Derek Eamus

Derek Eamus
University of Technology Sydney | UTS · School of the Environment

About

304
Publications
98,596
Reads
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18,908
Citations
Additional affiliations
January 2001 - present
University of Technology Sydney
Position
  • Professor (Full)
January 1990 - present
Charles Darwin University
Description
  • Ecophysiology of savannas; tree water relations; eddy covariance and sapflow
Education
September 1980 - August 1983
University of Wales
Field of study
  • Plant Physiology

Publications

Publications (304)
Article
Full-text available
In 2020, the Australian and New Zealand flux research and monitoring network, OzFlux, celebrated its 20th anniversary by reflecting on the lessons learned through two decades of ecosystem studies on global change biology. OzFlux is a network not only for ecosystem researchers, but also for those ‘next users’ of the knowledge, information and data t...
Article
Full-text available
p>The following authors were omitted from the original version of this Data Descriptor: Markus Reichstein and Nicolas Vuichard. Both contributed to the code development and N. Vuichard contributed to the processing of the ERA-Interim data downscaling. Furthermore, the contribution of the co-author Frank Tiedemann was re-evaluated relative to the co...
Article
Savannas, occupying a fifth of the global land surface, are characterized by the coexistence of trees and grasses. Accurate estimation of savanna evapotranspiration (ET) is vital for understanding the regional and global water balance and its feedback to climate. However, the overlapping phenology and different water-use patterns of trees and grass...
Article
Full-text available
Realistic representations and simulation of mass and energy exchanges across heterogeneous landscapes can be a challenge in land surface and dynamic vegetation models. For mixed life-form biomes such as savannas, plant function is very difficult to parameterise due to the distinct physiological characteristics of tree and grass plant functional typ...
Article
Full-text available
The FLUXNET2015 dataset provides ecosystem-scale data on CO2, water, and energy exchange between the biosphere and the atmosphere, and other meteorological and biological measurements, from 212 sites around the globe (over 1500 site-years, up to and including year 2014). These sites, independently managed and operated, voluntarily contributed their...
Article
Full-text available
The FLUXNET2015 dataset provides ecosystem-scale data on CO2, water, and energy exchange between the biosphere and the atmosphere, and other meteorological and biological measurements, from 212 sites around the globe (over 1500 site-years, up to and including year 2014). These sites, independently managed and operated, voluntarily contributed their...
Article
A comprehensive understanding of the effects of agricultural management on climate–crop interactions has yet to emerge. Using a novel wavelet–statistics conjunction approach, we analysed the synchronisation amongst fluxes (net ecosystem exchange NEE, evapotranspiration and sensible heat flux) and seven environmental factors (e.g., air temperature,...
Article
The southern hemisphere and especially Australian arid and semi-arid ecosystems played a significant role in the 2011 global land carbon sink anomaly. Arid and semi-arid regions occupy 70% of the Australian land surface, dominated by two biomes: Mulga woodlands and spinifex grasslands or savannas. We monitored carbon and water fluxes in two of thes...
Article
As the ratio of carbon uptake to water use by vegetation, water‐use efficiency (WUE) is a key ecosystem property linking global carbon and water cycles. It can be estimated in several ways, but it is currently unclear how different measures of WUE relate, and how well they each capture variation in WUE with soil moisture availability. We evaluated...
Article
Vapour pressure deficit (D) is projected to increase in the future as temperatures rise. In response to increased D, stomatal conductance (gs) and photosynthesis (A) are reduced, which may result in significant reductions in terrestrial carbon, water, and energy fluxes. It is thus important for gas exchange models to capture the observed responses...
Article
Full-text available
(You are invited to visit the Journal's page to view the video abstract.) The global challenge of understanding and forecasting ecosystem responses to climate extremes and climate change is addressed in this review of research enabled through environmental research infrastructure (RI) provided by Australia's Terrestrial Ecosystem Research Network...
Article
Full-text available
Early detection of crop water and heat stress for effective crop management requires continuous and accurate monitoring of cropland photosynthesis activity. Satellite measurements can complement the restrictive coverage afforded by in-situ measurements and have the potential to facilitate the monitoring of cropland photosynthesis over a large spati...
Article
The deforestation and degradation of natural habitats is the second largest contributor to carbon dioxide (CO2) emissions to the atmosphere. Temperate forests cover ∼16.5% of the Mexican landscape, and are a priority ecosystem for global conservation due to their high rate of endemism and species diversity. These forests also provide valuable ecosy...
