Document


Title

Comparative seed germination ecology of Austrostipa compressa and Ehrharta calycina (Poaceae) in a Western Australian Banksia woodland
Document Type: Journal Article
Author(s): M. A. Smith; D. T. Bell; W. A. Loneragan
Publication Year: 1999

Cataloging Information

Keyword(s):
  • Australia
  • disturbance
  • disturbance
  • Ehrharta
  • fire frequency
  • fire intensity
  • fire management
  • forest management
  • grasses
  • heat effects
  • heat shock
  • introduced species
  • light
  • light
  • Mediterranean habitats
  • Poaceae
  • population density
  • reserve management
  • seed dormancy
  • seed germination
  • seeds
  • smoke effects
  • soil management
  • soil seed bank
  • soil temperature
  • temperature
  • temperature
  • western Australia
  • wildfires
Region(s):
  • International
Record Maintained By:
Record Last Modified: June 1, 2018
FRAMES Record Number: 49704
Tall Timbers Record Number: 26141
TTRS Location Status: In-file
TTRS Call Number: Fire File
TTRS Abstract Status: Okay, Fair use, Reproduced by permission

This bibliographic record was either created or modified by the Tall Timbers Research Station and Land Conservancy and is provided without charge to promote research and education in Fire Ecology. The E.V. Komarek Fire Ecology Database is the intellectual property of the Tall Timbers Research Station and Land Conservancy.

Description

Austrostipa compressa, a native ephemeral of southwest Western Australia was stimulated to germinate under a range of temperatures, in the presence of light, and exposure to smoke-water. This combination of environmental cues results in winter-maximum germination in immediate postfire and disturbed-soil environments of this Mediterranean-type climate. In contrast, Ehrharta calycina, an introduced perennial grass from southern Africa that has invaded Banksia woodlands, germinated under a wide range of temperature and light conditions, but showed no promotive response to smoke-water. Although A. compressa seeds tolerated heat shock better than E. calycina, the self-burial mechanism of A. compressa seeds ensures protection from fire. High-intensity fire could have a greater impact on E. calycina, as the seeds of this species tend to accumulate in the top of the soil profile where they are more susceptible to high temperatures. Although seeds of E. calycina are more susceptible to high temperatures, survival of mature individuals by postfire resprouting ensures continued survival in native woodlands. Estimates of soil seed bank densities showed extreme variability, but some recently burnt areas of the Yule Brook Botany Reserve contained up to 8000 seed m-2 of A. compressa and nearly 75 000 seeds m-2 of E. calycina. Viable soil seed bank densities of A. compressa are reduced with time-since-last fire, but areas of greater than 45 years since the last fire, still contained up to 119 seeds m-2. In both species, only about half their soil seed bank germinates following fire, thus ensuring the potential for later recruitment. Massive soil seed populations of E. calycina in native Banksia woodlands pose a major problem to management of this plant community type.

Citation:
Smith, M. A., D. T. Bell, and W. A. Loneragan. 1999. Comparative seed germination ecology of Austrostipa compressa and Ehrharta calycina (Poaceae) in a Western Australian Banksia woodland. Australian Journal of Ecology, v. 24, no. 1, p. 35-42. 10.1046/j.1442-9993.1999.00944.x.