Basic Equation for Exponential Growth N t+1 = N t + bN t - dN t = N t + (b - d)N t r = b - d = Intrinsic rate of increase  N = N t+1 – N t = rN t Basic Equation for Logistic Growth  N = N t+1 – N t = rN t {(K – N t )/K} K = Carrying Capacity  N = 0 when K = N t