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Summary: Woody biomass is a large carbon store in terrestrial ecosystems. In calculating biomass, tree stems are assumed to be solid structures. However, decomposer agents such as microbes and insects target stem heartwood, causing internal wood decay which is poorly quantified.We investigated internal stem damage across five sites in tropical Australia along a precipitation gradient. We estimated the amount of internal aboveground biomass damaged in living trees and measured four potential stem damage predictors: wood density, stem diameter, annual precipitation, and termite pressure (measured as termite damage in downed deadwood).Stem damage increased with increasing diameter, wood density, and termite pressure and decreased with increasing precipitation. High wood density stems sustained less damage in wet sites and more damage in dry sites, likely a result of shifting decomposer communities and their differing responses to changes in tree species and wood traits across sites.Incorporating stem damage reduced aboveground biomass estimates by > 30% in Australian savannas, compared to only 3% in rainforests. Accurate estimates of carbon storage across woody plant communities are critical for understanding the global carbon budget. Future biomass estimates should consider stem damage in concert with the effects of changes in decomposer communities and abiotic conditions. [ABSTRACT FROM AUTHOR]

Restoration of coastal wetlands has the potential to deliver both climate change mitigation, called blue carbon, and adaptation benefits to coastal communities, as well as supporting biodiversity and providing additional ecosystem services. Valuing carbon sequestration may incentivize restoration projects; however, it requires development of rigorous methods for quantifying blue carbon sequestered during coastal wetland restoration. We describe the development of a blue carbon accounting model (BlueCAM) used within the Tidal Restoration of Blue Carbon Ecosystems Methodology Determination 2022 of the Emissions Reduction Fund (ERF), which is Australia's voluntary carbon market scheme. The new BlueCAM uses Australian data to estimate abatement from carbon and greenhouse gas sources and sinks arising from coastal wetland restoration (via tidal restoration) and aligns with the Intergovernmental Panel for Climate Change guidelines for national greenhouse gas inventories. BlueCAM includes carbon sequestered in soils and biomass and avoided emissions from alternative land uses. A conservative modeled approach was used to provide estimates of abatement (as opposed to on‐ground measurements); and in doing so, this will reduce the costs associated with monitoring and verification for ERF projects and may increase participation in blue carbon projects by Australian landholders. BlueCAM encompasses multiple climate regions and plant communities and therefore may be useful to others outside Australia seeking to value blue carbon benefits from coastal wetland restoration. [ABSTRACT FROM AUTHOR]

To address uncertainties surrounding the impacts of unprecedented 2019–20 bushfires in south‐eastern Australia, we convened a symposium on field‐measured impacts on biodiversity for the 2020 Ecological Society of Australia conference. Nine presentations covered a range of studies on plant species and communities, and reptiles and mammals. Here, we summarize the presentations and review other field studies from NSW, some of which are currently unpublished. The impacts were extensive, but results also estimated survival rate perhaps higher than first reported in the media. More than half of individual mammal, reptile and threatened rainforest trees may have survived the fire, though small populations remain very vulnerable to second fire in the near future. Comprehensive understanding of the impacts of these fires requires much more field study, and for the results to be interpreted in the context of the broader fire regime. The symposium was an important early step in that understanding. [ABSTRACT FROM AUTHOR]

Insect herbivores and their parasitoids make up a large proportion of biodiversity, but studies of their communities rarely involve geographic comparisons. If the community on a host plant varies geographically, insect diversity will be underestimated by ignoring this. In addition, community functional structure may vary geographically due to differential abundance of functional groups.To address these issues, we compared the composition and structure of the fig wasp community associated with Ficus rubiginosa between temperate (Sydney) and tropical (Townsville) regions of eastern Australia. We sampled figs from four sites per region, twice a year for 2 years, resulting in about 14,000 wasps from 11 genera and 19 sub‐generic taxa. Since two of these taxa each comprise two cryptic species, we refer to taxonomic diversity below, but this is largely at species level.Taxonomic richness (14) was the same in both regions and nine taxa were shared across regions. However, 10 taxa were found in only one of the two regions, driving a significant difference in the taxonomic composition of the tropical and temperate communities, and increasing overall diversity in the system.The wasps belong to five functional groups – pollinators, small and large gallers, and small and large parasitoids. In contrast to taxonomic composition and diversity, community functional structure did not differ significantly between regions.Our results highlight that there can be broad latitudinal conservation of functional community structure across regions, despite considerable regional differences in taxonomic composition. [ABSTRACT FROM AUTHOR]

Aim: Climate shapes the composition and function of plant communities globally, but it remains unclear how this influence extends to floral traits. Flowering phenology, or the time period in which a species flowers, has well‐studied relationships with climatic signals at the species level but has rarely been explored at a cross‐community and continental scale. Here, we characterise the distribution of flowering periods (months of flowering) across continental plant communities encompassing six biomes, and determine the influence of climate on community flowering period lengths. Location: Australia. Taxon: Flowering plants. Methods: We combined plant composition and abundance data from 629 standardised floristic surveys (AusPlots) with data on flowering period from the AusTraits database and additional primary literature for 2983 species. We assessed abundance‐weighted community mean flowering periods across biomes and tested their relationship with climatic annual means and the predictability of climate conditions using regression models. Results: Combined, temperature and precipitation (annual mean and predictability) explain 29% of variation in continental community flowering period. Plant communities with higher mean temperatures and lower mean precipitation have longer mean flowering periods. Moreover, plant communities in climates with predictable temperatures and, to a lesser extent, predictable precipitation have shorter mean flowering periods. Flowering period varies by biome, being longest in deserts and shortest in alpine and montane communities. For instance, desert communities experience low and unpredictable precipitation and high, unpredictable temperatures and have longer mean flowering periods, with desert species typically flowering at any time of year in response to rain. Main conclusions: Current climate conditions shape flowering periods across biomes, with implications for phenology under climate change. Shifts in flowering periods across climatic gradients reflect changes in plant strategies, affecting patterns of plant growth and reproduction as well as the availability of floral resources for pollinators across the landscape. [ABSTRACT FROM AUTHOR]

Aim: Pollination plays a crucial role in the conservation of many plant species persisting in fragmented, human‐dominated landscapes. Pollinators are known to be instrumental in maintaining genetic diversity and metapopulation dynamics for many plant species and are important for providing ecological services that are essential in agricultural landscapes where populations of native plants are highly isolated. Numerous studies have explored the value of remnant native vegetation for supporting pollination services to crop species, yet the effect of mass‐flowering crops on the pollinator communities and the pollination services they provide to native plant communities persisting in fragmented landscapes are less well understood. Here, we assess the influence of the presence and phenology of a mass‐flowering crop to pollinator community structure, abundance, and pollen load composition in remnant vegetation in complex agricultural landscapes. Location: South‐west Western Australia, Australia. Methods: We recorded the composition and abundance of insect flower visitors and their pollen loads in isolated remnants of York Gum‐Jam woodlands adjacent to canola (insect‐attracting) or wheat (non‐insect‐attracting) fields over two years. Results: All bees were much more sensitive to adjacent crop type (neighbouring canola or wheat) than non‐bee pollinators. Honeybees were the most abundant pollinators in canola fields during peak flowering. Honeybee abundance increased in canola‐adjacent reserves post canola bloom, potentially indicating a movement into reserves as crop flowering waned. Native bees were the most diverse in remnant vegetation. Pollen loads of native bees were more mixed (increased pollen richness and evenness) when sampled next to canola fields compared to wheat fields. Main conclusion: The availability of potential insect pollinators to remnant wildflower communities in agricultural landscapes is context dependent. Whether sampled communities were adjacent to wheat or canola in a landscape significantly impacted the abundance of potential pollinators in certain landscape elements, but not others, and the composition of pollen loads carried by these insects. Results offer novel insights about the influence of landscape context on pollinator communities and the potential pollination services available for the conservation of native plant species in highly fragmented agricultural landscapes. [ABSTRACT FROM AUTHOR]

