Exponential and Logistic Population Growth: Per Capita Rates and Carrying Capacity, Study notes of Ecology and Environment

Download Exponential and Logistic Population Growth: Per Capita Rates and Carrying Capacity and more Study notes Ecology and Environment in PDF only on Docsity! EVE 101 – W08 Lecture 6 Handout: p. 1 Single species population growth I. Geometric and exponential population growth Molles: Figs. 11.2-.7; pp. 255-9. Exponential population growth (see text for the geometric equivalents). a Time → Time → Rate of change in population size during a given time period, (t) dN dt = rN € dN dtN = r so r is the per capita (per individual) rate of growth in this population. By definition, r, the per- capita rate of population growth is constant; that is, it is independent of population density, no matter how much population density changes. Population size after a given time (t) (solution to the differential equation) Nt = No ert Symbols: N = number of individuals in a certain area; the population “size” or “density”. Nt = number of individuals at time t No = number of individuals at the start, time to t = one time unit r = per capita birth rate (b) – per capita death rate (d), r = b – d = intrinsic rate of increase, biotic potential. This r can also be called rm or rmax. e = base of the natural logarithms