AM107 AM107  Homework 2
Assigned: Thursday, September 14, 2000
Due:  Thursday, September 21, 2000

Problem 1:  In a 1982 paper (Ecology 63:1218-1222), Hal Caswell presented the following hypothetical life cycle which included both seed-based and vegetative reproduction:



a) Write down the projection matrix A for this life-cycle graph in the equation xn+1= Axn, where xn is a vector representing the abundance of individuals in each life stage.
 
 

b) Without computing the eigenvalues, etc. of this matrix, what can you say about the long term behaviour of this system?
 

c) Assume that all the parameters are set to 1.  Compute x2 for the initial condition x0=(0, 1, 3, 0, 2).  Also compute x2for the (non-physical) initial condition x0=(0, 1, 0, 0, -1).  What does this tell you about the eigenvalues of the matrix A?
Can you say anything more now about the long term behaviour of this system?
 

Problem 2: Edelstein-Keshet, p.62, Problem 3.

Problem 3: Edelstein-Keshet, p.62, Problem 4.