Sleeper weeds - a useful concept?
A.C. GriceA,C and N. AinsworthB,C
A CSIRO Sustainable Ecosystems, Private Bag PO, Aitkenvale, Queensland 4814, Australia.
B Victorian Department of Natural Resources and Environment, Keith Turnbull Research Institute, PO Box 48, Frankston, Victoria 3199, Australia.
C Co-operative Research Centre for Australian Weed Management.
Summary
The term 'sleeper' is widely and often somewhat loosely applied in weed science to describe introduced species that remain relatively scarce and/or scattered for a considerable period after they have become naturalized, with the implication that some species will subsequently become more highly invasive. We argue that the 'sleeper weed' concept actually encompasses a variety of ecological phenomena. We propose that individual weed species that could be regarded as 'sleepers' can be ascribed to one of six general classes that relate to either the characteristics of the species, the characteristics of the environment in which it has become naturalized, or to the perceptions of the observer. While the current concept of 'sleeper weeds' may help raise awareness of future weed risks, a more refined analysis would help focus attention on situations where the risks are most likely to be realized and identify times, places and mechanisms whereby this may occur.
Plant Protection Quarterly (2003) 18 (1) 35-39.