Complexity confers stability

climate variability, vegetation response and sand transport on longitudinal sand dunes in Australia's deserts

Paul P. Hesse*, Matt W. Telfer, Will Farebrother

*Corresponding author for this work

    Research output: Contribution to journalArticle

    12 Citations (Scopus)

    Abstract

    The relationship between antecedent precipitation, vegetation cover and sand movement on sand dunes in the Simpson and Strzelecki Deserts was investigated by repeated (up to four) surveys of dune crest plots (≈25 × 25 m) over a drought cycle (2002–2012) in both winter (low wind) and spring (high wind). Vegetation varied dramatically between surveys on vegetated and active dune crests. Indices of sand movement had significant correlations with vegetation cover: the depth of loose sand has a strong inverse relationship with crust (cyanobacterial and/or physical) while the area covered by ripples has a strong inverse relationship with the areal cover of vascular plants. However, the relationship between antecedent rainfall and vegetation cover was found to be complex. We tentatively identify two thresholds; (1) >10 mm of rainfall in the preceding 90 days leads to rapid and near total cover of crust and/or small plants <50 cm tall, and (2) >400 mm of rainfall in the preceding three years leads to higher cover of persistent and longer-lived plants >50 cm tall. These thresholds were used to predict days of low vegetation cover on dune crests. The combination of seasonality of predicted bare-crest days, potential sand drift and resultant sand drift direction explains observed patterns of sand drift on these dunes. The complex vegetation and highly variable rainfall regime confer meta-stability on the dunes through the range of responses to different intervals of antecedent rainfall and non-linear growth responses. This suggests that the geomorphic response of dunes to climate variation is complex and non-linear.

    Original languageEnglish
    Pages (from-to)45-61
    Number of pages17
    JournalAeolian Research
    Volume25
    DOIs
    Publication statusPublished - Apr 2017

    Keywords

    • Simpson Desert
    • Strzelecki Desert
    • Climate change
    • Aeolian

    Fingerprint Dive into the research topics of 'Complexity confers stability: climate variability, vegetation response and sand transport on longitudinal sand dunes in Australia's deserts'. Together they form a unique fingerprint.

    Cite this