A note on density dependence in population models

摘要: Abstract One of the most studied phenomena in ecology is density dependent regulation. The model frequently used to study this behaviour theta-logistic model. However, disagreement has developed within community pertaining interpretation model’s parameters, and thus as appropriate values for parameters assume. In particular, parameter θ been allowed take negative values, resulting ‘growth rate parameter’ estimated be species which are extant exhibit no signs becoming extinct short-term. Here we explain phenomenon by formulating manner original logistic was formulated Verhulst (1838) , doing so providing a simple restrictions on may We conclude that should (almost always) restricted greater than − 1 . This implications studies assessing form dependence from data. Additionally, another appearing literature presented provides more flexible at expense only one additional parameter.