Pauline Grierson

Better planning outcomes require adequate data and ecological understanding to be successful and credible: A reply to Evans et al., 2015

Publisher: Elsevier BV

Date: 08-2016

DOI: 10.1016/J.BIOCON.2016.06.010

Variation in stem radial growth of the Australian conifer, Callitris columellaris, across the world's driest and least fertile vegetated continent

Publisher: Springer Science and Business Media LLC

Date: 18-02-2012

DOI: 10.1007/S00468-012-0693-8

Organic acids in the rhizosphere of Banksia integrifolia L.f.

Publisher: Springer Science and Business Media LLC

Date: 08-1992

DOI: 10.1007/BF00012883

Potential for rural electrification based on biomass gasification in Cambodia

Publisher: Elsevier BV

Date: 09-2007

DOI: 10.1016/J.BIOMBIOE.2007.06.023

Multi-decadal scale variability in autumn-winter rainfall in south-western Australia since 1655 AD as reconstructed from tree rings of Callitris columellaris

Publisher: Springer Science and Business Media LLC

Date: 09-09-2009

DOI: 10.1007/S00382-008-0457-8

Source, biogeochemical cycling, and fluorescence characteristics of dissolved organic matter in an agro-urban estuary

Publisher: Wiley

Date: 24-12-2011

DOI: 10.4319/LO.2011.56.1.0243

Dendroecological potential of Callitris preissii for dating historical fires in semi-arid shrublands of southern Western Australia

Publisher: Elsevier BV

Date: 2010

DOI: 10.1016/J.DENDRO.2009.01.002

High-resolution secondary ion mass spectrometry analysis of carbon dynamics in mycorrhizas formed by an obligately myco-heterotrophic orchid

Publisher: Wiley

Date: 12-12-2014

DOI: 10.1111/PCE.12230

Abstract: Mycorrhiza formation represents a significant carbon (C) acquisition alternative for orchid species, particularly those that remain achlorophyllous through all life stages. As it is known that orchid mycorrhizas facilitate nutrient transfer (most notably of C), it has not been resolved if C transfer occurs only after lysis of mycorrhizal structures (fungal pelotons) or also across the mycorrhizal interface of pre-lysed pelotons. We used high-resolution secondary ion mass spectrometry (nanoSIMS) and labelling with enriched (13) CO2 to trace C transfers, at subcellular scale, across mycorrhizal interfaces formed by Rhizanthella gardneri, an achlorphyllous orchid. Carbon was successfully traced in to the fungal portion of orchid mycorrhizas. However, we did not detect C movement across intact mycorrhizal interfaces up to 216 h post (13) CO2 labelling. Our findings provide support for the hypothesis that C transfer from the mycorrhizal fungus to orchid, at least for R. gardneri, likely occurs after lysis of the fungal peloton.

Early physiological flood tolerance is followed by slow post‐flooding root recovery in the dryland riparian tree Eucalyptus camaldulensis subsp. refulgens

Publisher: Wiley

Date: 16-12-2014

DOI: 10.1111/PCE.12473

Abstract: 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 importance of extensive root systems in dryland environments. We conclude that early flood tolerance could be an adaptation to capitalize on scarce water resources in a water-limited environment. Overall, our findings highlight the need to assess flooding responses in relation to a species' fitness for particular flood regimes or ecological niches.

Diel cycles of δ 13CDIC and ecosystem metabolism in ephemeral dryland streams

Publisher: Springer Science and Business Media LLC

Date: 26-02-2020

DOI: 10.1007/S00027-020-0708-2

Spatial scale invariance of southern Australian forest fires mirrors the scaling behaviour of fire-driving weather events

Publisher: Springer Science and Business Media LLC

Date: 03-09-2008

DOI: 10.1007/S10980-008-9260-5

Bioavailability and composition of dissolved organic carbon and nitrogen in a near coastal catchment of south-western Australia

Publisher: Springer Science and Business Media LLC

Date: 16-09-2009

DOI: 10.1007/S10533-008-9238-Z

Resolution of the Eremophila tietkensii (Scrophulariaceae) species complex based on congruence between morphological and molecular pattern analyses

Publisher: CSIRO Publishing

Date: 02-03-2022

DOI: 10.1071/SB21005

Abstract: Eremophila R.Br. comprises at least 238 species endemic to Australia, with many more having not yet been formally described. Three putative new taxa, namely, E. sp. Hamersley Range (K. Walker KW 136), E. sp. Calvert Range (A. A. Burbidge 738) and E. sp. Rudall River (P. G. Wilson 10512), were segregated from a broadly defined E. tietkensii F.Muell. & Tate by J. Hurter at the Western Australian Herbarium in 2012. Both E. sp. Hamersley Range and E. sp. Rudall River are listed as being of conservation concern in Western Australia, the former occurring in the Pilbara region in areas of prospective interest for mining development. We sought to determine whether these phrase-named entities should be formally described as new species, using multivariate analyses of morphometric and molecular data derived from specimens in the Western Australia Herbarium. Eremophila sp. Rudall River could not be adequately separated from E. tietkensii by either morphological or molecular data, and is here included within that species. By contrast, E. sp. Hamersley Range and E. sp. Calvert Range are clearly morphologically and genetically distinct. We thus describe them here as the new species E. naaykensii A.L.Curtis & K.R.Thiele and E. hurteri A.L.Curtis & K.R.Thiele. The recognition of these taxa will help inform their conservation prioritisation and subsequent management.

Estimates of carbon storage in the aboveground biomass of victoria’s forests

Publisher: CSIRO Publishing

Date: 2100

DOI: 10.1071/BT9920631

Abstract: The pool of carbon in the world's forests is of similar magnitude to that in the atmosphere, yet little attention has been given to improving measures of carbon in terrestrial biomass. Much of the critical data for forest biomass on which models of global carbon cycling rely is, in fact, based on the accurate s ling of less than 100 ha of forest. Uncertainties in biomass estimation at the local and regional level may be responsible for much of the current speculation as to unidentified sinks for carbon. We have used a forest inventory (i.e. records of forest volume obtained for harvesting purposes) approach to quantify the biomass of forests in Victoria, Australia. Forests were analysed by type, age and region. Regression equations were developed for the accumulation of biomass with age across all productivity classes for each forest type. The mean carbon density for above-ground components of Victorian native forests is 157 tonnes ha-1 (t ha-1), although forest types range in mean carbon density from 250 to 18 t ha-1. Pinus radiata D. Don plantations in Victoria have a mean carbon density of 91 t ha-1 in the above-ground components. Total carbon stored in above-ground biomass is estimated to be 1.2 X 109 t. Rates of carbon fixation vary with forest age, species and site. Mountain ash (Eucalyptus regnans F. Muell.) forests fix around 9 t of carbon ha-1 annually during the first few years of growth, decreasing to 6 t ha-1 by age 10. Rates of carbon accumulation by other forests are generally less than this and, at the lower end of the range, box-ironbark forests, mallee and woodlands accumulate between 0.5 and 2 t ha-1 year-1. P. radiata plantations in Victoria will accumulate around 7 t carbon ha-1 year-1.

Litter cover as an index of nitrogen availability in rehabilitated mine sites

Publisher: CSIRO Publishing

Date: 2000

DOI: 10.1071/SR99046

Abstract: The spatial heterogeneity of litter cover and bioavailability of nitrogen within a 9-year-old rehabilitated bauxite mine in south Western Australia was examined. Three replicate plots (6 m by 6 m) were each ided into 100 quadrats. Litter cover, vegetation distribution, and projected foliage cover were mapped, and litter (overstorey leaves, understorey leaves, and other assorted fractions) and soil (depth: 0–5, 5–10, and 10–30 cm) were s led from within each quadrat. Litter distribution reflected projected foliage cover, and accumulated within microtopographic depressions. Distribution of soil nitrate (NO3–) reflected the distribution of litter. The 15N natural abundance (d15N) values of soil (0–5 cm) and the understorey litter fraction were significantly correlated (R2 = 0.529, P 0.05), whereas carbon isotope composition (d13C) of soil (0–5 cm) was significantly correlated with the distribution of the assorted litter fraction (R2 = 0.296, P 0.05). It is concluded that site preparation practices that effect microtopography, such as contour ripping and revegetation along contours, will have a significant impact on nitrogen (N) distribution and bioavailability within rehabilitated mine sites.

