Ecosystem Dynamics Lab


“The dogger and prospector follow the explorer; the survey party follows both and makes record of their findings; and hard upon their heels has been the stockman with his cattle, horses, donkeys, and camels, his sheep and goats and dogs; and the great hosts of the uninvited also – the rabbits, the foxes and the feral cats.

The results of all this are hailed by the statistician and economist as progress, and a net increase in the wealth of the country, but if the devastation which is worked to the flora and fauna could be assessed in terms of the value which future generations will put upon them, it might be found that our wool-clips, and beef and timber trades have been dearly bought”

H.H. Finlayson, The Red Centre, 1935

Our Aim

As part of the School of Life and Environmental Sciences, University of Sydney, we aim to understand how ecosystems respond to disturbance events across space and time.


Principal Investigator

Dr Aaron Greenville


Our Research

Our research is organised around three themes:

1. Ecosystem responses to climate change: Climate change is the greatest global issue facing our civilization and the environment on which we depend. Our research aims to address the broad question of how the non-linear responses of species to climate and biotic interactions can be better understood and incorporated into improved analyses of ecosystem dynamics and function. Within this theme we also tackle the question of how altered fire regimes impact on biodiversity, a key challenge facing Australia and now also being recognised globally.

2. Species interactions (competition and predation): Interactions among species are crucial for ecosystem functioning and for maintaining biological diversity. Our research theme aims to uncover the direct and indirect roles of competitive and predatory interactions between species. We are particularly interested in understanding how these interactions are modified by climate over space and time.

3. Technology for ecology and Agricultural sciences: Advances in technology, such as drones, remote camera traps, acoustic recorders and more recently open-source hardware and software have revolutionised data collection for cryptic species and surveys in remote locations. We investigate how scientists can use open-source hardware (e.g. Raspberry Pi and Arduino platforms) and software within their research programs, such as by building remote environmental sensors coupled with advanced analytical techniques. This theme uses the latest innovations in technology from computer science, engineering and electronics to build custom devices with a reproducible workflow.


Projects

Our projects range from focusing on the population biology of individual species to how ecosystem function changes across space and time.

We study various animal and plant species from arid to agricultural environments, and employ a range of techniques from traditional field ecology and advances in technology.

Read more about our projects.

New Honours projects here.


Our People

William La Marca (PhD; University of Sydney)

I am undertaking a project that will focus on filling key knowledge gaps for the kowari (Dasyuroides byrnei) and how we can best manage its conservation. The kowari is a small marsupial carnivore which is largely restricted to the gibber plains of central Australia. Despite appearing to be at a high risk of extinction over the coming decades, it remains under-studied and under-protected.

My work will help us to understand the current and historical distributions of the kowari and the reasons for its decline, as well as elucidate several aspects of its ecology. Topics covered will include social organization and habitat associations that allow the persistence of kowari populations in refuge sites; population dynamics and their relationships across spatially distant sub-populations; the relative threats posed by introduced predators and other extrinsic factors; and the diet of the kowari and its potential role as a keystone species.

This project will develop alongside and support work being done by the South Australian Department of Environment and Water, as well as the not-for-profit conservation initiative Arid Recovery. This includes the potential to study multiple translocated populations in different environments and under different selection pressures to understand more about the species and how it navigates the landscape.

To raise the public profile of this unique Australian species, I have worked with these partners alongside environmental philanthropist Jim Phillipson to create a not-for-profit organisation – Team Kowari – dedicated to raising public awareness and funds to support ongoing research initiatives. For more information, visit http://www.teamkowari.com

To get in touch with me directly, email me at william.lamarca@sydney.edu.au or tweet me using @eco_blam

Emma Spencer (PhD; University of Sydney)

Photo credit: Guillaume Tutton

I am investigating Australia’s scavenging community and the wider effects of carrion in a range of biomes across the continent. In particular, I am interested in the diversity of life present on and around carrion resources, including both the vertebrate and invertebrate species that make use of this resource, as well as the potential cascading effects of carrion on live prey in the surrounding system. I am also interested in nutrient cycling and the influence of carrion on soil properties and plant growth.

Spanning across a number of locations in NSW and QLD, I will utilise animal carcasses, motion sensor cameras, invertebrate traps and a series of behavioural experiments to determine the extent to which different scavenger guilds use carrion resources within the landscape, to examine the factors that influence the use of carrion by different scavengers and to explore the indirect effects of carrion on a variety of mammalian and avian species. Concurrent collection of soil and plant samples surrounding carrion resources will also enable me to determine whether nutrient-rich carcasses enhance soils and contribute to plant growth. Together, my observations will contribute to greater understanding of Australia’s scavenger community and the myriad of effects that carrion can have on the surrounding environment.

