Chapter 52

Question 1

Interaction types among species in a community

Answer 1

1. Commensalism: when one species benefits but the other species in unaffected
2. Competition: when individuals use the same resources - results in lower fitness for both
3. Consumption: when one organism eats or absorbs nutrients from another - increases consumer’s fitness but decreasing the victim’s fitness
4. Mutualism: when two species interact in a way the congers fitness benefits to both

Question 2

Intraspecific competition

Answer 2

density-dependent competition

Question 3

interspecific competition

Answer 3

when members of different species use the same limiting resources
-can be divided into direct and indirect

Question 4

niche

Answer 4

a range of resources and conditions that species deals with
-overlap in niches leads to competition

Question 5

Fundamental niche

Answer 5

the total theoretical range of environmental conditions that a species can tolerate

Question 6

Realized Niche

Answer 6

the portion of the fundamental niche that a species actually occupies, given limiting factors - competition with other species

Question 7

Fitness trade-offs in competion

Answer 7

Ability to compete trades off with ability to withstand other factors

Question 8

Niche differentiation

Answer 8

natural selection selects against individuals that compete

Question 9

Herbivory

Answer 9

the consumption of plant or algal tissues by herbivores

Question 10

Predation

Answer 10

the killing and consumption of most or all of another individual by a predator

Question 11

Endoparasites

Answer 11

Live inside a host’s body and are usually simple and wormlike

Question 12

Ectoparasites

Answer 12

live outside of hosts and typically have adaptations for harvesting fluids from host

Question 13

Parasitoids

Answer 13

free living as adults but have endoparasitic larvae - usually fatal to hosts

Question 14

Constitutive or Standing defenses

Answer 14

defenses that are always present
-cryptic coloration and object resemblance
-Escape behaviour
-toxins and other chemicals
-schooling flocking
-defense armor and weapons

Question 15

Mimicry

Answer 15

the close resemblance of one species to another
-Batesian Mimicry: when nontoxic prey species resemble dangerous prey species. One species benefits
-Mullerian mimicry: when two harmful prey species resemble each other - Both benefit

Question 16

Inducible defenses

Answer 16

traits produced in response to the presence of a predator
-less costly but take time - chemical, physical, behavioral

Question 17

Attributes of community structure

Answer 17

1. The total number of species
2. the general types and outcomes of interactions among all species
3. the relative abundance of those species
4. they physical aspects that matter

Question 18

Bottom-up influences on a food web

Answer 18

from plants/algae up the food chain

Question 19

Top down influences on a food web

Answer 19

primary by predators down the food chain

Question 20

Ecosystem engineers in food web

Answer 20

make habitats for other animals in web

Question 21

Trophic cascade

Answer 21

when impacts in a food web propagate down the web

Question 22

Disturbance

Answer 22

any strong, short-lived disruption to a community that changes the distribution of living or nonliving resources

Question 23

What factors is a disturbances impact a function of

Answer 23

1. type of disturbance
2. frequency of disturbance
3. severity of disturbance

Question 24

Primary Succession

Answer 24

organisms colonize bare mineral soil

Question 25

secondary succession

Answer 25

the soil is already present
-faster recovery than primary succession

Question 26

Steps of secondary succession in temperate forests

Answer 26

1. pioneering species: weedy species become established in disturbed soils
2. early successional community: weedy species are replaced with longer-lived herbaceous species
3. Mid-successional community: shrubs and short-lived trees begin to invade
4. climax community: long-lived trees species mature

Question 27

Development of communities after disturbances

Answer 27

early succession species:
-are short lived
-small stature
-disperse their seeds over long distances
Later species:
-long lived
-larger
-good competitors for light and nutrients

Question 28

The role of species interactions in succession

Answer 28

1. Facilitation: existing species help those that arrive
2. Tolerance: existing species of not affect the arrivals
3. Inhibition: presence of one species inhibits the success of another

Question 29

Species richness

Answer 29

the number of species present in a given community

Question 30

species diversity

Answer 30

a weighted measure that incorporates a species’ relative abundance

Question 31

What factors predict species richness on islands

Answer 31

1. the number of existing species
   -immigration vs extinction
2. Island size
   -large vs small
3. remoteness of the island
   -nearshore vs remote

Question 32

how does the size of an island effect species richness

Answer 32

-large island causes increased species richness
-small island causes decreased species richness

Question 33

How does the remoteness of an island effect species richness

Answer 33

-Remote island will decrease richness
-nearshore island will increase richness

Question 34

Global species richness patterns hypotheses

Answer 34

-high-productivity hypothesis
-area and age hypothesis
-environmental variability