DAVID ELDRIDGE Profiles Research Opportunities PublicationsPhotosContactCollaborators & Links

Alex James

Email: a.jamesstudent.unsw.edu.au

PhD in Ecology 2009, University of New South Wales

Development of resource-rich patches by soil-disturbing animals

In arid landscapes resources are concentrated into patches that allow greater productivity than would otherwise be expected. Species that modify, maintain or create habitat have been termed ecosystem engineers. One group of soil disturbing ecosystem engineers create new fertile patches by modifying soil microtopography through foraging for food and creating habitat. This activity may enhance resource retention at local and landscape scales and ensures the persistence of patches.

The effects of ecosystem engineers are likely moderated by the type of engineer, the morphology of the disturbances they create, and the magnitude of disturbance at the landscape scale. The effects of engineers are also likely to differ between landforms due to large scale variation in resource availability. Understanding how fertile patch creation is moderated by species that create morphologically similar disturbances is crucial given escalating changes in species distributions and increases in the number of invasive engineers. Invasive engineers that create morphologically similar habitat to extirpated native engineers may play crucial roles in ecosystem function that need to be understood. Similarly, reintroductions of native ecosystem engineers may determine the success of restoration efforts, given the need to restore both biotic and abiotic resource flows that have been altered as a result of species losses.

We are examining the effects of soil foraging animals on resource concentration in arid environments and how effects are moderated by species and landscape.  We are comparing the ecosystem engineering role of two species that have suffered massive range declines, the Greater bilby (Macrotis lagotis) and the Burrowing bettong (Bettongia lesueur) with the Sand goanna (Varanus gouldii) and the invasive European rabbit (Oryctolagus cuniculus).

Publications

James, AI, Eldridge, DJ, Koen TB, and Moseby KE. (submitted) Can an invasive species fulfil the soil-engineering role of locally extinct natives? Submitted to Oecologia

James, AI, Eldridge, DJ, and Moseby KE. (2009) Foraging pits, litter, and plant germination in an arid shrubland. Journal of Arid Environments (in press).

James, AI, Eldridge, DJ, and Hill, BM. (2009) Foraging animals create fertile patches in an Australian desert shrubland. Ecography 32, 23-32

Eldridge, DJ, and James, AI. (2009) Soil-disturbance by native animals plays a critical role in maintaining healthy Australian landscapes. Ecological Management and Restoration 10, S27-S34.

James, AI, Eldridge, DJ, Koen, TK, and Whitford, WG. (2008) Landscape position moderates how ant nests affect hydrology and soil chemistry across a Chihuahuan Desert watershed. Landscape Ecology 23, 961–975.

James, AI, and Eldridge, DJ. (2007) Reintroduction of fossorial native mammals potential impacts on ecosystem processes in an Australian desert landscape. Biological Conservation 138, 351 – 359.

Conference Presentations:

James, AI, Hill, BM, Moseby, KE  Eldridge, DJ. Can reintroduction of the bilby and bettong aid ecosystem restoration in arid Australia? Australian Rangeland Society, Charters Towers, Queensland. September 2008

Eldridge, DJ, James, AI, Huang, N, Kwok, A. A role for reintroduced native animals in the restoration of degraded rangelands. Australian Rangeland Society, Charters Towers, Queensland, September 2008

James, AI, Eldridge, DJ, Hill, BM. Can species reintroductions aid ecosystem restoration? A case study from Arid Australia. Society for Conservation Biology, Chattanooga Tennessee, July 2008

James, AI, Eldridge, DJ, Whitford, WG. Ant nests moderate water infiltration in a Chihuahuan Desert ecosystem. Ecological Society of Australia, Brisbane, Queensland, November 2005.

James, AI. Creation of fertile patches by four ecosystem engineers in arid South Australia. Ecological Society of Australia, Adelaide, South Australia , November 2004.

Recent Achievements:

Society for Conservation Biology, First Place Student Award Competition, July 2008
Australian Rangeland Society, Best Student Spoken paper, September 2008
Zoological Parks Board of NSW, Conservation Prize, June 2008, BEES Postgraduate Forum.