Peter D. Erskine

• PhD
• Professor at The University of Queensland

The basic methods for rehabilitating degraded land left after mining are reasonably well-understood and there are examples across Australia of these being currently implemented. But there are many other situations where further research will be needed to achieve rehabilitation objectives. In addition, a number of mines are yet to embark on any sust...

Sabah (Malaysia) has one of the largest surface expressions of ultramafic rocks on Earth and in parallel hosts one of the most species-rich floras. Despite the extensive knowledge of the botanical diversity and the chemistry of these substrates, until recently the records for nickel (Ni) hyperaccumulators in the area have been scant. Recent intensi...

The current scale of deforestation in tropical regions and the large areas of degraded lands now present underscore the urgent need for interventions to restore biodiversity, ecological functioning, and the supply of goods and ecological services previously used by poor rural communities. Traditional timber plantations have supplied some goods but...

Crotalaria is a genus of ~600 species of legumes predominantly found in (sub)tropical regions of Africa and Australia. Crotalaria novae‐hollandiae from Australia is a polymetallic zinc (Zn)‐cadmium(Cd)‐copper(Cu) hyperaccumulator, but only when growing in metalliferous soils. This study aimed to test metal tolerance in Australian Crotalaria species...

The discovery of the nickel-rich latex of the New Caledonian endemic tree Pycnandra acuminata introduced the term 'hyperaccumulator' and gave rise to a new field of research. This then instigated a global quest for these unusual hyperaccumulator plants, even while the underlying mechanisms of nickel acquisition, transport, and internal elemental di...

Context Pasture dieback has emerged as a significant threat to the health and productivity of sown pastures in eastern Queensland and northern New South Wales, Australia. Aims We aimed to address knowledge gaps on spatial spread patterns, recovery trajectories and floristic changes using remote sensing and ground surveys. Methods We used a time s...

The use of x‐ray fluorescence (XRF) instruments for metallome analysis of herbarium specimens to discover hyperaccumulator plant species has gained popularity, but a growing concern arises about intercomparability from the use of different instrument makes and models. Therefore, this study aimed to assess the performance and comparability of the re...

Background and Aims The tropical shrub Coelospermum decipiens (Rubiaceae) is an extreme selenium (Se) hyperaccumulator, reported to accumulate up to 1140 µg Se g−1 when found growing on soils with levels of Se below the limit of detection (i.e. <0.01 mg Se kg−1) leading to a bioconcentration factor of >100 000. Methods Coelospermum decipiens plant...

Background and Aims Indonesia is one of the most biodiverse regions in the world, but only a few metal hyperaccumulator plants have been reported from this vast country. This study aimed to discover rare earth element (REE) hyperaccumulator plants on Bangka Island, an area known to have REE enriched soils associated with tin placer deposits. Metho...

The global energy transition from fossil fuels to renewable sources poses substantial challenges to increase metal production, including industry-critical rare earth elements (REEs). Environmental and social concerns obfuscate the production of these 'green' metals and only ~1% of REE demand is met from recycling. This work highlights the potential...

The crises of climate change and biodiversity loss are interlinked and must be addressed jointly. A proposed solution for reducing reliance on fossil fuels, and thus mitigating climate change, is the transition from conventional combustion‐engine to electric vehicles. This transition currently requires additional mineral resources, such as nickel a...

Background and aims The Richmond District of Queensland (Australia) hosts seleniferous soils and is the habitat of selenium (Se) hyperaccumulator plants. These soils are also naturally enriched in vanadium (V) and molybdenum (Mo). This study aimed to survey soils and plants of the Richmond area with a focus on the Se hyperaccumulator Neptunia ample...

Background and aims Nickel (Ni) deficiency has been reported to occur in soybean (Glycine max) grown on leached tropical soils in Brazil. We aimed to determine whether an internal or external Ni supply can compensate for low Ni within the seed by assessing whether the amount of Ni in the seed whether the foliar-application of aqueous NiSO4 influenc...