Aim: Our ability to understand how species may respond to changing climate conditions is hampered by a lack of high‐quality data on the adaptive capacity of species. Plant functional traits are linked to many aspects of species life history and adaptation to environment, with different combinations of trait values reflecting alternate strategies for adapting to varied conditions. If the realized climate limits of species can be partially explained by plant functional trait combinations, then a new approach of using trait combinations to predict the expected climate limits of species trait combinations may offer considerable benefits. Location: Australia. Time period: Current and future. Methods: Using trait data for leaf size, seed mass and plant height for 6,747 Australian native species from 27 plant families, we model the expected climate limits of trait combinations and use future climate scenarios to estimate climate change impacts based on plant functional trait strategies. Results: Functional trait combinations were a significant predictor of species climate niche metrics with potentially meaningful relationships with two rainfall variables (R2 =.36 &.45) and three temperature variables (R2 =.21,.28,.30). Using this method, the proportion of species exposed to conditions across their range that are beyond the expected climate limits of their trait strategies will increase under climate change. Main conclusions: Our new approach, called trait strategy vulnerability, includes three new metrics. For example, the climate change vulnerability (CCV) metric identified a small but important proportion of species (4.3%) that will on average be exposed to conditions beyond their expected limits for summer temperature in the future. These potentially vulnerable species could be high priority targets for deeper assessment of adaptive capacity at the genomic or physiological level. Our methods can be applied to any suite of co‐occurring plants globally. [ABSTRACT FROM AUTHOR]

Aim: Exotic perennial grasses (EPGs) are significant invaders of native grassy communities. We sought to determine how the profile of invading perennial grasses varies among different climatic regions and different grassy communities, to understand at which scale management is best undertaken. We investigated whether invader occurrence was related to specific plant traits. Location: New South Wales, Australia. Method: Field surveys of EPGs at 139 sites from nine grassy communities across four regions were assessed for variation in invasion profiles amongst regions and communities. We used a ranking of invasion risk based on plant characteristics to identify grasses likely to be more invasive and tested whether this ranking predicted the level of invasion in the survey. Results: Using multivariate analysis, we found that all communities were significantly invaded. These assemblages were distinct regionally, and for most plant communities. Five widespread invaders were established in all regions and communities. Invasion by pasture grasses (termed trade‐off species) was the most significant threat, coupled with capacity to develop long‐term seed banks and use allelopathy. Species with higher risk rankings were recorded in more sites, although a few grasses had much greater occurrences than their ranking predicted. Conclusions: Grassy communities across all regions were invaded by a suite of EPGs, some that have not been considered as problematic previously. Higher levels of invasion were associated with higher ranked species based on plant traits, indicating that our risk assessment is valuable as a management prioritization tool. Findings support community level management, although some species are important widespread invaders and could be managed at larger scales. Differences in species assemblages compared to nearby agricultural areas confirm different invasion pathways, with significant invasion from pasture grasses. Aided by the risk assessment tool, we propose that EPG management in native communities considers the climatic, community (including surrounding) and species level for prioritization. [ABSTRACT FROM AUTHOR]

Aim: Megafires are increasing in intensity and frequency globally. The impacts of megafires on biodiversity can be severe, so conservation managers must be able to respond rapidly to quantify their impacts, initiate recovery efforts and consider conservation options within and beyond the burned extent. We outline a framework that can be used to guide conservation responses to megafires, using the 1.5 million hectare 2019/2020 megafires in Victoria, Australia, as a case study. Location: Victoria, Australia. Methods: Our framework uses a suite of decision support tools, including species attribute databases, ~4,200 species distribution models and a spatially explicit conservation action planning tool to quantify the potential effects of megafires on biodiversity, and identify species‐specific and landscape‐scale conservation actions that can assist recovery. Results: Our approach identified 346 species in Victoria that had >40% of their modelled habitat affected by the megafire, including 45 threatened species, and 102 species with >40% of their modelled habitat affected by high severity fire. We then identified 21 candidate recovery actions that are expected to assist the recovery of biodiversity. For relevant landscape‐scale actions, we identified locations within and adjacent to the megafire extent that are expected to deliver cost‐effective conservation gains. Main conclusion: The 2019/2020 megafires in south‐eastern Australia affected the habitat of many species and plant communities. Our framework identified a range of single‐species (e.g., supplementary feeding, translocation) and landscape‐scale actions (e.g., protection of refuges, invasive species management) that can help biodiversity recover from megafires. Conservation managers will be increasingly required to rapidly identify conservation actions that can help species recover from megafires, especially under a changing climate. Our approach brings together commonly used datasets (e.g., species distribution maps, trait databases, fire severity mapping) to help guide conservation responses and can be used to help biodiversity recover from future megafires across the world. [ABSTRACT FROM AUTHOR]

Biological invasions are a leading threat to biodiversity globally. Increasingly, ecosystems experience multiple introductions, which can have significant effects on patterns of diversity. The way these communities assemble will depend partly on whether rare and common alien species respond to environmental predictors in the same manner as rare and common native species, but this is not well understood. To examine this question across four national parks in south‐eastern Australia, we sampled the understory plant community of eucalypt‐dominated dry forest subject to multiple plant introductions. The drivers of diversity and turnover in alien and native species of contrasting frequency of occurrence (low, intermediate, and high) were each tested individually. We found alien species diversity and turnover were both strongly associated with abiotic conditions (e.g., soil pH), while distance had little influence because of the greater extent of occurrence and more homogeneous composition of common aliens. In contrast, native species diversity was not associated with abiotic conditions and their turnover was as strongly influenced by distance as by abiotic conditions. In both alien and native species, however, the most important predictors of turnover changed with frequency of occurrence. Although local coexistence appears to be facilitated by life history trade‐offs, species richness of aliens and natives was negatively correlated and native species might face greater competition in areas with more neutral soils (e.g., pH > ~5.5) where alien richness and relative frequency were both highest. We conclude that diversity and turnover in the generally more widespread alien species are mainly driven by species sorting along an environmental gradient associated with pH and nutrient availability, whereas turnover of native species is driven by more neutral processes associated with dispersal limitation. We show alien and native plant species respond to different environmental factors, as do rare and common species within each component. [ABSTRACT FROM AUTHOR]

Mining activity causes major changes in site topography, soil physical and chemical properties, hydrology, and biological assemblages. Reassembling plant communities in these highly altered environments is dependent on interactions between environmental drivers and management intervention techniques through time, yet the long‐term effects of these interactions have rarely been quantified. This study examined a 19‐year‐old, postmining woodland restoration chronosequence in southwest Australia to understand plant community compositional development in postmine restoration sites. We tested the effects of environmental drivers (rainfall regimes, site aspect, slope) and management intervention techniques (substrate ripping and material properties) in terms of four restoration criteria: species richness, plant density, vegetation cover, and compositional similarity to reference sites. Irrespective of environmental drivers or management intervention techniques, vegetation cover increased through time, while plant density and species richness declined. Bray–Curtis similarity to reference communities remained unchanged. Within these trends, ripping and first‐year rainfall significantly affected restoration criteria outcomes; species richness and plant density were greatest when rainfall in the first winter immediately following site restoration was low but followed by a high summer rainfall. The most effective ripping depth was dependent on rainfall, deep‐ripped sites performed best when rainfall was high, and nonripped sites performed best under low‐mean rainfall conditions. Measured restoration criteria had not reached the levels of the target reference community after 19 years, which may be attributable to the still‐developing vegetation structure. This emphasizes the importance of assessing postmining restoration outcomes over longer time frames (>>5 years) with implications for determining appropriate, time‐dependent completion criteria. [ABSTRACT FROM AUTHOR]

Classical biological control (CBC) can be used to decrease the density of invasive species to below an acceptable ecological and economic threshold. Natural enemies specific to the invasive species are selected from its native range and released into the invaded range. This approach has drawbacks, despite the performance of specificity tests to ensure its safety, because the fundamental host range defined under controlled conditions does not represent the actual host range in natura, and these tests omit indirect interactions within community.We focus on Sonchus oleraceus (Asteraceae), a weed species originating from Western Palearctic that is invasive in many countries and notably in Australia. We explore how analyses of interaction network within its native range can be used to (a) inventory herbivores associated to the target plant, (b) characterize their ecological host ranges and (c) guide the selection of candidate biocontrol agents considering interactions with species from higher trophic levels. Arthropods were collected from plant community sympatric to S. oleraceus, in three bioclimatic regions, and interactions were inferred by a combination of molecular and morphological approaches.The networks reconstructed were structured in several trophic levels from basal species (plant community), to intermediate and top species (herbivorous arthropods and their natural enemies). The sub‐network centred on S. oleraceus‐related interactions contained 116 taxa and 213 interactions. We identified 47 herbivores feeding on S. oleraceus, 15 of which were specific to the target species. Some discrepancies with respect to published findings or conventional specificity tests suggested possible insufficient sampling effort for the recording of interactions or the existence of cryptic species. Among potential candidate agents, six exhibited interactions with natural enemies.Synthesis and applications. Adopting a network approach as prerequisite step of the classical biological control programme can provide a rapid screening of potential agents to be tested in priority. Once ecological host range defined, we suggest that priority should be given to agent used by a minimum species, and, when they exist, to agents that possess enemies from the most distant taxonomical group from those occurring in the range of introduction. [ABSTRACT FROM AUTHOR]

