New molecular techniques showing that an iconic palm only grows in central Australia because humans moved it there thousands of years ago pose the question: should we still regard this as a native species? And if it's not native, what implications does this have for species conservation and management?
In a paper published in the prestigious Proceedings of the Royal Society B: Biological Sciences, plant biologists at The University of Western Australia highlight how current conservation policy is contradictory and inadequate to deal with the management of native and non-native species as we strive to protect biodiversity in a world of rapid global change.
PhD student Melinda Trudgen, Adjunct Associate Professor Bruce Webber and Adjunct Professor John Scott also explore a new framework for assessing species movements using scientific best practice.
They write that there is a growing body of evidence documenting human-mediated establishment of populations of species over many millennia and across many regions, suggesting the need for the concept of a ‘projected dispersal envelope' to define the region where populations are or could be native.
"Native and non-native status provides an important premise for developing management strategies, but should not be used to automatically determine specific management goals," they write. "We need to move away from the simplistic arguments of ‘conserving natives' and ‘controlling aliens'.
"These goals should also reflect any ecosystem impacts, ecological functionality and cultural heritage among other factors."
The authors advocate that a change is needed for guidelines and policy currently used to determine and define native status. While most approaches link non-native status to human movements or native status to presence before a given date, an arbitrary mix of both is applied in Australia.
For example, in the Northern Territory, plants or animals will still be considered native if they were moved by Indigenous people before 1788, but for all other people a date of 1400 is applied.
The authors caution that these concepts are becoming increasingly irrelevant and unworkable in a world of rapid global change.
Melinda Trudgen (UWA School of Plant Biology) (+61 8) 9333 6627
Adjunct Associate Professor Bruce Webber (UWA School of Plant Biology) (+61 8) 9333 6802
Janine MacDonald (UWA Public Affairs) (+61 8) 6488 5563 / (+61 4) 32 637 716