The role of fire in managing an endangered plant species: design and analysis of a long-term experiment
by
Warren J Muller
CSIRO Mathematical and Information Sciences, Canberra
Coauthors: John D Briggs (NSW National Parks and Wildlife Service, Queanbeyan NSW)

Swainsona recta (Small Purple-pea) is a nationally endangered Australian perennial forb which is now only known from seven very isolated occurrences in south-east NSW and the ACT. Prior to European settlement S. recta occurred in grassy woodlands, but has declined due to habitat fragmentation, degradation, and possibly also due to an absence of fire on some sites.

A long-term study was initiated in 1993 to investigate in detail the role of fire in the maintenance of S. recta populations. Thirty-two research plots used for this study were established within the largest known population of S. recta, which occurs in remnant native secondary grassland distributed along a 30km section of railway easement in NSW south of Queanbeyan, and which borders the ACT. This area had been regularly burnt by railway authorities since the railway was constructed over 100 years ago.

This paper describes the design of a study to investigate a range of frequencies of spring and autumn burning, and to allow for possible residual effects of grazing by domestic stock for five years prior to 1993. The response of S. recta to the initial spring and autumn burns in 1994, and to a second application of spring and autumn burns in 1996, compared to controls and plots burnt in 1994 only, were determined. An overall increase of around 300% in the number of S.recta plants along the railway easement between 1993 and 1996 was recorded. However the response was uneven across burning regimes, with considerable between-plot variability. Repeated measures techniques used to analyse the responses of numbers of plants and several other plant attributes are described, and the implications for future management of the species in relation to the ongoing use of fire are discussed.

Date received: September 16, 2001

Copyright © 2001 by the author(s). The author(s) of this document and the organizers of the conference have granted their consent to include this abstract in Atlas Conferences Inc. Document # caic-05.