ORCID Profile
0000-0003-0716-0093
Current Organisation
University of Western Australia
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Hydrogeology | Palaeoclimatology | Archaeology | Ecosystem Function | Environmental Science and Management | Geochemistry | Environmental Monitoring | Aboriginal and Torres Strait Islander Archaeology | Ecology not elsewhere classified | Geochronology | Isotope Geochemistry
ANZSRC Socio-Economic Objective (SEO)
Sparseland, Permanent Grassland and Arid Zone Land and Water Management | Ecosystem Adaptation to Climate Change | Water Allocation and Quantification | Climate Change Models | Expanding Knowledge in the Environmental Sciences | Conserving Aboriginal and Torres Strait Islander Heritage | Mining Land and Water Management | Forest and Woodlands Water Management | Farmland, Arable Cropland and Permanent Cropland Water Management |
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Publications
Drone photogrammetry and KMeans point cloud filtering to create high resolution topographic and inundation models of coastal sediment archives
Publisher: Wiley
Date: 11-06-2018
DOI: 10.1002/ESP.4419
Subsurface architecture of two tropical alpine desert cinder cones that hold water
Publisher: American Geophysical Union (AGU)
Date: 06-2016
DOI: 10.1002/2016JF003853
Rock-art microbiome
Publisher: CSIRO Publishing
Date: 2018
DOI: 10.1071/MA18009
Abstract: The Burrup Peninsula in north-west Western Australia is home to one of the most substantial collections of rock engravings, or petroglyphs, in the world. These petroglyphs are carved through the dark coloured patina, commonly referred to as rock varnish, into the weathering rind of the local parent rock. Rock varnish is essentially a thin layer of manganese (Mn) and iron (Fe) oxides and hydroxides with embedded clay minerals, the formation of which is relatively poorly understood. It is generally considered to be a hostile environment for microorganisms due to extreme environmental conditions including low nutrient availability, lack of water, exposure to extreme ultraviolet radiation and intense seasonal and diurnal temperature fluctuations. However, despite these environmental extremes, microorganisms have been found on and in rock varnish and have been reported as playing a significant role in the formation of rock varnish. Given this, it is likely that any change in local environmental conditions will influence the types and activities of microorganisms found in and on rock varnish and associated rock art. This article focuses on the major influences on the microbiome of culturally important rock art in the Burrup Peninsula and the implications of any environmental change on the rock art itself.
A comparison of gap-filling algorithms for eddy covariance fluxes and their drivers
Publisher: Copernicus GmbH
Date: 07-09-2020
DOI: 10.5194/GI-2020-21
Abstract: Abstract. The errors and uncertainties associated with gap-filling algorithms of water, carbon and energy fluxes data, have always been one of the prominent challenges of the global network of microclimatological tower sites that use eddy covariance (EC) technique. To address this concern, and find more efficient gap-filling algorithms, we reviewed eight algorithms to estimate missing values of environmental drivers, and separately three major fluxes in EC time series. We then examined the performance of mentioned algorithms for different gap-filling scenarios utilising data from five OzFlux Network towers during 2013. The objectives of this research were (a) to evaluate the impact of training and testing window lengths on the performance of each algorithm (b) to compare the performance of traditional and new gap-filling techniques for the EC data, for fluxes and their corresponding meteorological drivers. The performance of algorithms was evaluated by generating nine different training-testing window lengths, ranging from a day to 365 days. In each scenario, the gaps covered the data for the entirety of 2013 by consecutively repeating them, where, in each step, values were modelled by using earlier window data. After running each scenario, a variety of statistical metrics was used to evaluate the performance of the algorithms. The algorithms showed different levels of sensitivity to training-testing windows The Prophet Forecast Model (FBP) revealed the most sensitivity, whilst the performance of artificial neural networks (ANNs), for instance, did not vary considerably by changing the window length. The performance of the algorithms generally decreased with increasing training-testing window length, yet the differences were not considerable for the windows smaller than 60 days. Gap-filling of the environmental drivers showed there was not a significant difference amongst the algorithms, the linear algorithms showed slight superiority over those of machine learning (ML), except the random forest algorithm estimating the ground heat flux (RMSEs of 30.17 and 34.93 for RF and CLR respectively). For the major fluxes, though, ML algorithms showed superiority (9 % less RMSE on average), except the Support Vector Regression (SVR), which provided significant bias in its estimations. Even though ANNs, random forest (RF) and extreme gradient boost (XGB) showed close performance in gap-filling of the major fluxes, RF provided more consistent results with less bias, relatively. The results indicated that there is no single algorithm which outperforms in all situations and therefore, but RF is a potential alternative for the ANNs as regards flux gap-filling.
State of High‐Altitude Permafrost on Tropical Maunakea Volcano, Hawaii
Publisher: Wiley
Date: 02-07-2017
DOI: 10.1002/PPP.1954
Black soils, sediments and brown calcic luvisols: A pedological description of a newly discovered neolithic ring ditch system at Stephansposching, Eastern Bavaria, Germany
Publisher: Elsevier BV
Date: 10-2011
Integrating pedological and geophysical methods to enhance the informative value of an archaeological prospection – The example of a Roman villa rustica near Regensburg, Germany
Publisher: Elsevier BV
Date: 07-2010
Geophysical prospection of a bronze foundry on the southern slope of the acropolis at athens, Greece
Publisher: Wiley
Date: 2011
DOI: 10.1002/ARP.402
Quasi-3D mapping of soil moisture in agricultural fields using electrical conductivity sensing
Publisher: Elsevier BV
Date: 2022
Significance of slope sediments layering on physical characteristics and interflow within the Critical Zone – Examples from the Colorado Front Range, USA
Publisher: Elsevier BV
Date: 06-2011
Introducing Pour Points: Characteristics and hydrological significance of a rainfall-concentrating mechanism in a water-limited woodland ecosystem
Publisher: Authorea, Inc.
