No-Growth Isocline Models in Ecology

The video tutorial explains how to use no-growth isocline models to predict competition outcomes between two species. It covers plotting the isoclines for each species, analyzing population growth or decline based on their positions relative to these lines, and determining stable equilibrium points. The tutorial includes examples to illustrate how starting population densities affect competition outcomes.

What is the primary purpose of using no-growth isocline models?

• To predict the weather patterns

• To measure the height of plants

• To determine the outcome of competition between two species

• To calculate the speed of animal movement

In the no-growth isocline model, what does K1 represent?

• The initial population size of species 2

• The competition coefficient of species 1

• The carrying capacity of species 1

• The growth rate of species 2

What happens to the population of species 1 when it is above its no-growth isocline?

• It remains constant

• It increases

• It fluctuates randomly

• It decreases

How is the no-growth isocline for species 2 plotted?

• Using the competition coefficient of species 1

• Using the growth rate of species 1

• Using the carrying capacity of species 2 and K2/Alpha21

• Using the carrying capacity of species 1

What does it mean if a population density is below the no-growth isocline for a species?

• The population will remain constant

• The population will become extinct

• The population can increase

• The population will decrease

What occurs when both species start above their respective no-growth isoclines?

• Both populations will shrink

• Species 1 will grow and species 2 will shrink

• Species 2 will grow and species 1 will shrink

• Both populations will grow

When species 2 is decreasing, what happens to species 1?

• Species 1 decreases

• Species 1 remains constant

• Species 1 increases

• Species 1 becomes extinct

What is the stable equilibrium point when species 1 outcompetes species 2?

• The average population size of both species

• The carrying capacity of species 1

• The initial population size of species 1

• The carrying capacity of species 2

If both species start below their no-growth isoclines, what is the expected outcome?

• Species 2 will decrease and species 1 will grow

• Species 1 will decrease and species 2 will grow

• Both species will grow

• Both species will decrease

What happens when starting between the no-growth isoclines of the two species?

• Both species will increase

• Both species will decrease

• Species 2 will decrease and species 1 will increase

• Species 1 will decrease and species 2 will increase