Chapter 54 Community Ecology

Question 1

an assemblage of populations of various species living close enough for potential interaction

Answer 1

biological community

Question 2

what kind of interaction is interspecific competition?

Answer 2

-/-

Question 3

strong competition can lead to ______________, local elimination of a competing spevies

Answer 3

competitive exclusion

Question 4

this states that two species competing for the same limiting resources cannot coexist in the same place

Answer 4

competitive exclusion principle

Question 5

the total of a species use of biotic and abiotic resources is called the species…

Answer 5

ecological niche

can also be thought of an organisms ecological role

Question 6

ecologically similar species can coexist in a community if there are one or more significant _________ in their niches

Answer 6

differences

Question 7

differentiation of ecological niches, enabling similar species to coexist in a community

Answer 7

resource partitioning

Question 8

the niche potentially occupied by that species

Answer 8

species fundamental niche

Question 9

the niche actually occupied by that species

Answer 9

species’ realized niche

Question 10

when both species are both normally nocturnal but one becomes diurnal

Answer 10

temporal partitioning

Question 11

a tendency for characteristics to be more divergent in sympatric populations of two species than in allopatric populations of the same two species
ex: beak sizes

Answer 11

character displacement

Question 12

effective chemical defense often exhibit bright warning coloration

Answer 12

aposematic coloration

ex: frogs

Question 13

two or more unpalatable species resemble each other

ex: yellow jacket and bee

Answer 13

mullerian mimicry

Question 14

palatable or harmless mimic resembles unpalatable mode or harmful model.
ex: coral snake and king snake

Answer 14

balesian mimicry

Question 15

not part of a plant’s primary energy-generating metabolic pathway

Answer 15

secondary metabolites

ex: nicotine, morphine, caffeine

Question 16

a relationship where two or more species live in direct and intimate contact with one another
what are the three types?

Answer 16

symbiosis

• parasitism
• mutualism
• commensalism

Question 17

what are the two types of mutualism?

Answer 17

obligate- where one species cannot survive without the other

facultative- where both species can survive alone

Question 18

one species benefits and the other is neither harmed nor helped

Answer 18

commensalism

Question 19

is an interaction in which one species has positive effects on another species without direct and intimate contact +/+ or 0/+
ex: black rush makes the soil more hospitable for other plants species

Answer 19

facilitation

Question 20

two fundamental features of community structure are species ______ and __________.

Answer 20

diversity, feeding relationships

Question 21

species diversity depends on what two factors?

Answer 21

species richness- the number of different species in the community
relative abundance- the proportion each species represents of all individuals in the community

Question 22

the ______ the value of Shannons index, the more diverse the community

Answer 22

higher

Question 23

what are the benefits of a more diverse community?

Answer 23

• more productive
• more stable
• better able to withstand and recover from environmental stresses
• more resistant to invasive species

Question 24

_________ link trophic levels from producers to top carnivores

Answer 24

food chains

Question 25

-feeding relationships between organisms in a community

Answer 25

trophic structure

-a key factor in community dynamics

Question 26

each food chain in a food web is usually only…

Answer 26

a few links long

Question 27

what are the two hypotheses that attempt to explain food chain length?

Answer 27

• the energetic hypothesis

- dynamic stability hypothesis

Question 28

the hypothesis that suggests that length is limited by inefficient energy transfer
-most data support this hypothesis

Answer 28

energetic hypothesis

Question 29

the hypothesis that proposes that long food chains are less stable than short ones

Answer 29

dynamic stability hypothesis

Question 30

• most abundant or have the highest biomass

- exert powerful control over the occurrence and distribution of other species

Answer 30

dominant species

Question 31

-exert strong control on a community by their ecological roles, or niches

Answer 31

keystone species

Question 32

• cause physical changes in the environment that affect community structure
  ex: beavers

Answer 32

ecosystem engineers

Question 33

describes communities as constantly changing after being buffeted by disturbances

Answer 33

nonequilibrium model

Question 34

what type of disturbance can foster the greatest diversity

Answer 34

intermediate *intermediate disturbance hypothesis

Question 35

disturbance that allows dominate species to exclude less competitive species

Answer 35

low level of disturbance

Question 36

disturbance that excludes many slow-growing species

Answer 36

high level of disturbance

Question 37

ealry-arriving species and later-arriving species may be linked in one of three processes…

Answer 37

• early arrivals may facilitate* the appearance of later species by making the environment favorable
• they may inhibit* the establishment of later species
• they may tolerate* later species but have no impact on their establishment

Question 38

________ pathogens have been transferred from other animals to humans

Answer 38

zoonotic

many of today’s emerging human diseases are zoonotic

Question 39

the transfer of pathogens can be direct or through an intermediate species called a…

Answer 39

vector