Ecology Population Growth Models 5

Question 1

In a source-sink metapopulation model, a 'sink' habitat is best described as one where:

Accepted Answer

Local deaths exceed local births and the patch requires immigration to persist

Answer

Local births exceed local deaths and the patch exports individuals

Answer

Carrying capacity is exactly equal to current population size

Answer

Competition is absent and resources are unlimited

Question 2

Which population growth model assumes that the per capita growth rate decreases as a linear function of population size?

Accepted Answer

Logistic (Verhulst) model

Answer

Exponential (Malthusian) model

Answer

Ricker model

Answer

Gompertz model

Question 3

A conservation biologist estimates a minimum viable population (MVP) of 500 individuals for a large mammal. This threshold is primarily set to minimize risk from:

Accepted Answer

Genetic drift, inbreeding, and demographic stochasticity

Answer

Habitat fragmentation only

Answer

Interspecific competition

Answer

Overharvesting by humans

Question 4

Environmental stochasticity in population models refers to:

Accepted Answer

Year-to-year variation in environmental conditions affecting population rates

Answer

Random variation in individual birth and death events

Answer

Unpredictable dispersal of individuals between habitat patches

Answer

Genetic drift causing random allele frequency changes

Question 5

The Ricker model, commonly used in fisheries, produces population cycles and chaos at high values of which parameter?

Accepted Answer

The intrinsic growth rate r

Answer

Carrying capacity K

Answer

The harvesting intensity h

Answer

The survival rate s

Question 6

When ecologists speak of 'time lags' in density-dependent population models, they are referring to:

Accepted Answer

Delayed regulatory response where current growth depends on past density

Answer

The delay between birth and first reproduction

Answer

The time required for immigrants to establish in a new patch

Answer

Seasonal variation in resource availability

Question 7

Which of the following best explains why island populations often show boom-bust dynamics compared to mainland populations of the same species?

Accepted Answer

Small island populations are more vulnerable to stochastic events and lack rescue immigration

Answer

Islands have higher predation pressure from seabirds

Answer

Islands lack density-dependent feedback mechanisms entirely

Answer

Island environments are more stable and predictable than mainland habitats