Question

Consider the following scenario: For many years, the population size of Species 1 has consistently hovered around 100 individuals/km2 while Species 2’s population size has been approximately 50 individuals. Species 1 uses resources at one-quarter the rate of Species 2. Use the information to answer the following:

a. Given the information available, sketch the Lotka-Volterra isocline diagram that best represents the scenario above. Do not forget to label your graph. Are the populations of each species likely to be stable or unstable?

b. Now imagine a case where the values above are the carrying capacities, not the population sizes. For simplicity’s sake, assume that resource use is the only factor that determines competition coefficients (alpha and beta). Sketch the isocline diagram that describes this new scenario. Which species should win?

Answer 1