Summary: Native herbivores can affect the structure and function of plant communities. Most studies of overabundant native herbivore effects on native plant communities in south‐eastern Australia are observational or compare, at most, two levels of herbivory (ambient vs. none), and typically do not separate out the impacts of multiple herbivores. Several studies show that high densities of herbivores had mostly negative effects on plant regeneration and growth. These effects were usually attributed to palatability differences amongst plant species. Surprisingly, few studies have quantified vegetation responses across a gradient of herbivore density, and impacts on plant communities (i.e. species richness, composition, beta diversity) have not been well studied. Hence, there remains a need to better understand how native herbivores impact plant communities at different densities. [ABSTRACT FROM AUTHOR]

Globally, high‐density populations of feral deer have been associated with a range of negative ecological consequences. Within Australia, limited quantitative research has assessed the impacts of deer, particularly in threatened ecological communities (TECs). Our study aimed to quantify the impact of feral deer on the herbivory of a range of woody plant species, non‐woody growth forms and TECs; and assess whether feral deer increase herbivory in TECs above background rates caused by native herbivores. We surveyed 356 transects across 89 sites representing eight TECs and collected herbivory data for woody and non‐woody plants. At each site, we recorded the presence or absence of deer sign and abundance of macropod pellets to account for variations in herbivory between groups of sympatric species. Generalised linear mixed models were developed to predict: (i) proportion of individual plants browsed (or grazed); and (ii) average browsing (or grazing) intensity for woody plant species and non‐woody plants. Controlling for macropod abundance, we found the average grazing intensity and proportion of non‐woody plants grazed was higher when deer were present compared to absent. Specifically, grazing pressure on rushes, cycads, sedges and grasses was significantly higher where deer were present. In contrast, we did not observe a significant impact of deer on woody plant species. The presence of deer resulted in higher grazing intensity in coastal saltmarsh, freshwater wetland, littoral rainforest and bangalay sand forest TECs. Although the deer population across our study region generally appears to be at low density compared to neighbouring regions, their presence is resulting in grazing pressure above that caused by native herbivores for a range of non‐woody plants. Our results contribute to a growing body of research about the ecological impacts of feral deer in Australia and can be used as a baseline for ongoing regional monitoring of deer impacts in TECs. [ABSTRACT FROM AUTHOR]

1. Forest ecosystems experience a myriad of natural and anthropogenic disturbances that shape ecological communities. Seedling emergence is a critical, preliminary stage in the recovery of forests post disturbance and is triggered by a series of abiotic and biotic changes. However, the long-term influence of different disturbance histories on patterns of seedling emergence is poorly understood. 2. Here, we address this research gap by using an 11-year dataset gathered between 2009 and 2020 to quantify the influence of different histories of natural (wildfire) and anthropogenic (clearcut and postfire salvage logging) disturbances on emerging seedlings in early-successional Mountain Ash forests in southeastern Australia. We also describe patterns of seedling emergence across older successional forests varying in stand age (stands that regenerated in <1900s, 1939, 1970-90, and 2007-11). 3. Seedling emergence was highest in the first three years post disturbance. Stand age and disturbance history significantly influenced the composition and abundance of plant seedlings. Specifically, in salvage-logged forests, plant seedlings were the most different from similarly aged forests with other disturbance histories. For instance, relative to clearcut and unlogged, burnt forests of the same age, salvage logging had the lowest overall richness, the lowest counts of Acacia seedlings, and an absence of common species including Acacia obliquinervia, Acacia frigescens, Cassinia arcuealta, Olearia argophylla, Pimelea axiflora, Polyscias sambucifolia, and Prosanthera melissifolia over the survey period. 4. Synthesis: Our findings provide important new insights into the influence of different disturbance histories on regenerating forests and can help predict plant community responses to future disturbances, which may influence forest recovery under altered disturbance regimes. [ABSTRACT FROM AUTHOR]

1. Forest ecosystems experience a myriad of natural and anthropogenic disturbances that shape ecological communities. Seedling emergence is a critical, preliminary stage in the recovery of forests post disturbance and is triggered by a series of abiotic and biotic changes. However, the long- term influence of different disturbance histories on patterns of seedling emergence is poorly understood. 2. Here, we address this research gap by using an 11- year dataset gathered between 2009 and 2020 to quantify the influence of different histories of natural (wildfire) and anthropogenic (clearcut and postfire salvage logging) disturbances on emerging seedlings in early- successional Mountain Ash forests in southeastern Australia. We also describe patterns of seedling emergence across older successional forests varying in stand age (stands that regenerated in <1900s, 1939, 1970– 90, and 2007– 11). 3. Seedling emergence was highest in the first three years post disturbance. Stand age and disturbance history significantly influenced the composition and abundance of plant seedlings. Specifically, in salvage- logged forests, plant seedlings were the most different from similarly aged forests with other disturbance histories. For instance, relative to clearcut and unlogged, burnt forests of the same age, salvage logging had the lowest overall richness, the lowest counts of Acacia seedlings, and an absence of common species including Acacia obliquinervia, Acacia frigescens, Cassinia arcuealta, Olearia argophylla, Pimelea axiflora, Polyscias sambucifolia, and Prosanthera melissifolia over the survey period. 4. Synthesis: Our findings provide important new insights into the influence of different disturbance histories on regenerating forests and can help predict plant community responses to future disturbances, which may influence forest recovery under altered disturbance regimes. [ABSTRACT FROM AUTHOR]

Aim: Perennial plant communities are crucial for regulating ecological processes and maintaining ecosystem functions. Variation in community structure is driven by both biotic and abiotic factors, reflecting adaptation strategies of plant communities to various environments. Although much is known about the response of individual perennial plants to drier climates, empirical evidence of the community‐level responses to increasing dryness is limited. Location: Eastern Australia; 1500 km gradient. Taxon: Perennial plants. Methods: We measured the abundance and size distribution (median, skewness and variance) of perennial plant communities from different growth forms (trees, shrubs and grasses), the spatial arrangement of trees in the overstorey and both biotic (competition) and abiotic (climate, soil properties) factors at 150 sites along an extensive aridity gradient from humid to arid areas. We used regression analyses and linear models to explore variation in community structure with increasing aridity and key driving factors for different perennial plant communities. Results: Variation in community structure differed with growth form. As aridity increased, trees had wider canopies and were spatially aggregated, shrubs became miniaturised, but highly variable in size, and grasses comprised more larger individuals. Biotic and abiotic factors exerted different effects on different growth forms, with trees and shrubs consistently affected by competition and aridity, respectively, whereas grasses were weakly affected by aridity, summer rainfall and soil texture. Main conclusions: Our study highlights the idiosyncratic adaptation strategies used by trees, shrubs and grasses in response to drying climates at the community level through their effect on the size distribution or spatial aggregation. The structure of different perennial growth forms was influenced by different effects from either biotic (competition) or abiotic (climate, soil) factors. Under forecasted drier climates, canopy expansion and greater aggregation of trees might enhance resource sinks and shelter for diverse biota, potentially shielding plant communities against predicted aridification. [ABSTRACT FROM AUTHOR]

Alien invasive aquatic macrophytes tend to displace native species and transform diverse macrophyte communities into monospecific stands. It is often thought that superior competitiveness allows alien invaders to achieve this.Cabomba caroliniana is a submersed macrophyte that is highly invasive worldwide and frequently monopolises habitats. However, field observations in Queensland, Australia, found that the native floating attached Nymphoides indica can co‐exist with C. caroliniana, highlighting N. indica as a potential candidate for habitat restoration. To identify factors and processes that regulate the coexistence of these species, we conducted a field survey and two experiments in artificial mesocosms.We found that N. indica leaf areal coverage of the water surface significantly reduced C. caroliniana standing crop biomass in the field. C. caroliniana growth was also linked to water depth; N. indica was not able to grow beyond 2 m depth. There was a small reduction in N. indica root and shoot biomass when co‐cultured with C. caroliniana in our experiment. Therefore, there was reciprocal competitive inhibition between the two species. However, the effect of N. indica on C. caroliniana was much larger.There was evidence that a reduction of C. caroliniana biomass below a threshold of c. 300 g dry mass/m is critical for protecting native submersed macrophyte diversity and abundance. Once C. caroliniana biomass exceeds this threshold, it dominates plant communities and forms high biomass monocultures. The experimental work identified shading as the most important factor that reduces C. caroliniana biomass, corroborating the relationship between leaf areal cover and C. caroliniana biomass found in the field.Based on these findings, N. indica could be useful for restoring the shallow lake littoral habitat, because it suppresses biomass of the invasive species to a level that allows other macrophytes to coexist and additionally increases habitat heterogeneity. Similarly, N. indica could be suitable to restore areas where C. caroliniana was previously removed to reduce the likelihood of future habitat monopolisation by C. caroliniana and realise long‐term ecological benefits from invasive macrophyte management. [ABSTRACT FROM AUTHOR]

