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Nectar analysis has been used to understand pollination systems, but nectar storage methods have rarely been considered as potential sources of inaccuracy in the recovery of data. Prompt nectar sugar analysis is not always possible and storage methods can affect results. We aimed to develop an effective method to store nectar on filter paper. Nectars from two subspecies of Eremophila maculata (Scrophulariaceae) and Strelitzia reginae (Strelitziaceae) were spotted on filter papers. Nectars were redissolved and assayed by high-performance liquid chromatography to determine the masses of sugars recovered from the papers from Day 0 to Day 30. We evaluated the effects of the method of elution, paper type and size, and storage treatments on sugar recovery. Liquid nectars were also stored in the refrigerator. Sugars were best eluted from filter papers in 15 mL of water and agitated for 1 min. Nectar sugars stored on small papers tended to be recovered more successfully than those stored on larger papers (significantly for glucose). Paper performed better than nylon for glucose. Desiccant had a marginal positive effect on nectar sugar recovery, and filter paper performed better than did refrigeration of liquid nectar for storage. If highly accurate measurements are needed, nectars should be eluted with large volumes of water from small filter papers stored with desiccant within a few days of collection. Floral nectar is a primary driver of pollination. Storage of nectar between collection and analysis can greatly affect sugar characteristics. We aimed to develop an effective method to store nectar on filter paper. Nectar is best eluted with large volumes of water from small filter papers stored with desiccant. Nectar storage methods have rarely been considered as sources of inaccuracy; however, we have demonstrated that prompt analysis is necessary for the most reliable results. [ABSTRACT FROM AUTHOR]

In a recent paper in Southern Forests , Jaganathan and co-workers indicated that the low constant-temperature drying method (LCTDM) (103°C for 17 h) is satisfactory for determining moisture content (MC) in seeds with physical dormancy (PY). Would this recommendation apply to Acacia , a large genus (1000+ species) with a seed coat so strong that seeds in the soil can maintain high viability for many decades? MC was assessed, using the LCTDM, in six Australian Acacia species by comparing intact seeds with those cut in half. Halved seeds of all species lost moisture rapidly and their mass had largely stabilised after about 2–3 h. Intact seeds had a wide variation in moisture-loss patterns. In some species, the testa was morphologically unchanged after 24 h at 103°C and this was associated with a relatively slow moisture loss. In other species, the testa had completely shattered after 8 h, leading to a rapid moisture loss. If the LCTDM is used to determine MC in Acacia species, it is advisable to employ a technique that substantially disrupts the testa. Moisture content (MC) is an important property of seeds, associated with many aspects of physiological seed quality. Acacias have very hard seed coats, which means that seeds can survive for decades in the soil, but in standard methods of determining MC (e.g. heating in an oven at 103°C for 17 h), the moisture in the seed might not be able to escape. The standard method can work for some Acacia species; however, to ensure accurate results, seeds should be halved before going into the oven. Image by Geoff Burrows. [ABSTRACT FROM AUTHOR]

Themeda triandra (Forssk.) is a tussock grass of international importance for its keystone role in grassy ecosystems and, hence, is often a focus for seed production, research and ecological restoration. However, these applications can be challenged by its seed biology, including seed dormancy and the variability of seed traits among populations. The literature on these topics has not been well synthesised. To address this, we reviewed the relevant literature for Themeda triandra seed and found that seed quality is often poor but highly variable, and there are no current quality-assurance standards. Seed characteristics such as weight, awn length and desiccation tolerance can vary with seed ploidy (i.e. the number of chromosome sets). Germination rates of fresh Themeda triandra seed can be as low as 5%, which may be due to seed dormancy. Dormancy varies among populations and with seasonal conditions, and a period of dry storage at room temperature for 8–10 months may be needed before it will reach its full germination potential. No single treatment is effective in overcoming dormancy across all populations. The application of gibberellic acid can increase germination by ~30% in some populations. Although plant-derived smoke products can be effective, they also lack standardisation. Other treatments including the application of heat, or wet–dry cycling warrant further investigation. We recommend the standardisation of Themeda triandra seed testing and labelling, which would allow end users to assess value for money when purchasing seed commercially. Kangaroo grass (Themeda triandra), a tussock grass with an international distribution, plays an important role in grassy ecosystems; however, since colonisation, it has decreased or been degraded across much of its range. It can be re-established from seed but seed quality has high population variability and seed dormancy can be a problem. With increasing calls for native-seed quality-assurance labelling, we show that this could be standardised for Themeda triandra. Photograph by Ellen Bennett. [ABSTRACT FROM AUTHOR]

Context: Until now, Wollemia nobilis was thought to differ from all other members of the Araucariaceae in having unbranched primary branches, except following some instances of traumatic damage to the branch apex. This paper reports on the serendipitous discovery of abundant secondary branching on seedling Wollemi pines. Aims: I document the occurrence of secondary branches from axillary meristems, along the whole length of annual growth cycles of primary branches. Methods: The abundance and location of secondary branching was observed, photographed and documented in over 90 nursery seedlings being grown for sale across two growing seasons. Key results: Secondary buds and both secondary and tertiary branches occurred on 1-year-old primary branch segments on numerous seedlings being grown under standard commercial-nursery conditions. Conclusions: Wollemia is capable of secondary and tertiary branch development without traumatic injury to the primary or secondary branch apex, thus confirming an earlier report that all or nearly all leaf axils in Wollemia may contain viable axillary meristems. This contradicts previous expectations that secondary branches will not develop without prior apical trauma to primary branches. Implications: Secondary branching, as reported here, opens the door to further assessment of the fossil record for specimens that may broaden the concept of Wollemia and possibly its former distribution. The occurrence of these secondary branches should allow a reconsideration of the characters that distinguish the genus from other members of the family. They also broaden the understanding of the evolutionary potential of the species. Wollemia are distinguished from other members of their family by their long, unbranched, short-lived primary branches. An abundance of secondary branches, growing from the axils of leaves of primary branches of Wollemi pines were found on many seedlings. Tertiary branches growing from the leaf axils of the secondaries were also produced. The cause of this branching is known, but confirmed the prediction that buds occur in every leaf axil. The fossil record and evolutionary links of Wollemia to other Araucariaceae should be re-examined. [ABSTRACT FROM AUTHOR]

Vegetation classification systems form a base for conservation management and the ecological exploration of the patterns and drivers of species' distributions. A standardised system crossing administrative and geographical boundaries is widely recognised as most useful for broad-scale management. The Queensland Government, recognising this, uses the Regional Ecosystem (RE) classification system and accompanying mapping as a state-wide standardised vegetation classification system. This system informs legislation and policy at local, state and national levels, underpinning decisions that have wide-ranging implications for biodiversity and people's livelihoods. It therefore needs to be robust from a scientific and legal perspective. The current approach in the RE system for identifying vegetation communities relies on expert-based class definition procedures. This is in contrast to best practice, which is based on quantitative procedures. This paper discusses the RE system in a global context and outlines the updated approach that incorporates quantitative class definition procedures, synthesises the research behind the updated approach and discusses its implications and implementation. The Regional Ecosystem (RE) classification system, with accompanying mapping, is used in the state of Queensland for conservation management. This paper discusses the RE system in a global context and outlines an updated, quantitative based, classification approach for identifying vegetation communities within it. The paper finally discusses the implications and implementation of the updated approach. [ABSTRACT FROM AUTHOR]