Date: 08-07-2023
DOI: 10.22541/ESSOAR.168881763.39649059/V1
Abstract: The interception of rainfall by plant canopies alters the depth and spatial distribution of water arriving at the soil surface, and thus the location, volume, and depth of infiltration. Mechanisms like stemflow are well known to concentrate rainfall and route it deep into the soil, yet other mechanisms of flow concentration are poorly understood. This study characterises pour points, formed by the detachment of water flowing on the lower surface of a branch, using a combination of field observations in Western Australian banksia woodlands and rainfall simulation experiments on Banksia menziesii branches. We aim to establish the hydrological significance of pour points in a water-limited woodland ecosystem, along with the features of the canopy structure and rainfall that influence pour point formation and fluxes.Pour points were common in the woodland and could be identified by visually inspecting trees. Water fluxes at pour points were upto 15 times rainfall and were usually comparable to or greater than stemflow. Soil water content beneath pour points was greater than in adjacent control profiles, with 20-30% of seasonal rainfall volume infiltrated into the top 1m of soil beneath pour points, compared to 5% in controls. Rainfall simulations showed that pour points lified the spatial heterogeneity of throughfall, violating water balance closure assumptions. The simulation experiments demonstrated that pour point fluxes depend on the interaction of branch angle and foliation for a given branch architecture. Pour points can play a significant part in the water balance, depending on their density and rainfall concentration ability.
The Coldest Places in Hawaii: The Ice-Preserving Microclimates of High-Altitude Craters and Caves on Tropical Island Volcanoes
Publisher: American Meteorological Society
Date: 11-2018
Abstract: The coldest places on the Hawaiian island chain are not on the very summits of its tallest volcanoes, Mauna Kea (19.82°N 4,207 m) and Mauna Loa (19.48°N 4,169 m), but within craters and caves with perennial ice. Here, we explore unique microclimates in the alpine stone deserts of two tropical island volcanoes, report new temperature extremes for Hawaii, and study the role of microclimates in the preservation of perennial ice bodies. Nocturnal cold-air pools are common in the craters and are responsible for the coldest temperature ever reported from the Hawaiian Islands (–20°C). These cold-air pools are not frequent enough to substantially affect the annual heat budget of the ground, but cold air is frequently trapped between boulders and contributes to freezing conditions in this way. Perennial ice is found beneath even warmer environments in lava tube caves. The lowest annual-mean temperature (–0.7°C) was measured at the distal end of a spectacular ice cave on Mauna Loa, where the outside air temperature averages +8°C. In the current climate, the outside temperature rarely falls below freezing, so the air’s sensible heat cannot contribute to freezing conditions. Considering the effect of recent climate warming and the buoyancy of humid air, cold air that flowed down the lava tubes in winter nights, combined with sublimation cooling, is still a plausible explanation for the perennial ice ponds found there.
Valuable phosphorus retained by ironstone gravels can be measured as bicarbonate extractable P
Publisher: Elsevier BV
Date: 07-2022
Cryosphere: ice on Niwot Ridge and in the Green Lakes Valley, Colorado Front Range
Publisher: Informa UK Limited
Date: 02-03-2015
Changing mountain permafrost from the 1970s to today - comparing two examples from Niwot Ridge, Colorado Front Range, USA
Publisher: Schweizerbart
Date: 02-2014
Edaphic niche characterization of four Proteaceae reveals unique calcicole physiology linked to hyper‐endemism of Grevillea thelemanniana
Publisher: Wiley
Date: 25-08-2020
DOI: 10.1111/NPH.16833
Abstract: Endemism and rarity have long intrigued scientists. We focused on a rare endemic and critically‐endangered species in a global bio ersity hotspot, Grevillea thelemanniana (Proteaceae). We carried out plant and soil analyses of four Proteaceae, including G. thelemanniana , and combined these with glasshouse studies. The analyses related to hydrology and plant water relations as well as soil nutrient concentrations and plant nutrition, with an emphasis on sodium (Na) and calcium (Ca). The local hydrology and matching plant traits related to water relations partially accounted for the distribution of the four Proteaceae. What determined the rarity of G. thelemanniana , however, was its accumulation of Ca. Despite much higher total Ca concentrations in the leaves of the rare G. thelemanniana than in the common Proteaceae, very few Ca crystals were detected in epidermal or mesophyll cells. Instead of crystals, G. thelemanniana epidermal cell vacuoles contained exceptionally high concentrations of noncrystalline Ca. Calcium ameliorated the negative effects of Na on the very salt‐sensitive G. thelemanniana . Most importantly, G. thelemanniana required high concentrations of Ca to balance a massively accumulated feeding‐deterrent carboxylate, trans ‐aconitate. This is the first ex le of a calcicole species accumulating and using Ca to balance accumulation of an antimetabolite.