The relationships between productivity, fire frequency and fire severity shape the distribution of plant communities globally. Dry forests are expected to burn frequently and wet forests to burn infrequently. However, the effect of productivity on intensity and severity of wildfire is less consistent and poorly understood. One productive ecosystem where this is especially true is the Australian tall wet Eucalyptus‐dominated forest (TWEF), which spans wet areas across the continent. This study aims to characterise how climate shapes the likelihood of low‐ and high‐severity wildfire across Australian TWEF.We performed a continental‐scale analysis of fuels in 48 permanent plots in early‐mature stage TWEF across four climate regions in Australia. We estimated fuel loads and measured understorey microclimate. We then obtained historical fire‐weather observations from nearby meteorological stations and used fuel moisture and fire behaviour equations to predict the historical frequency with which TWEF could burn and what fire severities were expected. We investigated how this varies across the different TWEF climate regions. Lastly, we validated our approach by remeasuring eight plots that burned unexpectedly post‐measurement.We found that surface fuels in cooler, moister regions were available to burn 1–16 days per year historically, with only low‐severity, surface fire possible most of these days: high‐severity fire was only possible under rare, extreme fire‐weather conditions. However, in warmer, drier regions, fuels were available to burn 23–35 days annually, and high‐severity fire was more likely than low‐severity fire. Validation showed that we slightly overestimated flame heights, inflating high‐severity risk estimates. If we used elevated fuel loads to predict flame heights, however, high‐severity fire was more likely than low‐severity fire everywhere. Lastly, the likelihood of high‐severity fire increased with increasing temperature and worsening fire weather.Synthesis. Fire activity in early‐mature TWEF is limited by climatic constraints on fire weather and availability to burn, with high‐severity fire more likely in warmer, drier regions than in cooler, wetter ones. This indicates a particularly worrisome vulnerability to climate change, given TWEF's diminished ability to recover from disturbance in a warmer world. The occurrence of both low‐ and high‐severity fire means the fire regimes of TWEF are best described as mixed severity. [ABSTRACT FROM AUTHOR]

Ecological resilience is widely acknowledged as a vital attribute of successful ecosystem restoration, with potential for restoration practice to contribute to this goal. Hence, defining common metrics of resilience to naturally occurring disturbances is essential for restoration planning, efforts, and monitoring. Here, we reviewed how plant community ecologists have measured resilience of restoration projects to disturbances and propose a framework to guide measurement of restoration projects to disturbance. We found 22 studies that investigated the impact of disturbances on restoration projects, from three continents and for three disturbance types. Over half of the studies were from Australia, with the dataset biased toward fire responses of restored, or partially restored, forest ecosystems. Native plant species richness, cover, and density were common response variables. Studies varied in restoration context, design, response variables, and statistical approaches, limiting generalizations. Nonetheless we have identified several response variables that offer potential as lagging indicators (e.g. species richness) and leading indicators (e.g. recruitment) of resilience in diverse vegetation types exposed to a variety of disturbance regimes. We suggest a third set of variables, proxy measures of resilience (e.g. functional redundancy), to complement lagging and leading indicators. We conclude with a framework to guide decisions about when to use each of the three types of measures to assess resilience of restoration projects to disturbance, providing some clarity to decision‐making despite the uncertainty of changing disturbance regimes. Lastly, we invite researchers to understand the impact of disturbance on the resilience of restoration projects, rather than assume resilience. [ABSTRACT FROM AUTHOR]

Understorey plant communities comprise a large portion of biodiversity of forests and woodlands globally, where they contribute to tree species dynamics, biogeochemical cycling and carbon sequestration.Here we evaluated the effects of elevated CO2 (400 vs. 550 ppm) on the spatial distribution of understorey plant communities from a mature eucalypt woodland in Eastern Australia (EucFACE experiment).Three years of elevated CO2 resulted in a loss of the characteristic aggregated and segregated spatial pattern of species richness at both short and long distances (20 cm–227 cm), respectively. Changes in spatial patterns emerged over time, indicating that these results are due to a relatively slow reordering of the understorey plant community. In contrast, when analysed from a multivariate perspective, changes in terms of community composition were not as clear as changes in the spatial rearrangement of plant communities.Synthesis. Given that the spatial patterns of communities are likely a reflection of the way in which multiple species interact and how energy and matter flow throw ecosystems, community reordering due to global change may have far‐reaching implications in terms of ecosystem functioning. Moreover, subtle early changes in the spatial pattern of understorey plant communities may represent an early‐warning indicator of global change impacts in forest ecosystems. [ABSTRACT FROM AUTHOR]

Summary: Exotic perennial grasses (EPGs) pose a significant risk to native communities globally. With over 2,200 species in Australia, understanding which characteristics enable high threat invasions, and comparing between functionally similar EPGs, can help prioritise species management. We developed a framework of risk and used the literature to rank 21 EPGs considered a threat to plant communities in New South Wales, while also evaluating the reliability of information currently available. Characteristics were scored within five broad categories that distinguish invasiveness: Arrival, Establishment, Persistence, Impact and Distribution. These included aspects of reproductive biology, competitive ability and environmental tolerance. The risk assessment was effective in assessing key characteristics of invasion. EPGs with an economic benefit (trade‐off species) were more likely to have reliable research and frequently ranked as high‐risk invaders in natural habitats due to the overlap of characteristics important in invasion with those considered important in agriculture. Lack of formal scientific research hindered assessment for some species, and some traits had been poorly assessed in the literature. High uncertainty was associated with key characteristics for Establishment, Persistence and Impact. Uncertainty in key characteristics revealed a need for improved integration of less formal research validated by more formal scientific research. This may lead to more informed decisions in the management of EPGs in native habitats and assist in early control of EPGs not yet assessed. [ABSTRACT FROM AUTHOR]

The expansion of rainforest pioneer trees into long‐unburnt open forests has become increasingly widespread across high rainfall regions of Australia. Increasing tree cover can limit resource availability for understorey plant communities and reduce understorey diversity. However, it remains unclear if sclerophyll and rainforest trees differ in their competitive exclusion of understory plant communities, which contain most of the floristic diversity of open forests. Here, we examine dry open forest across contrasting fire histories (burnt and unburnt) and levels of rainforest invasion (sclerophyll or rainforest midstorey) to hindcast changes in understorey plant density, richness and composition. The influence of these treatments and other site variables (midstorey structure, midstorey composition and soil parameters) on understorey plant communities were all examined. This study is the first to demonstrate significantly greater losses of understorey species richness, particularly of dry open‐forest specialists, under an invading rainforest midstorey compared to a typical sclerophyll midstorey. Rainforest pioneers displaced over half of the understorey plant species, and reduced ground cover and density of dry forest specialists by ~90%. Significant understorey declines also occurred with increased sclerophyll midstorey cover following fire exclusion, although losses were typically less than half that of rainforest‐invaded sites over the same period. Understorey declines were closely related to leaf area index and basal area of rainforest and wattle trees, suggesting competitive exclusion through shading and potentially belowground competition for water. Around 20% of displaced species lacked any capacity for population recovery, while transient seed banks or distance‐limited dispersal may hinder recovery for a further 68%. We conclude that rainforest invasion leads to significant declines in understorey plant diversity and cover in open forests. To avoid elimination of local native plant populations in open forests, fires should occur with sufficient frequency to prevent overstorey cover from reaching a level where shade‐intolerant species fail to thrive. [ABSTRACT FROM AUTHOR]