Context: Seed germination and seedling emergence are affected by many environmental factors. Knowledge regarding factors affecting seed germination of spiny cocklebur (Xanthium spinosum L.) and common cocklebur (X. strumarium L.) could help determine their potential distribution and control strategies. Aims: The present study was conducted to investigate the effect of key environmental factors on seed germination and seedling emergence of spiny cocklebur and common cocklebur. Methods: Seed germination of spiny cocklebur and common cocklebur was tested at various constant and alternating temperatures, pH, salinity and moisture stress. The effect of flooding height, burial depth and soil type on seedling emergence was also investigated. Key results: The optimum constant temperature for germination of spiny cocklebur was 25°C, and 35°C and higher for common cocklebur. Under alternating temperature, maximal germination was at 25/15°C and 35/15°C for spiny cocklebur and common cocklebur, respectively. Maximum germination of both spiny cocklebur and common cocklebur was at neutral pH. Spiny cocklebur germination was not suppressed as much by lower and higher pH or by an increasing salinity as was common cocklebur germination. Conclusions: Common cocklebur appears to be better adapted to warmer environments than is spiny cocklebur, but less so to a broad range of soil pH and salinity stress. Implications: The different germination responses of common cocklebur and spiny cocklebur to the environmental factors of temperature, pH and salinity imply that the two species may occupy different niches across the landscape. Our knowledge of these responses can help in identifying potential areas for invasion for increased monitoring and management. Information on factors affecting spiny cocklebur (Xanthium spinosum) and common cocklebur (X. strumarium) seed germination could help us determine their potential distribution in different regions and their effective control strategies. Maximum germination of both spiny cocklebur and common cocklebur was at neutral pH. Spiny cocklebur germination was less sensitive to high and low pH, salinity, flooding and surface burial than was common cocklebur germination, indicating that it may be better adapted to the broader range of conditions. Image by Faezeh Zaefarian. [ABSTRACT FROM AUTHOR]

This paper uses data from previous worldwide myxomycete surveys to determine the controls on the occurrence of myxomycete species, and on species assemblages. The main findings are as follows. The effect of substrate pH can be modelled, in that each species has a preferred pH value relative to the mean of a survey; errors from the model are 0.2 pH units. The substrate physical properties, evaluated by subjective hardness, showed no correlation with pH measurements. Hence, myxomycete species seem to have distinct ecological niches in substrate, with preferred pH and preferred physical properties. Comparison of the species found from the liana stem substrate shows that the species association does not change within angiosperm forests. Further, the species association is the same as that found in other angiosperm litter substrates: twigs on trees or on the ground, and leaves. This and a previous finding are consistent with similar ecological environments around the world having the same myxomycete species association within sampling error. In mixed angiosperm forests around the world the pH of un-decayed wood is ~4.9, and for decayed wood and tree litter is ~6.5 in tropical latitudes, and ~5.5 at 35° latitude, so on decaying the change in pH varies with latitude. The pattern of occurrence of individual myxomycetes (plasmodial slime moulds) species, and their species associations, often appears difficult to understand. This paper investigates the geographic extent of species associations, and the controls on species distribution by the substrate's acidity and hardness. The controls on the species occurrence appear to be relatively simple: the pattern of occurrence can largely be explained by the species having different ecological niches differing in both acidity and physical properties. [ABSTRACT FROM AUTHOR]

The historic influence of human fire and the role of 'top-down' vs 'bottom-up' drivers on ecosystems globally is highly contested, and our knowledge of regime diversity is poor. This paper uses an early European account as a case study to describe Aboriginal fire history in south-eastern Australia based on links between fire and: grasslands, native foods and culture. The route and observations detailed in Assistant Protector William Thomas' 1840 account of a journey led by Aborigines to Western Port, Victoria, were overlayed with grass-tree boundaries compiled from historic plans. The narrative provides direct evidence of up to moderate-scale and intensity burns (with minimal fine-scale patchiness), undertaken in the height of the dry season, opportunistically linked to rainfall. The fires targeted open grassy 'plains' to maintain and access preferred hunter-gathering grounds. A synthesis of the earliest records supports high frequency anthropogenic burning maintaining alternative vegetation states with dynamic boundaries on elevated alluvial plains and, in places, adjoining swamps. The narrative represents an important primary source for studying traditional society, including the description of a local historic fire regime ('koyuga burning'). Establishing such a fire regime 'benchmark' has the potential to stimulate new interdisciplinary research around the complex processes controlling grass-tree patterns, and build confidence that fire-stick farming was potentially instrumental in grassland formation, and integral to grassland maintenance throughout this region. The historic influence of human fire on ecosystems globally is highly contested, and our knowledge of regime diversity is poor. This paper uses an early European account as a case study to describe Aboriginal fire history in south-eastern Australia based on links between fire and: grasslands, native foods and culture. Establishing such a fire regime 'benchmark' has the potential to stimulate new interdisciplinary research around the complex processes controlling grass-tree patterns, and build confidence that fire-stick farming was potentially instrumental in grassland formation, and integral to grassland maintenance throughout this region. [ABSTRACT FROM AUTHOR]

This paper presents an integrated model of the variation over a continental landmass of myxomycetes, a single-celled organism in the phylum Amoebozoa. Bark samples were collected on long traverses across Australia, and cultivated in Petri dishes by the moist chamber technique to obtain large assemblages of common species. The results of this survey and previous surveys are consistent with there being four major myxomycete assemblages: Tropical, Northern Arid, Southern Arid and Temperate. Where mapped, these species assemblage regions are consistent with the Australian phytogeographical regions. The myxomycetes differ between arid and non-arid areas; the arid areas have slightly higher productivity per wetting event, with members of the Physarales and Liceales relatively important and the Stemonitidales, Trichiales and Cribrariales less important. When the bark samples are placed in a moist culture there is a myxomycete growth cycle and then the population declines to resting phases. The population increase during a growth phase can be modelled by a linear plot of log(abundance) against species rank, where abundance is total harvested spore volume of a species. The population decline appears to be linear from two weeks after watering, declining to negligible activity 4 weeks after watering. The distribution of a group of single-celled organisms in the phylum Amoebozoa is mapped over a continental area. The species assemblages vary slowly in productivity and in relative importance of the orders. The paper is important in that continental wide studies of single-celled organisms are generally not possible using traditional methods. [ABSTRACT FROM AUTHOR]

To examine the potential applications of hyperaccumulator plants in the Philippines, we reviewed current data on the extent of metal hyperaccumulation in native species and partitioning of metals within the plant tissue. Twenty-eight species had reported tissue concentrations above the hyperaccumulator threshold, 11 species were endemic to the Philippines. Nickel was present in higher concentrations in the aboveground tissue than in the belowground tissue, but the reverse was found for copper, aluminium and chromium. The fact that copper accumulates belowground rather than above, and most hyperaccumulators of nickel identified were trees, has implications for the potential of phytoextraction using native Philippines flora. Photograph of a native metal-accumulating plant in the Philippines. Soils of the Philippines often have high concentrations of heavy metals and low nutrient concentrations, which are conditions that are normally unfavourable for plant growth. However, many plants in the area have adapted to these conditions and can grow well. Here we have compiled data currently available on Philippine plants that can accumulate metals in their tissue, and the potential applications of these plants in restoration efforts. Photograph by Edwino S. Fernando. [ABSTRACT FROM AUTHOR]

