A5066500086- Groundwater and Isotope Geochemistry
- Atmospheric and Environmental Gas Dynamics
- Methane Hydrates and Related Phenomena
- Marine and coastal ecosystems
- Coastal wetland ecosystem dynamics
- Geophysical and Geoelectrical Methods
- Fire effects on ecosystems
- Peatlands and Wetlands Ecology
- Groundwater flow and contamination studies
- Coastal and Marine Dynamics
- Soil and Water Nutrient Dynamics
- Geology and Paleoclimatology Research
- Ocean Acidification Effects and Responses
- Hydrocarbon exploration and reservoir analysis
- Microbial Community Ecology and Physiology
- Oceanographic and Atmospheric Processes
- Coral and Marine Ecosystems Studies
- Coal Properties and Utilization
- Geophysical Methods and Applications
- Isotope Analysis in Ecology
- Constructed Wetlands for Wastewater Treatment
- Flood Risk Assessment and Management
- Geological and Geophysical Studies
- Underwater Acoustics Research
- Groundwater and Watershed Analysis
Southern Cross University
2016-2025
ORCID
2020
Abstract Mangrove forests are hot spots in the global carbon cycle, yet fate for a majority of mangrove net primary production remains unaccounted for. The relative proportions alkalinity and dissolved CO 2 [CO *] within inorganic (DIC) exported from mangroves is unknown, therefore, effect DIC exports on coastal acidification unconstrained. Here we measured parameters over complete tidal diel cycles six pristine creeks covering 26° latitudinal gradient Australia calculated exchange DIC,...
Abstract Mangrove forests produce significant amounts of organic carbon and maintain large stocks in tidally inundated, anoxic soils. This work analyzes new published data from 17 regions spanning a latitudinal gradient 22°N to 38°S assess some the global drivers (temperature, tidal range, latitude, rainfall) mangrove stocks. tropics have larger (895 ± 90 t C ha −1 ) than subtropics temperate (547 66 ). A multiple regression model showed that 86% observed variability is associated with...
Maximizing carbon sequestration in mangroves is part of the global effort to combat climate crisis. However, methane (CH4) emissions can partially offset mangroves. Previous estimates have suggested that CH4 organic burial by 20% with substantial freshwater inputs and/or highly impacted Here we resolve magnitude and drivers mangrove using multiple isotopic tracers across a latitudinal gradient. emission offsets were smaller high-salinity (~7%) than freshwater-influenced (~27%) Carbon was...
Abstract We combined observations of the natural tracer radon ( 222 Rn) with hydrodynamic models across a broad latitudinal gradient covering several climate zones to estimate pore water exchange rates in mangroves. Pore ranged from 2.1 35.5 cm d −1 temperate tropical regions and averaged 16.3 ± 5.1 . If upscaled global weighted mangrove area, mangroves would recirculate entire volume overlying continental shelf less than 153 years. Although (recirculated seawater) river discharge represent...
Summary Growing evidence indicates that tree‐stem methane (CH 4 ) emissions may be an important and unaccounted‐for component of local, regional global carbon (C) budgets. Studies to date have focused on upland freshwater swamp‐forests; however, no data fluxes from estuarine species currently exist. Here we provide the first‐ever mangrove CH flux measurements >50 trees ( n = 230 measurements), in both standing dead living forest, a region suffering recent large‐scale climate‐driven...
Abstract Nitrous oxide (N 2 O) is an important greenhouse gas, but large uncertainties remain in global budgets. Mangroves are thought to be a source of N O the atmosphere spite limited available data. Here we report high resolution time series observations pristine Australian mangroves along broad latitudinal gradient assess potential role Surprisingly, five out six creeks were under-saturated dissolved O, demonstrating mangrove creek waters sink for atmospheric O. Air-water flux estimates...
Tree stems are an important and unconstrained source of methane, yet it is uncertain whether internal microbial controls (i.e. methanotrophy) within tree bark may reduce methane emissions. Here we demonstrate that unique communities dominated by methane-oxidising bacteria (MOB) dwell Melaleuca quinquenervia, a common, invasive globally distributed lowland species. In laboratory incubations, methane-inoculated M. quinquenervia mediated consumption (up to 96.3 µmol m-2 d-1) reveal distinct...
Abstract Terrestrial groundwater travels through subterranean estuaries before reaching the sea. Groundwater‐derived nutrients drive coastal water quality, primary production, and eutrophication. We determined how dissolved inorganic nitrogen (DIN), phosphorus (DIP), organic (DON) are transformed within estimated submarine discharge (SGD) nutrient loads compiling > 10,000 samples from 216 sites worldwide. Nutrients exhibited complex, nonconservative behavior in estuaries. Fresh DIN DIP...
Coastal ecosystems play a major role in marine carbon budgets, but substantial uncertainties remain the sources and fluxes of coastal dioxide (CO 2 ). Here, we assess when, where, how submarine groundwater discharge (SGD) releases CO to shallow ecosystems. Time-series observations dissolved radon ( 222 Rn, natural tracer) across 40 systems from 14 countries revealed large SGD-derived fluxes. The mean partial pressure was 35 times higher than surface seawater. flux 148 ± 226 millimoles per...
Coral reefs are characterized by high gross productivity in spite of low nutrient concentrations. This apparent paradox may be partially reconciled if seawater recirculation permeable sediments over large (meters) and long (hours to days) scales is an important source recycled nitrogen phosphorus coral reefs. In this paper we use radon ( 222 Rn, a natural tracer) quantify tidally driven pore water (or groundwater) exchange between (1) offshore cay island its fringing reef lagoon (2) the...
Abstract Wetlands represent the largest natural source of methane; however, very few studies have simultaneously quantified three main atmospheric flux pathways (i.e., diffusive, ebullition, and plant‐mediated). Unlike better‐studied northern hemisphere systems, many Australian subtropical wetlands undergo extreme wet/dry oscillations, which may strongly impact methane dynamics. We assessed diurnal emissions multiple during distinct seasonal events within an freshwater wetland. Six‐fold...
Abstract The influence of groundwater and pore‐water exchange on dissolved organic matter (DOM) dynamics in coastal surface waters remains poorly understood. Here, we combine bottom up (i.e., groundwater‐derived flux estimates) top down water column response) evidence to assess whether drives DOM shallow waters. We rely automated chromophoric (CDOM, a proxy for DOM) radon ( 222 Rn, proxy) measurements over tidal time scales 12 systems, including freshwater wetlands, estuaries, mangroves,...
Submarine groundwater discharge (SGD) is an important pathway for carbon and nutrients to the coastal ocean, sometimes exceeding river inputs. SGD fluxes can have implications long-term storage, ocean acidification nutrient dynamics. Here, we used radium (223Ra 226Ra) isotopes quantify SGD-derived of dissolved inorganic (DIC) organic (DOC) carbon, nitrate (NO3−), nitrite (NO2−), ammonium (NH4+) phosphate (PO43−) in a spring-fed bay Japan Sea. The average water residence times using...
Abstract Exchangeable dissolved organic carbon (EDOC) makes up a significant proportion of the oceanic (DOC) pool, yet EDOC sources to coastal ocean are poorly constrained. We measured exchange and concentrations DOC in mangrove waters over 26° latitudinal gradient. A clear trend was observed, with highest tropics. exports were 4.7 ± 1.9 mmol m −2 d −1 , equivalent 11% (42.1 6.7 ). Pore‐water groundwater minor EDOC. equal 13% 4% concentrations. Based on previous global export estimates, our...