Soil water repellency in sandy soil depends on the soil drying method, incubation temperature and specific surface area
Publisher: Elsevier BV
Date: 11-2021
Mineralogy, magnetic susceptibility and geochemistry of Fe-rich Oxisols developed from several parent materials
Publisher: FapUNIFESP (SciELO)
Date: 09-2018
Insights into recharge processes and speleothem proxy archives from long-term monitoring networks of cave drip water hydrology
Publisher: Copernicus GmbH
Date: 23-03-2020
DOI: 10.5194/EGUSPHERE-EGU2020-1686
Abstract: & & Since 2010 we have established cave drip water hydrological monitoring networks in four contrasting climate zones (Mediterranean, montane, semi-arid and sub-tropical) across continental Australia. Deploying over one hundred automated drip loggers, we combine these long-term monitoring datasets with climate and water isotope data, lidar mapping, electrical resistivity imaging and karst hydrological modelling to provide insights into recharge processes and the impact of hydrological variability on speleothem proxy archives.& & & & We identify increases in drip discharge and compare the timing of those events to antecedent climate conditions (rainfall, evapotranspiration). We find rainfall recharge thresholds vary with climate. At our montane site, recharge occurs after 13 to 31 mm rainfall events, depending on antecedent conditions. At the semi-arid site, recharge occurs after 40 mm rainfall events, and at our sub-tropical sites, recharge occurs following all instances where & 93 mm / week of precipitation occurs, with lower precipitation thresholds (down to 33 mm / week) possible depending on antecedent conditions and at sites with limited vegetation cover. We use these recharge thresholds to constrain simple soil moisture balance models to better understand soil and karst storage volumes. Combined with electrical resistivity imaging, we can relate recharge to the caves to subsurface water flow paths and karst water stores.& & & & At our montane and Mediterranean climate sites, relatively consistent drip water isotopic composition confirms the presence of well-mixed water stores. This allows us to quantify the extent of speleothem oxygen isotope variability due to fractionation associated with changes in drip rate. We identify significant differences in long-term mean drip rates between different drip sites within a cave, and significant differences in event-based drip rate responses within a cave. Drip hydrological variability helps explain the within-cave variability of speleothem oxygen isotope composition observed at both sites, and helps identify the primary drip water oxygen isotope signal.& & & & At our semi-arid site, drip water isotopic composition is dominated by epikarst evaporation and our drip water monitoring demonstrates that recharge events are infrequent (~1.6 per year). Using both observational and modelling data, we quantify the relative importance of evaporative fractionation in the epikarst and fractionation during calcite precipitation. Using modern speleothem s les, we demonstrate that the oxygen isotope signal in this water limited environment reflects the balance between the oxygen isotope composition of recharge and its subsequent fractionation in the soil, epikarst and cave.& &
Geophysics reveals forest vulnerability to drought
Publisher: Wiley
Date: 13-10-2023
DOI: 10.1002/ECO.2596
Combining sediment analysis and seismic refraction to describe the structure, thickness and distribution of periglacial slope deposits at Niwot Ridge, Rocky Mountains Front Range, Colorado, USA
Publisher: Schweizerbart
Date: 09-2008
Time lapse electric resistivity tomography to portray infiltration and hydrologic flow paths from surface to cave
Publisher: Elsevier BV
Date: 02-2021
Geomorphic signatures of large-scale glacier detachments
Publisher: Copernicus GmbH
Date: 23-03-2020
DOI: 10.5194/EGUSPHERE-EGU2020-4110
Abstract: & & The catastrophic detachment of Kolka Glacier in Russia was long thought to be a unique occurrence (e.g., Haeberli et al., 2004), but recent events in Tibet, Alaska, Argentina and China have increased the urgency to understand these processes and the risk they pose to mountain communities and infrastructure. Most notably, the tongues of two neighboring glaciers in Tibet detached only a few weeks apart in 2016, the first killing nine herders and hundreds of their livestock. In 2013 and 2015 Flat Creek Glacier in Alaska& #8217 s Saint Elias Mountains lost half of its total area in two large detachments. The resulting destructive mass flows left a clear scar in the landscape, piling debris up to 30 m thick and spreading it over 8 km& sup& & /sup& . Recent investigations by K& #228 & #228 b et al. (2018), Gilbert et al. (2018) and Jacquemart et al. (in review) suggest that the failures in Tibet and Alaska share three main drivers: temperate ice restricted by a frozen glacier tongue, a clay-rich bed, and increased meltwater input to the base of the glacier, driven by increasing summer temperatures.& & & & Here we ask whether these glacier detachments are indeed a new, emerging hazard or whether we simply have not previously recognized the signs they leave in the landscape. Only a long-term record of observations stretching beyond the modern satellite era, can reliably answer the question about possibly increasing frequencies. In order to start building some understanding of the nature of such deposits, we investigated the internal structure and landscape setting of the 2013 and 2015 detachment deposits at Flat Creek. We performed electrical resistivity tomography surveys to estimate their ice content and ice distribution. In addition we analyzed grain size distributions and orientations in the deposits to see if they can be clearly distinguished from other glacio-fluvial deposits. To understand if glacier detachments have happened in this region before, we performed the same analysis on large debris deposits found downstream of a neighboring glacier. We combine this field evidence with remote sensing analysis of the temporal evolution of the glaciers and detachment deposits in Alaska, Tibet and Russia to understand the signatures of these catastrophic events in the landscape. Our preliminary results for Alaska show that the glacier itself is a bad indicator of past events, as the ice response quickly masks the detachment. Additionally, we found ice in the deposits to be highly broken up and ground, though never the less able to endure multiple years. Unlike a traditional debris-flow deposits, the glacier-detachment deposits exhibit a lack of grain-size sorting, and the grain orientations appear highly chaotic, with a tendency toward vertical orientations. As such, the deposits appear clearly distinct from the surrounding hillslope, and further analysis will show to what extent they can be distinguished from other glacio-fluvial deposits.& &
Soil Mapping Using Electromagnetic Induction to Assess the Suitability of Land for Growing Leptospermum nitens in Western Australia
Publisher: Frontiers Media SA
Date: 19-07-2022
DOI: 10.3389/FENVS.2022.883533
Abstract: Leptospermum sp. with dihydroxyacetone in their nectar are a source of high-value medicinal honey production and can provide income from agriculturally marginal lands. The current study was from two newly planted Leptospermum nitens sites, one with duplex soil and the other in deep sandy soil, in the low rainfall areas of the south-west of Western Australia, with the aim of identifying key soil parameters influencing the plantation’s survival and growth. Electromagnetic induction (EMI) at different depths was used to investigate the possible impact of soil variability on the Leptospermum nitens plantations. Two EMI surveys were conducted at each site, at different times of the year, to account for soil moisture variability (relatively dry and wet conditions). A least-square inversion algorithm was used to determine true electrical conductivities at three different soil depths (0–0.5, 0.5–0.8, and 0.8–1.6 m) to produce quasi-3D maps of soil inverted electrical conductivity. Corresponding soil s les from each depth were used for the physico-chemical analysis of soil parameters and to develop laboratory-based electrical resistivity to soil volumetric moisture calibrations with R 2 values between 0.95 and 0.99. Shrub survival and growth (canopy diameter) were estimated using unmanned aerial vehicle (UAV) images and machine learning. Comparing EMI soil mapping with UAV imagery results showed significantly greater shrub survival and growth ( p & 0.001) in areas with higher ECa ranges of 12–24 mS m −1 at the variable textured site and 6–9 mS m −1 at the uniformly sandy site. Overall, the variable textured site, with an 82% survival rate, had a significantly higher shrub count and larger plants than the uniformly sandy site, with a 75% survival rate. A principal component analysis (PCA) identified inverted EC to be strongly correlated with soil moisture & pH & soil texture. Such soil mapping may be a robust and effective method for risk assessment of new shrub plantations.