Ornithophily is a widespread pollination syndrome that has evolved independently several times along the evolution of plants. It is reported in sixty-five plant families, including Gesneriaceae. One of the most diverse genera within gesneriads is Sinningia , which comprises species pollinated by bees, hummingbirds and bats. However, little is known about the reproduction biology of either species or on pollinator specificity in this genus. Based on investigations on flowering phenology, flower morpho-anatomy, volume and concentration of floral nectar, pollinators, and breeding system, this paper reports the reproduction and the pollinator specificity of Sinningia douglasii and Sinningia araneosa in natural areas in Brazil. Both species offer nectar as a resource and are exclusively pollinated by a single species of hermit hummingbird. Nectar is produced by glands around the ovary. Pollen is deposited between the base of the beak and the head feathers. Both species are self-compatible and pollinator-dependent. In both Sinningia species, the combination of protandry, pollinator specificity, due to long corolla tubes that exclude the visitation of short-billed hummingbirds. The presence of particular flower features influence the occurrence of pollination by specific pollen vectors, such as hermit hummingbirds, in deterrence of illegitimate visitors (i.e. territorial hummingbirds), protection against vigorous foraging, and accurate placement of pollen on legitimate pollinators. In addition, the foraging of Phaethornis on flowers of Sinningia is independent of relative humidity and air temperature, whereas the main factor influencing hummingbird visits is the luminosity. In this paper we explore the reproduction and pollinator specificity of Sinningia occurring in Brazilian semi-deciduous forests. The presence of particular flower features influence the occurrence of pollination by specific pollen vectors in deterrence of illegitimate visitors. This discovery provides new insights on the specificity in Neotropical habitats, and sheds light on the evolution of floral rewards and pollination mechanisms within this diverse group of plants. [ABSTRACT FROM AUTHOR]

Plot-based vegetation data have been collected in the Northern Territory since the 1950s. The purpose of data collection broadly includes land resource and vegetation community mapping, flora surveys, habitat assessment for fauna surveys, rare and threatened species surveys, development assessment and monitoring. These datasets were stored in disparate database systems until 2012. Currently over 423 surveys, 69 000 geocoded plots, comprising almost 838 164 flora records, are maintained using a corporate database. The data are of varying degrees of attribute detail including floristics, structure, strata and associated environmental information. The original territory-wide standardised vegetation classification was based on the 1:1 000 000 vegetation mapping project where 112 broad vegetation types were described from 2245 plots using an intuitive appraisal of numerical analytical techniques. This approach continues to be used; however, a standard method would be desirable to classify plot data into meaningful vegetation types in the Northern Territory. The National Vegetation Information System (vegetation hierarchy) was used to qualitatively assess the level of detail of vegetation plot data. Only 9% of the plot data can be assigned to sub-association level, and 28% to the association level. In addition to reviewing the compatibility of plot data to the National Vegetation Information System, we also provide examples of how it can conform with the International Vegetation Classification. This paper provides an overview of vegetation plot-data collection, storage and classification in the Northern Territory. The vegetation plot data maintained by the Department of Environment, Parks and Water Security was appraised in terms of the six National Vegetation Information System (NVIS) vegetation hierarchy levels. As a result of inconsistencies between surveys and varying degrees of floristic and structural information collected in the field, 49% of the Northern Territory plot data are compliant with the NVIS vegetation hierarchical levels. [ABSTRACT FROM AUTHOR]

In areas of poor plot data, limited funding and expertise, alternate approaches are needed to create elements of a hierarchical classification schema to assist in landscape planning. This is especially important for vulnerable systems under pressure from human activities. Within this paper we introduce an approach to help create a consistent classification section for riparian vegetation at a subcontinental scale, within the context of low plot data availability. We collated occurrence data for selected dominant plants known to occur within riparian environments from electronic databases and our own unpublished survey data. We used generalised dissimilarity modelling (GDM), which models species turnover between pairs of 0.01° grid cells as a function of environmental differences between those cells. Eight climatic and landscape variables were derived for each grid cell. Average temperature and average rainfall had the greatest contribution to species turnover followed by elevation. A model incorporating eight climatic, physiognomic and spatial variables accounted for 48% of the turnover of species. Six ecoregions were defined and used to circumscribe the equivalent number of interim Macrogroups based on the GLM outputs and diagnostic species. In areas of poor plot data, limited funding and expertise, alternate approaches are needed to create elements of a hierarchical classification schema to assist in landscape planning. We used generalised dissimilarity modelling (GDM), which models species turnover between pairs of 0.01° grid cells as a function of environmental differences between those cells. Here we created a subjective semi-supervised alternative protocol to fully supervised classifications within areas of disproportional and often poor plot data coverage, using individual species occurrences from accessible databases. [ABSTRACT FROM AUTHOR]

This paper presents insights from long-term monitoring into the dynamics of savanna plant species composition, specifically on the ground layer. Key questions are (1) how much variation is there from year to year in plant species abundance and composition? And (2) is there evidence of directional change in community composition? Five sites were located near Mareeba, north-eastern Australia, and sampled 18 times with fixed 500-m2 plots at the annual peak of plant species richness over 23 years. The sites were located in eucalypt communities across an altitudinal range of 460 m. Sampling involved systematic searching of all plant species visible above ground. The results show variation from year to year among satellite herbaceous species, with more than 50% of grasses and forbs observed at a given site only being detected at half or fewer of the 18 samplings. Herbaceous composition did not show clear signs of directional change relative to inter-annual variability. Over the 23 years, there were three very dry periods and 4 very wet years. Rainfall variation affected total cover more than plant species composition or richness. Several fires and episodes of grazing affected ground cover but did not have a lasting impact on cover or diversity. The cover and composition of the ground layer is consistently dominated by the core perennial grasses Themeda triandra Forssk. and Heteropogon triticeus (R.Br.) Stapf, with many species collectively contributing minimally to the overall cover but significantly to richness. Many herb species are persistent long-lived perennials which do not appear above ground every year. The number of naturalised plants in the ground layer was consistently low. Overall, the ground layer communities appear to be very stable in these woodlands that have been burnt 3–5 times in 23 years. High inter-annual variability of subdominant species is consistent with other studies, and emphasises the need for replication in time in ecological sampling. Are the species-rich herbaceous layers of the tropical savannas changing over time due to the impacts of the magnitude of the wet season, the frequency of fires or the invasion of non-native species? In this study conducted over a 23-year period it was found that the ground layer communities appear to be very stable, with the cover and composition of the ground layer consistently dominated by perennial grasses, and annual plants only contributing low proportions to the overall cover. The study shows that repeat samplings over time, or additional samplings in space, are required to capture the full floristic variation. [ABSTRACT FROM AUTHOR]

Aiming to develop a new stratification protocol for yerba mate seeds, we evaluated how different combinations of temperature, substrate, and period influence the embryonic development of the species, compared to fresh seeds and conventionally stratified seeds. We measured the seeds' moisture content and performed a tetrazolium test to evaluate embryo viability and embryonic development. Seeds' initial moisture content was 10.1% and reached 40.6% after stratification. We observed more embryos in advanced development stages after stratification in all treatments, indicating that the protocols used were adequate for the species and have a great potential to be explored for yerba mate seedling. Yerba mate (Ilex paraguariensis) is an important forest essence, and its cultivation generates employment and income for small and medium rural landowners, especially in Brazil, Argentina, and Paraguay. The seedling production of the species is hindered by seeds' dormancy, which demands long periods of stratification to germinate. Low temperatures, substrates, and periods were tested in order to accelerate and homogenise yerba mate seeds germination. [ABSTRACT FROM AUTHOR]

