Hints for ECCB 403 Chapter 10: Insights into Ecology and Competition Models

interspecific competition occurs when two species use the same limited resource to the detriment of both

True

In the Lotka-Volterra equations, a and b represent

competition coefficients

which statements about resource and interference competition is correct?

Resource competition occurs when organisms utilize common resources that are in short supply

Interference competition can occur among organisms when resources are not in short supply

Tilman's model of competition includes the effects of

rate of resource use

K selection implies

resource competition

Niches overlap graph

phytoplankton are an exception to the principle of competition exclusion

true

The Lotka-Volterra model of competition emphasizes the mechanisms by which competition occurs

false

The main feature of Tilman's model of competition that that distinguishes it from the Lotka-Volterra model of competition is that Tilman's emphasizes the mechanisms by which competition occurs

True

Which statement regarding inter-specific and intra-specific competition is correct?

Inter-specific competition occurs among members of different species

α-selection implies

interference competition

Which of the following are among the most important results of the "classical" laboratory experiments dealing with inter-specific competition that help us understand the coexistence of closely related competitors in nature?

Both competing species invariably reached a steady state equilibrium

Under which of the following conditions would you expect that competitive exclusion would not occur?

In unstable environments that never reach equilibrium and are occupied by colonizing species

In fluctuating environments in which competitive advantage is repeatedly shifted from one species to another

BOTH

What assumption of the competitive exclusion principle was relaxed (not met) in the "classical" laboratory experiments to allow coexistence of closely related competing species?

More than two species were allowed to compete with each other

figures with outcomes of lotka volterra model

Tilman's model of competition graph

The ecological paradox of competition could be stated correctly as follows: How can we reconcile the frequent extinction of closely related species in laboratory experiments with the apparent coexistence of large numbers of closely related species in the field?

True

Which of the following statements about r-selection and K-selection is correct?

According to Westoby's Leaf-Height-Seed Theory of plant strategies, which of the following statements is correct?

A. r-selected species of plants produce relatively many small seeds with relatively low survival through the seedling stage

B. K-selected species of plants produce relatively few large seeds with relatively high survival through the seedling stage

BOTH

The following is an example of "apparent competition" between Species A and Species B. Species A and B do not interact directly with one another, but both are prey for predatory Species C. As a result of Species C shifting its primary predation pressure back and forth between Species A and Species B, the population sizes of Species A and B are negatively correlated. That is, as the population size of Species A goes down, the population size of Species B goes up, and vice versa

True