Characterizing the post‐recolonization of Antechinus flavipes and its genetic implications in a production forest landscape

Abstract

Production landscapes, where activities such as timber harvesting, grazing, and resource extraction take place, have considerably reduced the extent of natural habitats. The ecological restoration of these landscapes is, in many cases, the best remaining option to protect biodiversity. However, it is unclear whether restoration designed to avert biodiversity loss in restored landscapes can also maintain genetic diversity in recolonizing faunal populations. We employed core concepts in the field of population genetics to address questions of genetic diversity and gene flow in recolonizing faunal populations, using a small and vagile marsupial (Antechinus flavipes) inhabiting a mined landscape under restoration. We did not detect a disruption of gene flow that led to genetic substructuring, suggesting adequate levels of gene flow across the landscape. Parameters of neutral genetic diversity were high in groups of individuals sampled in both restored and unmined sites. Our results are encouraging as they indicate that ecological restoration has the potential to not just increase available habitat, but also to maintain genetic diversity. However, there is evidence that past anthropogenic disturbances affected the genetics of the population at the regional level. Although restoration at the local level may seem to be successful, it is necessary to manage populations at larger spatial scales than where restoration is conducted, and over long temporal scales, if genetic diversity is to be maintained in restored landscapes. The field of population genetics is an underused tool in ecological restoration yet can provide important insights into how well restoration achieves its goals.

Making the connection: expanding the role of restoration genetics in restoring and evaluating connectivity

“…To better integrate connectivity into restoration practice, it is also important to explicitly evaluate the impacts of restoration projects on genetic connectivity, not only during translocations (Aavik et al ; Reynolds et al ), but also in species that naturally recolonize restored habitat (Cosentino et al ; Isselin‐Nondedeu et al ; Mijangos et al ). When evaluating the restoration of habitat for connectivity, it is important to note that “gene flow” should be considered as the incorporation via reproduction of genes into another population; “movement” of genes alone is insufficient to realize the fitness benefits of gene flow.…”

“…Differences in mutation rates and inheritance patterns of genetic markers can be exploited to estimate and contrast patterns of historical and contemporary genetic connectivity. For example, Mijangos et al () used a mitochondrial DNA marker and microsatellites to reconstruct regional historical migration rates and population sizes of a small marsupial across a landscape containing restored mine sites. They then used microsatellite markers to assess whether postmining rehabilitation restored contemporary connectivity to recolonizing populations at a local scale.…”

“…These include identifying barriers to gene flow (McRae et al ) or spread of adaptive genetic variation (Apgar et al ); mapping gradients of adaptive variation in species (Shryock et al ); and setting genetic targets for restored populations that reflect diversity and connectivity in reference populations (Drury et al ). Connectivity of restored populations to the surrounding landscape is also becoming an important metric of restoration success, both for translocated (Aavik et al ; Reynolds et al ) and naturally recolonizing species (Cosentino et al ; Isselin‐Nondedeu et al ; Mijangos et al ). Given the rapid development of sequencing technology and analytical approaches to assessing genetic connectivity, and increasing interest in incorporating this into restoration genetics, we feel that it is timely to synthesize current and emerging genetic techniques that can support decision‐making in ecological restoration.…”

Discovered and disappearing? Conservation genetics of a recently named Australian carnivorous marsupial

“…As well as land clearing, threats such as introduced predators (feral cats, Felis catus and foxes, Vulpes vulpes) and climate change may have caused population reductions in A. mysticus and will likely continue to negatively affect both species and many other mammals (Woinarski et al, 2015). Indeed, a recent microsatellite study identified that land clearing and related anthropogenic changes are driving a substantial decline in the population size of southwestern Australian A. flavipes (Mijangos, Pacioni, Spencer, Hillyer, & Craig, 2017). However, the evidence of decline throughout the range of A. mysticus, which is possibly severe at Cooloola, suggests that A. mysticus is at a more immediate extinction risk than A. subtropicus.…”