an area over time.
Ecological Succession
Two main types of Ecological succession
Primary ecological succession &
Secondary ecological succession
The development of an ecosystem in an area that has never
had a community living within it.
Primary Succession
It begins in a place without soil.
Primary Succession
Example of Primary Succession
New lava or rock from a volcanic eruption
are the first species to colonize a disturbed area
Pioneering Species
Example of Pioneering Species
Lichens
What happens during Primary Succession?
- New lava or rock from a volcanic eruption
- Pioneering Species first colonized the disturbed area
- Simple plants like mosses begins to grow
- Mid-successional species grow (herbs, grasses, low shrubs)
- Larger plants, trees, and animals continue to move in
- The Climax Community
- New lava or rock from a volcanic eruption
- Pioneering Species first colonized the disturbed area
- Simple plants like mosses begins to grow
- Mid-successional species grow (herbs, grasses, low shrubs)
- Larger plants, trees, and animals continue to move in
- The Climax Community
Primary Succession
Mature, stable, community that is the final stage of ecological succession.
The Climax Community
Threats to Climax Communities
- Forest fires
- Human buildings, cities, and roads
- Clearing a community for agricultural purpose
It occurs on a surface an ecosystem has previously existed.
Secondary succession
It is the process by which one community replaces another
which has partially or totally destroyed.
Secondary succession
What happens during Secondary succession?
- Some seeds in the soil begin to grow
- Larger shrubs move in
- Fast-growing trees move in, followed by slower-growing hardwood trees
Why does Ecological
Succession Occur?
• Because it is the process of life for plants
and other organisms
• Organisms alter soil structure and the
species communities constantly change
over time
Importance of Ecological Succession in Biodiversity
As one community of organisms is replaced by another, the variety of species within the
ecosystem changes.
Importance of Ecological Succession in Ecosystem Stability
Mature ecosystems tend to be more stable and resistant to disturbances.
Importance of Ecological Succession in Nutrient Cycling
Different plant species contribute to the nutrient content of the soil, and the cycling of nutrients
between the biotic and abiotic components of the ecosystem is crucial for sustained
productivity.
Importance of Ecological Succession
- Biodiversity
- Ecosystem Stability
- Nutrient Cycling
Rearrange the proper sequence of events
___Climax community that is more
or less stable will become
established and have the
ability to reproduce itself.
___New species of plants displace
existing plants because their
seedlings are better able to
become established in the
changed environment.
___Pioneer species colonize a
bare or disturbed site. Soil
building.
___Newly arriving species
alter the physical
conditions
___Disturbances will start the
process of succession
again.
___Changes in the physical
environment occur (e.g.,
light, moisture).
- Pioneer species colonize a
bare or disturbed site. Soil
building. - Changes in the physical
environment occur (e.g.,
light, moisture). - New species of plants displace
existing plants because their
seedlings are better able to
become established in the
changed environment. - Newly arriving species
alter the physical
conditions - Climax community that is more
or less stable will become
established and have the
ability to reproduce itself. - Disturbances will start the
process of succession
again.