Mineralisation of nitrogen in a chronosequence of rehabilitated bauxite mines

Publisher: CSIRO Publishing

Date: 2000

DOI: 10.1071/SR99047

Abstract: Mine site rehabilitation should aim to establish quickly and maintain the processes of nutrient cycling at rates comparable with, or approaching, those of native forests. Current management strategies for rehabilitating bauxite mines and other mine sites in Australia usually include planting fast-growing understorey species at high densities and applying fertiliser. We provide the first detailed study of nitrogen (N) availability and N transformations (mineralisation/immobilisation) in such rehabilitated mine sites. Mean concentrations of NO3– (0–5 cm) in a chronosequence (7, 13, 22, and 27 years old) of rehabilitated mine sites ranged from 0.5 to 1.3 kg/ha, and NH4+ from 4.0 to 9.5 kg/ha. In burnt and unburnt native jarrah (E. marginata Donn ex. Smith) forests adjacent to the mine site, mean NO3– concentrations in surface soil (0–5 cm) were 0.8 kg/ha (burnt) and 1.1 kg/ha (unburnt), and mean NH4+ concentrations were 6.8 kg/ha (burnt) and 7.8 kg/ha (unburnt). Concentration of NH4+ at 0–5 cm was strongly related to soil water content (R2 = 0.69, P 0.05) in rehabilitation sites, but not at 5–10 cm depth. Rates of N mineralisation (0–5 cm) in rehabilitation sites ranged from 34 to 52 kg/ha.year, of the same order as rates in native forest soil. In all rehabilitation and native forest sites, rates of N mineralisation were significantly related to rates of N-uptake at both 0–5 and 5–10 cm depth (R2 0.63, P 0.05). Soil C/N ratios (0–5 cm) in rehabilitation sites ranged from 22.4 to 38.8, and in native forests from 35.6 (burnt) to 40.3 (unburnt). Soil C/N ratios increased with depth in both rehabilitation and native forest sites (ranged from 31.2 to 51.6). Availability of water was the major determinant of nitrogen availability in this strongly Mediterranean climate.

Climatic anomalies drive wildfire occurrence and extent in semi-arid shrublands and woodlands of southwest Australia

Publisher: Wiley

Date: 11-2011

DOI: 10.1890/ES11-00189.1

Drought variability in the eastern Australia and New Zealand summer drought atlas (ANZDA, CE 1500-2012) modulated by the Interdecadal Pacific Oscillation

Publisher: IOP Publishing

Date: 24-11-2015

DOI: 10.1088/1748-9326/10/12/124002

Evidence for extreme floods in arid subtropical northwest Australia during the Little Ice Age chronozone (CE 1400–1850)

Publisher: Elsevier BV

Date: 07-2016

DOI: 10.1016/J.QUASCIREV.2016.05.004

A stable oxygen, but not carbon, isotope chronology of Callitris columellaris reflects recent climate change in north-western Australia

Publisher: Springer Science and Business Media LLC

Date: 15-02-2007

DOI: 10.1007/S10584-006-9206-3

Megadroughts in the Common Era and the Anthropocene

Publisher: Springer Science and Business Media LLC

Date: 04-10-2022

DOI: 10.1038/S43017-022-00329-1

Role of soil drying in nitrogen mineralization and microbial community function in semi-arid grasslands of north-west Australia

Publisher: Elsevier BV

Date: 07-2007

DOI: 10.1016/J.SOILBIO.2007.01.014

The use of stable isotopes of oxygen and hydrogen to identify water sources in two hypersaline estuaries with different hydrologic regimes

Publisher: CSIRO Publishing

Date: 2012

DOI: 10.1071/MF12042

Abstract: Stable isotopes of oxygen and hydrogen are used here with salinity data in geochemical and mass-balance models to decipher the proportion of different sources of water in two hypersaline estuaries that vary in size and hydrologic condition. Shark Bay, located on the mid-western coast of Australia, is hypersaline year round and has an arid climate. Florida Bay, located in the south-eastern United States, is seasonally hypersaline and has a subtropical climate. The water budget in both bays can be explained by evaporation of seawater, with seasonal inputs of surface-water runoff and precipitation. In Shark Bay, discharge from the Wooramel River associated with a recent major flood was detected in the relationship between the stable isotopic composition and salinity of surface waters near the mouth of the river, despite the persistence of hypersalinity. The volume of water equal to one pool volume replenished Hamelin Pool (a hypersaline water body located at the southern end of eastern Shark Bay that supports living stromatolites) once every 6–12 months. The eastern portion of Florida Bay received a greater proportion of freshwater from overland flow (70–80%) than did the western portion where rainfall was the dominant source of freshwater.

NITROGEN DYNAMICS IN AN AUSTRALIAN SEMIARID GRASSLAND SOIL

Publisher: Wiley

Date: 08-2006

DOI: 10.1890/0012-9658(2006)87[2047:NDIAAS]2.0.CO;2

Abstract: We conducted a four-week laboratory incubation of soil from a Themeda triandra Forsskal grassland to clarify mechanisms of nitrogen (N) cycling processes in relation to carbon (C) and N availability in a hot, semiarid environment. Variation in soil C and N availability was achieved by collecting soil from either under tussocks or the bare soil between tussocks, and by amending soil with Themeda litter. We measured N cycling by monitoring: dissolved organic nitrogen (DON), ammonium (NH4+), and nitrate (NO3-) contents, gross rates of N mineralization and microbial re-mineralization, NH4+ and NO3- immobilization, and autotrophic and heterotrophic nitrification. We monitored C availability by measuring cumulative soil respiration and dissolved organic C (DOC). Litter-amended soil had cumulative respiration that was eightfold greater than non-amended soil (2000 compared with 250 microg C/g soil) and almost twice the DOC content (54 compared with 28 microg C/g soil). However, litter-amended soils had only half as much DON accumulation as non-amended soils (9 compared with 17 microg N/g soil) and lower gross N rates (1-4 compared with 13-26 microg N x [g soil](-1) x d(-1)) and NO3- accumulation (0.5 compared with 22 microg N/g soil). Unamended soil from under tussocks had almost twice the soil respiration as soil from between tussocks (300 compared with 175 microg C/g soil), and greater DOC content (33 compared with 24 microg C/g soil). However, unamended soil from under tussocks had lower gross N rates (3-20 compared with 17-31 microg N x [g soil](-1) d(-1)) and NO3- accumulation (18 compared with 25 microg N/g soil) relative to soil from between tussocks. We conclude that N cycling in this grassland is mediated by both C and N limitations that arise from the patchiness of tussocks and seasonal variability in Themeda litterfall. Heterotrophic nitrification rate explained >50% of total nitrification, but this percentage was not affected by proximity to tussocks or litter amendment. A conceptual model that considers DON as central to N cycling processes provided a useful initial framework to explain results of our study. However, to fully explain N cycling in this semiarid grassland soil, the production of NO3- from organic N sources must be included in this model.

Global variation in postoperative mortality and complications after cancer surgery: a multicentre, prospective cohort study in 82 countries

Publisher: Elsevier BV

Date: 2021

DOI: 10.1016/S0140-6736(21)00001-5

Evaluating recharge to an ephemeral dryland stream using a hydraulic model and water, chloride and isotope mass balance

Publisher: Elsevier BV

Date: 02-2015

DOI: 10.1016/J.JHYDROL.2014.12.017

Stable isotope and hydrochemical evolution of groundwater in the semi-arid Hamersley Basin of subtropical northwest Australia

Publisher: Elsevier BV

Date: 12-2012

DOI: 10.1016/J.JHYDROL.2012.10.004

Influence of stream–floodplain biogeochemical linkages on aquatic foodweb structure along a gradient of stream size in a tropical catchment

Publisher: University of Chicago Press

Date: 03-2013

DOI: 10.1899/11-117.1

Long-term impacts of prescribed burning on regional extent and incidence of wildfires-Evidence from 50 years of active fire management in SW Australian forests

Publisher: Elsevier BV

Date: 12-2009

DOI: 10.1016/J.FORECO.2009.10.005

Impacts of high inter-annual variability of rainfall on a century of extreme hydrologic regime of northwest Australia

Publisher: Copernicus GmbH

Date: 29-04-2015

DOI: 10.5194/HESS-19-2057-2015

Abstract: Abstract. Long-term hydrologic records provide crucial reference baselines of natural variability that can be used to evaluate potential changes in hydrologic regimes and their impacts. However, there is a dearth of studies of the hydrologic regimes for tropical drylands where intraseasonal and interannual variability in magnitude and frequency of precipitation are extreme. Here, we sought to identify the main hydroclimatic determinants of the strongly episodic flood regime of a large catchment in the semi-arid, subtropical northwest of Australia and to establish the background of hydrologic variability for the region over the last century. We used a monthly sequence of satellite images to quantify surface water expression on the Fortescue Marsh, the largest water feature of inland northwest Australia, from 1988 to 2012. We used this sequence together with instrumental rainfall data to build a statistical model with multiple linear regression and reconstruct monthly history of floods and droughts since 1912. We found that severe and intense regional rainfall events, as well as the sequence of recharge events both within and between years, determine surface water expression on the floodplain (i.e. total rainfall, number of rain days and carried-over inundated area R2adj = 0.79 p value 0.001, ERMSP = 56 km2). The most severe reconstructed inundation over the last century was in March 2000 (1000 km2), which is less than the 1300 km2 area required to overflow to the adjacent catchment. The Fortescue Marsh was completely dry for 32% of all years, for periods of up to four consecutive years. Extremely wet years (seven of the 100 years) caused the Marsh to remain inundated for up to 12 months only 25% of years (9% of all months) had floods of greater than 300 km2. The prolonged, severe and consecutive yearly inundations between 1999 and 2006 were unprecedented compared to the last century. While there is high inter-annual variability in the system, if the frequency and intensity of extreme rainfall events for the region were to increase (or be similar to 1999–2006), surface water on the Marsh will become more persistent, in turn impacting its structure and functioning as a wetland.

