Assessing the benefits and risks of translocations in changing environments: a genetic perspective

Abstract

Translocations are being increasingly proposed as a way of conserving biodiversity, particularly in the management of threatened and keystone species, with the aims of maintaining biodiversity and ecosystem function under the combined pressures of habitat fragmentation and climate change. Evolutionary genetic considerations should be an important part of translocation strategies, but there is often confusion about concepts and goals. Here, we provide a classification of translocations based on specific genetic goals for both threatened species and ecological restoration, separating targets based on 'genetic rescue' of current population fitness from those focused on maintaining adaptive potential. We then provide a framework for assessing the genetic benefits and risks associated with translocations and provide guidelines for managers focused on conserving biodiversity and evolutionary processes. Case studies are developed to illustrate the framework.

Figure 1

Genetic considerations in establishing populations outside the current or historical distribution of a species. Relevant scenarios depend particularly on whether levels of genetic variability in the populations are high or low, but also on the distribution of populations along the gradient.

Figure 2

Simplified decision tree for determining whether to proceed or assess risk in translocation.