Habitat fragmentation and species conservation The size of a class-structured population is modeled in Section 8.8. In certain situations the long-term growth rate of a population is given by r = (1 + 1+ 8s), where s is the annual survival probability of juveniles. Suppose this survival probability is related to habitat area a by a function s(a). Determine an expression for the rate of change of growth rate with respect to a change in habitat area.