Impact of Ecosystem Management on Microbial Community Level Physiological Profiles of Postmining Forest Rehabilitation

Publisher: Springer Science and Business Media LLC

Date: 25-09-2007

DOI: 10.1007/S00248-007-9278-2

Abstract: We investigated the impacts of forest thinning, prescribed fire, and contour ripping on community level physiological profiles (CLPP) of the soil microbial population in postmining forest rehabilitation. We hypothesized that these management practices would affect CLPP via an influence on the quality and quantity of soil organic matter. The study site was an area of Jarrah (Eucalyptus marginata Donn ex Sm.) forest rehabilitation that had been mined for bauxite 12 years previously. Three replicate plots (20 x 20 m) were established in nontreated forest and in forest thinned from 3,000-8,000 stems ha(-1) to 600-800 stems ha(-1) in April (autumn) of 2003, followed either by a prescribed fire in September (spring) of 2003 or left nonburned. Soil s les were collected in August 2004 from two soil depths (0-5 cm and 5-10 cm) and from within mounds and furrows caused by postmining contour ripping. CLPP were not affected by prescribed fire, although the soil pH and organic carbon (C), total C and total nitrogen (N) contents were greater in burned compared with nonburned plots, and the coarse and fine litter mass lower. However, CLPP were affected by forest thinning, as were fine litter mass, soil C/N ratio, and soil pH, which were all higher in thinned than nonthinned plots. Furrow soil had greater coarse and fine litter mass, and inorganic phosphorous (P), organic P, organic C, total C, total N, ammonium, microbial biomass C contents, but lower soil pH and soil C/N ratio than mound soil. Soil pH, inorganic P, organic P, organic C, total C and N, ammonium, and microbial biomass C contents also decreased with depth, whereas soil C/N ratio increased. Differences in CLPP were largely (94%) associated with the relative utilization of gluconic, malic (greater in nonthinned than thinned soil and mound than furrow soil), L-tartaric, succinic, and uric acids (greater in thinned than nonthinned, mound than furrow, and 5-10 cm than 0-5 cm soil). The relative utilization of amino acids also tended to increase with increasing soil total C and organic C contents but decreased with increasing nitrate content, whereas the opposite was true for carboxylic acids. Only 45% of the variance in CLPP was explained using a multivariate multiple regression model, but soil C and N pools and litter mass were significant predictors of CLPP. Differences in soil textural components between treatments were also correlated with CLPP likely causes of these differences are discussed. Our results suggest that 1 year after treatment, CLPP from this mined forest ecosystem are resilient to a spring prescribed fire but not forest thinning. We conclude that differences in CLPP are likely to result from complex interactions among soil properties that mediate substrate availability, microbial nutrient demand, and microbial community composition.

Nitrogen mineralization potential in rewetted soils from a semi-arid stream landscape, north-west Australia

Publisher: Elsevier BV

Date: 2009

DOI: 10.1016/J.JARIDENV.2008.09.011

Groundwater seepage controls salinity in a hydrologically terminal basin of semi-arid northwest Australia

Publisher: Elsevier BV

Date: 11-2016

DOI: 10.1016/J.JHYDROL.2016.09.033

Cacao quality: Highlighting selected attributes

Publisher: Informa UK Limited

Date: 11-04-2016

DOI: 10.1080/87559129.2016.1175011

Low light availability alters root exudation and reduces putative beneficial microorganisms in seagrass roots

Publisher: Frontiers Media SA

Date: 11-01-2018

DOI: 10.3389/FMICB.2017.02667

Short-term microbial respiration in an arid zone mangrove soil is limited by availability of gallic acid, phosphorus and ammonium

Publisher: Elsevier BV

Date: 12-2017

DOI: 10.1016/J.SOILBIO.2017.08.010

Taxonomic resolution of the Tetratheca hirsuta (Elaeocarpaceae) species complex using an integrative approach

Publisher: CSIRO Publishing

Date: 2017

DOI: 10.1071/SB16040

Abstract: The Tetratheca hirsuta Lindl. species complex from south-west Western Australia is one of the last unresolved complexes in this Australian endemic genus, and comprises the highly variable T. hirsuta, two rare, phrase-named taxa, and the closely allied T. hispidissima Steetz. An integrative approach, incorporating multivariate morphometric analysis and molecular phylogenetic and phenetic analyses of nrDNA (ETS) and cpDNA (ndhF–trnL, rpl16, trnS–trnG5ʹ2S), was used to investigate taxonomic boundaries within the complex. Morphological data showed clear ergence within the complex, and allowed several taxonomically uncertain in iduals to be assigned. Phenetic and phylogenetic analyses of ETS showed substantial congruence with morphology, indicating that the groups recognised through morphometric analyses are also genetically ergent. By comparison, the chloroplast regions yielded incongruent gene trees, perhaps owing to incomplete lineage sorting, hybridisation or slow evolution of cpDNA. The present results support the recognition of the following four taxa: a morphologically and geographically expanded T. hispidissima, which is highly ergent from the remainder of the complex, and a closer grouping of T. hirsuta subsp. boonanarring Joyce & R.Butcher subsp. nov., T. hirsuta subsp. viminea (Lindl.) Joyce comb. et stat. nov. and T. hirsuta subsp. hirsuta.

Carbon and nitrogen supply to the underground orchid, Rhizanthella gardneri

Publisher: Wiley

Date: 26-03-2010

DOI: 10.1111/J.1469-8137.2010.03246.X

Abstract: *Rhizanthella gardneri is a rare and fully subterranean orchid that is presumably obligately mycoheterotrophic. R. gardneri is thought to be linked via a common mycorrhizal fungus to co-occurring autotrophic shrubs, but there is no experimental evidence to support this supposition. *We used compartmentalized microcosms to investigate the R. gardneri tripartite relationship. (13)CO(2) was applied to foliage of Melaleuca scalena plants and [(13)C-(15)N]glycine was fed to the common mycorrhizal fungus, and both sources traced to R. gardneri plants. *In our microcosm trial, up to 5% of carbon (C) fed as (13)CO(2) to the autotrophic shrub was transferred to R. gardneri. R. gardneri also readily acquired soil C and nitrogen (N), where up to 6.2% of C and 22.5% of N fed as labelled glycine to soil was transferred via the fungus to R. gardneri after 240 h. *Our study confirms that R. gardneri is mycoheterotrophic and acquires nutrients via mycorrhizal fungus connections from an ectomycorrhizal autotrophic shrub and directly from the soil via the same fungus. This connection with a specific fungus is key to explaining why R. gardneri occurs exclusively under certain Melaleuca species at a very limited number of sites in Western Australia.

Vegetation and landscape connectivity control wildfire intervals in unmanaged semi-arid shrublands and woodlands in Australia

Publisher: Wiley

Date: 16-08-2011

DOI: 10.1111/J.1365-2699.2010.02381.X

Evaluation of anion exchange membranes to estimate bioavailable phosphorus in native grasslands of semi-arid northwestern Australia

Publisher: Informa UK Limited

Date: 09-1999

DOI: 10.1080/00103629909370368

Relationships among net primary productivity, nutrients and climate in tropical rain forest: a pan-tropical analysis

Publisher: Wiley

Date: 08-11-2011

DOI: 10.1111/J.1461-0248.2011.01711.X

Reply to Comment on 'Drought variability in the eastern Australia and New Zealand summer drought atlas (ANZDA, CE 1500-2012) modulated by the Interdecadal Pacific Oscillation'

Publisher: IOP Publishing

Date: 30-05-2017

DOI: 10.1088/1748-9326/AA7281

Quercitol and osmotic adaptation of field-grown Eucalyptus under seasonal drought stress

Publisher: Wiley

Date: 27-02-2008

DOI: 10.1111/J.1365-3040.2008.01803.X

Abstract: This study investigated the role of quercitol in osmotic adjustment in field-grown Eucalyptus astringens Maiden subject to seasonal drought stress over the course of 1 year. The trees grew in a native woodland and a farm plantation in the semi-arid wheatbelt region of south Western Australia. Plantation trees allocated relatively more biomass to leaves than woodland trees, but they suffered greater drought stress over summer, as indicated by lower water potentials, CO(2)assimilation rates and stomatal conductances. In contrast, woodland trees had relatively fewer leaves and suffered less drought stress. Plantation trees under drought stress engaged in osmotic adjustment, but woodland trees did not. Quercitol made a significant contribution to osmotic adjustment in drought-stressed trees (25% of total solutes), and substantially more quercitol was measured in the leaves of plantation trees (5% dry matter) than in the leaves of woodland trees (2% dry matter). We found no evidence that quercitol was used as a carbon storage compound while starch reserves were depleted under drought stress. Differences in stomatal conductance, biomass allocation and quercitol production clearly indicate that E. astringens is both morphologically and physiologically 'plastic' in response to growth environment, and that osmotic adjustment is only one part of a complex strategy employed by this species to tolerate drought.

