Ch 54 Community Ecology

Question 1

community

Answer 1

group of populations of different species living in close enough proximity to interact

Question 2

ecological niche

Answer 2

the specific set of biotic and abiotic resources that

an organism uses in its environment

Question 3

species richness

Answer 3

the number of species in a community

Question 4

species abundance

Answer 4

the number of individuals per species

Question 5

species diversity

Answer 5

the number and relative abundance of species found in a given biological organisation

Question 6

diversity index

Answer 6

a quantitative measure that reflects the number of different species and how evenly the individuals are distributed among those species

Question 7

Shannon diversity index

Answer 7

equation that tells you how diverse the species in a given community are

Question 8

Diversity often varies with

Answer 8

Environmental conditions

Question 9

What influences species abundance and diversity?

Answer 9

Species interactions

Question 10

Competition

Answer 10

a -/- interaction that occurs when individuals of different species compete for a resource that limits
the survival and reproduction of each species

Question 11

Competitive exclusion

Answer 11

the inevitable elimination from a habitat of one of two different species with identical needs for resources

Question 12

Species can coexist if:

Answer 12

They use different resources

Question 13

Fundamental niche

Answer 13

the set of conditions within which a species can live in the absence of competitors

Question 14

Realized niche

Answer 14

the set of conditions actually used by given animal (pop, species), after interactions with other species (predation and especially competition) have been taken into account.

Question 15

Potential impacts of competition - 2 things

Answer 15

1. Reduced local diversity

2. Non-native species suppresses native species

Question 16

Herbivory

Answer 16

an exploitative (+/-) interaction in which an organism—an herbivore—eats parts of a plant or alga, thereby harming it

Question 17

Predation

Answer 17

a +/- interaction between species in which one species, the predator, kills and eats the other, the prey

Question 18

Parasitism

Answer 18

a +/- exploitative interaction in which one
organism, the parasite, derives its nourishment from
another organism, its host, which is harmed in the process

Question 19

ectoparasite

Answer 19

a parasite, such as a flea, that lives on the outside of its host.

Question 20

endoparasite

Answer 20

a parasite, such as a tapeworm, that lives inside its host.

Question 21

Mutualism

Answer 21

an interspecific interaction that benefits both species (+/+)

Question 22

Commensalism

Answer 22

An interaction between species that benefits one of the species but neither harms nor helps the other (+/0)

Question 23

trophic structure

Answer 23

the feeding relationships between organisms

Question 24

Food chain

Answer 24

The transfer of food energy upward from its source

Question 25

Food web

Answer 25

a group of food chains are linked together

Question 26

Facilitators

Answer 26

have positive effects on survival & reproduction of other species

Question 27

Facilitation

Answer 27

describes species interactions that benefit at least one of the participants and cause harm to neither

Question 28

Succession

Answer 28

The disturbed area may be colonized by a variety of species, which are gradually replaced by other species, which are in turn replaced by still other species

Question 29

Plant succession

Answer 29

changes in abiotic & biotic conditions induced by the vegetation

Question 30

Primary succession example

Answer 30

Glacier retreating

Question 31

Process of plant succession - 3 steps

Answer 31

1. conditions shift from low nutrient/high light  high nutrient/low light
2. species colonize & change conditions
3. early-arriving species influence later-arriving species

Question 32

Secondary succession

Answer 32

occurs when an existing community has been cleared by a disturbance that leaves the soil intact, as in Yellowstone following the 1988 fires