Integration of demography and genetics in population restorations

Abstract

By definition, restoration projects involve small populations, which are subject to demographic, genetic, and environmental stochasticities. Besides its fundamental interest for ecology, the integration of these stochastic factors in population viability models is required to make such models more realistic. In this paper, we report previous attempts to integrate population dynamics and population genetics, two disciplines that are generally treated as separate fields. We then evaluate their potential interactions in the context of population restoration. In the first part, we investigate the interactions among stochastic factors of extinction and various species characteristics, such as growth rate, generation length, and mating system. In the second part, we discuss how demographic and genetic models can be used to compare the relative efficiencies of different reintroduction and reinforcement strategies in different environments. For that purpose, we examine spatial and temporal aspects of release, as well as the number and type of individuals to release. In many cases, these comparisons uncover opposite effects among the genetic and demographic factors that antagonistically influence short- and long-term viabilities. Choosing an appropriate restoration strategy should therefore involve the integration of different disciplines in population viability analyses.