Species in VARIABLE ENVIRONMENTS

Question 1

the gradual and
fairly predictable change in species
composition of an area over time.

Answer 1

Ecological Succession

Question 2

Two main types of Ecological succession

Answer 2

Primary ecological succession &
Secondary ecological succession

Question 3

The development of an ecosystem in an area that has never
had a community living within it.

Answer 3

Primary Succession

Question 4

It begins in a place without soil.

Answer 4

Primary Succession

Question 5

Example of Primary Succession

Answer 5

New lava or rock from a volcanic eruption

Question 6

are the first species to colonize a disturbed area

Answer 6

Pioneering Species

Question 7

Example of Pioneering Species

Answer 7

Lichens

Question 8

What happens during Primary Succession?

Answer 8

1. New lava or rock from a volcanic eruption
2. Pioneering Species first colonized the disturbed area
3. Simple plants like mosses begins to grow
4. Mid-successional species grow (herbs, grasses, low shrubs)
5. Larger plants, trees, and animals continue to move in
6. The Climax Community

Question 9

1. New lava or rock from a volcanic eruption
2. Pioneering Species first colonized the disturbed area
3. Simple plants like mosses begins to grow
4. Mid-successional species grow (herbs, grasses, low shrubs)
5. Larger plants, trees, and animals continue to move in
6. The Climax Community

Answer 9

Primary Succession

Question 10

Mature, stable, community that is the final stage of ecological succession.

Answer 10

The Climax Community

Question 11

Threats to Climax Communities

Answer 11

1. Forest fires
2. Human buildings, cities, and roads
3. Clearing a community for agricultural purpose

Question 12

It occurs on a surface an ecosystem has previously existed.

Answer 12

Secondary succession

Question 13

It is the process by which one community replaces another
which has partially or totally destroyed.

Answer 13

Secondary succession

Question 14

What happens during Secondary succession?

Answer 14

1. Some seeds in the soil begin to grow
2. Larger shrubs move in
3. Fast-growing trees move in, followed by slower-growing hardwood trees

Question 15

Why does Ecological
Succession Occur?

Answer 15

• Because it is the process of life for plants
and other organisms

• Organisms alter soil structure and the
species communities constantly change
over time

Question 16

Importance of Ecological Succession in Biodiversity

Answer 16

As one community of organisms is replaced by another, the variety of species within the
ecosystem changes.

Question 17

Importance of Ecological Succession in Ecosystem Stability

Answer 17

Mature ecosystems tend to be more stable and resistant to disturbances.

Question 18

Importance of Ecological Succession in Nutrient Cycling

Answer 18

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.

Question 19

Importance of Ecological Succession

Answer 19

1. Biodiversity
2. Ecosystem Stability
3. Nutrient Cycling

Question 20

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).

Answer 20

1. Pioneer species colonize a
   bare or disturbed site. Soil
   building.
2. Changes in the physical
   environment occur (e.g.,
   light, moisture).
3. New species of plants displace
   existing plants because their
   seedlings are better able to
   become established in the
   changed environment.
4. Newly arriving species
   alter the physical
   conditions
5. Climax community that is more
   or less stable will become
   established and have the
   ability to reproduce itself.
6. Disturbances will start the
   process of succession
   again.