On an upper bound for the spreading speed

Abstract

<p style='text-indent:20px;'>In this paper, we use the exponential transform to give a unified formal upper bound for the asymptotic rate of spread of a population propagating in a one dimensional habitat. We show through examples how this upper bound can be obtained directly for discrete and continuous time models. This upper bound has the form <inline-formula><tex-math id="M1">\begin{document}$ \min_{s&gt;0} \ln (\rho(s))/s $\end{document}</tex-math></inline-formula> and coincides with the speeds of several models found in the literature.</p>