Biology Ch 36 Round 2

K-selection because carrying capacity K is maximized. Population growth limited by density dependent factors.

One life history pattern is typified by large-bodied, long lived animals that develop slowly and produce few but well cared for offspring AND/OR plants like coconut palms that produce few seeds that are well stocked with nutrient rich material (the plant's version of parental care). Ecologists hypothesize that selection for this set of life history traits occurs in environments where population size is near carry capacity. What is this called and why?

To protect wildlife from overharvest yet maintaining lower population levels so that growth is high and mortality from resource limitation is reduced

Explain why managers often try to maintain populations of fish and game species at about half their carrying capacity.

r-selection because r (the per capita rate of increase) is maximized

One life history pattern is typified by small-bodied, short lived animals that develop and reach sexual maturity rapidly, have a large number of offspring, and offer little or no parental care AND/OR plants like dandelions that produce thousands of seeds. Ecologists hypothesize that selection for this set of life history traits occurs in environments where resources are abundant permitting exponential growth. What is this called and why?

When N is 1/2 K (population = 1/2 carrying . At this population size there are more reproductive individuals than at lower population sizes and still lots of space or other resources available for growth. (N=population size, K=carrying capacity)

In logistic growth at what population size is the population increasing most rapidly? Explain why.

Hare population cycles are not primarily caused by food shortage

In one experiment, increasing food supply to hares increased their population density, but the population continued to show cyclic collapses. What might you conclude from these results?

The 1981 "boomlet" is a consequence of rapid reproduction in 1946-1965, as girls born during the baby boom entered their reproductive years

Point out an example of population momentum in figure 36.10

Type III for a population experiencing r-selection; Type I for a population experiencing r-selection.

Refer to Module 36.3. Which type of survivorship curve would you expect to find in a population experiencing r-selection? K-selection?

intrinsic rate of growth

The rate at which a population increases in size if there are no density-dependent forces regulating the population

Clumped, uniform, and random

What are the 3 types of dispersion patterns?

G = rN

What is the equation for the exponential growth model?

G = rN x (K - N)/K

What is the equation for the logistic growth model?

demographic tranistion

a shift from zero population growth in which birth rates and death rates are high but roughly equal to zero population growth characterized by low birth and death rates

ecological footprint

an estimate of the amount of land required to provide the raw materials an individual or a nation consumes including food, fuel, water, housing, and waste disposal; it is one approach to understanding resource availability and usage

exponential growth model

an idealized picture of unregulated population growth; the rate of population increase under ideal conditions, no restrictions on the organism to live, grow, and reproduce

per capita rate of increase

average contribution of each individual to population growth

Density-dependent rates

declining birth rates and rising death rates in response to increasing population density (increased density causes population grown rate to recline by reducing birth rate and/or increasing death rate

boom-bust cycle

dramatic fluctuations in density; rapid exponential growth that is typically followed by population falls to a minimal level (eg lemmings)

population momemtum

in a population in which r = 0, the continuation of population growth as girls in the reproductive age group reach their reproductive years [an age structure with a broad base has a high proportion of children and a high birth rate because on average, each woman is substantially exceeding the replacement rate of two children per couple. When this occurs, the proportion of women of childbearing years increases and now a situation called __________________ exists. }

Maximum sustained yeild

harvesting a resource as a level which can be sustained without population decline

Sustainable resource managment

harvesting a resource without damaging it

maximum standard yield

harvesting should be done at a level that produces a constant yield without forcing a population into decline.

Density-independent

have same effect on population growth regardless of density

survivorship curves

plots survivorship as the proportion of individuals from an initial population that are alive at each stage

carrying capacity

the maximum population size that a particular environment can sustain

life history

the traits that affect an organism's schedule of reproduction and death make up its _______________

dispersion pattern

the way the individuals are spaced within their area

life tables

track the chance of an individual in a given population surviving to various ages

age structure

used to predict a populations future growth; it is the number of individuals in different age groups