The Bass Strait islands are some of the few areas in Australia that were not occupied by humans at the time of European contact. There is archaeological evidence that Flinders Island at the eastern end of Bass Strait supported people until c. 4500 years ago but after that there is no evidence of human presence. Two previous pollen studies, covering the Holocene, from a swamp on the eastern side of the island were interpreted rather differently in terms of how influential humans were in their effects on the island's vegetation. In this paper, two short pollen diagrams from very different places than the earlier studies are described. These add to the evidence of the type of vegetation on the island over the late Quaternary. One diagram covers only the last 1500 years and is from a 1-m deposit from near the highest peak on the island in the south. This shows that there has been little change over that time in the vegetation around the site and there has been no influence of fire in the area. By contrast, a thin peat deposit, overlying lake sediments containing freshwater mollusc shells and Characeae oogonia, from Killiecrankie Bay in the north of the island dated at c. 34 000 14C calibrated (cal) before present (BP) shows evidence of fire. The vegetation at the time was not similar to the vegetation during the Holocene with little representation of eucalypts but prominence of shrubby species (Leptospermum , Melaleuca) and herbaceous taxa such as Restionaceae and Asteraceae, particularly the Pleistocene Asteraceae pollen type. The vegetation on the eastern Bassian isthmus at that time was likely to have had less tree cover than in the Holocene and was more heath-dominated. Pollen diagrams from Flinders Island indicate that the higher peaks of the Strzelecki Range have been a refuge for mesic vegetation and there has been little change in the vegetation in the last 1500 years. In contrast ~30 000 years ago the vegetation of what was then the Bassian Isthmus supported a more heath-like vegetation with less tree coverage than in the Holocene. [ABSTRACT FROM AUTHOR]

Following European settlement of Australia, numerous plant species were deliberately introduced for use in crops, pastures, gardens and horticulture, and others arrived by chance. Many subsequently escaped and became weedy. Of the 54 weed species of natural environments of arid and semi-arid Australia that are considered here, 27 were apparently accidentally introduced, 20 were intentionally introduced and 7 were probably introduced both accidentally and intentionally. Livestock including camels and their harness, and contaminated seed and hay were the most common vectors for accidental introduction. Amongst intentional introductions, rather more ornamental species appear to have invaded successfully than pasture species, but the former generally occupy niche habitats. Recent new introductions are few due to pre-border, border and post-border protections, but many current arid zone weeds continue to spread. Understanding the history of weed invasions can help to guide current and future management by clarifying pathways for introduction. The historical record of weed invasions in arid Australia is scattered and unsynthesised. This paper documents the introduction of 54 widespread plant species that have become invasive in arid Australia. The historical context of plant introductions into arid Australia can help to guide current and future management. [ABSTRACT FROM AUTHOR]

Context: A poorly characterised carnivorous tropical pitcher plant (Nepenthes) was identified from old reports of a rarely visited low-elevation ultramafic peak in central Sabah, Malaysian Borneo. Potentially apomorphic characters in the limited photographic evidence available led the authors to hypothesise that the taxon represented an undescribed species. Aims: To locate and document the unknown taxon in situ and, if appropriate, gather sufficient data and voucher material to enable its formal description and associated conservation status assessment. Methods: An expedition was made to the type locality to make field observations of the taxon, record habitat, population and ecological data such as infauna, prey spectra and numbers of individuals, and to collect representative vouchers, minimising negative impacts on the small population by taking material in the form of terminal cuttings to allow for the in situ regeneration of sampled individuals from axillary nodes. Key results: Nepenthes pongoides is described and illustrated as new to science. The species is characterised by its large size, peltate tendril exsertion, absence of upper pitchers and extremely well-developed, persistent indumentum of long, coarse, dark reddish trichomes, the extent of which is unsurpassed in any other known Bornean Nepenthes species. Conclusions: One of the largest species of Nepenthes described in recent years, N. pongoides is endemic to the relatively low-elevation ultramafic Meliau Range of central Sabah. Only 39 mature individuals have been observed across two subpopulations, therefore the species is here assessed as CR (Critically Endangered) under the IUCN Red List criteria owing to its extremely small population size, limited area of occurrence and very high threat of unsustainable poaching for the horticultural trade. As is the case for many microendemic species, the taxon is extremely vulnerable to stochastic events such as fire which, on sufficient scale, could represent extinction level events. Implications: The documentation of such remarkable new species in comparatively well-explored rainforest regions such as those of northern Borneo highlights the importance of targeted exploration in remaining wilderness areas to uncover hidden biodiversity. Doing so closes gaps in scientific knowledge, and specifically increases the critical taxonomic and ecological knowledge necessary to support the development and implementation of conservation measures required to reduce the risk of species extinction and concomitant loss of biodiversity. A giant carnivorous tropical pitcher plant is described as new to science from Sabah, Malaysian Borneo. Named after the orangutan genus Pongo on account of its abundant covering of long, dark, rusty red hairs, Nepenthes pongoides naturally occurs in low numbers with fewer than fifty plants recorded. Coupled with the severe threat of poaching for the horticultural trade, not to mention vulnerability to single extinction level events such as wildfire, the species is assessed as critically endangered against IUCN criteria. Photograph by Alviana Damit. [ABSTRACT FROM AUTHOR]

Context: Estimating chloroplast pigment content by using chlorophyll meters is faster and cheaper than by using traditional pigment-extraction protocols. However, the reliability of chlorophyll meters requires a preliminary test of the relationship between the estimated and actual concentrations. Aims: To establish an optimized protocol for extracting leaf chloroplast pigments from Eucalyptus urophylla and Khaya senegalensis seedlings. Moreover, we evaluated the relationship between chlorophyll-content estimation by using chlorophyll meters with the SPAD index by using SPAD-502 and with Falker chlorophyll index (FCI) by using ClorofiLOG, and that by using the optimal chloroplast pigment-extraction protocol. Methods: The effectiveness of dimethylsulfoxide (DMSO) saturated with CaCO3 at 25°C and 65°C and 80% acetone (v/v) was assessed as extractors, by using different incubation times. Chlorophyll-content estimation was assessed using chlorophyll meters with the SPAD index by using SPAD-502 and with Falker chlorophyll index (FCI) by using ClorofiLOG. Key results: For both Eucalyptus urophylla and Khaya senegalensis seedlings, the optimal protocol for extracting pigments from chloroplasts was incubation for 4 h by using DMSO saturated with CaCO3 at 65°C. Chlorophyll-content estimation using SPAD-502 and ClorofiLOG showed a strong positive correlation with measurements from the optimized pigment-extraction protocol. Furthermore, the regression equations of the chlorophyll-content estimation with chlorophyll meters allowed predicting the real content, because the values were very close to those measured using traditional extraction protocols. Conclusions: The SPAD index and the FCI were reliable methods for estimating chlorophyll content in seedlings of both species. This could make measuring the chloroplast pigments faster and cheaper, especially regarding experimentation under field conditions. The protocol to estimate photosynthetic-pigment content was optimized in Eucalyptus urophylla and Khaya senegalensis seedlings by using different extraction methods to evaluate its relationship with values estimated using chlorophyll meters. In both species, a strong positive correlation was observed between estimated values and the values from extraction that used DMSO saturated with CaCO3 at 65°C. Photograph by the authors. [ABSTRACT FROM AUTHOR]