Non‐native species can dominate plant communities by competitively displacing native species, or because environmental change creates conditions favourable to non‐native species but unfavourable to native species. We need to disentangle these mechanisms so that management can target competitively dominant species and reduce their impacts.Joint‐species distribution models (JSDMs) can potentially quantify competitive impacts by simultaneously modelling how species respond to environmental variation and to changes in community composition. We describe a JSDM to model variation in plant cover and show how this can be applied to compositional data to detect dominant competitors that cause other species to decline in abundance.We applied the model to an experiment in an invaded grassy‐woodland community in Australia where we manipulated biomass removal (through slashing and fencing to prevent grazing by kangaroos) along a fertility gradient. Non‐native species dominated plant cover at high fertility sites in the absence of biomass removal. Results from the JSDM identified three of the 72 non‐native plant species (Bromus diandrus, Acetosella vulgaris and especially Avena fatua) as having a strong competitive impact on the community, driving changes in composition and reducing the cover of both native and non‐native species, particularly in the absence of grazing. The dominant non‐native grasses Bromus diandrus and Avena fatua were among the tallest species in the community and had the greatest impact on shorter‐statured species, most likely through competition for light under conditions of high fertility and low grazing.Synthesis. We demonstrate a method to measure competitive impact using a joint‐species distribution model, which allowed us to identify the species driving compositional change through competitive displacement, and where on the landscape competitive impacts were greatest. This information is central to managing plant invasions: by targeting dominant non‐native species with large competitive impacts, management can reduce impacts where they are greatest. We provide details of the modelling procedure and reproducible code to encourage further application. [ABSTRACT FROM AUTHOR]

Summary: Most high value grasslands of south‐eastern Australia are restricted to small fragmented areas of public land. However, a significant proportion of native grassland is privately owned, managed with grazing rather than fire and is rarely monitored. Hence, a better understanding of grassland management and conservation on the private estate is required. Eco‐markets are policy instruments that incentivise private landholders to effectively manage and conserve native vegetation. However, short funding cycles restrict the capacity of monitoring programs to assess long‐term vegetation changes. In this study, 17 native grassland remnants on private land managed with livestock grazing were monitored before and during a 4‐year eco‐market and 6 years after it ended to determine how composition had changed over 10 years of monitoring. Numerous grassland attributes were either maintained or improved over the 10‐year period, which coincided with one of the most severe and long‐lasting droughts in recent history (i.e. the Millennium drought). In addition, several threatened species were identified as part of the program. A decline in exotic forb richness, native grass cover and native forb richness suggests there is also some impact of the Millennium drought on plant mortality as evidenced by altered litter dynamics. Inherent variability year‐to‐year for most measures of grassland attributes over the monitoring period indicates that climatic conditions have a strong influence on grassland dynamics. Our ability to determine the driver(s) of grassland composition was limited by monitoring program design. Future eco‐market monitoring programs should have adequate resources allocated to enable effective monitoring designs, that incorporate reference information and control sites, and should aim to be long‐term (i.e. >10 years). This will provide clearer insights into the drivers of grassland dynamics and allow for refinement of management options for conservation of this threatened community. [ABSTRACT FROM AUTHOR]

Question: What are the differences between plant communities recognised using supervised versus un‐supervised methods? Location: Northeastern Australia. Methods: Two classifications of savanna plant communities were formed independently with two different approaches: supervised and un‐supervised (using agglomerative hierarchical clustering). Each approach used the same vegetation datasets and, importantly, classification criteria. The communities occur on two different landscapes, with differing environmental gradients, covering an area of 53,500 km2. We compared the internal characteristics of plant communities between approaches and landscapes using four evaluation criteria: identifiability, distinctiveness, similarity of internal heterogeneity and predictability of species foliage cover. Additionally, we compared the central floristic concepts and compositional boundaries of communities identified by each approach. Results: Supervised and un‐supervised approaches recognised similar floristic community concepts. Compositional boundaries between communities were similar on the landscape with steeper environmental gradients but significantly different on the landscape with gradual environmental gradients. However, communities distinguished using supervised methods were significantly less distinct and identifiable, worse at predicting species foliage cover and significantly more variable in species composition than those identified using un‐supervised methods. Conclusions: Using supervised rather than un‐supervised approaches to distinguish plant communities can result in less recognisable communities, possibly reducing their usefulness for land management planning. Importantly, we found a large disparity between the two approaches in delineating compositional boundaries between communities on landscapes with gradual environmental gradients. This is particularly relevant to communities in biomes such as the savanna which comprises 20% of the Earth's landmass. Ecologists can be more confident using a supervised approach on landscapes with steep environmental gradients but should target landscapes with gradual environmental gradients for un‐supervised classification. [ABSTRACT FROM AUTHOR]

Question: What are the differences between plant communities recognised using supervised versus un‐supervised methods? Location: Northeastern Australia. Methods: Two classifications of savanna plant communities were formed independently with two different approaches: supervised and un‐supervised (using agglomerative hierarchical clustering). Each approach used the same vegetation datasets and, importantly, classification criteria. The communities occur on two different landscapes, with differing environmental gradients, covering an area of 53,500 km2. We compared the internal characteristics of plant communities between approaches and landscapes using four evaluation criteria: identifiability, distinctiveness, similarity of internal heterogeneity and predictability of species foliage cover. Additionally, we compared the central floristic concepts and compositional boundaries of communities identified by each approach. Results: Supervised and un‐supervised approaches recognised similar floristic community concepts. Compositional boundaries between communities were similar on the landscape with steeper environmental gradients but significantly different on the landscape with gradual environmental gradients. However, communities distinguished using supervised methods were significantly less distinct and identifiable, worse at predicting species foliage cover and significantly more variable in species composition than those identified using un‐supervised methods. Conclusions: Using supervised rather than un‐supervised approaches to distinguish plant communities can result in less recognisable communities, possibly reducing their usefulness for land management planning. Importantly, we found a large disparity between the two approaches in delineating compositional boundaries between communities on landscapes with gradual environmental gradients. This is particularly relevant to communities in biomes such as the savanna which comprises 20% of the Earth's landmass. Ecologists can be more confident using a supervised approach on landscapes with steep environmental gradients but should target landscapes with gradual environmental gradients for un‐supervised classification. [ABSTRACT FROM AUTHOR]

Searching for food is the first critical stage of foraging, and search efficiency is enhanced when foragers use cues from foods they seek. Yet we know little about food cues used by one major group of mammals, the herbivores, a highly interactive component of most ecosystems. How herbivores forage and what disrupts this process, both have significant ecological and evolutionary consequences beyond the animals themselves., Our aim was to investigate how free-ranging mammalian herbivores exploit leaf odour cues to find food plants amongst a natural and complex vegetation community. Our study system comprised the native 'deer equivalent' of eastern Australian forests, the swamp wallaby Wallabia bicolor, and seedlings of Eucalyptus, the foundation tree genus in these ecosystems. We quantified how foraging wallabies responded to odour cues from plants manipulated in several ways: varying the quantity of visually concealed leaves, comparing damaged vs. undamaged leaves, and whole plants vs. those with suppressed cues., The rate of discovery of leaves by wallabies increased with odour cue magnitude, yet animals were extremely sensitive to even a tiny odour source of just a few leaves. Whole seedlings were discovered faster if their leaves were damaged. Wallabies found whole seedlings and those with suppressed visual cues equally rapidly, day and night. Seedlings with very little odour were discovered mainly by day, as nocturnal foraging success was severely disrupted., This study shows how leaf odour attracts mammalian herbivores to food plants, enabling non-random search for even tiny odour sources. As damaged leaves enhanced discovery, we suggest that the benefit of attracting natural enemies to invertebrate herbivores feeding on plants (potential 'cry for help') may be offset by a cost-increased browsing by mammalian herbivores. This cost should be incorporated into multi-trophic plant-animal studies. Finally, the breakdown in capacity to find plants at night suggests substantial but unrecognized foraging costs to herbivores when abiotic factors, such as cold temperatures or pollution, reduce or degrade plant odour cues. We predict that an increasingly polluted world will alter the foraging success of mammalian herbivores, with significant ecological ramifications given that browsing can shape ecosystems. [ABSTRACT FROM AUTHOR]

