Density Dependence
Slide 43 of 47
As suggested by Boyce (1992), Stacey and Taper (1992), and Burgman et al. (1993), density dependence is an important part of estimating a population’s persistence. Lande (1993) demonstrates that the importance of environmental stochasticity and random catastrophes depends on the density-dependence mechanism operating in the population based on the value of €K€ carrying capacity. However, how density dependence is incorporated into the model greatly affects the estimates of persistence. In persistence models, as a population declines, compensation for small population size takes the form of increased birth rates and decreased death rates (density dependence), and so is a significant factor in increasing population persistence.
or € = 1, the 2 models are identical. Although Stacey and Taper’s data precluded a significant test between these models, their data did show significant correlations between adult survival and population size, suggesting that density dependence was operating in the population.