Article
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Drought‐induced tree mortality is expected to increase in future climates with the potential for significant consequences to global carbon, water, and energy cycles. Xylem embolism can accumulate to lethal levels during drought, but species that can refill embolized xylem and recover hydraulic function may be able to avoid mortality. Yet the potent...
Article
Hydrological responses of catchments to climate change require detailed examination to ensure sustainable management of both water resources and natural ecosystems. This study evaluated the impacts of climate change on water resource availability of a catchment in eastern Australia (i.e. the Manning River catchment) and analyzed climate-hydrology r...
Article
The ratio of leaf intercellular to ambient CO2 (χ) is modulated by stomatal conductance (gs ). These quantities link carbon (C) assimilation with transpiration, and along with photosynthetic capacities (Vcmax and Jmax ) are required to model terrestrial C uptake. We use optimization criteria based on the growth environment to generate predicted val...
Article
Water use efficiency (WUE), the ratio of gross primary productivity (GPP) over evapotranspiration (ET), is a critical ecosystem function. However, it is difficult to distinguish the individual effects of climatic variables and leaf area index (LAI) on WUE, mainly due to the high collinearity among these factors. Here we proposed a partial least squ...
Article
Full-text available
Groundwater-dependent vegetation is globally distributed, having important ecological, social, and economic value. Along with the groundwater resources upon which it depends, this vegetation is under increasing threat through excessive rates of groundwater extraction. In this study we examined one shallow-rooted and two deep-rooted tree species at...
Article
Arid environments can support the seemingly unlikely coexistence of species tolerant of, or sensitive to, dry soil moisture. Here, we examine water-use and carbon-gain traits in two widespread tree species in central Australia: Acacia aptaneura and Eucalyptus camaldulensis. The former has a shallow root distribution and relies on soil moisture, whi...
Article
Full-text available
Climate change (CC) presents a challenge for the sustainable development of wheat production systems in Australia. This study aimed to (1) quantify the impact of future CC on wheat grain yield for the period centred on 2030 from the perspectives of wheat phenology, water use and water use efficiency (WUE) and (2) evaluate the effectiveness of chang...
Article
Full-text available
Thermal infrared sensing of evapotranspiration (E) through surface energy balance (SEB) models is challenging due to uncertainties in determining the aerodynamic conductance (gA) and due to inequalities between radiometric (TR) and aerodynamic temperatures (T0). We evaluated a novel analytical model, the Surface Temperature Initiated Closure (STIC1...
Article
Water and carbon fluxes simulated by 12 Earth system models (ESMs) that participated in phase 5 of the Coupled Model Intercomparison Project (CMIP5) over several recent decades were evaluated using three functional constraints that are derived from both model simulations, or four global datasets, and 736 site-year measurements. Three functional con...
Article
Full-text available
1.Plant species show considerable leaf trait variability that should be accounted for in dynamic global vegetation models (DGVMs). In particular, differences in the acclimation of leaf traits during periods more and less favourable to growth have rarely been examined. 2.We conducted a field study of leaf trait variation at seven sites spanning a r...
Article
Full-text available
Accurate quantification of terrestrial evapotranspiration and ecosystem productivity are of significant merit to better understand and predict the response of ecosystem energy, water and carbon budgets under climate change. Existing diagnostic models have different focus on either water or carbon flux estimates with various model complexity and unc...
Article
Xylem traits such as xylem vessel size can influence the efficiency and safety of water transport and thus plant growth and survival. Root xylem traits are much less frequently examined than those of branches despite such studies being critical to our understanding of plant hydraulics. In this study, we investigated primary lateral and sinker roots...
Article
The rainfed cropland belt in Australia is of great importance to the world grain market but has the highest climate variability of all such regions globally. However, the spatial-temporal impacts of climate variability on crops during different crop growth stages across broadacre farming systems are largely unknown. This study aims to quantify the...
Poster
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Despite occupying one-third of the terrestrial surface and being highly sensitive to changes in hydrology, agricultural ecosystems are under-represented in flux studies of water and carbon cycles across the globe. Consequently, the primary objective of this study was to investigate and compare the responses of agricultural energy (sensible heat flu...
Poster
Full-text available
Mulga woodlands and hummock grasslands cover vast portions of the Australian interior, where their large fluctuations in carbon budget can have global implications. Abiotic decomposition as a result of photo-degradation (i.e., light-mediated breakdown of lignin in leaf litter) can be a major source of carbon to the atmosphere in these ecosystems, e...
