PhD conferred: 2017
Project title: Integrating physiological, ecological and evolutionary approaches to assess stress resilience of a habitat-forming macroalga.
Supervisors: Dr Martina Doblin (C3 UTS), Dr Alistair Poore (UNSW), Dr Melinda Coleman (NSW Department of Primary Industries)
Project background: Australia is home to the most diverse, species rich and most endemic macroflora in the world. Habitat-forming species are exceedingly important because they facilitate a wide range of organisms that would otherwise be rare or absent. They also provide ecosystem services including nutrient cycling and raw materials, making them a valuable ecological and economic resource. Major climate change factors including global warming, sea-level rise, ocean acidification and increased frequency of extreme weather events are threatening the sustainability of macroalgal ecosystems. In particular isolated, small and fragmented populations found on species distribution boundaries tend to have reduced genetic diversity (through genetic drift and spatial isolation) and this is turn may cause reduced fitness. To be resilient to forecasted climate scenarios, factors such as stress tolerance, genetic diversity and gene-flow among populations will be critical. Currently we have little understanding of how genetic structure and diversity of macroalgal populations interacts with physiological and ecological factors in determining their resilience.
Aims: This project aims to investigate the adaptive potential of the intertidal macroalga, Hormosira banksii, to determine the effects of predicted climate change on marginal populations or individuals growing at their physiological limit. It will test the hypothesis that fitness erodes with declining genetic diversity and that smaller populations lack the capacity to adapt due to low effective population size, low standing genetic variation as well as reduced physiological tolerance.
Publications: Jennifer S. Clark, Alistair G. B. Poore, Peter J. Ralph, Martina A. Doblin, Potential for adaptation in response to thermal stress in an intertidal macroalga Journal of Phycology DOI: 10.1111/jpy.12067