Context: Seagrasses form an important habitat that provides diverse ecosystem services essential for both the environment and people. In tropical Queensland, Australia, these meadows hold significant economic and cultural value, serving as nurseries for marine species and sustaining dugongs and green turtles. The biomass and size of tropical seagrass meadows in Queensland varies considerably and are influenced by various factors, both biotic and abiotic. Aims: Functional trait-based approaches can improve the estimation of seagrass-meadow resilience and services provision by describing the relationship between environment and individual performance. To support these approaches, we provide a seagrass functional-trait database focusing on resilience and function provision for tropical Queensland. Methods: We employed a combination of literature reviews, database searches, botanical information, and structured expert elicitation to target 17 functional traits across 13 seagrass species in tropical Queensland. Key results: We developed a traits database to inform functional trait-based approaches to assessing seagrass-meadow resilience and dynamics. The outputs included trait information for approximately 78% of the targeted traits (of 221 unique trait–seagrass combinations). Conclusions: With current information on functional traits, we can improve the estimation of resilience and ecosystem services for tropical Queensland seagrass species. We have also highlighted trait data gaps and areas for further research. Implications: We have provided examples of applying this database within the tropical Queensland context, with the potential to facilitate regional comparative studies. Our database complements existing plant-trait databases and serves as a valuable resource for future trait-based seagrass research in tropical Queensland. Tropical seagrasses provide important ecosystem services, but they are dynamic habitats under threat from multiple stressors. Functional trait-based approaches have the potential to increase our understanding of these dynamics. We present a comprehensive trait database for seagrasses in tropical Queensland, with a focus on services and resilience. Photograph by Chieh Lin. [ABSTRACT FROM AUTHOR]

Context: Although shrub encroachment is a common phenomenon in grasslands, which often suppress co-existing herbaceous plants, little is known about how encroaching native shrubs affect endemic and threatened orchid species. Aims: We assessed the effect of the native dwarf shrub Helichrysum species on orchid species in a protected mountainous grassland system in Tanzania. Methods: We selected five Helichrysum shrub-dominated blocks and applied four treatments in each, i.e. no or low encroachment (<20% Helichrysum cover; 'low cover'), high encroachment (>50% Helichrysum cover; 'high cover'), cutting all stems of Helichrysum shrubs to ground level ('stem cut') and removing both stems and roots of all Helichrysum shrubs ('uprooted'). We then compared orchid species diversity, abundance and functional traits by using a mixed linear model across treatments. Key results: Orchid species diversity and abundance were significantly lower in 'high cover' plots than in other treatments. In 'high cover' plots, orchid species such as Disa robusta, Satyrium acutirostrum , and S. sphaeranthum had a significantly lower chlorophyll content than they did in 'low cover' plots. The 'uprooting' treatment showed significantly higher orchid species diversity in the second field season. Conclusion: The expansion of Helichrysum shrubs adversely affected orchid abundance, diversity, and individual vigour, which in turn affected the regenerative ability of orchids. Implications: We suggest that management should focus on shrub removal, because only 'cutting' had a beneficial effect on orchids. Shrub removal should be focused on areas of high shrub cover to promote further orchid species growth in this mountainous grassland of Tanzania. Five blocks dominated with Helichrysum splendidum were identified and, in each block, four plots were established by cutting and in other plot cutting and uprooting the stems of H. splendidum. High abundance of orchids was found in plots with a low Helichrysum cover. The orchids had physiological differences across the plots. Photograph by Christopher Mgimba. [ABSTRACT FROM AUTHOR]

Nutrient use efficiency (NUE) has been used as a method to evaluate the utilisation and processes of cycling of nutrient in forests. In publications, different methods have been used to calculate NUE, but as efficiency they are all expressed as ratios and these cover the basic areas of: (1) absorption from the soil and uptake, (2) efficiency in their requirement or utilisation of nutrients including physiological efficiency and (3) efficiency in the retention and internal re-utilisation of nutrients. Few studies address NUE based on complete nutrient cycling information but use indices based on litterfall or foliage nutrient concentrations. In this study different expressions of NUE were defined and evaluated for N and P using data on nutrient cycles on species in the genus Eucalyptus in regrowth and mature native eastern Australian forests. It has been hypothesised that NUE increases with decreasing nutrient availability however increasing such efficiency has a cost reflected in reduced productivity. The hypothesis was proven for all expressions of NUE correlating NUE against estimates of soil N or P availability but there were differences between coastal and tableland Eucalyptus forests. The level of significance varied for different types of NUE and in these ecosystems P was of greater significance than N. This reflected the importance of P in relation to productivity on many of the weathered soils or the limited value of the soil available N indices. It is suggested that the difference expressions of NUE differ in their significance with species so some will be relatively more efficient in terms of uptake, others in utilisation and others in redistribution. Only in extreme situations of nutrient availability do species have relatively high efficiency for all methods NUE calculation. It is proposed that these differences are of importance in site/species distribution and more importantly in mixed stands where they provide advantages either at different stages of stand development or after significant disturbances such as fire. Nutrient use efficiency provides a linkage between the use of nutrients in a forest and productivity. The paper addresses different methods for analysing nutrient efficiency and their implications for forest ecology. The hypothesis that as nutrients become more limiting the forests increase in nutrient use efficiency is analysed and considers that species differ in their various forms of efficiency providing competitive advantages. Efficiency of P uptake in relation to availability is shown in figure with differences between coastal and tableland eucalypt forests. [ABSTRACT FROM AUTHOR]

Groundwater dependent ecosystems (GDEs) require access to groundwater to meet all or some of their water requirements to maintain community structure and function. The increasing demand of surface and groundwater resources has seen the NSW Government put in place management mechanisms to enable the sharing of water between irrigators, the environment, industry, towns and communities via water sharing plans. The groundwater sharing plans aim to provide adaptive management of GDEs by prioritising for protection those that are considered the most ecologically valuable within each plan area. The High Ecological Value Aquatic Ecosystems (HEVAE) framework has already been adopted to prioritise riverine ecosystems for management in surface water sharing plans. Here, we provide a method developed using the HEVAE framework to prioritise vegetation GDEs for management. The GDE HEVAE methods provide a derived ecological value dataset for identified groundwater dependent vegetation that is used to inform the planning and policy decisions in NSW. These decisions are required to manage and mitigate current and future risks caused by groundwater extraction. This is achieved via the identification of ecologically valuable assets to then use as the consequence component in a risk assessment for the groundwater sources, to provide vegetation GDE locations for setback distances for new groundwater production bores, and for the assessment of impacts due to current and potential future groundwater extraction. The GDE HEVAE method uses recorded and predicted spatial data to provide weighted scores for each attribute associated with the four HEVAE criteria (distinctiveness, diversity, vital habitat and naturalness). The combined scores categorise the ecological value of each groundwater dependent vegetation community (depicted as geographic information system (GIS) polygon features) from very high to very low. We apply the GDE HEVAE method to three catchments in order to demonstrate the method's applicability across the Murray–Darling Basin with varying elevation and climate characteristics. The ecological value outcomes derived from the methods have been used to inform planning and policy decisions by NSW Government processes to allow for protection in not only areas that are currently at risk but to also manage for potential future risks from groundwater extraction. This paper provides detail on the first attempt to place an ecological value on groundwater dependent ecosystems on a statewide scale, in Australia. The work revealed that National ecological classification systems could be applied to groundwater at a scale that allows its use in policy decision-making. The results of the work have been used to guide water access rules in groundwater systems to protect high value terrestrial groundwater dependent ecosystems, within a risk management framework. [ABSTRACT FROM AUTHOR]

