The Lotka-Volterra competition equations (6a and 6b in your text)
are described: \[
\frac{\mathrm{d}N_1}{\mathrm{d}t} = r_1N_1\left(\frac{K_1 - N_1 - \alpha
_{12}N_2}{K_1}\right) \\
\frac{\mathrm{d}N_2}{\mathrm{d}t} = r_2N_2\left(\frac{K_2 - N_2 - \alpha
_{21}N_1}{K_2}\right).
\] These are the same equations that you studied in Ecology
(BI/ES271). For these equations, (a) first, show your work and
algebraically find the nullclines. Next, (b) plot the four nullclines
all (not using phaseR
), for the 4 different outcomes of
competition; i.e., remake figure 8.4. Use segments()
or
lines()
, but don’t use nullclines()
.
Recreate figure 8.4. using phaseR
’s functions
flowField()
and nullclines()
. For each of the
outcomes, plot two trajectories using trajctory()
(see help
for details): with one set of initial conditions with a larger \(N_1\) and a smaller \(N_2\) and one set with a smaller \(N_1\) and larger \(N_2\).