The known manganese (Mn) hyperaccumulator Gossia bidwillii, and G. acmenoides unknown to hyperaccumulate Mn are tree species native to subtropical eastern Australia, where they co-occur on Mn-rich soils. Here, we investigate Mn accumulation and distribution in G. acmenoides collected from its natural habitat, and propagated G. bidwillii plants in a...

Desires that mine sites are restored to self‐sustaining native ecosystems providing benefits for people have been longstanding. However, achieving and demonstrating progress toward mine restoration goals is complex and requires sustained assessment of numerous disparate components. The recently released Society for Ecological Restoration Mine Site...

Background and aims Hyperaccumulation is generally defined as plants exhibiting concentrations of metal(loid)s in their shoots at least an order of magnitude higher than that found in ‘normal’ plants, but this notional threshold appears to have limited statistical underpinning. The advent of massive (handheld) X-ray fluorescence datasets of herbari...

Background and aims An innovative approach “Herbarium Ionomics” used a handheld X-ray fluorescence (XRF) device to non-destructively extract quantitative elemental data (i.e. , the metallome) from herbarium specimens. This has led to the discovery of numerous hyperaccumulator plants. Once a new hyperaccumulator is identified through XRF screening,...

Context Mitigating the impacts of mining on biodiversity and ecosystem services (ES) is critical for maintaining human wellbeing in mineral-rich landscapes. Environmental assessments and mitigation plans almost always consider impacts on biodiversity, yet few extend to the individual ES valued by local communities. As a result, mine site management...

Main conclusion The VNIR reflectance spectra of nickel hyperaccumulator plant leaves have spectral variations due to high nickel concentrations and this property could potentially be used for discovery of these plants. Abstract Hyperaccumulator plants accumulate high concentrations of certain metals, including manganese, cobalt, or nickel. Of the...

The primary solid waste product of surface coal mining is overburden (also known as spoil), the material that is moved to access the underlying coal seams. Once removed, this material is generally stored in large (>100 m in height) piles until it is re-contoured in preparation for post-mining rehabilitation, often remaining there for decades. Under...

Context Fewer than 10 plant species from Australia were known to hyperaccumulate metal(loid)s, despite metal-rich soils being widespread in Australia. By measuring herbarium specimens with non-destructive portable X-ray fluorescence spectroscopy (XRF) instrumentation their metal(loid)s concentrations can be determined, providing information that co...

Landscape rehabilitation following mining is required to be resilient to disturbance impacts such as fire, drought and disease. As mining companies undergo the process of rehabilitation certification and mine closure, there are notable knowledge gaps on the ecological risks associated with mature rehabilitated landscapes, based largely on the assum...

Examples of successful mine closure and acceptable regional transitioning of mining areas are scarce. The recent changes to the environmental, social and governance (ESG) obligations of mining companies should help to ensure that water and land resources as well as post-mining employment opportunities are considered as a part of mine closure. Integ...

Background: “Herbarium X-ray Fluorescence (XRF) Ionomics” is a new quantitative approach for extracting the elemental concentrations from herbarium specimens using handheld XRF devices. These instruments are principally designed for dense sample material of infinite thickness (such as rock or soil powder), and their built-in algorithms and factory...

Background and aims Proteaceae species strongly acidify their rhizosphere to increase soil phosphorus (P) availability, which also inadvertently increases the availability of other elements, such as manganese and rare earth elements (REE). This study aimed to investigate REE (hyper) accumulation in the Proteaceae genus Helicia from Queensland, Aust...

Main conclusion Micro-analytical techniques to untangle Se distribution and chemical speciation in plants coupled with molecular biology analysis enable the deciphering of metabolic pathways responsible for Se tolerance and accumulation. Abstract Selenium (Se) is not essential for plants and is toxic at high concentrations. However, Se hyperaccumu...

Context Hyperaccumulator plants are of considerable interest for their extreme physiology. Stackhousia tryonii is a nickel (Ni) hyperaccumulator plant endemic to ultramafic outcrops in Queensland (Australia) capable of attaining up to 41 300 μg g⁻¹ foliar Ni. Aims This study sought to elucidate the distribution of Ni in S. tryonii by using synchro...

