York Gum (Eucalyptus loxophleba) woodlands were formally extensive in the Western Australian Wheatbelt, but persist now as smaller patches in a cropped landscape. For most of the year these woodlands have a bare understory until winter rain triggers germination of carpet-forming annual plants. These annual plants include many native species (daisies largely) but introduced annual grasses and daisies are increasingly common, particularly where woodlands adjoin crops. Introduced species often grow amongst native species in new combinations, creating "novel" communities.
We are interested in the mechanisms behind the formation of these mixtures and also those that maintain annual plant diversity in general. Specifically we aim to determine the relative importance of the local environment, plant competition and random processes in forming the observed plant communities. This information will enable us to predict the types of mixtures we might see as the climate continues to dry and warm in the southwest.
The broad vision for UWA Future Farm is to develop it with inputs from the farming community, and to facilitate multidisciplinary state, national and international research into future farming systems involving staff and students from across the Schools and Faculties at UWA. Our research team aims to assist with achieving this vision by exploring innovative options for ecosystem management that reconcile future farming enterprises with biological diversity and the provision of ecosystem services.
Our first field experiment addresses the question: Do trees planted for carbon benefit other ecosystem services such as soil health and resistance to weed invasion. read more
Apis mellifera, the European honeybee, was introduced to Australia in the 1800s. While its pollination of crops and production of honey are recognized as beneficial services, it may also be negatively affecting native flora and fauna. Studies in Europe and South America have shown that A. mellifera may benefit from habitat fragmentation whereas native bees may need more contiguous tracts of habitat to thrive. This project is examining native and honey bee distribution in urban bushland fragments that vary in size and time since isolation. The project will also experimentally investigate the role of honey bees and native bees in pollinating specific native plants.
Peniup Farm is one of several properties owned by Greening Australia and their partners situated between the Fitzgerald River and Stirling Range national parks. Their ultimate aim is to restore native vegetation between the Great Western Woodlands near Kalgoorlie to the coastal scrub around Margaret River, starting with the lands between these two national parks. Our role in the visionary “Gondwana Link” project has been to help improve understanding of the ecological filters to seedling establishment, the trade-off between carbon and biodiversity in restoration plantings (in collaboration with Suzanne Prober at CSIRO and Justin Jonson at Threshold Environmental), and more recently to understand the role of soil biological properties in restoration success.
World-wide, fertilisers are used to kick-start the restoration of native vegetation after mining disturbance. The amount of fertilisers to apply present a conundrum for restoration practitioners working to restore jarrah forest after mining in south-western Australia because these forests are inherently low in available nutrients, especially phosphorus. We determined the effect of P-fertiliser on the restoration of jarrah forest and their mycorrhizas after bauxite mining with funding from the Australian Research Council, Alcoa of Australia and BHP Billiton Worsley Alumina. At the same time as answering this applied question, the project has offered a unique opportunity to explore more fundamental ecological questions, such as that of the relationship between floristic diversity and productivity during ecosystem development.
Serpentine grassland in northern California consists predominantly of native annual forb species. Because of the unusual chemical composition of the serpentine soil, these grasslands have been less invaded by non-native grasses and forbs than the majority of other grassland areas in California. The small-scale spatial patterning of this grassland is linked to localised disturbance by gophers, burrowing rodents which dig tunnels underground and excavate soil to the surface where it covers existing vegetation and forms areas of bare soil. These bare areas have to be recolonised, mostly by seed, the following season. The dynamics of the grassland are also affected by climatic variation, particularly the highly variable rainfall.
A collaborative long-term research project with Prof Hal Mooney and others at Stanford University, California, has resulted in a 29-year data set on experimental plots in serpentine grassland at Jasper Ridge Nature Preserve in northern California. These data consist of plant cover and density measures within marked plots in replicated experimental exclosures and control areas. Interim results from these plots have been published previously in Ecology (1991) and Journal of Vegetation Science (1995), and the full data set is now being analysed and written up. Further studies with Dr Stuart Weiss complement this data set with data from a variety of other sites in the San Francisco Bay Area, in particular at Kirby Canyon, where vegetation composition has been studied annually since 1991.
Lauren Hallett, UC Berkeley, joined the project in 2010 and is working on the analysis of the long-term dataset and the continued recording of the experimental plots.
This project examined the effect of thinning and burning mine-site rehabilitation on the abundance of terrestrial mammals and reptiles. This nationally significant project provided Resource Managers in Western Australia with measures of impacts of forestry thinning and burning (for timber production and drinking water catchment) on vertebrates, and provided management tools to conserve biodiversity within productive forest environments. Outcomes are procedures to accelerate returns of vertebrate fauna to mine-sites, measurements of thinning and burning practices on tree-health, and trial procedures for forest thinning (the 12000 Ha Wungong catchment) that minimise impacts on terrestrial vertebrates.