Viola banksii , the type species of section Erpetion , is endemic in eastern mainland Australia. In this paper we characterise morphological and anatomical features and assess genome size and genetic diversity in combination with the breeding system. V. banksii develops exclusively chasmogamous flowers. Ovules are anatropous, crassinucellate and bitegmic, the female gametophyte is of the Polygonum type, and the embryo is of Asterad type surrounded by nuclear endosperm. Pollen is non-heteromorphic, 3-aperturate, and highly viable. V. banksii grows in shade on moist, well drained, often sandy soils, and this is reflected in the anatomy of its organs, which includes a lack of subepidermal collenchyma in aerial parts, large leaf epidermal cells with thin cell walls, a narrow cuticle layer, and vascular bundles with xylem that are not rich in vessels. V. banksii is tolerant to zinc and lead based on phytotoxicity test. The high chromosome number (2 n = 10 x = 50) does not correspond to a small genome size (2C DNA = 1.27 pg). Low mean intra-populational gene diversity (H S = 0.077) detected by ISSR markers confirms the strong influence of selfing and clonal propagation by pseudostolons. Unique morphological traits of V. banksii include nyctinastic petal movement, the lack of a floral spur, the presence of gland-like protuberances on two stamens, and the presence of pseudostolons, which could be a synapomorphy for the whole section. Viola banksii occurs exclusively in Australian flora and is a type species of the native, Australian Erpetion section of the genus Viola. Some traits described in these studies are new for the Viola genus and could be unique for the Erpetion section. The Australian flora is particularly interesting for the study of evolution because of its long isolation from other continental floras, the high degree of endemism, and its distinctive character. [ABSTRACT FROM AUTHOR]

Since 1991, researchers from approximately 45 nations have participated in eight International Conferences on Serpentine Ecology (ICSE). The Conferences are coordinated by the International Serpentine Ecology Society (ISES), a formal research society whose members study geological, pedological, biological and applied aspects of ultramafic (serpentine) ecosystems worldwide. These conferences have provided an international forum to discuss and synthesise multidisciplinary research, and have provided opportunities for scientists in distinct fields and from different regions of the world to conduct collaborative and interdisciplinary research. The 8th ICSE was hosted by Sabah Parks in Malaysia, on the island of Borneo, and attracted the largest delegation to date, 174 participants from 31 countries. This was the first time an ICSE was held in Asia, a region that hosts some of the world's most biodiverse ultramafic ecosystems. The presentations provided a cross-section of the current status of research in all aspects of ultramafic-biota relations. In this Special Issue of Australian Journal of Botany (Issues 1-2 combined and 3-4 combined), we have compiled a selection of papers from among the oral and poster presentations to provide insights into recent advances in geoecological and applied studies of ultramafic habitats worldwide. Here we provide a preview of select papers found in this Special Issue and summarise some of the contributions made during the 8th ICSE and describe some of the exciting challenges awaiting future research. The 8th ICSE was hosted by Sabah Parks in Malaysia attracted 174 participants from 31 countries and was the first held in Asia, the region that hosts some of the world's most biodiverse ultramafic ecosystems. Here we summarise some of the contributions made during the 8th ICSE and describe some of the exciting challenges awaiting future research. [ABSTRACT FROM AUTHOR]

Botanical exploration on ultramafic sites in Palawan, Surigao and Zambales has resulted in the discovery of a new hypernickelophore species (nickel (Ni) concentration >1%) of Phyllanthus (Phyllanthaceae). This paper reports in detail the Ni uptake of populations of P. erythrotrichus in Candelaria, Masinloc and Santa Cruz, Zambales, and confirms the status of P. securinegoides in Taganito, Surigao del Norte, which had been analysed only through herbarium specimens, and these were compared with a known hypernickelophore, P. balgooyi, which was collected in Narra and Puerto Princesa, Palawan. Nickel content of the dried leaves, stems and root tissues was quantified using atomic absorption spectrophotometer. P. erythrotrichus and P. securinegoides both had more than 10 000 µg g-1 Ni in the leaves, whereas the roots had 1195 µg g-1 and 4636 µg g-1. P. balgooyi accumulated 6319 µg g[sup -1] of Ni in the leaves, whereas the roots had a higher Ni concentration of up to 8116 µg g-1, respectively. All three species had values of translocation factor and enrichment factor of >1.0, implying that all species have great potential in phytoremediation, specifically, phytoextraction of Ni. These three species of Phyllanthus are prominent in ultramafic scrub communities and, hence, should be used in ecological restoration of mined-out Ni lateritic areas. The implications of the unique adaptation of these species are also discussed in relation to a conservation strategy for their natural populations. The genus Phyllanthus has at least 42 species from various parts of the world reported to accumulate more than 0.1% nickel in their leaves. This paper compared nickel accumulation in seven species of Phyllanthus from the Philippines and reports Phyllanthus erythrotrichus as a hypernickelophore, accumulating more than 1% nickel in the leaves. Three of the species examined have potential in nickel farming. [ABSTRACT FROM AUTHOR]

Melaleuca deanei F.Muell. is listed under state and national protection legislation occurring as small, disjunct populations restricted to the Central Coast botanical district of New South Wales. This paper reports on the population structure, reproductive output and phenology of large and small field populations of M. deanei, compared with three common congeneric species in the area, namely, Melaleuca nodosa (Sol. ex Gaertn.) Sm., Melaleuca thymifolia Sm. and Melaleuca styphelioides Sm. Both M. deanei and M. styphelioides had few seedlings per population at the sites studied. Results indicated that seedling recruitment is rare and would appear to require specific conditions. In addition, M. deanei had a low incidence of flowering within the small populations, significantly fewer fruiting plants per population and significantly lower numbers of viable seeds per square metre, most likely compounding its limited recruitment. Flowering, when it occurred in M. deanei, was from mid to late October through to late November-early December with increased flowering in response to fire and along road edges. Further study is needed to determine reproductive success at the individual-plant level, the breeding system and recruitment requirements of these species. The paper reports reproductive and structural attributes at the population level for three common species of Melaleuca and from large and small populations of the rare congener Melaeuca deanei. Within relatively smaller populations, M. deanei exhibitted a lower plant density, a lower incidence of flowering, significantly lower proportions of fruiting plants, fewer viable seeds per square metre and limited recruitment. [ABSTRACT FROM AUTHOR]

This paper reports plant-level measures of reproductive performance from large and small field populations of the vulnerable species Melaleuca deanei F.Meull. compared with three common species within the genus: Melaleuca nodosa (Sol. ex Gaertn.) Sm., Melaleuca thymifolia Sm. and Melaleuca styphelioides Sm. Measures reported include average seed numbers per capsule and per plant; average fruit loads per plant; the proportion of buds that become flowers and thence fruits (fruit set); the number of ovules per flower and seed : ovule ratios (seed set); and floral morphologies. Results indicate that when M. deanei flowers, bud to flower ratios and flower to fruit ratios are not reduced compared with the congeners or between large and small populations. Seed loads per plant held by fruiting plants were comparable between the species and between large and small populations of M. deanei. Seed to ovule ratios were in the order of 5-9% in M. nodosa; 5-7% in M. styphelioides; 7-10% in M. deanei; and 12-15% in M. thymifolia. Larval herbivory of ovules was recorded in M. nodosa and pre-dispersal seed predation noted in M. thymifolia. Andromonoecy was recorded in two of the species at rates of 0.9-3.1% (M. deanei) and 2.9-7% (M. thymifolia). Results suggest that seed production within smaller populations of M. deanei is poor because of a low frequency of flowering and a low proportion of flowering plants per population, rather than plant-level pollination, fruit- or seed-set barriers. Further study is needed to determine the triggers to flowering, the breeding systems, the extent of clonality and the germination and establishment requirements in these species. This paper reports fecundity and floral morphs from four Australian eastern-coast Melaleuca species, including the vulnerable species M. deanei. Measures reported include fruit and seed loads per plant, fruit set, ovule numbers and seed : ovule ratios under natural conditions. Andromonoecy at low rates is reported for M. deanei and M. thymifolia. Results suggest that significantly lower seed loads per population within the smaller populations of M. deanei reflect a lower seasonal incidence of flowering and lower proportions of flowering plants per population, rather than any limitations in pollination, fruit/seed set or predation. [ABSTRACT FROM AUTHOR]