Forest ecosystems and their associated natural, cultural and economic values are highly vulnerable to climate driven changes in fire regimes. A detailed knowledge of forest ecosystem responses to altered fire regimes is a necessary underpinning to inform options for adaptive responses under climate change, as well as for providing a basis for understanding how patterns of distribution of vegetation communities that comprise montane forest ecosystems may change in the future. Unplanned consequential adaptation of both natural and human systems, i.e. autonomous adaptation, will occur without planned intervention, with potentially negative impacts on ecosystem services. The persistence of forest stands under changing fire regimes and the maintenance of the ecosystem services that they provide pivot upon underlying response traits, such as the ability to resprout, that determine the degree to which composition, structure and function are likely to change. The integration of ecosystem dynamics into conceptual models and their use in exploring adaptation pathways provides options for policy makers and managers to move from autonomous to planned adaptation responses. Understanding where autonomous adaptation provides a benefit and where it proves potentially undesirable is essential to inform adaptation choices. Plausible scenarios of ecological change can be developed to improve an understanding of the nature and timing of interventions and their consequences, well before natural and human systems autonomously adapt in ways that may be detrimental to the long-term provision of ecosystem services. We explore the utility of this approach using examples from temperate montane forest ecosystems of southeastern Australia. [ABSTRACT FROM AUTHOR]

To investigate the impact of invasion by Chrysanthemoides monilifera ssp. monilifera (boneseed) on plant communities, sites that were invaded and uninvaded were surveyed across Tasmania, South Australia and Victoria, Australia. Above-ground cover abundance was estimated and samples of the seed bank from invaded and uninvaded sites in each state were collected and germinated in the glasshouse. We compared species richness and composition between invaded and uninvaded sites for both above-ground and belowground samples. Across this broad geographic area, C. monilifera invaded sites had 25% fewer species than uninvaded sites and twice as many exotic species. Most growth forms showed reduced richness in invaded sites. There were no differences in the composition of native species communities between invaded and uninvaded sites in most regions, except South Australia. The composition of the seed bank differed from the above-ground vegetation, but was similar within each state. Herbs and grasses were most abundant. The species composition of the seed bank was different in invaded sites only in Victoria, suggesting that invasion may negatively influence the capacity of the seed bank to restore vegetation in some areas. However, the underlying mechanisms for the observed patterns were not tested in this study. The capacity of all sites to regenerate effectively from the seed bank was limited and, in order to ensure the conservation of biodiversity into the future, monitoring of species richness at smaller scales, particularly those where management of C. monilifera has occurred, will be needed to ensure management can facilitate the establishment of missing species. This study suggests that C. monilifera impacts a range of functional groups and different species across its distribution and is therefore non-selective in how it influences changes in communities. [ABSTRACT FROM AUTHOR]

The pentatomoid family Acanthosomatidae is best known for maternal care, and their behaviour is a favoured subject of evolutionary biologists. Despite this interest, knowledge of the taxonomy of Australian acanthosomatid is cursory and their biology has not been investigated. A significant taxonomic impediment exists for Australian acanthosomatids, and many new species await description, and when fully documented Australia will in all likelihood be the centre of diversity for this family. In line with this, the Australian acanthosomatid genus P anaetius ( Blaudusinae: Blaudusini) is revised, P . lobulatus Stål and P . trabifer Horváth are redescribed, and two new species are described: P anaetius eliasi sp. nov. and P . laevicornis sp. nov. A key to species is provided. The male and female genitalia are illustrated. The plant associations of P anaetius are documented, and a fern host plant is documented for P . eliasi. A phylogenetic analysis of P anaetius establishes its monophyly, and the ingroup relationships are fully resolved, with P . laevicornis sister to all other species of P anaetius. [ABSTRACT FROM AUTHOR]

The mechanisms of community assembly underpinning plant invasion are contested; limiting similarity predicts divergence in the traits of native and alien species whilst habitat filtering predicts trait convergence. Using site-based floristic data collected three decades apart, we ask whether the competitor-stress tolerator-ruderal ( CSR) strategies of herbaceous alien and native plant species in Australian woodlands show evidence of divergence (indicating limiting similarity) or convergence (indicating habitat filtering). We also ask whether increasing dereliction between the two sampling periods, as a result of declining fire frequency, has influenced habitat filtering processes., Null models were used to assess the similarity in CSR strategies of native and alien species in order to identify the community assembly processes driving woodland invasions. The observed frequencies of CSR types were also compared to randomly assembled communities from null models for species experiencing increases, decreases or static abundance changes between the two surveys to assess the impacts of dereliction on habitat filters., The spectrum of CSR strategies of the most common aliens ( n = 25) was highly convergent with the strategies of the most common natives ( n = 51). Competitive-ruderal species dominated the flora (> 30% of all species), and strict competitors were absent. No aliens exhibited a stress-tolerant strategy, and ruderals were more common in the alien flora (i.e. 36% vs. 18% of native species). Null models revealed differences in the CSR strategies of increaser and decreaser species at three of the ten sites examined, although none of these trends were consistent across the sites, indicating that increasing dereliction has not dramatically altered the habitat filters determining species admission., Synthesis. The similarity of CSR types between alien and native species indicates that habitat filtering is the principal community assembly process operating in the study region. We discuss our findings with respect to suggestions that limiting similarity and environmental filtering may be occurring simultaneously to structure plant communities. Species abundance changes due to dereliction were not evident as a coordinated shift in the functional composition of woodland dominants suggesting that time lags between altered management regimes (dereliction) and the functional response of species to habitat filters may still be playing out. [ABSTRACT FROM AUTHOR]

There are concerns that frequent intense fires are reducing biodiversity on the Arnhem Plateau within Kakadu National Park, northern Australia. Since the 1980s, prescribed burning in the early dry season has aimed to reduce the extent of late dry season wildfires. A programme of more strategic prescribed burning has been undertaken since 2007, aiming to increase intervals between fires affecting heathland and rain forest communities., We assess the effectiveness of prescribed burning in Kakadu's Stone Country using a Landsat satellite-derived fire history (1980-2011), in terms of achieving 'tolerable fire intervals' for dominant plant communities., Our analysis indicates that fire regimes have become substantially more favourable for biodiversity since the early 1980s. Although annual extent of burning has remained unchanged, two significant changes in fire regimes have occurred over the long term: (i) a switch from late dry season dominance to early dry season dominance and (ii) an increase in the abundance of long-unburnt vegetation, both of which are likely to benefit biodiversity. Demonstrating the statistical significance of changes associated with recent, more strategic fire management (2007-2011) is limited by the short duration of this management approach, although there is evidence of increasing abundance of long-unburnt vegetation during this time., The view that the Arnhem Plateau's fire regimes are increasingly driving biodiversity loss (due to frequent late dry season wildfires) is erroneous; they are in a more benign state now than at any time over the last three decades, most likely due to extensive use of prescribed burning., Synthesis and applications. In highly fire-prone landscapes, such as savannas, prescribed burning can be an effective means of: (i) bringing forward peak fire activity to the time of year when fire conditions are relatively mild and (ii) increasing abundance of long-unburnt vegetation. These changes are likely to favour persistence of a range of fire-sensitive communities. Our case study supports the strategic use of prescribed burning to protect fire-sensitive biota within highly fire-prone landscapes throughout the world. [ABSTRACT FROM AUTHOR]

The conifer Agathis australis ( New Zealand kauri; Araucariaceae) has a significant influence on soil processes beneath its canopies, reducing soil pH, stalling nitrogen cycling processes, and sometimes forming podzols. Distinctive plant species assemblages have been anecdotally observed to occur in association with A. australis stands; however, the authenticity of these proposed associations has not been formally assessed. Owing to the effects of A. australis on its soil environment and the recorded vegetation patterns, we hypothesized that this species may act as a foundation species, playing a significant role in structuring plant community composition in its vicinity. To test this, we investigated the influence of proximity to A. australis on plant community composition at stand and individual tree scales. We also investigated compositional variation with distance from the conifer Dacrydium cupressinum (rimu, Podocarpaceae) within the same forests to directly compare A. australis effects to those of another large conifer. We examined changes in stand composition relative to the abundance of each of these conifers at two forests, and measured changes in environmental conditions and plant composition with increasing distance from mature individuals at one of the same and one other study site. The organic soil formed beneath A. australis individuals was highly acidic, with high levels of NH4-N, carbon and total nitrogen, but low levels of NO3-N. We recorded a difference in species composition in the vicinity of A. australis compared to forest without this species in the same environment, describing three groups of species: stress-tolerant species dependent on the presence of A. australis within mature forest; those dependent on areas with A. australis absent; and those with distributions unaffected by A. australis presence. Such effects on the abiotic and biotic environments were not recorded in the vicinity of individuals of D. cupressinum. These results highlight the substantial effect that A. australis has in enhancing landscape-scale habitat heterogeneity and influencing overall forest diversity. [ABSTRACT FROM AUTHOR]