Purpose Hyperaccumulators are plants with the ability to tolerate and accumulate high concentrations of potentially phytotoxic metals. The Australian legume Crotalaria novae-hollandiae accumulates remarkably high concentrations of zinc (Zn), cadmium (Cd) and copper (Cu) in its shoots when growing on metalliferous (Zn-Cd ‘calamine’) soils. This stud...

Macadamia integrifolia and M. tetraphylla, unlike M. ternifolia, are known for their edible nuts. All three species over-accumulate the trace metal nutrient manganese (Mn) in their shoots. This study seeks to examine tissue- and cellular-level distribution of Mn and other plant nutrients in the three Macadamia species. The distribution of Mn, calci...

Context Forest restoration plays an important role in global efforts to slow biodiversity loss and mitigate climate change. Vegetation in remnant forests can form striking patterns that relate to ecological processes, but restoration targets tend to overlook spatial pattern. While observations of intact reference ecosystems can help to inform resto...

Purpose The Cunoniaceae are a major component of the New Caledonian flora with 91 endemic species that are highly unusual in that multiple metals are hyperaccumulated in different species. This makes it an ideal model system for studying the nature of the hyperaccumulation phenomenon. Methods X-ray fluorescence spectroscopy (XRF) scanning of all h...

The commencement of the United Nations Decade on Ecosystem Restoration has highlighted the urgent need to improve restoration science and fast‐track ecological outcomes. The application of remote sensing for monitoring purposes has increased over the past two decades providing a variety of image datasets and derived products suitable to map and mea...

Ultramafic rain forests in New Caledonia evolved on some of the most nutrient impoverished soils globally and are some of the slowest-growing tropical forests known. This study aimed to determine nutrient stocks and elucidate the biogeochemical cycling of nutrients in a remnant lowland rain forest in southern New Caledonia. Based on an inventory of...

The manganese (Mn) hyperaccumulator Gossia bidwillii is a tree species native to subtropical eastern Australia where it occurs on Mn-rich soils. Here, we conducted the first Mn accumulation and tissue-level distribution study on wild and experimentally grown G. bidwillii . Gossia bidwillii plants were subjected to different levels of Mn (250 µg g ⁻...

Globally, there is a major shift to electric vehicles to combat climate change and these vehicles are currently powered by lithium-ion batteries that consist mainly of lithium nickel cobalt manganese oxide materials. This technological change from internal combustion engines means that demand for battery minerals will need to increase by factors of...

Background and aimsMetallophytes are plants that can tolerate extreme metal concentrations in the soil in which they grow. The Dugald River zinc (Zn)-lead (Pb) gossan in Queensland (Australia) is one of the largest metal deposits in the world with a surface gossan formed after weathering over millions of years. It hosts a range of metallophytes whi...

Background and aims Australian Macadamia species are known for their edible nuts as well as their ability to take up high concentrations of manganese (Mn) into their leaves. However, little is known about the ecophysiology of Mn in species of Macadamia. Methods This study investigated (i) Mn accumulation in wild Macadamia using portable X-ray fluo...

Bauxite mining operations are increasingly sited on Indigenous-owned land, particularly in tropical areas, including northern Australia. The environmental impacts of bauxite mining are significant. Native vegetation, including commercially valuable forests, is cleared and typically windrowed and burnt. For many Indigenous Australians, mining of the...

Background and aimsPhosphorus is one of the major nutrients that directly or indirectly affects all aspects of plant growth. Tropical nickel hyperaccumulators, including Phyllanthus rufuschaneyi and Rinorea cf. bengalensis from Borneo Island (in the Malaysian state of Sabah), have evolved to grow in extremely P-impoverished ultramafic soils. This s...

Background and Aims In tropical ultramafic soils, potassium (K) is typically the most growth limiting nutrient. However, tropical nickel (Ni) hyperaccumulator plants, including Phyllanthus rufuschaneyi and Rinorea cf. bengalensis (which are ‘metal crops’ used in agromining) from Malaysia, have unusually high K shoot accumulation compared to other s...