Virtual Issues consist of previously published papers that are repackaged into an online themed collection. With appropriate marketing, and making them free for a limited time, these issues are a powerful tool that allow all readers to rediscover and access content already published. Release of this Virtual Issue of Australian Journal of Botany was timed to coincide with the 11th Australasian Plant Conservation Conference (APCC11), held on 14-18 November at the Royal Botanic Gardens, Melbourne. For more information, please visit: http://www.publish.csiro.au/bt/content/VirtualIssues. [ABSTRACT FROM AUTHOR]

Context: Global climate is changing rapidly, necessitating timely development of specific, actionable species conservation strategies that incorporate climate-change adaptation. Yet, detailed climate-change adaptation planning is noticeably absent from species management plans. This is problematic for restricted species, which often have greater extinction risk. Aims: Focusing on the restricted and endangered Tarengo leek orchid (Prasophyllum petilum), we aimed to adapt and test a framework for producing strategies for its management under climate change. Methods: We used expert elicitation to estimate the severity of threats and assess potential management actions to mitigate threat impacts. We created a conceptual model detailing ecology, threats and likely impacts of climate change on the species, including the interactions between components. Key results: Although climate change-related threats will affect the species, the most severe threats were non-climate threats including grazing, weeds, and habitat degradation. Fire management was deemed highly beneficial but had low feasibility for some populations. Without management, experts estimated up to a 100% decrease in one P. petilum population, and up to 50% decrease if management remained unchanged. Conclusions: Management actions with the highest benefit and feasibility addressed the non-climate threats, which, in turn, can give the species the best opportunity to withstand climate-change impacts. Experts highlighted the difficulty of addressing climate threats with such limited knowledge; therefore, further research was recommended. Implications: This adapted framework enabled a structured analysis of threats, and informed selection of priority adaptation options. We recommend its use for other restricted species for efficient and robust decision-making in climate-change management. Climate change is posing a significant extinction risk to rare and restricted species. Following consultation with species' experts, managers of the Tarengo leek orchid (Prasophyllum petilum) should address the region- or population-specific non-climate threats to increase its resilience to climate change. We present an adapted framework for incorporating climate-change adaptation into management, a critical tool for quantifying the severity of threats and assessing management actions for restricted species with highly specialised requirements. Photograph by Erika Roper. [ABSTRACT FROM AUTHOR]

Context: Controlled pollination is an important technique for maintaining intraspecific diversity in integrated plant conservation practices, particularly in genera such as Rhododendron , where open pollination usually produces hybrids with unknown paternal lineages. Aims: This study investigated the capacity for viable seed set from self- and intraspecific cross-pollination for Rhododendron taxa in different categories of the International Union for Conservation of Nature (IUCN) Red List, to guide conservation management of threatened species in botanic garden collections. Methods: The following five taxa of subsection Maddenia were studied: R. dalhousiae var. dalhousiae (Least Concern), R. dalhousiae var. rhabdotum (Vulnerable), R. lindleyi (Least Concern), R. nuttallii (Near Threatened), and R. excellens (Vulnerable). Controlled pollination was performed on selected garden accessions, and seed germination was tested at an alternating temperature regime of 15/25°C, 8 h photoperiod, and ~6 μmol m−2 s−1 photosynthetic photon flux density (PPFD). Key results: Intraspecific compatibilities varied among different taxa and between self- and outcross treatments. X-ray images for Rhododendron seeds showed low capacity to predict seed germination. Neither X-ray scan nor fungicide (Ridomil) treatment showed any adverse impact on seed germination, which has positive implications for seed-banking and subsequent raising of Rhododendron seedlings. Conclusions: Controlled intraspecific pollination can be used to maintain diversity of ex situ accessions for selected Rhododendron species. However, the zero or low compatibility demonstrated in some species, such as R. excellens , suggests that these species may require a different approach. Implications: Intraspecific pollination should be evaluated for each Rhododendron species before a propagation program is initiated in ex situ conservation. Successful controlled pollination of threatened species can increase the reproduction of new plants for safeguarding germplasm in botanic gardens. Fruit set and seed germination identified varied levels of self- and cross-compatibilities within each of the five examined Rhododendron species or varieties. Controlled pollination should be tested for each Rhododendron species to understand the intraspecific compatibility before deciding the propagation strategy. Image by Ling Hu. [ABSTRACT FROM AUTHOR]

Carnivorous plants have access to several potential sources of nitrogen, including root uptake, predation, litterfall, atmospheric deposition and defecation by mutualistic animals. Our aim was to assess the relative importance of different N sources so as to better understand the ecology of these physiologically diverse plants that include many genera and species inhabiting terrestrial and aquatic environments worldwide. Plant physiology and habitat were the major determinants of the relative importance of N source. Our secondary aim was to examine protocarnivorous plants that do not fit the exact definition for carnivory. Several protocarnivorous plants were classified as carnivorous based on specialised trapping mechanisms, isotopic data and mixing models. Several carnivorous plants can transfer their functions of prey capture and digestion to mutualistic animal partners, which is termed ecological outsourcing. Outsourcing arthropod prey capture and digestion to mutualistic bats is a beneficial strategy for the carnivorous plant Nepenthes hemsleyana. Carnivorous plants acquire nutrients by several mechanisms, including insect predation, root uptake, litterfall, atmospheric deposition and defecation by mutualistic animals. The relative importance of these nutrient sources for a range of terrestrial and aquatic species with a wide geographical distribution was estimated by 15N stable-isotope tracing. [ABSTRACT FROM AUTHOR]

The use of native plant seeds is fundamental to large-scale rehabilitation and the re-establishment of self-sustaining ecosystems after high-impact mining activity has ceased. However, many of the biological attributes of seeds are often overlooked in large-scale rehabilitation programs. Multi-disciplinary, long-term research collaborations are required to improve seed-based mine rehabilitation. In this paper, we review the steps that BHP Western Australia Iron Ore (WAIO), a large iron ore mining company that operates in the Pilbara bioregion of north-west Western Australia, has taken over the past 9 years to ensure continuous improvement in rehabilitation procedures. We introduce the mining activities that WAIO undertake in the Pilbara, and emphasise specific examples of how research findings have led to incremental improvements in the seed management cycle, growth media management and mine rehabilitation practices. Specifically, we outline how the implementation of structured seed collection and storage programs has created the capacity to maintain high-quality seed stocks sufficient for 3-5 years of future rehabilitation. Research has documented the prevalence of seed dormancy in the flora (>70% of 105 species examined produce dormant seeds), with physical and physiological classes of dormancy most commonly encountered. We discuss the development of seed-treatments such as optimised wet-heat and dry after-ripening that have increased the germination capacity of many previously dormant seed batches. In addition, we highlight how seed enhancement technologies, such as hydro-priming with smoke-derived germination stimulants and polymer seed coating, and a greater understanding of the biological and physical limitations present in the growing environment, have vastly improved seedling emergence performance under field conditions for key framework Triodia species. Ongoing industry support (e.g. construction of a purpose-built rain manipulation shelter) has ensured research in the Pilbara will continue to unpack and resolve the complex challenges associated with seed regeneration of biodiverse native plant communities after mining. [ABSTRACT FROM AUTHOR]