Scale-dependent thresholds in the dominant controls of wildfire size in semi-arid southwest Australia

Publisher: Wiley

Date: 07-2014

DOI: 10.1890/ES14-00145.1

Linking stream ecology with morphological variability in a native freshwater fish from semi‐arid Australia

Publisher: Wiley

Date: 16-07-2015

DOI: 10.1002/ECE3.1590

Identity and specificity of the fungi forming mycorrhizas with the rare mycoheterotrophic orchid Rhizanthella gardneri

Publisher: Elsevier BV

Date: 10-2009

DOI: 10.1016/J.MYCRES.2009.07.007

Abstract: Fully subterranean Rhizanthella gardneri (Orchidaceae) is obligately mycoheterotrophic meaning it is nutritionally dependent on the fungus it forms mycorrhizas with. Furthermore, R. gardneri purportedly participates in a nutrient sharing tripartite relationship where its mycorrhizal fungus simultaneously forms ectomycorrhizas with species of Melaleuca uncinata s.l. Although the mycorrhizal fungus of R. gardneri has been morphologically identified as Thanatephorus gardneri (from a single isolate), this identification has been recently questioned. We sought to clarify the identification of the mycorrhizal fungus of R. gardneri, using molecular methods, and to identify how specific its mycorrhizal relationship is. Fungal isolates taken from all sites where R. gardneri is known to occur shared almost identical ribosomal DNA (rDNA) sequences. The fungal isolate rDNA most closely matched that of other Ceratobasidiales species, particularly within the Ceratobasidium genus. However, interpretation of results was difficult as we found two distinct ITS sequences within all mycorrhizal fungal isolates of R. gardneri that we assessed. All mycorrhizal fungal isolates of R. gardneri readily formed ectomycorrhizas with a range of M. uncinata s.l. species. Consequently, it is likely that R. gardneri can form a nutrient sharing tripartite relationship where R. gardneri is connected to autotrophic M. uncinata s.l. by a common mycorrhizal fungus. These findings have implications for better understanding R. gardneri distribution, evolution and the ecological significance of its mycorrhizal fungus, particularly in relation to nutrient acquisition.

Alluvial ground water influences dissolved organic matter biogeochemistry of pools within intermittent dryland streams

Publisher: Wiley

Date: 06-08-2016

DOI: 10.1111/FWB.12656

Is cellulose extraction necessary for developing stable carbon and oxygen isotopes chronologies from Callitris glaucophylla?

Publisher: Elsevier BV

Date: 06-2006

DOI: 10.1016/J.PALAEO.2005.11.003

Population structures of the widespread Australian conifer Callitris columellaris are a bio-indicator of continental environmental change

Publisher: Elsevier BV

Date: 07-2011

DOI: 10.1016/J.FORECO.2011.03.030

Climate relationships with tree-ring width and¹³C of three Callitris species from semiarid woodlands in south-western Australia

Publisher: CSIRO Publishing

Date: 2010

DOI: 10.1071/BT09222

Abstract: Proxy measures of climate based on tree rings can allow reconstruction of climate back past the limit of instrumental records, thereby improving understanding of natural climate variability. We assessed the dendroclimatic potential of tree-ring widths and δ13C of three broadly co-occurring species of Callitris in south-western Western Australia. Ring width chronologies of C. columellaris F.Muell., C. canescens (Parl.) S.T. Blake and C. preissii Miq. met standard measures of dendrochronological acceptability. For all three species, the Expressed Population Signal (EPS) was .93 and mean correlations between series in each chronology was .79. In contrast, δ13C chronologies were of poorer statistical quality (EPS ranged 0.59 to 0.88, mean correlations ranged 0.33 to 0.65) with both less year-to-year and lower-frequency information (lower mean sensitivity and standard deviation values). The dominant climatic signal in the ring width chronologies was related to rainfall and was strongest over the March–September season (correlations ranged 0.27 to 0.70, all P 0.05). Consistent with the poorer quality of the δ13C chronologies compared with those from ring widths, tree-ring δ13C was also less strongly correlated with rainfall and rarely significant (P = 0.05). The weaker δ13C correlations may be due to a strong water conservation strategy by Callitris. Our analysis of the whole ring rather than latewood and low s ling effort may also have d ened the δ13C response. However, combining the ring width and δ13C chronologies using Principal Components Analysis did not enhance the extraction of a climatic signal. While the variance explained by the first principal component (PC) was high for all three species (76 to 87%), correlations between the first PC and rainfall were not stronger than for ring widths alone. Tree-ring δ13C, in conjunction with δ18O in particular, may nevertheless provide insight into physiological responses of Callitris to climate variation. However, dendroclimatic studies using Callitris to develop past rainfall records should focus on developing chronologies from ring widths. Further effort to find sites with old trees (250 years or more) should be undertaken and are likely to provide much needed information on past rainfall in Australia.

Leaf litter age, chemical quality, and photodegradation control the fate of leachate dissolved organic matter in a dryland river

Publisher: Elsevier BV

Date: 02-2013

DOI: 10.1016/J.JARIDENV.2012.10.011

Geochemical and hydrological processes controlling groundwater salinity of a large inland wetland of northwest Australia

Publisher: Elsevier BV

Date: 10-2013

DOI: 10.1016/J.CHEMGEO.2013.08.035

Controls on Interactions Between Surface Water, Groundwater, and Riverine Vegetation Along Intermittent Rivers and Ephemeral Streams in Arid Regions

Publisher: American Geophysical Union (AGU)

Date: 02-2021

DOI: 10.1029/2020WR028429

Abstract: Intermittent rivers and ephemeral streams (IRES) make up the majority of waterways in arid and semi‐arid regions. While the physical underpinnings of surface water‐groundwater (SW‐GW) flow systems are well understood, how ephemerality, hydraulic properties and vegetation interact along IRES is not clear, posing severe challenges to their sustainable management. This study sought to identify the controls for SW‐GW‐vegetation interactions along IRES. To this end, numerical experiments on a quasi‐hypothetical IRES cross‐section with an integrated surface‐subsurface hydrological model were undertaken. The influence of different degrees of ephemerality on infiltration and riverine transpiration was tested by varying the duration of no‐flow periods. The influence of hydraulic conductivity (K), moisture retention capacity, root density, and local rainfall was also explored. Experiments showed that infiltration is controlled by ephemerality and K, with infiltration decreasing rapidly with increasing ephemerality and decreasing K. Transpiration is influenced by a complex interplay between ephemerality, hydraulic properties, and vegetation. While transpiration is strongly controlled by the degree of ephemerality, the capacity of the subsurface to maintain variably saturated conditions can strongly attenuate the effects of ephemerality. A large moisture retention capacity of the subsurface can partly compensate for the reduced infiltration under increasing ephemerality. Transpiration can be as large under ephemeral as under perennial conditions, especially where water table fluctuations exhibit large litudes within the zone of high root density. Overall, the results provide important insights into the complex dynamics of IRES and highlight how changes in flow dynamics can have significant impacts beyond instream processes.

Stable isotopes at natural abundance in terrestrial plant ecology and ecophysiology: An update

Publisher: Wiley

Date: 07-2001

DOI: 10.1055/S-2001-16454

Phosphorus mineralization and microbial biomass in a Florida Spodosol: Effects of water potential, temperature and fertilizer application

Publisher: Springer Science and Business Media LLC

Date: 1999

DOI: 10.1007/S003740050489

Plant species affect acid phosphatase, ergosterol and microbial P in a Jarrah (Eucalyptus marginata Donn ex Sm.) forest in south-western Australia

Publisher: Elsevier BV

Date: 11-2000

DOI: 10.1016/S0038-0717(00)00155-3

Three-dimensional xylem networks and phyllode properties of co-occurring Acacia

Publisher: Wiley

Date: 19-09-2011

DOI: 10.1111/J.1365-3040.2011.02411.X

Abstract: Reduced leaf size is often correlated to increased aridity, where smaller leaves demand less water via xylem conduits. However, it is unknown if differences in three-dimensional (3D) xylem connectivity reflect leaf-level adaptations. We used X-ray microtomography (micro-CT) to quantify 3D xylem connectivity in ∼5 mm diameter branch sections of co-occurring semi-arid Acacia species of varied phyllode size. We compared 3D connectivity to minimum branch water potential and two-dimensional (2D) vessel attributes derived from sections produced by micro-CT. 2D attributes included vessel area, density, vessel size to number ratio (S) and vessel lumen fraction (F). Trees with terete phyllodes had less negative water potentials than broad phyllode variants. 3D xylem connectivity was conserved across all trees regardless of phyllode type or minimum water potential. We also found that xylem connectivity was sensitive to vessel lumen fraction (F) and not the size to number ratio (S) even though F was consistent among species and phyllode variants. Our results demonstrate that differences in phyllode anatomy, and not xylem connectivity, likely explain ersity of drought tolerance among closely related Acacia species. Further analysis using our approach across a broader range of species will improve understanding of adaptations in the xylem networks of arid zone species.