The hyperaccumulator Pycnandra acuminata is a New Caledonian rainforest tree known to have the highest concentration of nickel in any living organism, with 25 wt% nickel in its latex. All trees (with a diameter of >10 cm) and soil profiles in a 0.25‐hectare permanent plot were sampled to assess the biogeochemical compartmentalisation of nickel in a...

Background and aims Investigations on the biogeochemical behaviour of rare earth elements (REE) in natural systems broaden our understanding on their occurrence and fate in ecosystems. The aim of this study was to assess the prevailing REE concentration patterns in soils and plants in a uranium (U)-REE rich area in Central Queensland, Australia. Me...

The diameter distribution of savanna tree populations is a valuable indicator of savanna health because changes in the number and size of trees can signal a shift from savanna to grassland or forest. Savanna diameter distributions have traditionally been monitored with forestry techniques, where stem diameter at breast height (DBH) is measured in t...

Background and aimsThe genus Denhamia(Celastraceae) includes fifteen Australian species, many of which have a propensity for manganese (Mn) (hyper)accumulation. Among the key aims of this study were to: i) elucidate Mn accumulation in D. bilocularis, D. celastroides, D. pittosporoides and D. silvestris under controlled conditions; ii) examine the i...

The rare phenomenon of plant manganese (Mn) hyperaccumulation within the Australian flora has previously been detected in the field, which suggested that the tree genus Gossia (Myrtaceae) might contain new Mn hyperaccumulators. We conducted the first growth experiment on Gossia using a multi-factorial dosing trial to assess Mn, cobalt (Co) and zin...

The rare phenomenon of plant manganese (Mn) hyperaccumulation within the Australian flora has previously been detected in the field, which suggested that the tree genus Gossia (Myrtaceae) might contain new Mn hyperaccumulators. We conducted the first growth experiment on Gossia using a multi-factorial dosing trial to assess Mn, cobalt (Co) and zinc...

Background and aims Neptunia amplexicaulis, endemic to Central Queensland (Australia), is one of the strongest selenium (Se) hyperaccumulators known globally, capable of accumulating up to 13 600 µg Se g− 1 in its leaves. This work aimed to elucidate root foraging in response to Se in N. amplexicaulis applied in two different chemical forms and con...

The ability of Australian native metallophytes to tolerate extreme metal concentrations in the soil and other difficult edaphic conditions is still not well understood. Copper is an essential micronutrient for plants to survive, but at high concentrations (> 20 µg g−1) in plant tissues, it can cause foliar chlorosis, stunted growth, and ultimately...

Mining activities can pose negative, sometimes irreversible damage to ecosystems, yet consequences for ecosystem services (ES) and their contribution to human wellbeing are more uncertain. Obtaining a clear understanding of where and how mining impacts ES and the methods used to show this is crucial for determining management approaches to overcome...

Hyperaccumulation of elements in plants has been previously defined as an element-specific behaviour resulting in concentrations in foliar dry mass that are at least two orders of magnitude greater than the average concentrations of the same element in typical plants. The recognition of trace element hyperaccumulation of Ni, Co, Cu, Zn, Cd, Pb, Mn,...

The identification and use of hyperaccumulator plants in mining projects has been recognized as an important component of life of mine planning at several sites around the world. Mine planning that includes hyperaccumulator plants requires operators to maximize the biological resources of a site by discovering and utilizing these unusual plant spec...

Aims – This study aimed to establish elemental profiles and to spatially resolve the elemental distribution in five New Caledonian woody Ni hyperaccumulator plant species (Geissois pruinosa var. pruinosa, Homalium francii, Hybanthus austrocaledonicus, Psychotria gabriellae, and Pycnandra acuminata) originating from the Cunoniaceae, Salicaceae, Viol...

To meet future technological demands of our growing global community new sources of industry critical metals need to be identified. To meet these demands, extracting minerals from larger, lower grade deposits across most commodities is required, which in turn generates ever increasing amounts of mine wastes. We propose that agromining could be used...

