45. Invasive Plants in Tropics

Organised by Denise Hardesty, CSIRO. First meeting to be held 9-12 December, 2008 at Macquarie U.

PARTICIPANTS INCLUDE Denise Hardesty - CSIRO Sustainable Ecosystems (Leader) David Westcott - CSIRO Sustainable Ecosystems Saara DeWalt - Clemson U (USA) Carol Horvitz - U Miami (USA) Helen Murphy - CSIRO Sustainable Ecosystems Curtis Daehler - University of Hawai'i (USA) Marcel Rejmanek - University of California, Davis (USA) Jan Pergel - Institute of Botany, Academy of Sciences (Czech Republic) Brad Murray - University of Technology, Sydney Philip Hulme - Lincoln University (NZ) Peter Bellingham - Landcare Research (NZ) Andy Sheppard - CSIRO Entomology Ray Callaway - University of Montana (USA) Jane Catford - U Melbourne

see list ...

BACKGROUND

While well recognised in temperate environments, it is only recently that the importance of plant invasions in tropical rainforests has gained attention. The ecological processes that drive invasions can also shed light on processes structuring and maintaining tropical forest ecosystems.  Invasions represent perturbations of ecosystems and the responses of the invader and the invaded communities can provide clues to the nature of the interactions and processes driving ecosystem function on ecological and evolutionary timeframes. 

An important feature of the global epidemic of biological invasions is that they are replicated events.  The same or a closely related species invades on different continents or in geographically distinct regions within a continent and these events can also be compared with population dynamics and patterns of movement across the landscape within the native range.  This phenomenon provides an opportunity to examine the processes and outcomes of the invasion by a single species under differing circumstances.  Comparisons of continentally replicated invasion experiments provide opportunities to test hypotheses about the mechanisms underpinning invasion and the functioning and maintenance of the ecosystems in which they occur.

Previous comparisons of biological invasions at multiple sites have not addressed weedy species in tropical ecosystems nor utilised the full potential of these comparisons.  Furthermore, there has been little consideration of how this might best be done and the methodological issues associated with these comparisons. 

Background papers relating to this working group can be found here.

AIMS

The working group will address the following questions:

• What are the experimental design constraints and opportunities associated with large-scale comparisons and how can the most benefit be obtained from them while maintaining scientific rigor? e.g.
• appropriateness in scale at which to establish and conduct such research
• specific methodologies required to address focal research questions that will result in desired outcomes (whether containment, eradication, or population reduction) as well as to understand the processes driving the patterns we observe across multiple landscapes

• What are the scientific insights gained from geographic comparisons to date, what are the key questions we should be addressing, and, what are the questions we can actually ask from the appropriate and significant evolutionary, ecological and management perspectives? e.g.
• review and critique of current large scale studies comparing species ecology in native and invasive ranges. 

• How can this information be most appropriately incorporated into management of plant invasions in tropical forests?

Last updated April 2008