Geomorphic and sedimentary signatures of catastrophic glacier detachments: A first assessment from Flat Creek, Alaska
Publisher: Elsevier BV
Date: 10-2022
Contribution of soil bacteria to the atmosphere across biomes
Publisher: Elsevier BV
Date: 05-2023
Eolian and fluvial sedimentation in the southwestern Sinai Mountains, Egypt: a record of flash floods during the late Pleistocene
Publisher: IWA Publishing
Date: 05-12-2012
DOI: 10.2166/NH.2012.172
Abstract: Wadis emerging from the southwestern Sinai Mountains (Egypt) westwards to the Gulf of Suez are filled by & m thick late Pleistocene sediments, which have been subsequently incised to bedrock after the Last Glacial Maximum (LGM). Sedimentation and erosion resulted from changes in the basin's hydrological conditions caused by climate variations. Sediment characteristics indicate distinct processes ranging from high to low energy flow regimes. Airborne material is important as a sediment source. The fills are associated with alluvial fans at wadi mouths at the mountain fronts. Each alluvial fan is associated and physically correlated with the respective sediment fill in its contributing wadi. The alluvial fans have steep gradients and are only a few kilometers long or wide. The alluvial fans converge as they emerge from the adjacent valleys. According to optically stimulated luminescence dating, the initial sediment has an age of ∼45 ka and the sedimentation ends ∼19 ka, i.e., happened mainly during marine isotope stage (MIS) 3 and early MIS 2 formation and initial incision sometime during LGM. As the delivery of sediments in such a hyper-arid environment is by extreme floods, this study indicates an interval of intense fluvial activity, probably related to increased frequency of extreme floods in Southern Sinai. This potentially indicates a paleoclimatic change in this hyper-arid environment.
Soil properties and floristic community distribution within a deeply weathered landscape within a biodiversity hotspot of Western Australia
Publisher: Springer Science and Business Media LLC
Date: 18-02-2023
DOI: 10.1007/S11104-023-05918-7
Abstract: This study aims to identify some of the key soil-related factors that underpin the distribution of plant communities and provide a more comprehensive understanding of an old, climatically buffered infertile landscape including kwongkan habitats. We investigate the pedological, topographical and hydrological correlates of abundance and floristic community distribution within the Alison Baird Reserve, a floristically erse, old and climatically weathered landscape in south-west Western Australia. Fifty-four soil s les were collected across 0.165 km 2 and analysed for a range of physical and chemical properties. S les were taken from the topsoil and subsurface, and a combination of statistical and geostatistical methods were used to examine soil–plant community distribution relationships. Elevation, sub-surface moisture, electrical conductivity and clay content were the most important factors in determining vegetation composition and distribution with sub-surface properties varying more between floristic communities and correlating more strongly than topsoil factors. Associations between soil nutrients (Phosphorus, Nitrogen, Carbon) and community distributions were not as significant as expected, likely due to the depleted nature of the soil system. The significance of soil parameters including particle size, moisture, elevation, water repellence and depth to water table suggests that water availability and retention within the soil is a key correlate of the distribution of floristic communities at the site and may act as a pathway to explain large scale variation in plant communities across the south-west of Western Australia. This understanding will help conservation and management of areas with such high bio ersity including relocation of endangered flora.