Follow project up-dates on Twitter by Emma (@EE_Spencer) #ProjectOZscav

Stefanie Bonat – (PhD student; University of Sydney)

My PhD project is focused on the effects of animal mass mortality events (AMMEs) on the environment. Extreme weather events and management practices such as large-scale culling of feral species can result in abnormally large carcass loads in the environment. Australia, like many other countries across the globe, has seen an increase in the number of AMMEs in the last few years, with events such as the Menindee fish kills, flying foxes and feral horses dying due to extreme heat, and cattle dying in Queensland due to flooding.

In my project I will be looking at the effects AMMEs can have on scavenging food webs, but also on soils and plant communities, replicating similar experiments carried out in the USA, where vultures and coyotes are the dominant scavengers. I will be looking at whether Australian scavengers can consume large carcass loads, and whether native or invasive species would benefit from this the most. I will also be looking at whether AMMEs result in excessive nutrient flows into the soil, and whether this nutrient load favours weed growth over native vegetation, possibly examining cascading effects on herbivore communities.

Fieldwork will be based in Kosciuszko National Park, in collaboration with local landowners and government agencies, such as National Parks and Wildlife Service, Department of Primary Industries and Local Land Services.

Honours:

Keeley Dart – Mapping the spread of the non-native African Carder Bee ‘Pseudoanthidium (Immanthidium) repetitum’ (Hymenoptera: Megachilidae) using citizen science. B. Ag. Sci. Hons. USYD

Meg Brown– Can machine learning accurately classify wildlife species in remote camera trap images? B. Ag. Sci. Hons, USYD

Lillian Shang– Can ecoacoustics be used to estimate biodiversity on farms? Bachelor Animal and Veterinary Bioscience Hons, USYD.

Perrie Carrett– Smart farming: incorporating technology to survey for on-farm biodiversity. Bachelor Animal and Veterinary Bioscience Hons, USYD.

Sarah Richter– Simpson Desert Insights: designing Citizen Science programs for identifying wildlife in remote camera trap images. Bachelor Animal and Veterinary Bioscience Hons, USYD.

 

Past Lab members:

2019: Elise Verhoeven (Honours; The University of Technology Sydney)

This project aims to understand how the ecosystem function of vegetation communities within the Blue Mountains changes after a wildfire and/or hazard reduction burn. This will be achieved by assessing the response of species and functional groups of vegetation to fire. This information can be used to calculate the change in ecosystem function. The project will involve both field work and data analysis.

2019: Stefanie Bonat – Masters in Wildlife Health and Population Management (University of Sydney)

Thesis title: Species activity at Ethabuka Spring, Simpson desert: conservation implications

The management of feral pests is a major concern in Australia, as these are key threatening processes for many native species. In arid Australia, management is often difficult due to the remote nature of conservation reserves. Water can be a useful tool for management in such areas, as it represents a limiting resource for mammal predators. The main aim of this study is to look at species activity patterns at a natural waterhole in the Simpson Desert, and to determine the detection of predators at increasing distances from water.

 

2017: Tamara Potter (Honours; University of Sydney)

Who Killed the Wolf Spider? A Who-dunnart Intraguild predation among taxonomically disparate micro-carnivores.

I recently completed my Bachelor of Science (Advanced) degree at the University of Sydney with first class honours and a university medal. I’m an avid adventurer with a passion for ecology.

There have been few studies examining intraguild predation between a mammal and an arthropod. I present such an example here. The lesser hairy-footed dunnart (Sminthopsis youngsoni) is a common generalist insectivore in arid Australia that consumes wolf spiders (Family Lycosidae) disproportionately often relative to their availability. In this study, I tested hypotheses to uncover the underlying mechanisms that drive this selective predation. Firstly, lycosids were not found to contain more water energy or nutrients than other available arthropod prey, thus discrediting the hypothesis that S. youngsoni forages to optimise hydration or caloric and nutritional intake. Secondly, I did find a high degree of spatial and temporal overlap in resources (diet and microhabitat) between S. youngsoni and lycosids, providing support consistent with the hypothesis of competition. This latter hypothesis, and the operation of intraguild predation, was further supported by results of cafeteria-style trials showing that S. youngsoni selectively targets lycosids when alternative prey types are equally available.

My conclusion is that S. youngsoni may predate lycosids to reduce competition for the same food resources. This study is one of the few to suggest intraguild predation between such taxonomically disparate groups, and its consequences extend beyond simple predator-prey relationships to suggest that IGP can have substantial impacts on community structure and ecosystem processes.

Read about some of Tamara’s work here:

Potter, T., Greenville, A.C. & Dickman, C.R. (2018). Assessing the potential for intraguild predation among taxonomically disparate micro-carnivores: marsupials and arthropods. Royal Society Open Science, 5: 171872.

This dunnart has competition for food… so it just eats the competition, Australian Geographic, May 2018.

Intraguild predation among marsupials and arthropods. Research findings factsheet, Threatened Species Recovery Hub, Oct 2019.