Germinable soil seed banks in a tropical savanna: seasonal dynamics and effects of fire

Title
Germinable soil seed banks in a tropical savanna: seasonal dynamics and effects of fire
Publication Date
2005
Author(s)
Williams, Paul R
Congdon, Robert A
Grice, Anthony C
Clarke, Peter John
Type of document
Journal Article
Language
en
Entity Type
Publication
Publisher
Wiley-Blackwell Publishing Asia
Place of publication
Australia
DOI
10.1111/j.1442-9993.2005.tb00368.x
UNE publication id
une:2944
Abstract
The germinable soil seed bank of a tropical eucalypt savanna of north-eastern Australia was found to be dominated by grasses and forbs, with seed bank density ranging from 58 to 792 seeds per square metre, from a total of 53 species. Late dry season fires and the fire-related cues, heat shock and smoke, broke the seed dormancy of a range of tropical savanna species. Heat shock promoted the germination of the species groups natives, exotics, subshrubs, ephemeral and twining perennial forbs, and the common species 'Indigofera hirsuta', 'Pycnospora lutescens' and 'Triumfetta rhomboidea'. Exposure to smoke at ambient temperature promoted germination from the soil seed bank of the species groups combined natives, upright perennial forbs and grasses, as well as the common grasses 'Digitaria breviglumis' and 'Heteropogon triticeus'. The germinable soil seed bank varied seasonally, increasing from the mid west season (February) and early dry season (May) to a maximum in the late dry season (October). The effect of recent fire history on soil seed bank dynamics was limited to the immediate release of some seed from dormancy; a reduction in seed densities of subshrubs and monocots, other than grasses, in recently burnt savanna; and enhanced seed density of the ephemeral 'I. hirsuta' in the year following fire. The seed banks of most savanna species were replenished in the year following burning.
Link
Citation
Austral Ecology, 30(1), p. 79-90
ISSN
1442-9993
1442-9985
Start page
79
End page
90

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