Seismic Constraints on Critical Zone Architecture, Boulder Creek Watershed, Front Range, Colorado
Publisher: Wiley
Date: 08-2011
DOI: 10.2136/VZJ2010.0108
Chronostratigraphy and geomorphology of washover fans in the Exmouth Gulf (NW Australia) – A record of tropical cyclone activity during the late Holocene
Publisher: Elsevier BV
Date: 08-2017
Influence of glacier advance on the development of the multipart Riffeltal rock glacier, Central Austrian Alps
Publisher: Wiley
Date: 16-01-2015
DOI: 10.1002/ESP.3695
 Quasi-3D mapping of soil moisture for agriculture using electric conductivity sensing  
Publisher: Copernicus GmbH
Date: 04-03-2021
DOI: 10.5194/EGUSPHERE-EGU21-7117
Abstract: & & Knowledge of real time spatial distribution of soil moisture has great potential to improve yield and profit in agricultural systems. Rapid and precise quantification of water in crop fields is challenging due to the influence of highly variable soil properties such as texture and porosity. & Recent advances in non-invasive electromagnetic induction (EMI) techniques have created an opportunity to determine soil moisture content with high-resolution and minimal soil intrusion. So far, EMI has mainly been validated for homogenous soils, which are not common in agriculture. This study from a field site in Western Australia converts time series apparent electrical conductivity data recorded with a Dualem 1Hs EM-meter into spatiotemporal domains. A least square inversion algorithm was used to determine electric conductivities for in idual soil layers (0-50cm, 50-80 cm and 80-160 cm) for two EMI surveys at a trial site, with different crop rotations and varying moisture conditions. A laboratory experiment under controlled conditions developed electric conductivity vs volumetric water content relations with power law functions for each layer with R& sup& & /sup& values between 0.98 and 0.99. Subsequently, EMI data were converted to volumetric water contents for each layer and predictions were spatially displayed. These EMI soil moisture predictions were compared with neutron moisture meter measurements, with R& sup& & /sup& values between 0.95 and 0.74 for the two surveys. The method is robust and offers a comparatively fast method to estimate the soil moisture status in fields and to subsequently make informed management decisions.& & &
A Third Pond on the Mauna Kea Summit Plateau
Publisher: Pacific Science
Date: 25-01-2023
DOI: 10.2984/76.3.3
Thermal imagery of woodland tree canopies provides new insights into drought-induced tree mortality
Publisher: Elsevier BV
Date: 08-2022
DOI: 10.1016/J.SCITOTENV.2022.155395
Abstract: Our understanding of how water dynamics determines the probability of tree mortality during drought is incomplete. Here we help address this shortcoming by coupling approaches from the disciplines of ecophysiology, geophysics and remote sensing in a woodland ecosystem undergoing protracted drying. Water uptake and use strategies varied between the dominant canopy species of the ecosystem. At one extreme were species that tightly regulate their water status, which is broadly consistent with the definition of isohydry. The higher leaf temperatures revealed by thermal imagery of these isohydric species are likely a reflection of reduced latent cooling owing to a stringent control of transpiration rate. Where silty sediments occur in the root zone, this strategy may have the effect of limiting the water sources available to these species during prolonged drought because of an insufficient hydraulic gradient for water uptake. In contrast were species that allowed their water status to fluctuate, operating in a fashion more consistent with anisohydry. For these species, latent cooling owing to relatively high transpiration rates maintained leaf temperatures near, or below, the ambient air temperature. The resulting drawdown in leaf water potential between soil and leaves in these anisohydric species may generate a sufficient hydraulic gradient to enable water uptake from silty soil during seasonal or prolonged droughts. In this way the spatial distribution of fine textured soil could indicate areas where the isohydric hydraulic control strategy is disadvantageous during prolonged droughts or where annual soil water recharge has fallen below a critical threshold.
Murujuga Rockshelter: First evidence for Pleistocene occupation on the Burrup Peninsula
Publisher: Elsevier BV
Date: 08-2018
What drives large-scale glacier detachments? Insights from Flat Creek glacier, St. Elias Mountains, Alaska
Publisher: Geological Society of America
Date: 27-04-2020
DOI: 10.1130/G47211.1
Abstract: Two large-scale glacier detachments occurred at the peaks of the 2013 and 2015 CE melt seasons, releasing a cumulative 24.4–31.3 × 106 m3 of ice and lithic material from Flat Creek glacier, St. Elias Mountains, Alaska. Both events produced highly mobile and destructive flows with runout distances of more than 11 km. Our results suggest that four main factors led to the initial detachment in 2013: abnormally high meltwater input, an easily erodible glacier bed, inefficient subglacial drainage due to a cold-ice tongue, and increased driving stresses stemming from an internal redistribution of ice after 2011. Under a drastically altered stress regime, the stability of the glacier remained sensitive to water inputs thereafter, culminating in a second detachment in 2015. The similarities with two large detachments in the Aru mountains of Tibet suggest that these detachments were caused by a common mechanism, driven by unusually high meltwater inputs. As meltwater production increases with rising temperatures, the possible increase in frequency of glacier detachments has direct implications for risk management in glaciated regions.
The application of quartz grain morphology measurements to studying iron-rich duricrusts
Publisher: Elsevier BV
Date: 11-2018
Plant-Dependent Soil Bacterial Responses Following Amendment With a Multispecies Microbial Biostimulant Compared to Rock Mineral and Chemical Fertilizers
Publisher: Frontiers Media SA
Date: 04-02-2021
Abstract: Biostimulants are gaining momentum as potential soil amendments to increase plant health and productivity. Plant growth responses to some biostimulants and poorly soluble fertilizers could increase soil microbial ersity and provide greater plant access to less soluble nutrients. We assessed an agricultural soil amended with a multispecies microbial biostimulant in comparison with two fertilizers that differed in elemental solubilities to identify effects on soil bacterial communities associated with two annual pasture species (subterranean clover and Wimmera ryegrass). The treatments applied were: a multispecies microbial biostimulant, a poorly soluble rock mineral fertilizer at a rate of 5.6 kg P ha –1 , a chemical fertilizer at a rate of 5.6 kg P ha –1 , and a negative control with no fertilizer or microbial biostimulant. The two annual pasture species were grown separately for 10 weeks in a glasshouse with soil maintained at 70% of field capacity. Soil bacteria were studied using 16S rRNA with 27F and 519R bacterial primers on the Mi-seq platform. The microbial biostimulant had no effect on growth of either of the pasture species. However, it did influence soil bio ersity in a way that was dependent on the plant species. While application of the fertilizers increased plant growth, they were both associated with the lowest ersity of the soil bacterial community based on Fisher and Inverse Simpson indices. Additionally, these responses were plant-dependent soil bacterial richness was highly correlated with soil pH for subterranean clover but not for Wimmera ryegrass. Soil bacterial richness was lowest following application of each fertilizer when subterranean clover was grown. In contrast, for Wimmera ryegrass, soil bacterial richness was lowest for the control and rock mineral fertilizer. Beta ersity at the bacterial OTU level of resolution by permanova demonstrated a significant impact of soil amendments, plant species and an interaction between plant type and soil amendments. This experiment highlights the complexity of how soil amendments, including microbial biostimulants, may influence soil bacterial communities associated with different plant species, and shows that caution is required when linking soil bio ersity to plant growth. In this case, the microbial biostimulant influenced soil bio ersity without influencing plant growth.
