chapter 19

Question 1

Succession occurs in a community when

Answer 1

species replace each other over time.

Question 2

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

Answer 2

Succession

Question 3

each stage of community change during succession.

Answer 3

Seral stage

Question 4

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

Answer 4

Pioneer species

Question 5

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

Answer 5

Climax community

Question 6

how long can succession in a community take

Answer 6

weeks or months or hundreds of years

Question 7

the clearest way to record succession in a community.

Answer 7

Direct observation of changes over time

Question 8

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

Answer 8

Various sites have similar abiotic conditions

The sites pass thru the same stages of growth


Question 9

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

Answer 9

Chronosequence

Question 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

Answer 10

Carbon dating

Question 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.

Answer 11

Primary succession

Question 12

examples of primary succession

Answer 12

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

Question 13

Secondary succession occurs

Answer 13

in a habitat that has organic soil but no plants.

Question 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

Answer 14

Secondary succession

Question 15

secondary succession examples

Answer 15

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

Question 16

The use of chronosequences assumes that

Answer 16

older and younger sites pass through similar seral stages

Question 17

The best approach to analyzing succession is to use

Answer 17

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

Question 18

Streams undergo rapid succession because

Answer 18

organisms can move downstream from sites that are less disturbed.

Question 19

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

Answer 19

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

Question 20

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

Answer 20

increase, plateau, decline

Question 21

During succession, species richness

Answer 21

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

Question 22

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

Answer 22

low shade tolerance

Question 23

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

Answer 23

Facilitation

Question 24

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

Answer 24

Inhibition

Question 25

when can inhibition can prevent movement toward a climax community.

Answer 25

Early in succession

Question 26

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

Answer 26

Late in succession

Question 27

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

Answer 27

succession occurs

Question 28

Why are transient climax communities not stable?

Answer 28

frequent disturbances

Question 29

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

Answer 29

Transient climax communities

Question 30

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

Answer 30

growth of species that are not considered climax species

Question 31

a successional stage that persists as the final seral stage due to periodic fires.

Answer 31

Fire-maintained climax community