Hyperaccumulation of elements in plants has been previously defined as an element-specific behaviour resulting in concentrations in foliar dry mass that are at least two orders of magnitude greater than the average concentrations of the same element in typical plants. The recognition of trace element hyperaccumulation of Ni, Co, Cu, Zn, Cd, Pb, Mn,...

Globally, the discovery of hyperaccumulator plants has been hindered by systematic screening of plant species and is highly biased towards Ni hyperaccumulators. This is mainly due to the existence of a reagent paper test that is only specific to Ni (based on dimethylglyoxime), such that more than 500 of the approximately 700 known hyperaccumulators...

The mining industry has been operating across the globe for millennia, but it is only in the last 50 years that remote sensing technology has enabled the visualization, mapping and assessment of mining impacts and landscape recovery. Our review of published literature (1970–2019) found that the number of ecologically focused remote sensing studies...

Rare earth elements are increasingly required for use in modern high-tech components, and primary production is necessary to meet the demand. Reprocessing legacy metallurgical tailings is advantageous, as the material has already been mined, beneficiated, upgraded, and contained in a single accessible location. The Mary Kathleen uranium process tai...

Aims Knowledge on the ecophysiology of facultative cobalt hyperaccumulators is limited. The nickel hyperaccumulator Rinorea cf. bengalensis from Borneo can accumulate high concentrations of cobalt in nature. This study investigates the cobalt accumulation potential of Rinorea cf. bengalensis in relation to nickel levels in soils and the subsequent...

The discovery of nickel hyperaccumulation, in Pycnandra acuminata, was the start of a global quest in this fascinating phenomenon. Despite recent advances in the physiology and molecular genetics of hyperaccumulation, the mechanisms and tolerance of Ni accumulation in the most extreme example reported to date, P. acuminata, remains enigmatic. We co...

Reference site selection associated with mining and resource development requires a comprehensive approach so that stakeholders can be confident that restoration efforts have appropriate target ecosystems. Here, we present our process to select reference sites, within a savanna ecosystem, which will be used to develop and assess closure criteria an...

Aims Nickel hyperaccumulator plants require highly evolved mechanisms to avoid cellular-level toxicity to cope with the high prevailing concentrations of nickel in their seeds and seedlings. This study aimed to investigate tissue distribution and dynamics of Ni and other physiologically relevant elements during the germination of hyperaccumulators....

Background and Aims – Hybanthus austrocaledonicus (Violaceae) is a Ni hyperaccumulator endemic to New Caledonia. One of the specimens stored at the local herbarium had a strip of bark with a remarkably green phloem tissue attached to the sheet containing over 4 Wt% Ni. This study aimed to collect field samples from the original H. austrocaledonicus...

Background and Aims –The aim of this study was to test the frequency distributions of foliar elements from a large dataset from Kinabalu Park (Sabah, Malaysia) for departure from unimodality, indicative of a distinct ecophysiological response associated with hyperaccumulation. Methods – We collected foliar samples (n = 1533) comprising 90 familie...

Background and Aims – Hybanthus austrocaledonicus (Violaceae) is a Ni hyperaccumulator endemic to New Caledonia. One of the specimens stored at the local herbarium had a strip of bark with a remarkably green phloem tissue attached to the sheet containing over 4 Wt% Ni. This study aimed to collect field samples from the original H. austrocaledonicus...

Three metallophyte species, Persicaria capitata, P. puncata (Polygonaceae), Conyza cordata (Asteraceae) from mineral wastes in the Zambian copper-cobalt belt were studied. This study focused on the elemental distribution in the roots, stems and leaves, using a range of techniques: micro-PIXE, SEM-EDS synchrotron XFM and XAS. The species differed in...

New Caledonia is a global biodiversity hotspot known for its metal hyperaccumulator plants. X-ray fluorescence technology (XRF) has enabled non-destructive and quantitative determination of elemental concentrations in herbarium specimens from the ultramafic flora of the island. Specimens belonging to six major hyperaccumulator families (the Cunonia...

Background Phytoextraction is an in situ technique that can be applied to minerals and mining wastes using hyperaccumulator plants to purposely bio-concentrate high levels of metals or metalloids into their shoots in order to remove them from the substrate, while achieving monetary gain. Phytoextraction can be applied to a limited number of element...