Karnatukul (Serpent’s Glen): A new chronology for the oldest site in Australia’s Western Desert
Publisher: Public Library of Science (PLoS)
Date: 19-09-2018
Thermal imaging of a hydrophobic soil’s response to surfactant application at the Avon River Catchment Critical Zone Observatory
Publisher: Elsevier BV
Date: 06-2020
Internal structure of the Green Lake 5 rock glacier, Colorado Front Range, USA
Publisher: Wiley
Date: 28-01-2011
DOI: 10.1002/PPP.706
Condensation of capillary water and decreased surface energy cause increased soil water repellency in sandy soil
Publisher: Wiley
Date: 11-2022
DOI: 10.1111/EJSS.13325
Abstract: Predicting soil water availability to crops in water‐repellent sandy soil is complicated as soil water repellency (SWR) responds non‐linearly to soil water content. Others have hypothesised that the development of a monolayer of water molecules results in SWR increasing before SWR declines with a further increase in soil water content. In a previous study, we found that SWR increases when above 0.28–0.86% threshold soil water content. Thus, our objective was to determine the underlying mechanisms responsible for why SWR increases when above a certain threshold soil water content in a sandy soil. A water adsorption isotherm was constructed by exposing a water‐repellent sandy soil to increasing relative humidity (dynamic vapour sorption technique) to evaluate if the development of a monolayer of water molecules was responsible for the increased SWR response. The increased SWR when above 0.66% threshold soil water content was found to coincide with the capillary condensation of water in the soil. The inverse gas chromatography technique was used for the first time in soil particles' surface energy analysis to investigate why SWR increases when above the threshold soil water content by determining the total, dispersive (non‐polar), and specific surface (polar) energy of the soil at two relative humidities (0% and 90%). Wettable sandy soil (98% soil organic carbon removed) was included as a control to further assess if soil organic carbon in the water‐repellent soil influences the surface energy of the soil. The mean of total, dispersive, and specific surface energy decreased for both wettable and water‐repellent sandy soils when exposed to 90% relative humidity, suggesting that there was limited effect of soil carbon on the increased SWR when above the threshold soil water content since most organic carbon was removed from the wettable soil. We also investigated if there is any difference in the surface energy heterogeneity when exposed to 90% relative humidity to gain insight into surface chemistry heterogeneity of the soil particles' surfaces. Exposing soils to 90% relative humidity decreased the heterogeneity of the total and dispersive surface energy of both wettable and water‐repellent sandy soil indicating a more uniform surface chemistry than when exposed to 0% relative humidity. Examined why soil water repellency (SWR) in a sandy soil increases at low soil water content. Explored underlying mechanisms via water adsorption isotherm and surface energy of a sandy soil. Increased SWR coincided with capillary water condensation and is likely due to counterion effects. Quantitative data presented new mechanisms on why SWR increases with increasing soil water content.
Characteristics of a paleosol and its implication for the Critical Zone development, Rocky Mountain Front Range of Colorado, USA
Publisher: Elsevier BV
Date: 06-2011
Impacts of Rock Mineral and Traditional Phosphate Fertilizers on Mycorrhizal Communities in Pasture Plants
Publisher: MDPI AG
Date: 17-04-2023
DOI: 10.3390/MICROORGANISMS11041051
Abstract: Intensive fertilizer use can constrain contributions from soil biological processes in pastures, including those associated with arbuscular mycorrhizal (AM) fungi. We evaluated the effect of fertilizers of different P solubility on the colonization of the roots of two common pasture plants by a community of AM fungi in a pasture soil. The treatments were a rock mineral fertilizer, a chemical fertilizer and a microbial inoculant. Subterranean clover and annual ryegrass were grown in pots for 10 weeks. Both fertilizers reduced the proportion and length of roots colonized by naturally occurring AM fungi. However, by 10 weeks, there was a much greater length of mycorrhizal root for annual ryegrass than for subterranean clover. The relative abundance of mycorrhizal fungi in the families Glomeraceae and Acaulosporaceae in roots was not affected by the form of fertilizer, but ersity indices of AM fungi in roots were altered. The chemical fertilizer had a greater negative effect on AM fungal ersity indices in the annual ryegrass roots compared with the subterranean clover roots. The reduction in OTU richness of AM fungi with fertilizer application corresponded with reduced soil pH. Differential effects of P fertilizers on naturally occurring AM fungi in this agricultural soil have the potential to influence the efficacy of P fertilizer use and dominance of plant species in grasslands.
The first radiometric Pleistocene dates for Aboriginal occupation at Weld Range, inland Mid West, Western Australia
Publisher: Informa UK Limited
Date: 02-01-2016
Enhancing nutrient recovery from food waste anaerobic digestate
Publisher: Elsevier BV
Date: 12-2023
Microbial influence on dolomite and authigenic clay mineralisation in dolocrete profiles of NW Australia
Publisher: Wiley
Date: 27-03-2023
DOI: 10.1111/GBI.12555
Abstract: Dolomite (CaMg(CO 3 ) 2 ) precipitation is kinetically inhibited at surface temperatures and pressures. Experimental studies have demonstrated that microbial extracellular polymeric substances (EPS) as well as certain clay minerals may catalyse dolomite precipitation. However, the combined association of EPS with clay minerals and dolomite and their occurrence in the natural environment are not well documented. We investigated the mineral and textural associations within groundwater dolocrete profiles from arid northwest Australia. Microbial EPS is a site of nucleation for both dolomite and authigenic clay minerals in this Late Miocene to Pliocene dolocrete. Dolomite crystals are commonly encased in EPS alveolar structures, which have been mineralised by various clay minerals, including montmorillonite, trioctahedral smectite and palygorskite‐sepiolite. Observations of microbial microstructures and their association with minerals resemble textures documented in various lacustrine and marine microbialites, indicating that similar mineralisation processes may have occurred to form these dolocretes. EPS may attract and bind cations that concentrate to form the initial particles for mineral nucleation. The dolomite developed as nanocrystals, likely via a disordered precursor, which coalesced to form larger micritic crystal aggregates and rhombic crystals. Spheroidal dolomite textures, commonly with hollow cores, are also present and may reflect the mineralisation of a biofilm surrounding coccoid bacterial cells. Dolomite formation within an Mg‐clay matrix is also observed, more commonly within a shallow pedogenic horizon. The ability of the negatively charged surfaces of clay and EPS to bind and dewater Mg 2+ , as well as the slow diffusion of ions through a viscous clay or EPS matrix, may promote the incorporation of Mg 2+ into the mineral and overcome the kinetic effects to allow disordered dolomite nucleation and its later growth. The results of this study show that the precipitation of clay and carbonate minerals in alkaline environments may be closely associated and can develop from the same initial amorphous Ca–Mg–Si‐rich matrix within EPS. The abundance of EPS preserved within the profiles is evidence of past microbial activity. Local fluctuations in chemistry, such as small increases in alkalinity, associated with the degradation of EPS or microbial activity, were likely important for both clay and dolomite formation. Groundwater environments may be important and hitherto understudied settings for microbially influenced mineralisation and for low‐temperature dolomite precipitation.