Conference Paper
Despite occupying one-third of the terrestrial surface and being highly sensitive to changes in hydrology, agricultural ecosystems are under-represented in flux studies of water and carbon cycles across the globe. Australia and New Zealand are no different, where only 16% of OzFlux sites are located in predominately agricultural landscapes. Consequ...
Article
The National Aeronautics and Space Administration's Soil Moisture Active Passive (SMAP) mission Level 4 Carbon (L4C) product provides model estimates of the Net Ecosystem CO₂ exchange (NEE) incorporating SMAP soil moisture information. The L4C product includes NEE, computed as total ecosystem respiration less gross photosynthesis, at a daily time s...
Article
Partitioning of water resources amongst plant species within a single climate envelope is possible if the species differ in key hydraulic traits. We examined 11 bivariate trait relationships across nine woody species found in the Ti-Tree basin of central Australia. We found that species with limited access to soil moisture, evidenced by low pre-daw...
Article
Low soil water content can limit photosynthesis by reducing stomatal conductance. Here, we explore relationships among traits pertaining to carbon uptake and pre-dawn leaf water potential (as an index of soil water availability) across eight species found in semiarid central Australia.Wefound that as pre-dawn leaf water potential declined, stomatal...
Article
Full-text available
Species are often classified along a continuum from isohydric to anisohydric, with isohydric species exhibiting tighter regulation of leaf water potential through stomatal closure in response to drought. We investigated plasticity in stomatal regulation in an isohydric (Eucalyptus camaldulensis) and an anisohydric (Acacia aptaneura) angiosperm spec...
Article
Full-text available
Non-forest ecosystems (predominant in semi-arid and arid regions) contribute significantly to the increasing trend and interannual variation of land carbon uptake over the last three decades, yet the mechanisms are poorly understood. By analysing the flux measurements from 23 ecosystems in Australia, we found the the correlation between gross prima...
Article
Drought strongly influences terrestrial C cycling via its effects on plant H 2 O and CO 2 exchange. However, the treatment of photosynthetic physiology under drought by many ecosystem and earth system models remains poorly constrained by data. We measured the drought response of four tree species and evaluated alternative model formulations for dro...
Article
Full-text available
Water resources and their management present social, economic and environmental challenges, with demand for human consumptive, industrial and environmental uses increasing globally. However, environmental water requirements, that is, the allocation of water to the maintenance of ecosystem health, are often neglected or poorly quantified. Further, t...
Article
Full-text available
Evapotranspiration (ET) of Amazon forests is a main driver of regional climate patterns and an important indicator of ecosystem functioning. Despite its importance, the seasonal variability of ET over Amazon forests, and its relationship with environmental drivers, is still poorly understood. In this study, we carry out a water balance approach to...
Article
Groundwater-dependent ecosystems (GDEs) are threatened by over-extraction of groundwater for human needs across the world. A fundamental understanding of relationships between naturally occurring gradients in depth-to-groundwater (DGW) across landscapes and the ecological properties of vegetation assemblages is essential for effective management of...
Article
Latent heat flux (LE) and corresponding water loss in non-moisture-limited ecosystems are well correlated to radiation and temperature. By contrast, in savannahs and arid and semi-arid lands LE is mostly driven by available water and the vegetation exerts a strong control over the rate of transpiration. Therefore, LE models that use optical vegetat...
Article
Full-text available
Evapotranspiration (ET) of Amazon forests is a main driver of regional climate patterns and an important indicator of ecosystem functioning. Despite its importance, the seasonal variability of ET over Amazon forests, and its relationship with environmental drivers, is still poorly understood. In this study, we carry out a water balance approach to...
Article
Terrestrial ecosystem gross primary production (GPP) is the largest component in the global carbon cycle.The enhanced vegetation index (EVI) has been proven to be strongly correlated with annual GPP withinseveral biomes. However, the annual GPP-EVI relationship and associated environmental regulationshave not yet been comprehensively investigated a...
Article
Full-text available
Back in 2010-11 Australia “greened”, as record-breaking rains triggered a boom in plant growth that removed huge amounts of carbon dioxide from the atmosphere and stored it as carbon in the landscape. But what happened after that? Our latest research, published in Scientific Reports, shows that this greening was short-lived and was rapidly dissipa...
Article
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Mulga, comprised of a complex of closely related Acacia spp., grades from a low open forest to tall shrublands in tropical and sub-tropical arid and semi-arid regions of Australia and experiences warm-to-hot annual temperatures and a pronounced dry season. This short synthesis of current knowledge briefly outlines the causes of the extreme variabil...
Article
Full-text available
This paper provides a synthesis of the ecophysiological behaviour of Mulga (Acacia spp) in Central Australia and uses leaf-scale, canopy-scale and remote sensing methodologies.