The paleoclimate context and future trajectory of extreme summer hydroclimate in eastern Australia

Publisher: American Geophysical Union (AGU)

Date: 12-11-2016

DOI: 10.1002/2016JD024892

Inter- and intra-specific variation in phyllode size and growth form among closely related Mimosaceae Acacia species across a semiarid landscape gradient

Publisher: CSIRO Publishing

Date: 2011

DOI: 10.1071/BT11057

Abstract: The mulga complex (Acacia aneura F. Muell ex Benth and closely related species) consists of woody trees and shrubs, and is distributed across 20% of the Australian continent. A. aneura is renowned for a wide variety of phyllode shapes and growth forms, which may co-occur at any one site. We examined the intra- and inter-specific variation in growth form and phyllode shape in four species of the mulga complex, including A. aneura, across topographic gradients in semiarid north-west Australia. We measured 792 trees across 28 sites stratified into six discrete landscape positions upper slope, lower slope, low open woodland, banded woodland, low woodland, and drainage line. Dominance of phyllode shapes was strongly related to landscape position. A. aneura with terete phyllodes were dominant on the hill slopes, whereas broad phyllodes were most common on A. aneura in all valley woodlands. Trends in growth form were less distinct, although single-stemmed forms were more common on hills, whereas the valleys had more multi-stemmed forms. The quantification of growth form and phyllode shape variability within the mulga complex provides a basis for the quantitative determination of functional links between morphology and environmental conditions at both the site and landscape level.

Rewetting and litter addition influence mineralisation and microbial communities in soils from a semi-arid intermittent stream

Publisher: Elsevier BV

Date: 2009

DOI: 10.1016/J.SOILBIO.2008.09.021

On the long-term context of the 1997-2009 'Big Dry' in South-Eastern Australia: Insights from a 206-year multi-proxy rainfall reconstruction

Publisher: Springer Science and Business Media LLC

Date: 04-11-2012

DOI: 10.1007/S10584-011-0263-X

Inter-specific differences in the dynamics of water use and pulse-response of co-dominant canopy species in a dryland woodland

Publisher: Elsevier BV

Date: 2016

DOI: 10.1016/J.JARIDENV.2015.09.004

Phosphorus mobilization in agroforestry: Organic anions, phosphatase activity and phosphorus fractions in the rhizosphere

Publisher: Springer Science and Business Media LLC

Date: 02-2004

DOI: 10.1023/B:PLSO.0000020970.40167.40

How cold was it for Neanderthals moving to Central Europe during warm phases of the last glaciation?

Publisher: Elsevier BV

Date: 03-2011

DOI: 10.1016/J.QUASCIREV.2010.12.018

Paleoenvironmental and paleohydrochemical conditions of dolomite formation within a saline wetland in arid northwest Australia

Publisher: Elsevier BV

Date: 04-2018

DOI: 10.1016/J.QUASCIREV.2018.02.007

Multidecadal variations in Southern Hemisphere atmospheric ¹⁴C: Evidence against a Southern Ocean sink at the end of the Little Ice Age CO2 anomaly

Publisher: American Geophysical Union (AGU)

Date: 02-2016

DOI: 10.1002/2015GB005257

Natural hazards in Australia: extreme bushfire

Publisher: Springer Science and Business Media LLC

Date: 06-10-2016

DOI: 10.1007/S10584-016-1811-1

Geomorphic and hydrological controls on groundwater dolocrete formation in the semi‐arid Hamersley Basin, northwest Australia

Publisher: Wiley

Date: 14-08-2019

DOI: 10.1002/ESP.4704

Phosphatase activity, microbial phosphorus, and fine root growth in forest soils in the Sierra de Gata, western central Spain

Publisher: Springer Science and Business Media LLC

Date: 09-2001

DOI: 10.1007/S003740100387

Root hydraulic conductance and aquaporin abundance respond rapidly to partial root-zone drying events in a riparian Melaleuca species

Publisher: Wiley

Date: 16-08-2011

DOI: 10.1111/J.1469-8137.2011.03834.X

Abstract: • Drying a portion of a root system (partial root-zone drying (PRD)) can induce partial stomatal closure, but this response is not always observed. We hypothesized that some of the variation in PRD response reflects adaptations to the native environment, where plants subjected to frequent PRD events may display a greater degree of root-level compensation. • Here, we examined PRD responses of Melaleuca argentea, a tree native to intermittent waterways in which PRD events are common. Seedlings were grown with part of their root system in soil and part in an aquatic compartment, mimicking conditions often observed in the field. • The aquatic roots initially provided two-thirds of total water uptake, but draining the aquatic compartment had no effect on stomatal conductance, so long as soil moisture remained c. 80% of field capacity. Water uptake from the soil compartment increased threefold within 24 h, with a corresponding transient threefold increase in root hydraulic conductance (L(p)), an increase in plasma membrane intrinsic protein 1 (PIP1) aquaporins at 24 h, and a decrease in PIP2 aquaporins by 48 h. • Our results demonstrate that PRD can induce rapid changes in L(p) and aquaporin expression in roots, which may play a role in short-term water uptake adjustments, particularly in species adapted to heterogeneous water availability.

Recent range expansion in Australian hummock grasses (Triodia) inferred using genotyping-by-sequencing

Publisher: Oxford University Press (OUP)

Date: 03-2019

DOI: 10.1093/AOBPLA/PLZ017

Habitat characteristics of the rare underground orchid Rhizanthella gardneri

Publisher: CSIRO Publishing

Date: 2008

DOI: 10.1071/BT08031

Abstract: Rhizanthella gardneri R.S.Rogers is an entirely subterranean mycoheterotrophic orchid known only from two isolated populations within south-western Western Australia (WA). This rare species appears restricted to habitats dominated by species of the Melaleuca uncinata complex. R. gardneri purportedly forms a tripartite relationship with Melaleuca1, via a connecting mycorrhizal fungus, for the purpose of carbohydrate and nutrient acquisition. Here, we quantify key climate, soil and vegetation characteristics of known R. gardneri habitats to provide baseline data for monitoring of known R. gardneri populations, to better understand how R. gardneri interacts with its habitat and to identify possible new sites for R. gardneri introduction. We found that the habitats of the two known R. gardneri populations show considerable differences in soil chemistry, Melaleuca structure and Melaleuca productivity. Multivariate analyses showed that both multidimensional scaling (MDS) and principal components analysis (PCA) ordinations of soil chemical characteristics were very similar. In idual sites within populations were relatively similar in all attributes measured, whereas overall northern and southern habitats were distinct from each other. These results suggest that R. gardneri can tolerate a range of conditions and may be more widespread than previously thought, given that there are extensive areas of Melaleuca thickets with similar habitat characteristics across south-western WA. Variability within the habitats of known R. gardneri populations suggests translocation of this species into sites with similar vegetation may be a viable option for the survival of this species.

Phosphorus mineralization kinetics and response of microbial phosphorus to drying and rewetting in a Florida spodosol

Publisher: Elsevier BV

Date: 09-1998

DOI: 10.1016/S0038-0717(98)00002-9

Chemical characteristics of the proteoid root mat of Banksia integrifolia L

Publisher: CSIRO Publishing

Date: 1989

DOI: 10.1071/BT9890137

Abstract: The proteoid roots of Banksia integrifolia are concentrated in the surface soil, forming a dense mat beneath the litter layer. Water extracts of the proteoid root mat contained a significantly greater amount of hydrogen ions, reductants and an unidentified chelating agent, than water extracts of soil beneath the root mat, of the litter layer and of soil from beyond the proteoid root zone. The results are discussed in relation to previously reported production of organic chelates by plants causing solubilisation of soil phosphates. It is suggested the proteoid roots of B. integrifolia chemically modify the soil environment thereby enhancing nutrient uptake.

