Adaptive and phylogeographic variation in sympatric parasitic and non-parasitic species in Western Australia

by Sheree Walters

Mining is a multibillion dollar industry in Western Australia and mine site restoration has increasingly become a concern for mining companies and the public. Monitoring is a crucial aspect of determining restoration success and indicating when further remediation may be necessary. Metabarcoding is a tool that may allow biological auditing from DNA in the environment, and can provide cost-effective monitoring that can detect flora, fauna and microbial communities. PhD student Mieke van der Heyde is undertaking research to determine how to optimize and apply metabarcoding monitoring for mine site restoration. 


Ecological restoration is becoming increasingly important globally. Paramount to the success of restoration efforts is the suitability of seed sources to the area under restoration. To determine the suitability of seed sources for restoration, information on species genetic diversity and local adaptation is required. While it has been well-established that life history traits play an important role in determining species genetic variation, few studies have included examinations of parasitic life history traits. This PhD project will compare patterns of adaptive and phylogeographic variation in sympatric parasitic and non-parasitic plant species’ important for mine site restoration in Western Australia. 

Next-generation sequencing technology will be utilised to assess whether a parasitic life history trait has an influence on adaptive variation and phylogeographic patterns in Western Australian plant species. Understanding the species local adaption and phylogeographic patterns will assist in determining the provenance delineation for restoration seed sourcing. The first part of the PhD will focus on comparing a generalist parasite with a sympatric non-parasitic species with similar life history traits. Further components of the project will involve examining adaptive and phylogeographic patterns in a host-specific parasite species and the dominant host. The information obtained throughout the research will enable provenances and seed sourcing strategies to be determined for these species which will guide restoration efforts in Western Australia.

Aims/Objectives/Hypotheses (select whichever is most relevant)

Determining the suitability of seed sources for restoration requires understanding local adaption and phylogeographic patterns of species. This project will examine patterns of adaptive and phylogeographic variation in parasitic plants and non-parasitic plant species’ important for mine site restoration in Western Australia. This project has the following objectives:

1) Study phylogeographic patterns and evolutionary processes on temporal and spatial scales;

2) Extrapolate species distributions to predict patterns of adaptive genetic variability across the landscape;

3) Determine whether parasitic and non-parasitic species have similar adaptive variation and phylogeographic patterns; and

4) Develop a tool to guide seed sourcing for restoration


Understanding the effect of evolutionary processes on genetic diversity of plant species is vital in designing seed sourcing strategies that maximise evolutionary potential of restored areas. To date, landscape genetics studies on plant species have been under-represented in the literature despite the need to conserve species evolutionary potential given the long-term nature of many restoration projects. Information on species phylogeographic patterns and historical gene flow is important for identifying climate refugia and designing seed sourcing strategies for long-term population outcomes. Identification of locally adapted populations and their geographical ranges will also be essential for provenance delineation and seed sourcing strategies that conserve genetic diversity and evolutionary potential of species. Furthermore, no study has yet addressed whether patterns of genetic variation of parasitic species are similar to that of non-parasitic plants species. Despite the importance of the information that landscape genetics can deliver for restoration outcomes, few studies have considered this from a Western Australian context.