The flora of Papua New Guinea is amongst the richest in the world with an estimated 25,000 plant species. The extreme levels of biodiversity, climatic ranges and soil types suggest a high possibility of metal hyperaccumulator plants existing in Papua New Guinea. However, no hyperaccumulator plants have been reported from this region yet. The use of...

Selenium (Se), a trace element essential for human and animal biological processes, is deficient in many agricultural soils. Some extremely rare plants can naturally accumulate extraordinarily high concentrations of Se. The native legume Neptunia amplexicaulis, endemic to a small area near Richmond and Hughenden in Central Queensland, Australia, is...

The fern Dicranopteris linearis (Gleicheniaceae) from China is a hyperaccumulator of Rare Earth Element (REE), but little is known about the ecophysiology of REE in this species. This study aimed to clarify tissue-level and organ-level distribution of REEs via synchrotron-based X-ray fluorescence microscopy (XFM). The results show that REEs (La + Ce...

New Caledonia is a global biodiversity hotspot known for its metal hyperaccumulator plants. X-ray fluorescence technology (XRF) has enabled non-destructive and quantitative determination of elemental concentrations in herbarium specimens from the ultramafic flora of the island. Specimens belonging to six major hyperaccumulator families (Cunoniaceae...

Aims This study investigated the physico-geochemical properties of three types of ultramafic substrates in Sabah (Malaysia) and further characterised their influence on nickel (Ni) accumulation in two selected tropical ‘metal crops’ (Phyllanthus rufuschaneyi and Rinorea cf. bengalensis). Methods Three experiments, consisting of a randomised block...

Society’s expectations for mining operations are that they are undertaken using the principles of sustainable development. Numerous mines have been ‘rehabilitated’ in past decades without clear closure criteria or regulatory oversight and are characterised by less than desirable environmental outcomes. These sites provide us with information and da...

The application of controlled fire on post-mine rehabilitation is currently underutilised as an ecological tool throughout fire prone landscapes such as eastern Australia. Despite widely accepted benefits of fuel management and ecological outcomes, mined land managers are generally reluctant to incorporate fire regimes on rehabilitated lands. We ap...

Agromining is an emerging technology that utilizes selected 'metal crops' (= hyperaccumulator plants) to extract valuable target metals from unconventional resources for profit from mineral-ised soils. Growth characteristics, shoot metal concentrations, and agrominable locations are important considerations in economic agromining. Globally, the gre...

Tropical ultramafic regoliths (derived from iron‑magnesium‑nickel-rich mantle rocks) can yield significant nickel and cobalt ore reserves and are mined across the Asia-Pacific Region. In some instances, ultramafic laterite deposits are also enriched in scandium. However, the behaviour of scandium in soil-plant systems, and any potential geobotanica...

Ranger uranium mine, surrounded by Kakadu National Park in northern Australia, is about to undertake broad-scale restoration of the first of its two pits and cease all mining and processing activities. Over the mine’s forty-year life information from two detailed vegetation maps and five significant reference site surveys has been used to assist wi...

Indonesiahas one of the largest surface expressions of ultramafic rocks on Earthand in parallel hosts one of the most species-rich floras. Despite the extensive knowledge of the botanical diversity and the chemistry of thesesubstrates, until recently the records for nickel hyperaccumulators in the region have been scant.Identification of native loc...

Global herbaria are the greatest repositories of information on the plant kingdom. Discoveries of trace element hyperaccumulator plants have historically required time-consuming destructive chemical analysis of fragments from herbarium specimens, which severely constrains the collection of large datasets. Recent advances in handheld X-Ray Fluoresce...

The Central African Copperbelt of the DR Congo and Zambia hosts more than 30 known Cu-Co hyperaccumulator plant species. These plants can accumulate extraordinarily high concentrations of Cu and Co in their living tissues without showing any signs of toxicity. Haumaniastrum robertii is the most extreme Co hyperaccumulator (able to accumulate up to...