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Projected soil temperature increase and seed dormancy response along an altitudinal gradient: Implications for seed bank persistence under climate change

Journal Article


Abstract


  • Background and aims Understanding the mechanistic

    effects of climate change on species key life-history

    stages is essential for predicting ecological responses.

    In fire-prone regions, long-term seed banks allow

    post-fire recovery and persistence of plant populations.

    For physically dormant species, seed bank

    longevity depends on the maintenance of dormancy

    which is controlled primarily by temperature. Successful

    inter-fire recruitment is rare and dormancy

    loss between fires produces a net loss to the seed

    bank. We assessed whether temperature increases related to climate change can affect seed dormancy

    and, potentially, seed bank longevity.

    Methods We quantified the relationship between air

    temperatures and soil temperatures. Seeds of two

    shrub species, from four populations along an

    altitudinal gradient, were then exposed to a range of

    soil temperatures calculated to occur at the end of the

    21st century, using projected mean and heat wave

    scenarios. Alterations to dormancy were assessed via

    germination.

    Results For every 1°C increase in air temperature,

    associated soil temperature increased by 1.5°C. Mean

    temperature increase had no affect on seed dormancy.

    However, future heat wave conditions produced soil

    temperatures that significantly increased dormancy

    loss. This impact was greatest in seeds from cooler,

    high elevation populations.

    Conclusions Projected heat wave events produce conditions

    that provide a mechanism for seed bank

    compromise. Dormancy-breaking temperatures for each

    population were positively related to parental environment

    temperatures, indicating local adaptation. Whilst

    heat from fire may govern post-fire recruitment

    response, we suggest that parental climate is the key

    selective force determining dormancy-breaking threshold

    temperatures, ensuring inter-fire seed bank

    persistence.

Publication Date


  • 2012

Citation


  • Ooi, M. K. J., Auld, T. D. & Denham, A. J. (2012). Projected soil temperature increase and seed dormancy response along an altitudinal gradient: Implications for seed bank persistence under climate change. Plant and Soil: international journal on plant-soil relationships, 353 (1-2), 289-303.

Scopus Eid


  • 2-s2.0-84858337523

Ro Metadata Url


  • http://ro.uow.edu.au/scipapers/4393

Has Global Citation Frequency


Number Of Pages


  • 14

Start Page


  • 289

End Page


  • 303

Volume


  • 353

Issue


  • 1-2

Place Of Publication


  • Netherlands

Abstract


  • Background and aims Understanding the mechanistic

    effects of climate change on species key life-history

    stages is essential for predicting ecological responses.

    In fire-prone regions, long-term seed banks allow

    post-fire recovery and persistence of plant populations.

    For physically dormant species, seed bank

    longevity depends on the maintenance of dormancy

    which is controlled primarily by temperature. Successful

    inter-fire recruitment is rare and dormancy

    loss between fires produces a net loss to the seed

    bank. We assessed whether temperature increases related to climate change can affect seed dormancy

    and, potentially, seed bank longevity.

    Methods We quantified the relationship between air

    temperatures and soil temperatures. Seeds of two

    shrub species, from four populations along an

    altitudinal gradient, were then exposed to a range of

    soil temperatures calculated to occur at the end of the

    21st century, using projected mean and heat wave

    scenarios. Alterations to dormancy were assessed via

    germination.

    Results For every 1°C increase in air temperature,

    associated soil temperature increased by 1.5°C. Mean

    temperature increase had no affect on seed dormancy.

    However, future heat wave conditions produced soil

    temperatures that significantly increased dormancy

    loss. This impact was greatest in seeds from cooler,

    high elevation populations.

    Conclusions Projected heat wave events produce conditions

    that provide a mechanism for seed bank

    compromise. Dormancy-breaking temperatures for each

    population were positively related to parental environment

    temperatures, indicating local adaptation. Whilst

    heat from fire may govern post-fire recruitment

    response, we suggest that parental climate is the key

    selective force determining dormancy-breaking threshold

    temperatures, ensuring inter-fire seed bank

    persistence.

Publication Date


  • 2012

Citation


  • Ooi, M. K. J., Auld, T. D. & Denham, A. J. (2012). Projected soil temperature increase and seed dormancy response along an altitudinal gradient: Implications for seed bank persistence under climate change. Plant and Soil: international journal on plant-soil relationships, 353 (1-2), 289-303.

Scopus Eid


  • 2-s2.0-84858337523

Ro Metadata Url


  • http://ro.uow.edu.au/scipapers/4393

Has Global Citation Frequency


Number Of Pages


  • 14

Start Page


  • 289

End Page


  • 303

Volume


  • 353

Issue


  • 1-2

Place Of Publication


  • Netherlands