Ecologists have long been concerned that contemporary fire regimes of central Australia have poor consequences for some plant species, vegetation communities and the native animals they support. Fire frequency, size and intensity (the 'fire regime') have all been implicated in the decline of native biota and in vegetation changes that potentially constitute ecological drift. However, not all perceived declines and changes are quantified or proven. The fire regimes themselves defy quantification and are arguably unknowable. We examine the relationships between fire, vegetation and the physical landscape and consider the adequacy of available knowledge for guiding fire management. Devising targeted 'fire management regimes', which take into account vegetation type and management objectives such as pastoral production, conservation and cultural observance, and which actively use fire to achieve those objectives, is a more realistic goal than controlling unquantifiable fire regimes in spatially diverse landscapes. [ABSTRACT FROM AUTHOR]

Aim Many mangrove communities form bands parallel to the shoreline with each community dominated by a single species. However, the key determinants of mangrove species distribution across the intertidal zone are not well understood. We aimed to quantify the relationship between species' dominance and the hydroperiod (defined as the duration of inundation in a year), soil salinity and the salinity of inundating water for three dominant species, Sonneratia alba, Rhizophora stylosa and Ceriops tagal. Location An extensive (20,000 ha), largely intact mangrove forest in northern Australia, of some note as mangrove forests are threatened globally. Methods We related species dominance to the explanatory variables by applying two statistical modelling approaches: generalized linear models ( GLMs), where a set of competing models were evaluated; and boosted regression tree models ( BRTs), an approach that automatically captures interactions and nonlinear relationships between variables. Results Both GLM and BRT models achieved strong predictive performance for all species based on cross-validation, with receiver operating characteristics above 0.85 for all species, and 88% of deviance explained for S. alba, 42% for R. stylosa and 35% for C. tagal. All models indicated that the hydroperiod was the key variable influencing distribution, followed by soil salinity. The salinity of inundating water was the least informative variable in the models. Ecological space, determined by gradients in hydroperiod and soil salinity, was partitioned between the three species with little overlap. Main conclusions As anticipated changes in sea level will alter the hydroperiod, our findings are critical for global forecasting of future distributions of mangrove communities, and for the design of mitigation and adaptation measures. [ABSTRACT FROM AUTHOR]

It is anticipated that anthropogenic climate change will lead to substantial reassembly within communities in coming decades as individual species shift their ranges to track optimal conditions for growth and survival. As species are lost and gained in communities, what are the consequences for functional trait diversity? Functional traits are the characteristics of species that affect individual performance and provide the vital link between biodiversity at the species level and ecosystem function. We investigated how projected changes in species richness in plant communities under climate change scenarios for the decade 2050 will affect the distribution and diversity of five functional traits. We aggregated range change projections made in Maxent for the decade 2050 across all species in the regional pool of littoral rainforest vines in eastern Australia (n = 163 species). The effect of richness changes on trait diversity was assessed in nine rainforest reserves along the east coast of Australia. Although richness was predicted to significantly decline across all communities, functional diversity remained stable, indicating a decoupling in response to climate change at these two different levels of biological organization. A high degree of redundancy in trait composition in communities may buffer against the loss of function in these plant communities. Scaling-up our understanding of the impact of climate change from the species level to communities is a critical step towards developing conservation strategies aimed at preserving ecosystem function. [ABSTRACT FROM AUTHOR]

1. Understanding the processes that structure community assembly across landscapes is fundamental to ecology and for predicting and managing the consequences of anthropogenically induced changes to ecosystems. 2. We assessed the community similarity of fish, macroinvertebrate and vegetation communities against geographic distances ranging from 4 to 480 km (i.e. distance-decay relationships) to determine the balance between local environmental factors and regional dispersal processes, and thus whether species-sorting (niche processes) or dispersal limitation (neutral processes) was more important in structuring these assemblages in Australia's wet-dry tropics. We investigated whether the balance between niche and dispersal processes depended on the degree of hydrological connectivity, predicting that dispersal processes would be more important at connected sites, and also whether there was spatial concordance among these three assemblage types. 3. There was significant but weak spatial concordance among the study communities, suggesting limited potential for surrogacy among them. Distance-decay in community similarity was not observed for any study assemblage at perennial sites, suggesting dispersal was not limiting and assemblages were structured more strongly by local niche processes at these connected sites. At intermittent sites, weak distance-decay relationships for each assemblage type were confounded by significant relationships with environmental dissimilarity, suggesting that dispersal limitation contributed, albeit weakly, to niche processes in structuring our three study assemblages at disconnected sites. 4. Two environmental factors, flow regime and channel width, explained significant proportions of variation in all three assemblages, potentially contributing to the observed spatial concordance between them and representing local environmental gradients along which these communities re-assemble after the wet season, according to niche rather than dispersal processes. [ABSTRACT FROM AUTHOR]

1. Changes to the natural flow regime of a river caused by flow regulation may affect waterborne seed dispersal (hydrochory), and this may be an important mechanism by which regulation affects riverine plant communities. We assessed the effect of altered timing of seasonal flow peaks on hydrochory and considered the potential implications for plant recruitment. 2. We sampled hydrochory within five lowland rivers of temperate Australia, three of which are regulated by large dams. These dams are operated to store winter and spring rains and release water in summer and autumn for agriculture. At three sites on each river, hydrochory was sampled monthly for 12 months using passive drift nets. The contents of the drift samples were determined using the seedling-emergence method. 3. More than 33 000 seedlings from 142 taxa germinated from the samples. In general, more seeds and taxa were observed in the drift at higher flows. By altering the period of peak flows from winter-spring to summer-autumn, flow regulation similarly affected the period of peak seed dispersal. The effect of regulation on seed dispersal varied between taxa depending on their timing of seed release and whether or not they maintain a persistent soil seed bank. 4. Hydrochory in rivers is a product of flow regime and the life history of plants. By altering natural flow regimes and thus hydrochorous dispersal patterns, flow regulation is likely to affect adversely the recruitment of native plant species with dispersal phenologies adapted to natural flow regimes (such as many riparian trees and shrubs) and encourage the spread of non-native (exotic) species. 5. Changes to hydrochorous dispersal patterns are an important mechanism by which altered flow timing affects riverine plant communities. Natural seasonal flow peaks (in this case spring) are likely to be important for the recruitment of many native riparian woody taxa. [ABSTRACT FROM AUTHOR]

Restoration of native vegetation often focuses on the canopy layer species, with the assumption that regeneration of the understory elements will occur as a consequence. The goal of this study was to assess the influence of canopy restoration on the composition and abundance of understory plant species assemblages along riparian margins in the Hunter Valley, NSW, Australia. We compared the floristic composition (richness, abundance, and diversity) of understory species between nonrevegetated (open) and canopy revegetated plots across five sites. A number of other factors that may also influence understory vegetation, including soil nutrients, proximity to main channel, and light availability, were also measured. We found that sites where the canopy had been restored had lower exotic species richness and abundance, as well as higher native species cover, but not native species richness, compared with open sites. Multivariate analysis of plots based on plant community composition showed that revegetated sites were associated with lower total species diversity, light availability, and exotic cover. This study has found that the restoration of the canopy layer does result in lower exotic species richness and cover, and higher native species cover and diversity in the understory, a desirable restoration outcome. Our results provide evidence that restoration of native canopy species may facilitate restoration of native understory species; however, other interventions to increase native species richness of the understory should also be considered as part of management practice. [ABSTRACT FROM AUTHOR]

Mallee-heath and mallee communities occur in a mosaic across large areas of south-western Australia, in topographically subdued and fire-prone landscapes. Consequently, it could be expected that these communities would have historically experienced similar fire regimes, and would respond similarly to variation in aspects of the fire regime. We studied the response of mallee-heath and mallee to time since the last fire, measuring species density, species-area relationships, diversity indices and vegetation structure. Floristic responses to time since fire accorded with the initial floristic composition model of plant succession, with declining species density and Shannon diversity with age in mallee-heath. Mallee-heath exhibited structural senescence when > approximately 45-55 years since fire, with increasing standing dead vegetation, bare ground and stagnating or declining size in sprouting Eucalyptus spp. Mallee showed no such evidence of senescence, and indeed continued to increase in stature beyond the mean fire interval but without the compositional change required to provide support for the relay floristic model of plant succession. These results indicate that mallee-heath is a fire maintained community and as such is reliant upon periodic burning to maintain diversity and vigour. Mallee, in contrast, is modified but not maintained by fire (at least over the period of time since fire examined) and hence is less susceptible to fire interval effects. Indeed, structural attributes likely to be significant for fauna habitat and carbon sequestration continue to develop in mallee unburnt for 55 years or more. Different responses to time since fire will create challenges for management, particularly in fragmented landscapes where fire potentially interacts with other threatening processes. [ABSTRACT FROM AUTHOR]

