In collaboration with several of my colleagues in the Waterway Ecosystem Research Group I am currently advertising 3 PhD top-up scholarships focused on the ecosystem structure and function of small headwater streams and urban waterways worth $15,000 per annum, plus fieldwork expenses of $5,000 per annum (each). Further details can be found by following the links below:
3. Understanding linkages between flow, organic matter and vegetation establishment in urban streams
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Below are listed several projects I am currently seeking a student to undertake in 2020. Please note, however, I also strongly welcome other project ideas, so feel free to contact me if you think our research interests are well aligned.
Urban flow ecology: Investigating relationships between flow, channel form, vegetation and ecosystem function
With Dr Samantha Imberger, Prof. Tim Fletcher, Dr Joe Greet and Dr Matthew Burns
Urbanisation drives increases in peak flow magnitude, frequency and geomorphically effective flows, increasing coarse sediment export and reducing organic matter storage, and the diversity and abundance of aquatic plants. Efforts to restore altered urban flow regimes are gaining pace; however, we still lack an understanding of which components of the flow regime are most significant at influencing sediment and organic matter dynamics and how they interact to influence in-stream vegetation, habitat availability and ecosystem structure and function. This project will seek to: 1) Identify the key urban flow metrics and hydraulic conditions which influence microhabitat (e.g. retention, storage and export of organic matter and coarse/fine sediment) 2) Determine the sensitivity of microhabitat to alterations in hydrology and hydraulic conditions 3) Investigate relationships (and feedback cycles) between sediment, organic matter and vegetation and 4) how the above influences ecosystem function such as denitrification and/or stream metabolism.
Understanding the function and sensitivity of small ephemeral headwater streams.
With Dr Samantha Imberger, Assoc. Prof. Chris Walsh and Dr Matthew Burns
Small streams with high sediment surface area to volume ratios are often regarded as ‘hot spots’ for biogeochemical processes and biodiversity. Despite this, we still have very limited understanding of these systems hydrology and how they contribute to nitrogen and carbon cycling at larger watershed scales. These systems are often severely impacted by land use change and this project seeks to: 1) characterise the hydrology and aquatic/terrestrial biodiversity values of these streams 2) identify and measure ecosystem service values (e.g. carbon processing and denitrification rates) 3) determine the contribution of these systems to biodiversity and ecosystem function at larger watershed scales and 4) assess the sensitivity of these systems to urban development.
Understanding leaf breakdown along an urban gradient: how you measure it and how you interpret it.
With Dr Samantha Imberger.
Leaf breakdown is a critical ecosystem process in freshwater systems; influencing the availability of organic matter to higher trophic levels and influencing food web structure. Published research suggests that urbanisation increases the microbial driven breakdown of labile leaf litter. However, recent experiments in local Melbourne streams suggest this impact model might be more complicated than first thought. This project will investigate the impacts of urbanisation on leaf litter breakdown; how you measure it and how you interpret it. This will be achieved through assessing decomposition using a variety of methods including differing; shapes of mesh exclusion bags, leaf species and substrate types.
Investigating the effects of urbanisation on groundwater quality.
With Dr Samantha Imberger, Prof. Tim Fletcher and Dr Matthew Burns.
The effects of urbanisation on surface water quality, biological structure and hydrology is well studied, but relatively little is known of the effect on groundwater quality and stygofauna communities. This project, working as part of the Waterways Ecosystem Research Group, will assess groundwater quality and stygofauna community diversity using a combination of morphological identification and metabarcoding in well-studied catchments located along an urban gradient.
Investigating the effects of catchment-scale restoration of hydrology on sediment processes and ecosystem function.
With Dr Samantha Imberger and Dr Geoff Vietz.
Sediments are the primary site of nutrient processing in small streams, providing habitat for microbes that cycle and transform nutrients, and for macrophytes. While these processes are well understood, in-stream processes have not been linked to catchment-scale restoration of hydrologic processes. We have observed greater reductions in dissolved P and N in Little Stringybark Creek than predicted by relationships between nutrients and reduction of urban stormwater impacts, and greater than can be explained by mass-balance estimates of tributary inflows. We hypothesise that observed N and P reductions are in part a result of sediment processes and macrophyte uptake promoted by reduced hydrologic disturbance. We are seeking a student to investigate (i) coarse sediment retention rates, (ii) macrophyte biomass and productivity, and (iii) reach-scale nutrient processing and uptake to test this hypothesis.
Modeling the effects of different climate change scenarios on the catchment scale performance of stormwater retention measures in the Little Stringybark Creek catchment.
With Dr Samantha Imberger, Prof. Tim Fletcher and Assoc. Prof. Chris Walsh.
A large number of stormwater retention works have been installed in the Little Stringybark Creek catchment, which have been monitored and modeled. This large set of models provides an opportunity to model the effect of climate change on the performance of the systems, and the hydrologic consequences for the creek. You will work with the MUSIC software to develop and test the scenarios.
Click here for more student research projects under the supervision of other Waterway Ecosystem Research Group (WERG) colleagues.
Dr Moss Imberger 