Data
Full-text available
Each year, terrestrial ecosystems absorb more than a quarter of the anthropogenic carbon emissions, termed as land carbon sink. An exceptionally large land carbon sink anomaly was recorded in 2011, of which more than half was attributed to Australia. However, the persistence and spatially attribution of this carbon sink remain largely unknown. Here...
Article
Full-text available
Each year, terrestrial ecosystems absorb more than a quarter of the anthropogenic carbon emissions, termed as land carbon sink. An exceptionally large land carbon sink anomaly was recorded in 2011, of which more than half was attributed to Australia. However, the persistence and spatially attribution of this carbon sink remain largely unknown. Here...
Article
Full-text available
OzFlux is the regional Australian and New Zealand flux tower network that aims to provide a continental-scale national research facility to monitor and assess trends, and improve predictions, of Australia’s terrestrial biosphere and climate. This paper describes the evolution, design, and current status of OzFlux as well as provides an overview of...
Article
Full-text available
A direct relationship between gross ecosystem productivity (GEP) estimated by the eddy covariance (EC) method and Moderate Resolution Imaging Spectroradiometer (MODIS) vegetation indices (VIs) has been observed in many temperate and tropical ecosystems. However, in Australian evergreen forests, and particularly sclerophyll and temperate woodlands,...
Article
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The Earth's Critical Zone, where physical, chemical and biological systems interact, extends from the top of the canopy to the underlying bedrock. In this study, we investigated soil moisture controls on phenology and productivity of an Acacia woodland in semi-arid central Australia. Situated on an extensive sand plain with negligible runoff and dr...
Article
Full-text available
Energy and water availability were identified as the first order controls of evapotranspiration (ET) in ecohyrodrology. With a ~1,000 km precipitation gradient and distinct wet-dry climate, the North Australian Tropical Transect (NATT) was well suited for evaluating how energy and water availabilities constrain water use by vegetation, but has not...
Article
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Changes in climatic characteristics such as seasonal and inter-annual variability may affect ecosystem structure and function, hence alter carbon and water budgets of ecosystems. Studies of modelling combined with field experiments can provide essential information to investigate interactions between carbon and water cycles and climate. Here we pre...
Article
Full-text available
Ecophysiological studies of remnant woodlands in saline environments are scarce. We investigated seasonal fluctuations in soil water and salinity together with leaf and branch traits (area-based maximum assimilation (Amax), foliar nitrogen, specific leaf area (SLA) and Huber value (Hv)) and sap velocities of Eucalyptus macrorhyncha at four semi-ari...
Article
Full-text available
OzFlux is the regional Australian and New Zealand flux tower network that aims to provide a continental-scale national research facility to monitor and assess trends, and improve predictions, of Australia’s terrestrial biosphere and climate. This paper describes the evolution, design and current status of OzFlux as well as an overview of data proce...
Article
Full-text available
Global carbon balances are increasingly affected by large fluctuations in productivity occurring throughout semiarid regions. Recent analyses found a large C uptake anomaly in 2011 in arid and semiarid regions of the southern hemisphere. Consequently, we compared C and water fluxes of two distinct woody ecosystems (a Mulga (Acacia) woodland and a C...
Article
Partitioning evapotranspiration (ET) into its components reveals details of the processes that underlie ecosystem hydrologic budgets and their feedback to the water cycle. We measured rates of actual evapotranspiration (ETa), canopy transpiration (Tc), soil evaporation (Eg), canopy-intercepted precipitation (EI), and patterns of stomatal conductanc...
Article
Full-text available
The global carbon cycle is highly sensitive to climate-driven fluctuations of precipitation, especially in the Southern Hemisphere. This was clearly manifested by a 20% increase of the global terrestrial C sink in 2011 during the strongest sustained La Niña since 1917. However, inconsistencies exist between El Niño/La Niña (ENSO) cycles and precipi...
Article
The optimisation of plant nitrogen-use-efficiency (NUE) has a direct impact on increasing crop production by optimising use of nitrogen fertiliser. Moreover, it protects environment from negative effects of nitrate leaching and nitrous oxide production. Accordingly, nitrogen (N) management in agriculture systems has been major focus of many researc...
Article
Full-text available
Key message Species with low density of intact branches are likely to have higher growth rates than species with high density of intact branches, but at the cost of a lower water-use efficiency and larger sensitivity to xylem embolism. Abstract The hydraulic niche separation theory proposes that species co-exist by having a range of traits to allow...