Environmental factors influencing the establishment, height and fecundity of the annual grass Sorghum intrans in an Australian tropical savanna

Kenneth Scott, Samantha Setterfield, Michael Douglas, Alan Andersen

    Research output: Contribution to journalArticleResearchpeer-review

    Abstract

    Environmental factors influencing grass establishment and performance in tropical savannas are poorly understood, particularly in relation to disturbance. We describe a seed sowing experiment that examined the effects of fire regime, canopy cover and litter cover on the emergence, establishment, height and fecundity (seed production) of the regionally dominant annual grass Sorghum intrans in northern Australia. Establishment was significantly lower under the woody canopy compared with canopy gaps, and where seeds were sown on a layer of litter compared with bare soil. However, variation in fire regime had no significant effect on establishment or seed production. Additionally, a shade-house experiment was conducted to test the effects of litter on seedling emergence of S. intrans and six other grass species representative of the local flora (Pseudopogonatherum contortum, Sorghum plumosum, Chrysopogon latifolius, Eriachne triseta, Heteropogon triticeus and Alloteropsis semialata). All species showed reduced emergence when sown either above or below litter, compared with bare soil. Our results demonstrate the importance of the overstorey as a determinant of S. intrans abundance and savanna grass composition more generally, through its effect on establishment. The aversion of savanna grasses to litter (and S. intrans to canopy shading) supports the notion of savanna species being highly adapted to disturbance. Copyright � 2010 Cambridge University Press.
    Original languageEnglish
    Pages (from-to)313-322
    Number of pages10
    JournalJournal of Tropical Ecology
    Volume26
    Issue number3
    DOIs
    Publication statusPublished - May 2010

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    sorghum
    Sorghum (Poaceae)
    savanna
    savannas
    fecundity
    litter
    environmental factor
    grass
    grasses
    environmental factors
    seed productivity
    fire regime
    canopy
    seed production
    bare soil
    Heteropogon
    Alloteropsis
    shade
    Chrysopogon
    Digitaria

    Cite this

    Scott, Kenneth ; Setterfield, Samantha ; Douglas, Michael ; Andersen, Alan. / Environmental factors influencing the establishment, height and fecundity of the annual grass Sorghum intrans in an Australian tropical savanna. In: Journal of Tropical Ecology. 2010 ; Vol. 26, No. 3. pp. 313-322.
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    title = "Environmental factors influencing the establishment, height and fecundity of the annual grass Sorghum intrans in an Australian tropical savanna",
    abstract = "Environmental factors influencing grass establishment and performance in tropical savannas are poorly understood, particularly in relation to disturbance. We describe a seed sowing experiment that examined the effects of fire regime, canopy cover and litter cover on the emergence, establishment, height and fecundity (seed production) of the regionally dominant annual grass Sorghum intrans in northern Australia. Establishment was significantly lower under the woody canopy compared with canopy gaps, and where seeds were sown on a layer of litter compared with bare soil. However, variation in fire regime had no significant effect on establishment or seed production. Additionally, a shade-house experiment was conducted to test the effects of litter on seedling emergence of S. intrans and six other grass species representative of the local flora (Pseudopogonatherum contortum, Sorghum plumosum, Chrysopogon latifolius, Eriachne triseta, Heteropogon triticeus and Alloteropsis semialata). All species showed reduced emergence when sown either above or below litter, compared with bare soil. Our results demonstrate the importance of the overstorey as a determinant of S. intrans abundance and savanna grass composition more generally, through its effect on establishment. The aversion of savanna grasses to litter (and S. intrans to canopy shading) supports the notion of savanna species being highly adapted to disturbance. Copyright � 2010 Cambridge University Press.",
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    Environmental factors influencing the establishment, height and fecundity of the annual grass Sorghum intrans in an Australian tropical savanna. / Scott, Kenneth; Setterfield, Samantha; Douglas, Michael; Andersen, Alan.

    In: Journal of Tropical Ecology, Vol. 26, No. 3, 05.2010, p. 313-322.

    Research output: Contribution to journalArticleResearchpeer-review

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