Hydrologic control of dissolved organic matter biogeochemistry in pools of a subtropical dryland river

Publisher: American Geophysical Union (AGU)

Date: 06-2011

DOI: 10.1029/2010WR010275

Potential for tree rings to reveal spatial patterns of past drought variability across western Australia

Publisher: IOP Publishing

Date: 02-2018

DOI: 10.1088/1748-9326/AAA204

Relationships among net primary productivity, nutrients and climate in tropical rain forest: a pan‐tropical analysis

Publisher: Wiley

Date: 12-07-2011

DOI: 10.1111/J.1461-0248.2011.01658.X

Abstract: Tropical rain forests play a dominant role in global biosphere-atmosphere CO(2) exchange. Although climate and nutrient availability regulate net primary production (NPP) and decomposition in all terrestrial ecosystems, the nature and extent of such controls in tropical forests remain poorly resolved. We conducted a meta-analysis of carbon-nutrient-climate relationships in 113 sites across the tropical forest biome. Our analyses showed that mean annual temperature was the strongest predictor of aboveground NPP (ANPP) across all tropical forests, but this relationship was driven by distinct temperature differences between upland and lowland forests. Within lowland forests (< 1000 m), a regression tree analysis revealed that foliar and soil-based measurements of phosphorus (P) were the only variables that explained a significant proportion of the variation in ANPP, although the relationships were weak. However, foliar P, foliar nitrogen (N), litter decomposition rate (k), soil N and soil respiration were all directly related with total surface (0-10 cm) soil P concentrations. Our analysis provides some evidence that P availability regulates NPP and other ecosystem processes in lowland tropical forests, but more importantly, underscores the need for a series of large-scale nutrient manipulations - especially in lowland forests - to elucidate the most important nutrient interactions and controls.

Soil water nitrate and ammonium dynamics under a sewage effluent-irrigated eucalypt plantation

Publisher: Wiley

Date: 11-2007

DOI: 10.2134/JEQ2007.0175

Abstract: Managed forests and plantations are appropriate ecosystems for land-based treatment of effluent, but concerns remain regarding nutrient contamination of ground- and surface waters. Monthly NO3-N and NH4-N concentrations in soil water, accumulated soil N, and gross ammonification and nitrification rates were measured in the second year of a second rotation of an effluent irrigated Eucalyptus globulus plantation in southern Western Australia to investigate the separate and interactive effects of drip and sprinkler irrigation, effluent and water irrigation, irrigation rate, and harvest residues retention. Nitrate concentrations of soil water were greater under effluent irrigation than water irrigation but remained <15 mg L(-1) when irrigated at the normal rate (1.5-2.0 mm d(-1)), and there was little evidence of downward movement. In contrast, NH4-N concentrations of soil water at 30 and 100 cm were generally greater under effluent irrigation than water irrigation when irrigated at the normal rate because of direct effluent NH4-N input and indirect ammonification of soil organic N. Drip irrigation of effluent approximately doubled peak NO3-N and NH4-N concentrations in soil water. Harvest residue retention reduced concentrations of soil water NO3-N at 30 cm during active sprinkler irrigation, but after 1 yr of irrigation there was no significant difference in the amount of N stored in the soil system, although harvest residue retention did enhance the "nitrate flush" in the following spring. Gross mineralization rates without irrigation increased with harvest residue retention and further increased with water irrigation. Irrigation with effluent further increased gross nitrification to 3.1 mg N kg(-1) d(-1) when harvest residues were retained but had no effect on gross ammonification, which suggested the importance of heterotrophic nitrification. The downward movement of N under effluent irrigation was dominated by NH4-N rather than NO3-N. Improving the capacity of forest soils to store and transform N inputs through organic matter management must consider the dynamic equilibrium between N input, uptake, and immobilization according to soil C status, and the effect changing microbial processes and environmental conditions can have on this equilibrium.

Unique stable isotope signatures of large cyclonic events as a tracer of soil moisture dynamics in the semiarid subtropics

Publisher: Elsevier BV

Date: 11-2019

DOI: 10.1016/J.JHYDROL.2019.124124

Estimation of evaporative loss based on the stable isotope composition of water using Hydrocalculator

Publisher: Elsevier BV

Date: 04-2015

DOI: 10.1016/J.JHYDROL.2015.02.010

Functional diversity of the lateral line system among populations of a native Australian freshwater fish

Publisher: The Company of Biologists

Date: 2017

DOI: 10.1242/JEB.151530

Abstract: Fishes use their mechanoreceptive lateral line system to sense nearby objects by detecting slight fluctuations in hydrodynamic motion within their immediate environment. Species of fishes from different habitats often display specialisations of the lateral line system, in particular the distribution and abundance of neuromasts, but the lateral line can also exhibit considerable ersity within a species. Here, we provide the first investigation of the lateral line system of the Australian western rainbowfish (Melanotaenia australis), a species that occupies a ersity of freshwater habitats across semi-arid northwest Australia. We collected 155 in iduals from eight populations and surveyed each habitat for environmental factors that may contribute to lateral line specialisation, including water flow, predation risk, habitat structure, and prey availability. Scanning electron microscopy (SEM) and fluorescent dye labelling were used to describe the lateral line system in M. australis, and to examine whether the abundance and arrangement of superficial neuromasts (SNs) varied within and among populations. We found that the SNs of M. australis were present in distinct body regions rather than lines. The abundance of SNs within each body region was highly variable, and also differed among populations and in iduals. Variation in SN abundance among populations was best explained by habitat structure and the availability of invertebrate prey. Our finding that specific environmental factors explain among-population variation in a key sensory system suggests that the ability to acquire sensory information is specialised for the particular behavioural needs of the animal.

Direct determination of phosphate in soil extracts by potentiometric flow injection using a cobalt wire electrode

Publisher: Elsevier BV

Date: 05-1998

DOI: 10.1016/S0003-2670(98)00137-8

Low resource availability limits weed invasion of tropical savannas

Publisher: Springer Science and Business Media LLC

Date: 13-10-2017

DOI: 10.1007/S10530-017-1578-Y

Chemotaxonomic responses of autotrophic periphyton communities to nutrient additions in pools of an intermittent stream

Publisher: Wiley

Date: 19-10-2022

DOI: 10.1111/FWB.14002

Abstract: The algal groups present in periphyton communities form an important base of autochthonous food webs in freshwater streams. Nitrogen (N) and phosphorus (P) are key macronutrients in aquatic systems. Excess nutrients benefit some algal groups over others. We paired a nutrient‐diffusing substrata limitation experiment with high performance liquid chromatography to (a) identify which nutrient(s) limit periphyton production, and (b) how the periphyton biomass and community structure changes between isolated pools of differing hydrological characteristics along an intermittent dryland stream. Unique peaks for 21 pigments were identified and matched with published values. We then produced a PERMANOVA model using pigment ratios and CHEMTAX analysis to explore changes in community structure resulting from nutrient addition. Periphyton communities in these pools were co‐limited by N and P. Nitrogen additions caused the periphyton to shift from diatom‐ to chlorophyte‐dominated community structure and benefited cyanophyta growth. Phosphorus additions reduced the relative proportion of diatoms and also resulted in an increase in pheophoribide‐ a , a pigment indicative of cell lysis, demonstrating a detrimental impact of P additions. Outcomes of this study show that when adding nutrient to a system there may be subtle shifts in community composition which can be telescoped up the food web regardless of the system's nutrient status.

SARS-CoV-2 vaccination modelling for safe surgery to save lives: data from an international prospective cohort study

Publisher: Oxford University Press (OUP)

Date: 24-03-2021

DOI: 10.1093/BJS/ZNAB101

Abstract: Preoperative SARS-CoV-2 vaccination could support safer elective surgery. Vaccine numbers are limited so this study aimed to inform their prioritization by modelling. The primary outcome was the number needed to vaccinate (NNV) to prevent one COVID-19-related death in 1 year. NNVs were based on postoperative SARS-CoV-2 rates and mortality in an international cohort study (surgical patients), and community SARS-CoV-2 incidence and case fatality data (general population). NNV estimates were stratified by age (18–49, 50–69, 70 or more years) and type of surgery. Best- and worst-case scenarios were used to describe uncertainty. NNVs were more favourable in surgical patients than the general population. The most favourable NNVs were in patients aged 70 years or more needing cancer surgery (351 best case 196, worst case 816) or non-cancer surgery (733 best case 407, worst case 1664). Both exceeded the NNV in the general population (1840 best case 1196, worst case 3066). NNVs for surgical patients remained favourable at a range of SARS-CoV-2 incidence rates in sensitivity analysis modelling. Globally, prioritizing preoperative vaccination of patients needing elective surgery ahead of the general population could prevent an additional 58 687 (best case 115 007, worst case 20 177) COVID-19-related deaths in 1 year. As global roll out of SARS-CoV-2 vaccination proceeds, patients needing elective surgery should be prioritized ahead of the general population.

