Chapter 9 - Population Distribution and Regulation

Question 1

Case study: Explain why some islands have kelp forests, and others have urchin barrens?

Answer 1

Urchins, otters, and potentially killer whales set in motion a chain of events influencing marine ecosystems.

• Grazing by sea urchins may prevent the formation of kelp forests.
• Sea Otters as Urchin Predators
• Killer Whales decrease Sea Otter Population

Question 2

Dominant kelp species in kelp forests

Answer 2

Laminaria and Nereocystis

Question 3

the geographic area where individuals of the species are present

Answer 3

Distribution

Question 4

the number of individuals of a species that are found in a given area

Answer 4

Abundance

Question 5

Trait of populations that state distributions and abundances can change greatly over time and space

Answer 5

Dynamic

Question 6

A group of individuals of the same species that live within a particular area and interact with one another.

Answer 6

Population

Question 7

In species that reproduce sexually, a population might be defined as

Answer 7

the group of individuals that interact by interbreeding

Question 8

In species that reproduce asexually, a population must be defined by

Answer 8

Interactions aside from interbreeding (i.e. competition for food, etc.)

Question 9

Number of individuals in a population

Answer 9

Population Size

Question 10

Number of individuals per unit area

Answer 10

Population Density

Question 11

Abundances change over time and space, why/how

Answer 11

Why: Because the number of individuals in population changes over time

How: Some can migrate to other populations or because of death, birth, etc.

Question 12

Movement of organisms from one place to another

Answer 12

Dispersal

Question 13

Significance of Dispersal

Answer 13

• Connects different populations
• Maintains interactions and biodiversity
• Spatial extent of populations vary significantly

Question 14

Influences the distribution, interaction, and diversity of animal populations.

Essential for spread and survival of plant species

Answer 14

Movement

Question 15

Results from both abiotic environmental factors and human activities

Answer 15

Patchy Population

Question 16

• The product of a single fertilization event
• A genetic individual resulting from a single fertilization event
• In organisms that can reproduce asexually, it may consist of multiple, genetically identical parts, each of which has the potential to function independently

Answer 16

Genet

Question 17

An actually or potentially physiologically independent member of a genet that may compete with other members for
resources.

Answer 17

Ramet

Question 18

Groups of genetically identical individuals identified by the detachment of clonal offspring from the parent.

Answer 18

Budding

Question 19

Identification involves recognizing clonal offspring produced from unfertilized eggs or parthenogenesis.

Answer 19

Apomixis

Question 20

Groups recognized as clonal offspring are produced as the organism grows horizontally

Answer 20

Horizontal spread

Question 21

Genet and Ramet are appropriate for studying what respectively?

Answer 21

Evolutionary change and Competition among independent organisms

Question 22

The distribution and abundances of a species are limited by these three factors

Answer 22

Habitat suitability
Historical Factors
Dispersal

Question 23

Refers to the degree to which an environment provides conditions necessary for a species to thrive.

Answer 23

Habitat Suitability

Question 24

Key Abiotic factors of the environment with regards to habitat suitability

Answer 24

Climate
Soil pH
Salt concentration
Available nutrients

Question 25

Key Biotic Features of the Environment with regards to habitat suitability

Answer 25

Dependency on Other Species Exclusion by Biotic Interactions Biological Control Considerations

Question 26

Interactions Between Abiotic and Biotic Features

Answer 26

Temperature Limits Geographic distribution Competition

Question 27

An abiotic event that kills or damages some individuals in an ecosystem creating opportunities for other individuals to grow and reproduce

Answer 27

Disturbance

Question 28

T/F Earth's Evolutionary and Geologic History significantly influences current distribution of organisms.

Answer 28

True

Question 29

Occurs when a species' limited capacity for dispersal prevents it from reaching suitable habitats

Answer 29

Dispersal Limitation

Question 30

T/F Dispersal is not influenced by population density.

Answer 30

False, it is

Question 31

Entire geographic region over which a species is found. Includes the areas it occupies during all of its life stages.

Answer 31

Geographic Range

Question 32

Spatial arrangement, of individuals within a population

Answer 32

Dispersion

Question 33

3 Basic Patterns of Dispersion

Answer 33

1. Regular 2. Random 3. Clumped

Question 34

Dispersion where individuals are relatively evenly spaced through their habitat

Answer 34

Regular dispersion

Question 35

Dispersion individuals were positioned at locations selected at random

Answer 35

Random dispersion

Question 36

Most common distribution, Individuals of a species are unevenly distributed throughout their habitat occurring in clustered group or patches

Answer 36

Clumped Dispersion

Question 37

The most direct way to determine how many individuals live in a population

Answer 37

Count all of them

Question 38

Actual abundance

Answer 38

Absolute population size

Question 39

Number of individuals in one time interval or place relative to the number in another

Answer 39

Relative Population Size

Question 40

To estimate the population sizes of immobile organisms Organisms are counted in a series of sample plots, or quadrats, and the resulting numbers are used to estimate the total population size.

Answer 40

Area-Based Counts

Question 41

Estimates of abundance based on various measurements of distance from a point or line. Each individual that the observer can see from the line is counted, and its perpendicular distance from the line is recorded.

Answer 41

Distance methods

Question 42

must be used to convert such distance measurements into an estimate of the absolute population size.

Answer 42

Detection Function

Question 43

Relies on releasing marked individuals and then recapturing them at a later time to see what fraction of the population is marked.

Answer 43

Mark-Recapture studies

Question 44

A tool that predicts a species' geographic distribution based on the environmental conditions at locations the species is known to occupy.

Answer 44

Niche model