Subsurface architecture of the Boulder Creek Critical Zone Observatory from electrical resistivity tomography
Publisher: Wiley
Date: 07-05-2013
DOI: 10.1002/ESP.3420
Chenier-type ridges in Giralia Bay (Exmouth Gulf, Western Australia) - Processes, chronostratigraphy, and significance for recording past tropical cyclones
Publisher: Elsevier BV
Date: 02-2018
Bacillus subtilis and surfactant amendments for the breakdown of soil water repellency in a sandy soil
Publisher: Elsevier BV
Date: 06-2019
Using Geophysical Methods to Study the Shallow Subsurface of a Sensitive Alpine Environment, Niwot Ridge, Colorado Front Range, U.S.A
Publisher: Informa UK Limited
Date: 08-2008
Colluvial filling of a glacial bypass channel near the Chiemsee (Stöttham) and its function as geoarchive
Publisher: Schweizerbart
Date: 09-2012
A comparison of gap-filling algorithms for eddy covariance fluxes and their drivers
Publisher: Copernicus GmbH
Date: 28-06-2021
Abstract: Abstract. The errors and uncertainties associated with gap-filling algorithms of water, carbon, and energy fluxes data have always been one of the main challenges of the global network of microclimatological tower sites that use the eddy covariance (EC) technique. To address these concerns and find more efficient gap-filling algorithms, we reviewed eight algorithms to estimate missing values of environmental drivers and nine algorithms for the three major fluxes typically found in EC time series. We then examined the algorithms' performance for different gap-filling scenarios utilising the data from five EC towers during 2013. This research's objectives were (a) to evaluate the impact of the gap lengths on the performance of each algorithm and (b) to compare the performance of traditional and new gap-filling techniques for the EC data, for fluxes, and separately for their corresponding meteorological drivers. The algorithms' performance was evaluated by generating nine gap windows with different lengths, ranging from a day to 365 d. In each scenario, a gap period was chosen randomly, and the data were removed from the dataset accordingly. After running each scenario, a variety of statistical metrics were used to evaluate the algorithms' performance. The algorithms showed different levels of sensitivity to the gap lengths the Prophet Forecast Model (FBP) revealed the most sensitivity, whilst the performance of artificial neural networks (ANNs), for instance, did not vary as much by changing the gap length. The algorithms' performance generally decreased with increasing the gap length, yet the differences were not significant for windows smaller than 30 d. No significant differences between the algorithms were recognised for the meteorological and environmental drivers. However, the linear algorithms showed slight superiority over those of machine learning (ML), except the random forest (RF) algorithm estimating the ground heat flux (root mean square errors – RMSEs – of 28.91 and 33.92 for RF and classic linear regression – CLR, respectively). However, for the major fluxes, ML algorithms and the MDS showed superiority over the other algorithms. Even though ANNs, random forest (RF), and eXtreme Gradient Boost (XGB) showed comparable performance in gap-filling of the major fluxes, RF provided more consistent results with slightly less bias against the other ML algorithms. The results indicated no single algorithm that outperforms in all situations, but the RF is a potential alternative for the MDS and ANNs as regards flux gap-filling.
Evaluation of surfactant effectiveness on water repellent soils using electrical resistivity tomography
Publisher: Elsevier BV
Date: 02-2017
Methods of surveying the thickness of humous horizons using ground penetrating radar (GPR): an example from the Garmisch-Partenkirchen area of the Northern Alps
Publisher: Springer Science and Business Media LLC
Date: 22-01-2011
Soil Salinity and pH Drive Soil Bacterial Community Composition and Diversity Along a Lateritic Slope in the Avon River Critical Zone Observatory, Western Australia
Publisher: Frontiers Media SA
Date: 02-07-2019
The Impact of Soil Water Repellency and Slope upon Runoff and Erosion
Publisher: Elsevier BV
Date: 2021
What to make of the 'Murchison Cement'?
Publisher: Informa UK Limited
Date: 12-2014
Environmental drivers of soil microbial community structure and function at the Avon River Critical Zone Observatory
Publisher: Elsevier BV
Date: 11-2016
DOI: 10.1016/J.SCITOTENV.2016.05.185
Abstract: The Critical Zone is defined as the thin, permeable layer from the tops of the trees to the bottom of the bedrock that sustains terrestrial life on Earth. The geometry and shape of the various weathering zones are known as the critical zone architecture. At the centre of the Critical Zone are soils and the microorganisms that inhabit them. In Western Australia, the million-year-old stable weathering history and more recent lateral erosion during the past hundreds of thousands of years have created a geomorphic setting where deep weathering zones are now exposed on the surface along the flanks of many lateritic hills. These old weathering zones provide erse physical and chemical properties that influence near surface pedologic conditions and thus likely shape current surface microbiology. Here, we present data derived from a small lateritic hill on the UWA Farm Ridgefield. Spatial soil s ling revealed the contrasting distribution patterns of simple soil parameters such as pH (CaCl2) and electric conductivity. These are clearly linked with underlying changes of the critical zone architecture and show a strong contrast with low values of pH3.3 at the top of the hill to pH5.3 at the bottom. These parameters were identified as major drivers of microbial spatial variability in terms of bacterial and archaeal community composition but not abundance. In addition, we used sensitive (14)C labelling to assess turnover of three model organic nitrogen compounds - an important biogeochemical functional trait relating to nutrient availability. Though generally rapid and in the order of rates reported elsewhere (t½ 10h). In conclusion, we have shown that the weathering and erosion history of ancient Western Australia affects the surface pedology and has consequences for microbial community structure and function.