The origin and function of dissolved organic matter in agro-urban coastal streams

Publisher: American Geophysical Union (AGU)

Date: 12-03-2011

DOI: 10.1029/2010JG001537

Dissolved organic carbon biolability decreases along with its modernization in fluvial networks in an ancient landscape

Publisher: Wiley

Date: 09-2014

DOI: 10.1890/13-1360.1

Mapping burned areas and burn severity patterns in SW Australian eucalypt forest using remotely-sensed changes in leaf area index

Publisher: Elsevier BV

Date: 15-12-2008

DOI: 10.1016/J.RSE.2008.08.005

Impact of severe forest dieback caused by Phytophthora cinnamomi on macrofungal diversity in the northern jarrah forest of Western Australia

Publisher: Elsevier BV

Date: 02-2010

DOI: 10.1016/J.FORECO.2009.12.015

Interpreting vegetation change in tropical arid ecosystems from sediment molecular fossils and their stable isotope compositions: A baseline study from the Pilbara region of northwest Australia

Publisher: Elsevier BV

Date: 10-2016

DOI: 10.1016/J.PALAEO.2016.07.023

Leaf litter chemistry, decomposition and assimilation by macroinvertebrates in two tropical streams

Publisher: Springer Science and Business Media LLC

Date: 18-10-2011

DOI: 10.1007/S10750-011-0903-1

Microbial community composition and functioning in the rhizosphere of three Banksia species in native woodland in Western Australia

Publisher: Elsevier BV

Date: 03-2005

DOI: 10.1016/J.APSOIL.2004.09.001

Phosphorus sorption characteristics and interactions with leaf litter-derived dissolved organic matter leachate in iron-rich sediments of a sub-tropical ephemeral stream

Publisher: Springer Science and Business Media LLC

Date: 12-09-2022

DOI: 10.1007/S00027-022-00888-X

Abstract: This study investigated the influence of dissolved organic matter (DOM) additions on phosphate sorption kinetics of iron-rich sediments (39–50% hematite and goethite) from an ephemeral stream in the arid Pilbara region of sub-tropical northwest Australia. While phosphate sorption in stream sediments is known to be strongly influenced by sediment mineralogy as well as interactions with DOM, the mechanisms and significance of DOM on P-release from sediments with high sorption capacities, are largely undescribed. We assessed phosphorus (P) sorption behaviours by adding a range of solutions of known inorganic P concentrations that were amended with variable loadings of DOM derived from leachates of leaf litter to sediments from stream pools during the non-flowing phase. We compared the sorption capacity of the sediments and concurrent changes in DOM composition measured using fluorescence spectroscopy. We show that the low-dose DOM addition (~ 4 mg L −1 DOC) had the effect of reducing sediment P adsorption capacity, while for the high-dose DOM addition (~ 45 mg L −1 DOC), it was increased. The high-dose DOM was similar to pore water DOC and likely saturated sediment surface adsorption sites and produced P–OM–Fe complexes. This resulted in increased removal of P from solution. Sediment P sorption characteristics were well fitted to both Freundlich and Langmuir isotherm models regardless of DOC concentration. Langmuir P sorption maxima ranged from 0.106 to 0.152 mg g −1 . General P sorption characteristics of these iron-rich sediments did not differ among pools of contrasting hydrological connectivity. Our results show how humic-rich DOM can modulate the sediment P availability in dryland streams. Unravelling the complexities of P availability is of particular significance to further our understanding of biogeochemical processes in aquatic ecosystems where P often acts as a limiting nutrient.

Colonizing tropical seagrasses increase root exudation under fluctuating and continuous low light

Publisher: Wiley

Date: 16-11-2018

DOI: 10.1002/LNO.10746

Nutrient status of seagrasses cannot be inferred from system-scale distribution of phosphorus in Shark Bay, Western Australia

Publisher: CSIRO Publishing

Date: 2012

DOI: 10.1071/MF12026

Abstract: Differences in phosphorus (P) availability can influence the ecology and physiology of seagrass communities and are usually inferred from changes in the relative P content in seagrass leaves. Shark Bay is a subtropical marine embayment, with decreasing P concentrations in the water column and sediments from north to south across the entire embayment. We examined the P and nitrogen (N) content of seagrass leaves and P content of sediments across the Faure Sill and Wooramel delta region of Shark Bay, to determine whether the leaf content of seagrasses in Shark Bay also decreased from north to south over smaller spatial scales. Nutrient content of Amphibolis antarctica and Halodule uninervis were highly variable and were not strongly correlated with sediment P concentrations. Mean N : P ratios of seagrasses ( .5) were not indicative of P limitation, as has been previously assumed for Shark Bay. We conclude that availability of P for uptake by seagrasses across Shark Bay may be highly localised and cannot be predicted from system-scale gradients ( km) of sedimentary P distributions. We suggest that P availability to seagrasses is more likely a complex function of differing nutrient inputs, rates of delivery to the plants and cycling rates.

Conservative water management in the widespread conifer genus Callitris

Publisher: Oxford University Press (OUP)

Date: 13-11-2013

DOI: 10.1093/AOBPLA/PLT052

Evidence for climate-driven synchrony of marine and terrestrial ecosystems in northwest Australia

Publisher: Wiley

Date: 11-03-2016

DOI: 10.1111/GCB.13239

Abstract: The effects of climate change are difficult to predict for many marine species because little is known of their response to climate variations in the past. However, long-term chronologies of growth, a variable that integrates multiple physical and biological factors, are now available for several marine taxa. These allow us to search for climate-driven synchrony in growth across multiple taxa and ecosystems, identifying the key processes driving biological responses at very large spatial scales. We hypothesized that in northwest (NW) Australia, a region that is predicted to be strongly influenced by climate change, the El Niño Southern Oscillation (ENSO) phenomenon would be an important factor influencing the growth patterns of organisms in both marine and terrestrial environments. To test this idea, we analyzed existing growth chronologies of the marine fish Lutjanus argentimaculatus, the coral Porites spp. and the tree Callitris columellaris and developed a new chronology for another marine fish, Lethrinus nebulosus. Principal components analysis and linear model selection showed evidence of ENSO-driven synchrony in growth among all four taxa at interannual time scales, the first such result for the Southern Hemisphere. Rainfall, sea surface temperatures, and sea surface salinities, which are linked to the ENSO system, influenced the annual growth of fishes, trees, and corals. All four taxa had negative relationships with the Niño-4 index (a measure of ENSO status), with positive growth patterns occurring during strong La Niña years. This finding implies that future changes in the strength and frequency of ENSO events are likely to have major consequences for both marine and terrestrial taxa. Strong similarities in the growth patterns of fish and trees offer the possibility of using tree-ring chronologies, which span longer time periods than those of fish, to aid understanding of both historical and future responses of fish populations to climate variation.

Growth, chemical composition, and carbon isotope discrimination of pistachio (Pistacia vera L.) rootstock seedlings in response to salinity

Publisher: CSIRO Publishing

Date: 2005

DOI: 10.1071/AR04088

Abstract: Pistachio is considered a potential crop for many semi-arid regions affected by salinisation. We examined the effects of salinity on growth of 3 pistachio rootstocks: Badami-e-zarand, Sarakhs, and Ghazvini. Rootstocks were grown in soil in 8-L polyethylene pots and irrigated every 3 days with treatments of 0, 75, 150, or 225 mm NaCl. We measured above-ground biomass, allocation of C to root systems and foliage, and carbon isotope discrimination (Δ) and proline accumulation after 30 days and again after 60 days. Relative growth rate (RGR) decreased with time for all treatments and rootstocks. RGR and net assimilation rates (NARw) decreased with increasing salinity. In all rootstocks, NARw, but not leaf weight ratio (LWR), was significantly correlated with RGR, indicating that NARw was an important factor underlying growth responses among rootstocks. Increased salinity did not affect leaf water potential (Ψleaf), even though proline concentrations increased with increasing NaCl concentration, particularly in the Ghazvini rootstocks. Both Cl– and Na+ concentrations in leaves increased from 30 to 60 days but not in roots and stems. The Sarakhs rootstocks accumulated more of Cl– and Na+ compared with other rootstocks. K+ concentration in the roots and stems of all rootstocks also decreased with increasing salinity at both 30 and 60 days. Concentrations of Ca2+ in stems and root systems, but not in leaves, were also reduced by increased salinity in all rootstocks but only after 60 days. Carbon isotope discrimination (Δ) decreased with increased salinity in the leaves, stems, and roots however, there was no significant difference in carbon isotope discrimination among rootstocks. We conclude that the Ghazvini rootstock was the most salt tolerant among the rootstocks tested. Carbon isotope discrimination in pistachio rootstocks may be a useful indicator of cumulative salinity history of the plant but is not a suitable indicator for pre-screening of pistachio rootstocks for salinity resistance.