This paper is the first embryological report on the genus Cephalanthus L. and contributes to future studies in other genera of the tribe Naucleeae. The development of the anther wall in Cephalanthus glabratus (Spreng.) K. Schum. corresponds to the dicot type and microsporogenesis is simultaneous. The young wall of the anther has four layers; epidermis, endothecium, one middle layer and the secretory tapetum. The tissue of the septum has idioblasts with crystalline sand. In the wall of the mature anther, only the endothecium and remnants of epidermal cells were preserved. The occurrence and morphology of orbicules were observed in the mature anthers of all three species of Cephalanthus with scanning electron microscopy. The orbicules have taxonomic value at species level, since these structures allow us to distinguish between the species analysed. The presence of a protruding oncus was observed for the first time in Cephalanthus in non-acetolysed pollen grains. According to our observations, this structure is not affected by the state of anther dehiscence in C. glabratus because the oncus is visible and prominent in the mature pollen grains in both indehiscent and dehiscent anthers. [ABSTRACT FROM AUTHOR]

Context: The South American grass Nassella trichotoma (serrated tussock) is widely distributed in central Argentina and one of the most damaging invasive species in Australia, New Zealand, and South Africa. In Australia, it is a weed of national significance. Aims: Our aim was to characterise the fungi able to colonise N. trichotoma seeds buried at a site in south-western Buenos Aires province, Argentina, and measure their impact on seed survival and germination. Methods: We tested the germination of healthy seeds at the beginning of the experiment (control). We buried 10 mesh bags containing 100 disinfected N. trichotoma seeds each, during 3 months in spring and autumn. At the end of each experiment, the contents of five of the bags were counted and classified as germinated, healthy, damaged, or disintegrated. Germination tests were then conducted with seeds of the latter three categories. The remaining seeds were used for recording fungal signs/symptoms, and the isolation of fungi. Key results: We identified and described a diverse group of fungi associated with the seeds and a seasonal variation in the specific composition. Seeds showing fungal signs and/or symptoms germinated less than the control. Conclusions: This is the first study on fungi associated with seeds of this species in the native range, which can affect their survival and longevity. Implications: It is expected that studies on the seed microbiome may help us understand the differences in behaviour of the plant between ranges, and test the enemy-release hypothesis. Serrated tussock is widely distributed in central Argentina and is one of the most damaging invasive species in Australia. We characterised the fungi able to colonise its seeds buried at a site in south-western Buenos Aires province, Argentina, and measured their impact on seed survival and germination during two contrasting seasons. Image by Alejandro Loydi. [ABSTRACT FROM AUTHOR]

Context: The concept of the fire regime is central to understanding and managing fire-prone ecosystems globally, and information on past regimes can provide useful insights into species disturbance adaptations. Although observations from satellite imagery or palaeoecological proxy data can provide direct evidence of past, pre-colonial fire regimes, they may be limited in temporal or spatial resolution and are not available for all ecosystems. However, fire-related plant-trait and demographic data offer an alternative approach to understand species–fire regime associations at the ecosystem scale. Aims: We aimed to quantify the life-history strategies and associated fire regimes for six co-occurring shrub and tree species from fire-prone, Mediterranean-climate Banksia Woodlands in south-western Australia. Methods: We collected static demographic data on size structure, seedling recruitment, and plant mortality across sites of varying time since last fire. We combined demographic data with key fire-related species traits to define plant life-history strategies. We then compared observed life histories with a priori expectations for surface, stand-replacing, and mixed-severity fire-regime types to infer historical fire-regime associations. Key results: Fire-killed shrubs and weakly serotinous trees had abundant post-fire seedling recruitment, but also developed multi-cohort populations during fire-free periods via inter-fire seedling recruitment. Resprouting shrubs had little seedling recruitment at any time, even following fire, and showed no signs of decline in the long absence of fire, likely owing to their very long lifespans. Conclusions: The variation in life-history strategies for these six co-occurring species is consistent with known ecological strategies to cope with high variation in fire intervals in a mixed-severity fire regime. Whereas resprouting and strong post-fire seedling recruitment indicate a tolerance of shorter fire intervals, inter-fire recruitment and weak serotiny are interpreted as a bet-hedging strategy to cope with occasional long fire-free periods that may otherwise exceed adult and seed-bank lifespans. Implications: Our findings suggested that Banksia Woodlands have evolved with highly variable fire intervals in a mixed-severity fire regime. Further investigations of species adaptations to varying fire size and patchiness can help extend our understanding of fire-regime tolerances. Information on past fire regimes can provide useful insights into species disturbance adaptations. To test the idea that contemporary demographic parameters provide a signature of past fire regimes, we assessed fire-related plant life-history strategies by using static demographic data collected along a 1–35-year fire-age chronosequence for species with a variety of traits. Species displayed a collection of life-history strategies associated with a historical mixed-severity fire regime, including adaptations for short and long fire intervals, interacting with varying fire severity. Photograph by Russell Miller. [ABSTRACT FROM AUTHOR]

Context: A combination of industrial activities, agricultural practices, and poor urban planning has led to soil and plant contamination throughout the world. Heavy metal stress responses in plants have been demonstrated in various studies, but it remains unclear how heavy metals affect tree germination and initial establishment. Aims: With a focus on species selection for phytoremediation programs in areas with copper (Cu) soil contamination, we aimed to evaluate seed germination, initial growth, and carbohydrate and protein metabolism of seedlings of Hymenaea courbaril, Stryphnodendron pulcherrimum , and Hevea brasiliensis subjected to normal and high (500 mg kg−1) concentrations of Cu. We hypothesised that there are differences in the Cu effects and plant responses on germination, initial growth, and the metabolism of seedlings from different Amazon tree species. Methods: The germination experiment was conducted with seeds of the tree forest species in the absence or presence of Cu. After germination-parameter analyses, biometric variables, soluble sugars, starch, and proteins were measured. Key results: In the presence of Cu, the germination traits, and morphological variables of H. brasiliensis were changed, whereas Cu did not strongly affect the other species. All species showed a high metabolic adjustment capacity, with little impact on the metabolism of carbon and nitrogen-related compounds in seeds. Overall, it was therefore possible to verify that S. pulcherrimum and H. courbaril were able to tolerate Cu because of their good performance in the germination stage and maintenance of essential metabolites, whereas H. brasiliensis was more sensitive to the presence of this heavy metal. Conclusions: Our results provided insights into the ability of tree species to cope with Cu stress and the hypothesis has been confirmed to interspecific differential tolerance. Implications: Amazonian tree species show valuable potential for improving phytoremediation programs with a focus on soil contamination by Cu. Industrial and agricultural activities increase heavy metal concentrations in the environment, contaminating soil and plants. Seeds and seedlings of Hymenaea courbaril, Stryphnodendron pulcherrimum , and Hevea brasiliensis (Amazonian tree species) subjected to copper (500 mg kg−1) were characterised by detrimental effects on germination, with negative implications for the initial seedling growth. Differential tolerance to copper was observed among species. Our findings provided insights into the resilience of tree species when facing copper-induced stress, shedding light on promising candidates for phytoremediation endeavours. Image by the authors. [ABSTRACT FROM AUTHOR]