Pauline Grierson | The University of Western Australia (original) (raw)
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Papers by Pauline Grierson
Limnology and Oceanography, 2010
ABSTRACT
PLOS ONE, 2015
An understanding of past hydroclimatic variability is critical to resolving the significance of r... more An understanding of past hydroclimatic variability is critical to resolving the significance of recent recorded trends in Australian precipitation and informing climate models. Our aim was to reconstruct past hydroclimatic variability in semi-arid northwest Australia to provide a longer context within which to examine a recent period of unusually high summer-autumn precipitation. We developed a 210-year ring-width chronology from Callitris columellaris, which was highly correlated with summer-autumn (Dec-May) precipitation (r = 0.81; 1910-2011; p < 0.0001) and autumn (Mar-May) self-calibrating Palmer drought severity index (scPDSI, r = 0.73; 1910-2011; p < 0.0001) across semi-arid northwest Australia. A linear regression model was used to reconstruct precipitation and explained 66% of the variance in observed summer-autumn precipitation. Our reconstruction reveals inter-annual to multi-decadal scale variation in hydroclimate of the region during the last 210 years, typically showing periods of below average precipitation extending from one to three decades and periods of above average precipitation, which were often less than a decade. Our results demonstrate that the last two decades (1995-2012) have been unusually wet (average summer-autumn precipitation of 310 mm) compared to the previous two centuries (average summer-autumn precipitation of 229 mm), coinciding with both an anomalously high frequency and intensity of tropical cyclones in northwest Australia and the dominance of the positive phase of the Southern Annular Mode.
Below-ground interactions in tropical agroecosystems: concepts and models with multiple plant components, 2004
Plant, cell & environment, Jan 18, 2014
We investigated physiological and morphological responses to flooding and recovery in Eucalyptus ... more We investigated physiological and morphological responses to flooding and recovery in Eucalyptus camaldulensis subsp. refulgens, a riparian tree species from a dryland region prone to intense episodic floods. Seedlings in soil flooded for 88 d produced extensive adventitious roots, displayed stem hypertrophy (stem diameter increased by 93%) and increased root porosity owing to aerenchyma formation. Net photosynthesis (Pn ) and stomatal conductance (gs ) were maintained for at least 2 weeks of soil flooding, contrasting with previous studies of other subspecies of E. camaldulensis. Gradual declines followed in both gs (30% less than controls) and Pn (19% less). Total leaf soluble sugars did not differ between flooded and control plants. Root mass did not recover 32 d after flooding ceased, but gs was not lower than controls, suggesting the root system was able to functionally compensate. However, the limited root growth during recovery after flooding was surprising given the importan...
Dendrochronologia, 2010
Historical fire regimes in the semi-arid shrublands of southern Western Australia are poorly unde... more Historical fire regimes in the semi-arid shrublands of southern Western Australia are poorly understood, largely owing to a lack of quantitative historical data. We sought to determine the dendroecological potential of fire-sensitive Callitris preissii Miq. trees to date historical fires and extend the length of fire-history data available from remotely sensed imagery. We sampled C. preissii trees from known fire
Limnology and Oceanography, 2010
ABSTRACT
PLOS ONE, 2015
An understanding of past hydroclimatic variability is critical to resolving the significance of r... more An understanding of past hydroclimatic variability is critical to resolving the significance of recent recorded trends in Australian precipitation and informing climate models. Our aim was to reconstruct past hydroclimatic variability in semi-arid northwest Australia to provide a longer context within which to examine a recent period of unusually high summer-autumn precipitation. We developed a 210-year ring-width chronology from Callitris columellaris, which was highly correlated with summer-autumn (Dec-May) precipitation (r = 0.81; 1910-2011; p < 0.0001) and autumn (Mar-May) self-calibrating Palmer drought severity index (scPDSI, r = 0.73; 1910-2011; p < 0.0001) across semi-arid northwest Australia. A linear regression model was used to reconstruct precipitation and explained 66% of the variance in observed summer-autumn precipitation. Our reconstruction reveals inter-annual to multi-decadal scale variation in hydroclimate of the region during the last 210 years, typically showing periods of below average precipitation extending from one to three decades and periods of above average precipitation, which were often less than a decade. Our results demonstrate that the last two decades (1995-2012) have been unusually wet (average summer-autumn precipitation of 310 mm) compared to the previous two centuries (average summer-autumn precipitation of 229 mm), coinciding with both an anomalously high frequency and intensity of tropical cyclones in northwest Australia and the dominance of the positive phase of the Southern Annular Mode.
Below-ground interactions in tropical agroecosystems: concepts and models with multiple plant components, 2004
Plant, cell & environment, Jan 18, 2014
We investigated physiological and morphological responses to flooding and recovery in Eucalyptus ... more We investigated physiological and morphological responses to flooding and recovery in Eucalyptus camaldulensis subsp. refulgens, a riparian tree species from a dryland region prone to intense episodic floods. Seedlings in soil flooded for 88 d produced extensive adventitious roots, displayed stem hypertrophy (stem diameter increased by 93%) and increased root porosity owing to aerenchyma formation. Net photosynthesis (Pn ) and stomatal conductance (gs ) were maintained for at least 2 weeks of soil flooding, contrasting with previous studies of other subspecies of E. camaldulensis. Gradual declines followed in both gs (30% less than controls) and Pn (19% less). Total leaf soluble sugars did not differ between flooded and control plants. Root mass did not recover 32 d after flooding ceased, but gs was not lower than controls, suggesting the root system was able to functionally compensate. However, the limited root growth during recovery after flooding was surprising given the importan...
Dendrochronologia, 2010
Historical fire regimes in the semi-arid shrublands of southern Western Australia are poorly unde... more Historical fire regimes in the semi-arid shrublands of southern Western Australia are poorly understood, largely owing to a lack of quantitative historical data. We sought to determine the dendroecological potential of fire-sensitive Callitris preissii Miq. trees to date historical fires and extend the length of fire-history data available from remotely sensed imagery. We sampled C. preissii trees from known fire