Deriving state-and-transition models from an image series of grassland pattern dynamics

Publisher: Elsevier BV

Date: 02-2010

DOI: 10.1016/J.ECOLMODEL.2009.10.027

Characterization of landscape pyrodiversity in Mediterranean environments: Contrasts and similarities between south-western Australia and south-eastern France

Publisher: Springer Science and Business Media LLC

Date: 20-02-2011

DOI: 10.1007/S10980-011-9582-6

Timing of surgery following SARS‐CoV‐2 infection: an international prospective cohort study

Publisher: Wiley

Date: 09-03-2021

DOI: 10.1111/ANAE.15458

Abstract: Peri‐operative SARS‐CoV‐2 infection increases postoperative mortality. The aim of this study was to determine the optimal duration of planned delay before surgery in patients who have had SARS‐CoV‐2 infection. This international, multicentre, prospective cohort study included patients undergoing elective or emergency surgery during October 2020. Surgical patients with pre‐operative SARS‐CoV‐2 infection were compared with those without previous SARS‐CoV‐2 infection. The primary outcome measure was 30‐day postoperative mortality. Logistic regression models were used to calculate adjusted 30‐day mortality rates stratified by time from diagnosis of SARS‐CoV‐2 infection to surgery. Among 140,231 patients (116 countries), 3127 patients (2.2%) had a pre‐operative SARS‐CoV‐2 diagnosis. Adjusted 30‐day mortality in patients without SARS‐CoV‐2 infection was 1.5% (95%CI 1.4–1.5). In patients with a pre‐operative SARS‐CoV‐2 diagnosis, mortality was increased in patients having surgery within 0–2 weeks, 3–4 weeks and 5–6 weeks of the diagnosis (odds ratio (95%CI) 4.1 (3.3–4.8), 3.9 (2.6–5.1) and 3.6 (2.0–5.2), respectively). Surgery performed ≥ 7 weeks after SARS‐CoV‐2 diagnosis was associated with a similar mortality risk to baseline (odds ratio (95%CI) 1.5 (0.9–2.1)). After a ≥ 7 week delay in undertaking surgery following SARS‐CoV‐2 infection, patients with ongoing symptoms had a higher mortality than patients whose symptoms had resolved or who had been asymptomatic (6.0% (95%CI 3.2–8.7) vs. 2.4% (95%CI 1.4–3.4) vs. 1.3% (95%CI 0.6–2.0), respectively). Where possible, surgery should be delayed for at least 7 weeks following SARS‐CoV‐2 infection. Patients with ongoing symptoms ≥ 7 weeks from diagnosis may benefit from further delay.

Analyses of  13C and  18O in tree rings of Callitris columellaris provide evidence of a change in stomatal control of photosynthesis in response to regional changes in climate

Publisher: Oxford University Press (OUP)

Date: 08-2008

DOI: 10.1093/TREEPHYS/28.10.1525

Abstract: We examined relationships between stable isotopes of carbon (delta(13)C) and oxygen (delta(18)O) in tree rings of Callitris columellaris F. Muell in the semi-arid Pilbara region of north-western Australia. To test the hypothesis that stomatal control of photosynthesis decreases during drier periods, we developed delta(13)C and delta(18)O chronologies spanning 1919-1999, and used a permutation regression approach to relate a 21-year running correlation between delta(13)C and delta(18)O to rainfall and temperature at Marble Bar and our study site. The relationship between delta(13)C and delta(18)O switched from being always negative before 1955 to being consistently positive after 1976, suggesting an increase in stomatal control of photosynthesis in recent decades. Changes in the delta(13)C-delta(18)O relationship reflected changes in rainfall, which has increased in the region by 30% since 1976. The correlation between delta(13)C and delta(18)O was positively related to the 21-year running mean of normalized rainfall anomalies at both the study site (P = 0.045, Adj. r(2) = 0.47) and Marble Bar (P = 0.046, Adj. r(2) = 0.48). In addition, the delta(13)C-delta(18)O correlation was negatively related (P = 0.047, Adj. r(2) = 0.61) to temperatures at Marble Bar. Our interpretation of the role of changes in climate affecting the relationship between tree-ring delta(13)C and delta(18)O is supported by evidence from the isotope composition of foliage s les: foliar delta(13)C and delta(18)O were negatively correlated with log stomatal conductance (delta(13)C, r = -0.41 delta(18)O, r = -0.42), whereas the correlation between foliar delta(13)C and delta(18)O was positive (r = 0.63, P = 0.027) after the summer wet period. Our data indicate that stomatal control of photosynthesis in Callitris adjusts to region-wide changes in climate and that, in a warmer and drier world, trees might adapt by increasing non-stomatal control of photosynthesis.

Nuclear science and the story of a preserved leaf from a copy of the Great Bible

Publisher: Elsevier BV

Date: 04-2013

DOI: 10.1016/J.JAS.2012.11.022

Morphological plasticity in a native freshwater fish from semiarid Australia in response to variable water flows

Publisher: Wiley

Date: 20-07-2017

DOI: 10.1002/ECE3.3167

Tree rings show recent high summer-autumn precipitation in northwest Australia is unprecedented within the last two centuries

Publisher: Public Library of Science (PLoS)

Date: 03-06-2015

DOI: 10.1371/JOURNAL.PONE.0128533

The Role of Habitus in the Maintenance of Traditional Noongar Plant Knowledge in Southwest Western Australia

Publisher: Springer Science and Business Media LLC

Date: 06-08-2011

DOI: 10.1007/S10745-011-9420-0

Assessing Temporal Changes in Groundwater Recharge Using Spatial Variations in Groundwater Ages

Publisher: American Geophysical Union (AGU)

Date: 31-07-2020

DOI: 10.1029/2020WR027240

Abstract: Determining variations in groundwater replenishment over a variety of time scales remains a challenge in the management and protection of groundwater resources. Specifically, capacity to use hydraulic data collected in small windows of time to infer long‐term changes can be limited by system responses. Groundwater ages offer an alternative approach as they represent the time since recharge occurred. Here we use spatial variations in groundwater ages and environmental tracer concentrations to infer temporal variations in groundwater recharge and apply the method to a mine site in northwest Australia, where a stream has been modified from ephemeral to perennial, resulting in enhanced recharge to groundwater. Measurements of 14 C and CFC‐12 at five transects along an ephemeral stream were interpreted with the new model to identify recharge rates and the proportion of recharge attributable to enhanced versus natural recharge from flood events. Enhanced recharge varied between 0.03 and 0.66 m/year compared to flood‐generated recharge values ranging between 0.07 and 1.3 m/year. Our results show that spatial variations of groundwater ages and environmental tracer concentrations preserve information about past flow regimes. While our study has demonstrated decadal variations in recharge, application of the method on larger scales could infer much greater extent of temporal variability in recharge, with the potential for significant insight into climate effects on groundwater.

Habitat disruption and the identification and management of functional trait changes

Publisher: Wiley

Date: 06-04-2018

DOI: 10.1111/FAF.12284

University Of Western Australia

Location: No location found

View Organisation

University Of Western Australia

Location: Australia

View Organisation

University Of Melbourne

Location: Australia

View Organisation

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE0775642

Start Date: 04-2007

End Date: 06-2009

Amount: $350,000.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP0882579

Start Date: 04-2008

End Date: 12-2011

Amount: $465,000.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP0214150

Start Date: 07-2002

End Date: 07-2007

Amount: $547,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP0557569

Start Date: 03-2005

End Date: 12-2008

Amount: $220,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP170101033

Start Date: 02-2017

End Date: 09-2020

Amount: $485,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE0775650

Start Date: 2007

End Date: 12-2008

Amount: $170,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE130100029

Start Date: 2013

End Date: 12-2013

Amount: $280,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE150100139

Start Date: 2015

End Date: 12-2015

Amount: $160,000.00

Funder: Australian Research Council

Discovery Projects - Grant ID: DP130104156

Start Date: 06-2013

End Date: 05-2016

Amount: $470,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE0561233

Start Date: 01-2005

End Date: 08-2006

Amount: $434,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE230100057

Start Date: 2023

End Date: 12-2024

Amount: $783,000.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP120200002

Start Date: 07-2012

End Date: 12-2015

Amount: $400,000.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP160101225

Start Date: 11-2017

End Date: 06-2021

Amount: $620,000.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP190100724

Start Date: 03-2021

End Date: 02-2026

Amount: $1,337,900.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP120100310

Start Date: 04-2012

End Date: 04-2015

Amount: $330,000.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP0454276

Start Date: 03-2004

End Date: 03-2007

Amount: $88,068.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP120100350

Start Date: 11-2012

End Date: 11-2016

Amount: $549,000.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP200300886

Start Date: 06-2022

End Date: 06-2027

Amount: $1,035,819.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE100100041

Start Date: 2010

End Date: 12-2010

Amount: $100,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE100100127

Start Date: 2010

End Date: 12-2010

Amount: $300,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE190100183

Start Date: 04-2019

End Date: 04-2020

Amount: $415,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE0882836

Start Date: 2008

End Date: 12-2009

Amount: $160,000.00

Funder: Australian Research Council

Linkage Infrastructure, Equipment And Facilities - Grant ID: LE170100219

Start Date: 2017

End Date: 12-2017

Amount: $170,000.00

Funder: Australian Research Council

Linkage Projects - Grant ID: LP0776626

Start Date: 09-2008

End Date: 12-2013

Amount: $840,000.00

Funder: Australian Research Council