Topic 19 - Population Ecology

Question 1

Carrying capacity (K)

Answer 1

The maximum population size of a certain species that a given habitat can support.

Question 2

Density dependent limits to population growth

Answer 2

Competition for resources, disease and parasitism, increased predation, toxic wastes, social behaviour (stress, dominance, cannibalism…)

Question 3

Density independent limits on population growth

Answer 3

Variation in weather patterns, cold snaps, hurricanes, volcanic eruptions, drought, etc.

Question 4

Exponential population growth

Answer 4

The accelerating increase in the size of a population that occurs when the per capita growth rate is constant and density independent.

Question 5

Fecundity

Answer 5

Potential ability of an organism to produce eggs or young; rate of production of young by a female.

Question 6

Four processes that affect population size

Answer 6

Births, deaths, immigration (individuals entering the population), emigration (individuals leaving the population)

Question 7

Intrinsic rate of increase (rmax)

Answer 7

The rate of increase of a population when conditions are ideal (birth rate per individual are as high as possible and death rates per individual are as low as possible). In species that breed at a young age and produce many offspring each year, rmax is high.

Question 8

Logistic population growth

Answer 8

The density-dependent decrease in growth rate as population size approaches the carrying capacity.

Question 9

Mortality rate

Answer 9

The probability of dying; the ratio of the number of individuals dying in a given time interval to the number of individuals alive at the beginning of time interval.

Question 10

Per capita rate of increase ( r)

Answer 10

Also called instantaneous rate of increase. The difference between the birth rate per individual and the death rate per individual.

Question 11

Population

Answer 11

A group of individuals of the same species living in the same geographic area at the same time.

Question 12

Population density

Answer 12

The number of individuals of a population per unit of area

Question 13

Population dynamics

Answer 13

Changes in the size and other characteristics of populations through time and space, due to its interactions with biotic and abiotic factors.

Question 14

Survivorship

Answer 14

The proportion of offspring produced that survive, on average, to a particular age.