Population Dynamics over Space and Time

Question 1

fluctuations

Answer 1

random and cyclic changes through time due to factors such as availability of resources, predation, competition, disease, parasites, and climate

Question 2

smaller organisms reproduce

Answer 2

faster so their populations often respond faster to favorable and unfavorable conditions

Question 3

larger organisms

Answer 3

have a lower surface-area-to-volume ration, which allows them to maintain homeostasis when faced with unfavorable environmental change

Question 4

overshoot

Answer 4

when a population grows beyond its carrying capacity; often occurs when the carrying capacity of a habitat decreases from one year to next (because less resources are produced)

Question 5

die-off

Answer 5

a substantial decline in density that typically goes well below the carrying capacity
-occur when a population overshoots its carrying capacity

Question 6

population cycles

Answer 6

regular oscillation of a population over a longer period of time
-some populations can exhibit highly regular fluctuations in size

Question 7

cyclic populations

Answer 7

can occur among related species and across large geographic areas

Question 8

delayed density dependence

Answer 8

when a density dependence occurs based on a population density at some time in the past

Question 9

damped oscillations

Answer 9

a pattern of population growth in which the population initially oscillates but the magnitude of the oscillations declines over time

Question 10

stable limit cycle

Answer 10

a pattern of population growth in which the population continues to exhibit large oscillations over time

Question 11

deterministic model

Answer 11

designed to predict a result without accounting for random variation in population growth rate

Question 12

stochastic model

Answer 12

a model that incorporates random variation in population growth rate; assumes that variation in birth and death rates is due to random chance

Question 13

demographic stochasticity

Answer 13

variation in birth rates and death rates due to random differences among individuals

Question 14

environmental stochasticity

Answer 14

variation in birth rates and death rates due to random changes in the environmental conditions (weather)

Question 15

metapopulation

Answer 15

a set of local populations linked by dispersal
-exist with a balance of colonization and extinction

Question 16

each subpopulation has its own independent

Answer 16

• birth rate
• death rate

Question 17

habitat fragmentation

Answer 17

the process of breaking up large habitats into a number of smaller habitats
(can happen from clearing forests, road construction, etc.)

Question 18

basic metapopulation model

Answer 18

assumes that all habitat patches are in equal in quality and that the matrix between patches is inhospitable

Question 19

source-sink model

Answer 19

assumes quality differences between patches

Question 20

sources

Answer 20

high quality patches that produce a large number of individuals that disperse to other patches

Question 21

sinks

Answer 21

low quality patches that produce few individuals and rely on dispersers to keep the sink population from going extinct

Question 22

landscape model

Answer 22

considers that the quality of habitat patch can be affected by the nature of the surrounding matrix and some matrix habitat are more easily traversed than others

Question 23

rescue effect

Answer 23

when dispersers supplement a declining subpopulation and thereby prevent it from going extinct