GEV 4517 Lecture Notes - Lecture 10: Density Dependence, Semelparity And Iteroparity, Chestnut Blight
1 Dec 2016
School
Department
Course
Professor
Document Summary
Growth curves: affected by r0, or variation in net reproductive rate: arithmetic: linear density y=mx+b, geometric: describes population growth for periodic breeders; determined by knowing the current population @ time t, and by knowing reproductive rate. Example: r0=1. 5, nt=100; nt+1=1. 5*100=150 for next generation: in 2 generations, Nt+2=1. 5*150=225 (no fractions round up or down) More generally: t is the number of generations and n0 is the number of females currently in the population. Calculating the population: ratio of first year over next year is the finite rate of increase; often given as a percent annual growth (can be used to calculate estimates for population dynamics in years to come). Or r0 < 1 population decline, or r0 > 1 population increase, or r0 = 1 equilibrium. Example: used to show exponential growth (have not reached the carrying capacity of their environments, resources are still unlimited).
