Search results
The intrinsic rate of increase, as defined in the exponential equation, is not a constant number at all but rather is itself a function of the density of the population.
- An Introduction to Population Growth
The power of exponential growth is worth a closer look. If...
- Introduction to Population Demographics
Similar to population size, population density displays...
- The Breeder's Equation
Annual Review Of Ecology and Systematics 23, 287-310 (1992)....
- Population Limiting Factors
No population can grow beyond certain limits. Why do...
- Ignoring Population Structure Can Lead to Erroneous Predictions of Future Population Size
Once the stable stage distribution is reached, the relative...
- Climate Change and Avian Population Ecology in Europe
Continental population changes have been demonstrated in...
- The Population Dynamics of Vector-borne Diseases
The dynamical theory of epidemics for vector-borne diseases...
- Aging and Its Demographic Measurement
Aging is an inevitable fact of life. But as life span...
- An Introduction to Population Growth
Intrinsic Rate of Increase. We can use our knowledge of exponential population growth and our value of R 0 to estimate the intrinsic rate of increase ( r ) (Gotelli 2001). The size of an exponentially growing population at some arbitrary time t is N t = N 0 ert , where e is the base of the natural logarithms and r is the intrinsic rate of increase.
The algebraic symbols b, d and r stand for the rates of birth, death, and the rate of change per individual in the general population, the intrinsic rate of increase. This formula can be read as the rate of change in the population ( dN / dt ) is equal to births minus deaths ( B − D ).
Obviously, a bacterium can reproduce more rapidly and have a higher intrinsic rate of growth than a human. The maximal growth rate for a species is its biotic potential, or \(r_{max}\), thus changing the equation to: \[\frac{dN}{dT} = r_{max}N \nonumber\]
The intrinsic rate of increase is inversely related to generation time, T. The maximal instantaneous rate of increase per head, r max, varies among animals by several orders of magnitude (see following Table).
The symbol r is called the instantaneous rate of increase or the intrinsic rate of increase. The parameters r and R are not equal, although they are related, as we will show below. As we did with the discrete-time model, we can calculate the per capita rate of population growth by dividing both sides of Equation 9 by N :
27 paź 2023 · The intrinsic rate of increase, r, and the carrying capacity of populations, K, are much more related than most people realise. Jim Mallet provides a useful history of this issue and we refer...