A threatened ecological community
Publisher: CSIRO Publishing
Date: 2021
DOI: 10.1071/BT20089
Abstract: The rapid expansion of urban areas worldwide is leading to native habitat loss and ecosystem fragmentation and degradation. Although the study of urbanisation’s impact on bio ersity is gaining increasing interest globally, there is still a disconnect between research recommendations and urbanisation strategies. Expansion of the Perth metropolitan area on the Swan Coastal Plain in south-western Australia, one of the world’s thirty-six bio ersity hotspots, continues to affect the Banksia Woodlands (BWs) ecosystem, a federally listed Threatened Ecological Community (TEC). Here, we utilise the framework of a 1989 review of the state of knowledge of BWs ecology and conservation to examine scientific advances made in understanding the composition, processes and functions of BWs and BWs’ species over the last 30 years. We highlight key advances in our understanding of the ecological function and role of mechanisms in BWs that are critical to the management of this ecosystem. The most encouraging change since 1989 is the integration of research between historically disparate ecological disciplines. We outline remaining ecological knowledge gaps and identify key research priorities to improve conservation efforts for this TEC. We promote a holistic consideration of BWs with our review providing a comprehensive document that researchers, planners and managers may reference. To effectively conserve ecosystems threatened by urban expansion, a range of stakeholders must be involved in the development and implementation of best practices to conserve and maintain both bio ersity and human wellbeing.
Comparing quasi-3D soil moisture derived from electromagnetic induction with 1D moisture sensors and correlation to barley yield in variable duplex soil
Publisher: Copernicus GmbH
Date: 15-05-2023
DOI: 10.5194/EGUSPHERE-EGU23-4650
Abstract: Farms in Western Australia (WA) are highly variable in soil texture and water retention capacity therefore, spatial information of soil moisture status in the field is important for crop management. In practice, farmers often rely on point sensors to determine soil moisture in their fields for crop planning. The limitation of point measurements to account for spatial variability highlights the need to develop methods to assess soil moisture across variable broadacre fields. This information could be used for more effective site-specific crop management practices. In this study, we used a mobile nonintrusive electromagnetic induction (EMI) sensor to map soil apparent electrical conductivity (ECa) and to predict soil moisture levels across the field at three depths (0 & #8211 0.5, 0.5 & #8211 0.8 and 0.8 & #8211 1.6m). The predicted soil moisture was compared with the point measurements of soil moisture sensors and soil s les. The inverted electrical conductivity (EC) from EMI surveys was converted into soil moisture using calibrations between electrical resistivity tomography (ERT) to volumetric moisture, which were developed for the different soil textural classes of the field, with R2 of 0.97 to 0.99. The soil moisture variability of the field was also compared with the spatial distribution of 2019 barley yield production. No significant difference was found between the EMI estimated soil moisture values and the point moisture measurements, as well as moisture extracted from soil s les for 0 & #8211 0.5m and 0.5 & #8211 0.8 m depths with Pearson R values of 0.62 and 0.73 respectively. Barley yield was not correlated with mapped soil moisture or soil texture, which may be due to relatively high initial moisture levels following two years of fallow rotation. This study successfully demonstrated spatial soil moisture estimation using EMI sensor in a field with horizontally and vertically variable soil texture.
Origin and age of the Lower Bavarian sand dune landscape around Abensberg and Siegenburg
Publisher: Schweizerbart
Date: 12-2011
Interspecific facilitation of micronutrient uptake between cluster-root-bearing trees and non-cluster rooted-shrubs in a Banksia woodland
Publisher: Springer Science and Business Media LLC
Date: 21-06-2023
DOI: 10.1007/S11104-023-06092-6
Abstract: Belowground interspecific plant facilitation is supposed to play a key role in enabling species co-existence in hyper erse ecosystems in extremely nutrient-poor, semi-arid habitats, such as Banksia woodlands in southwestern-Australia. Manganese (Mn) is readily mobilised by Banksia cluster root activity in most soils and accumulates in mature leaves of native Australian plant species without significant remobilisation during leaf senescence. We hypothesised that neighbouring shrubs are facilitated in terms of Mn uptake depending on distance to surrounding cluster root-forming Banksia trees. We mapped all Banksia trees and selected neighbouring shrubs within a study site in Western Australia. Soil s les were collected and analysed for physical properties and nutrient concentrations. To assesses the effect of Banksia tree proximity on leaf Mn concentrations [Mn] of non-cluster-rooted woody shrubs, s les of similarly aged leaves were taken. We used multiple linear models to test for factors affecting shrub leaf [Mn]. None of the assessed soil parameters showed a significant correlation with shrub leaf Mn concentrations. However, we observed a significant positive effect of very close Banksia trees (2 m) on leaf [Mn] in one of the understorey shrubs. We found additional effects of elevation and shrub size. Leaf micronutrient concentrations of understorey shrubs were enhanced when growing within 2 m of tall Banksia trees. Our model predictions also indicate that belowground facilitation of Mn uptake was shrub size-dependent. We discuss this result in the light of plant water relations and shrub root system architecture.
Vacuum drying water-repellent sandy soil
Publisher: Elsevier BV
Date: 08-2020
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