Environmental CH5

population

A group of interbreeding individuals of the same species in the same geographic region is called a

immigration

A population increases through birth and ____.

are in a state of continual disturbance and change

Most ecologists now recognize that mature, late-successional ecosystems ____.

range of tolerance

Each population in an ecosystem has a ____ to variations in its physical and chemical environment.

departure movement of individuals from a population to another area

Emigration is the ____.

logistic growth

Exponential growth followed by a steady decrease in population growth until the population size stabilizes is typical of ____.

10 trees per hectare

The density of Douglas firs in an old-growth forest is estimated by counting the Douglas firs in four sample plots of 1 hectare each. The number of fir trees in the plots is 10,12, 7, and 11, respectively. What is the estimated density of firs in the forest?

Take advantage of human activity, such as clearing woodlots

The life history strategy of an r-selected species is to

carrying capacity(k)

The maximum number of individuals a habitat can support is called its ______________

viceroy; monarch; mimicry

The non-poisonous ____ butterfly gains protection by looking like the bad-tasting ____ butterfly, which is a protective device known as ____.

are a keystone species

The primary reason why southern sea otter recovery is important is because they ____.

commensalism

The relationship between clownfish and sea anemone is called ____.

true

There are always limits to population growth in nature.

limiting factor

Too much or too little of any physical or chemical factor can prevent the growth of a population, even if all other factors are at or near the optimum conditions. What is this ecological principle?

secondary succesion

What is succession that begins in an area where an ecosystem has been disturbed, removed, or destroyed, and that contains soil or bottom sediment?

The growth curve of these populations is smooth and becomes increasingly steep over time (left). However, for all populations, exponential growth is curtailed by factors such as limitations in food, competition for other resources, or disease. As competition increases and resources become increasingly scarce, populations reach the carrying capacity (K) of their environment, causing their growth rate to slow nearly to zero. This produces an S-shaped curve of population growth known as the logistic curve

What is the difference between the logistic growth model and the exponential growth model? Be sure you can explain the differences in the growth model equations and graphs.

population density

What is the number of individuals in a population found within a defined area or volume that can limit the size of some populations?

commensalism

What occurs when an interaction benefits one species but has little, if any, effect on the other?

They have thick, luxurious fur.

What was the primary reason the southern sea otter nearly went extinct by the early 1900s?

mutualism

When two species behave in ways that benefit both by providing each with food, shelter, or some other resource, it is called ____.

uniform dispersion

You drive through Iowa in the spring and notice that along a stretch of several kilometers, every third fence post has a male redwing blackbird perched on it defending its nesting territory. This is an example of

many, little

A species with a Type I survivorship curve has _______________ (many/few) offspring, with ______________ (little/much) parental care.

density

Assume that there are five alligators per acre in a swamp in northern Florida. This is a measure of the alligator population's

Size will decrease

If an ecosystem has a carrying capacity of 1,000 individuals for a given species, and 2,000 individuals of that species are present, we can predict that the population

resource partitioning

If multiple species find themselves competing for the same resource, the competition can be reduced by which of the following?

a situation in which a population moves back and forth between rapid growth and decline

In terms of population dynamics, what is "boom and bust" cycling?

humans, sharks

Name an organism that illustrates K-selection.

rarely kill their hosts

Parasites ____.

resource partitioning

Species can, over a long period of time, develop adaptations that allow them to reduce or avoid competition by sharing resources. This is called ____.

carrying capacity

maximum population of a given species that a particular habitat can sustain indefinitely is the definition of ____.