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1

Succession occurs in a community when

species replace each other over time.

2

the process by which the species composition of a community changes over time.

Succession

3

each stage of community change during succession.

Seral stage

4

the earliest species to arrive at a site; typically are able to disperse long distances & arrive quickly at disturbed sites

Pioneer species

5

: the final seral stage in the process of succession; generally composed of organisms that dominate in a given biome.

Climax community

6

how long can succession in a community take

weeks or months or hundreds of years

7

the clearest way to record succession in a community.

Direct observation of changes over time

8

What are the assumptions when using a chronosequence to document succession?

Various sites have similar abiotic conditions
The sites pass thru the same stages of growth


9

a sequence of communities that exist over time at a given location.

Chronosequence

10

can be used to identify the age of the pollen in each layer, and helps to determine the changes in plant species composition around the lake over hundreds or thousands of year

Carbon dating

11

the development of communities in habitats that are initially devoid of plants and organic soil, such as such dunes, lava flows, and bare rock.

Primary succession

12

examples of primary succession

Glacial retreat
Roads
Gravel pads in tundra
Strip mines
Sea cliff
Landslides
Volcanic islands
Colonization of lava fields
Bog succession

13

Secondary succession occurs

in a habitat that has organic soil but no plants.

14

the development of communities in disturbed habitats that contain no plants but still contain organic soil (e.g., plowed fields, forests uprooted by a hurricane

Secondary succession

15

secondary succession examples

Fallow farmland
Fallow pastureland
Treefall / canopy opening
Area cleared by fire
Slash & burn farming
Cleared forest
Flood
Dieback
Pest outbreak

16


The use of chronosequences assumes that

older and younger sites pass through similar seral stages

17

The best approach to analyzing succession is to use

chronosequences, pollen records, and long-term studies of single sites.

18

Streams undergo rapid succession because

organisms can move downstream from sites that are less disturbed.

19

What is the difference in the classic and modern explanations for the succession of ponds and lakes?

Succession in the modern model is attributed to periods of extended drought.

20

When a community experiences succession, which is a common pattern of change in species richness?

increase, plateau, decline

21

During succession, species richness

increases rapidly at first, followed by a plateau and a small decline.

22

Which would be a characteristic of an early-succession species?

low shade tolerance

23

a mechanism in which one species increases the probability that a second species can become established.

Facilitation

24

a mechanism in which one species decreases the probability that a second species will become established (e.g., by competition, predation, or parasitism).

Inhibition

25

when can inhibition can prevent movement toward a climax community.

Early in succession

26

when can inhibition can prevent pioneer species from colonizing and surviving.

Late in succession

27

we typically observe changing environmental conditions and a progression from small to large life forms when

succession occurs

28

Why are transient climax communities not stable?

frequent disturbances

29

a climax community that is not persistent; occurs when a site is frequently disturbed so a climax community cannot persist.

Transient climax communities

30

Small-scale disturbances in an area with a climax community can allow

growth of species that are not considered climax species