Exam 7 part 1

Question 1

Species composition

Answer 1

the identity of all species in a community

Question 2

species abundance

Answer 2

the total number of individuals - can be measured at a community or species level

Question 3

Species richness

Answer 3

total number of species regardless of abundance

Question 4

species evenness

Answer 4

relative commonness or rarity of a species compared to the other species in the community

Question 5

species diversity

Answer 5

a weighted measure that incorporates a species relative abundance as well as its presence or absence; combo of evenness and richness

Question 6

What factors determine the distribution and abundance of species (community ecology)?

Answer 6

Selection, drift, dispersal, speciation/history

Question 7

selection

Answer 7

fitness, niche, deterministic factors

Question 8

intraspecific factors

Answer 8

physiology (abiotic limits) behavior density dependent mortality

Question 9

interspecific interactions

Answer 9

competition, consumption, mutualism, commensalism, predation

Question 10

drift

Answer 10

random factors, stochasticity

Question 11

dispersal

Answer 11

movement within and between systems

Question 12

speciation/ history

Answer 12

rise of new species, historical factors

Question 13

Vellend’s theory of Community Ecology

Answer 13

species are added to communities via speciation and dispersal
Relative abundances of these species are then shaped by selection drift and ongoing dispersal, which collectively drive community dynamics

Question 14

Deterministic factors

Answer 14

lead to non random, predictable patters over time

Question 15

fundamental niche

Answer 15

is the resources it uses or conditions it tolerates in the absence of species interactions

Question 16

realized niche

Answer 16

is the resources it uses or conditions it tolerates in the presence of species interaction

Question 17

Intraspecific factors limiting distribution and abundance of organism

Answer 17

abiotic factors, density dependent mortality(caused by intraspecific competition), behavior

Question 18

Interspecific factors limiting distribution and abundance of organisms

Answer 18

commensalism (0,+) Competition (-,-) mutualism (+,+) consumption (+,-)

Question 19

Why are commensalims hard to prove

Answer 19

it can be very conditional

Question 20

Gause’s competitive exclusion principle

Answer 20

complete competitiors cannot exist

Question 21

niche differentiation/resource partitioning

Answer 21

change in resource use due to niche overlap

Question 22

character displacement

Answer 22

An evolutionary change in species traits (Galapagos finches)

Question 23

Constitutive Defenses

Answer 23

standing defenses, always present, expensive in terms of energy and resources

Question 24

Inducible defenses

Answer 24

produced only in response to presence of predator, more efficient but slower

Question 25

mimicry

Answer 25

the close resemblance of one species to another