Summary Lantana ( Lantana camara) has adverse effects on plant communities across Australia. Fire, sometimes recommended as a management strategy for Lantana, is likely to have both beneficial and detrimental effects on Lantana and native trees. It is therefore important to evaluate the regeneration of Lantana-invaded woody plant communities postfire. We examined the effect of Lantana removal by herbicide spray on both Lantana density and small tree (<5 cm diameter at breast height; DBH) attributes (abundance, height, DBH and diversity) in an area previously burnt. On a subset of the data, which was not sprayed, we also examined small tree attributes along a gradient of Lantana density. The herbicide treatment of postfire Lantana regrowth significantly reduced Lantana density compared to the areas left unmanaged by herbicide and increased the stem diameter of Celery Wood ( Polyscias elegans). We found that, as Lantana stem density increased in no-spray plots, the abundance of Poison Peach ( Trema tomentosa), Celery Wood, and Eucalyptus and allied genera ( Angophora and Corymbia) decreased. In addition, height of wattles ( Acacia irrorata and A. maidenii) increased with increasing Lantana density. As postfire regeneration of Lantana reduced abundance of some species, additional control of Lantana was required to assist community regeneration. [ABSTRACT FROM AUTHOR]

Aim To examine the different uses and perceptions of introduced Australian acacias (wattles; Acacia subgenus Phyllodineae) by rural households and communities. Location Eighteen landscape-scale case studies around the world, in Vietnam, India, Réunion, Madagascar, South Africa, Congo, Niger, Ethiopia, Israel, France, Portugal, Brazil, Chile, Dominican Republic and Hawai'i. Methods Qualitative comparison of case studies, based on questionnaire sent to network of acacia researchers. Information based on individual knowledge of local experts, published and unpublished sources. Results We propose a conceptual model to explain current uses and perceptions of introduced acacias. It highlights historically and geographically contingent processes, including economic development, environmental discourses, political context, and local or regional needs. Four main groupings of case studies were united by similar patterns: (1) poor communities benefiting from targeted agroforestry projects; (2) places where residents, generally poor, take advantage of a valuable resource already present in their landscape via plantation and/or invasion; (3) regions of small and mid-scale tree farmers participating in the forestry industry; and (4) a number of high-income communities dealing with the legacies of former or niche use of introduced acacia in a context of increased concern over biodiversity and ecosystem services. Main conclusions Economic conditions play a key role shaping acacia use. Poorer communities rely strongly on acacias (often in, or escaped from, formal plantations) for household needs and, sometimes, for income. Middle-income regions more typically host private farm investments in acacia woodlots for commercialization. Efforts at control of invasive acacias must take care to not adversely impact poor dependent communities. [ABSTRACT FROM AUTHOR]

Riparian vegetation is known to affect aquatic macroinvertebrate communities through contributions of organic matter and shading. Despite the widespread degradation of riparian vegetation in Australia, there are relatively few studies examining the effect of changes in riparian vegetation on in-stream macroinvertebrate assemblages on individual catchments. In particular, information is lacking on the responses of macroinvertebrate communities in catchments dominated by agriculture, where farms that are managed at the paddock scale result in riparian vegetation condition varying over relatively short distances. In this study, macroinvertebrate assemblages were assessed from 12 reaches along a 25-km section of a small agricultural stream in south-eastern Australia. Riparian condition was assessed using in-stream coarse woody debris (CWD) levels and the rapid appraisal of riparian condition (RARC) index, a numerical system for categorising the health of riparian areas that incorporates sub-indices reflecting habitat continuity, vegetation cover, plant debris levels, native vegetation dominance, and other indicative features. There was a significant positive correlation between RARC scores and macroinvertebrate taxon richness ( p < 0.01), and also between CWD scores and macroinvertebrate taxon richness ( p < 0.05). In contrast, there was no significant correlation observed between riparian condition and the other macroinvertebrate indices (abundance, Shannon diversity, SIGNAL and SIGNAL2). Macroinvertebrate communities were significantly different in stream reaches from different riparian condition categories (ANOSIM; p < 0.05). Our results indicate that efforts to rehabilitate riparian vegetation may have a positive effect on in-stream biota even when implemented at a relatively small scale by individual landholders. [ABSTRACT FROM AUTHOR]

The invasion of Pinus radiata from long-term established plantations is contributing to the degradation of fragmented and isolated remnants of native vegetation. Within the south-east of South Australia, the 20 vegetation communities that occur within 500 m of a plantation edge are at risk, including nine state threatened communities. To plan effective mitigation strategies, the current extent and distribution of P. radiata needs to be ascertained. High spatial resolution, multispectral QuickBird imagery and aerial photography were used to classify P. radiata within eucalypt and acacia woodlands, melaleuca shrubland, modified pasture and an Eucalyptus globulus plantation. Unsupervised classification of aerial photography gave the best result showing reasonable conformity with the observed distribution of P. radiata at the site scale. However, the 9.4 ± 13.5 (SD) cover classified in the quadrats sampled for the accuracy assessment exceeded the 1.4 ± 2.4 (SD) P. radiata cover determined from an independent dataset. Only 30.1 ± 37.9% (SD) of trees within the quadrats and 9.40 ± 13.49% (SD) of their foliage cover were classified. Trees detected by partial classification of canopy were positively correlated with both tree height and canopy diameter. Overall, the low detection rates were attributed to insufficient spectral resolution. Using higher resolution imagery, together with an object-based image analysis or combination of multispectral and airborne digital image classification, restricted to large emergent adult trees using LiDAR analysis, is likely to improve adult P. radiata detection accuracy. [ABSTRACT FROM AUTHOR]

Large scale ecological restoration in a highly heterogeneous and species-rich landscape requires big commitment to fine scale planning. In the southwest of Western Australia, in the Fitz-Stirling area of Gondwana Link, the Peniup Restoration project aimed to improve on such works. A multi-faceted approach was employed to re-establish a self-replicating biologically diverse plant system, ecologically informed in its design and consistent with the heterogeneous mosaic of plant associations found in the surrounding landscape. Outcomes from the project included a 950-ha restoration map composed of nine newly developed soil landscape/vegetation associations. A new 6 m wide direct seeding machine was developed to improve delivery and spatial configuration of establishing plants. These two developments were put to the test in 2008 through a 250 ha biodiverse carbon-funded restoration effort. This paper summarises the approaches used and initial results of those works. [ABSTRACT FROM AUTHOR]

Question: The drivers of spatial patterning among plant species and the implications of those patterns for the structure and function of plant communities are of ongoing interest and debate. Here we explore the spatial patterning shown by individual species in species-rich plant communities. We (1) compare the levels of aggregation in these communities to those observed in other species-rich communities, in particular tropical rain forests, and (2) consider how abiotic conditions might influence the levels of aggregation observed. Location: We describe the spatial structure of four species-rich Mediterranean-type shrubland communities near Eneabba, Western Australia. The four sites each contain > 10 000 plants and up to 113 species, and differ in substrate-type, species richness and composition. Methods: We analysed the spatial patterning of all species with more than 20 individuals (233 species patterns), and used point process models for aggregated patterns to separate first-order gradient effects from second-order clustering. Results: Aggregated distributions were most common at all sites, but especially at the site with the highest resource availability and heterogeneity and lowest species richness. A Poisson cluster process best described the majority of aggregated species, suggesting that local interactions drive fine-scale patterns in these communities. Conclusions: As with many previous studies, we found that most species showed strong local aggregation. The proportion of species showing aggregation was less than has been described in species-rich tropical rainforests but was higher than observed in many temperate plant communities. The highest proportion of aggregated species was seen at the most resource-abundant site; this is in direct contrast to conceptual models that suggest that competition should be weakest, and aggregation most prevalent, in the most resource-limited sites. [ABSTRACT FROM AUTHOR]

To protect native biodiversity from environmental weeds, the impacts that these weeds cause need to be known before weed control commences. Asparagus asparagoides (L.) Druce (bridal creeper) (Asparagaceae) is a serious environmental weed and has been selected for biological control in Australia. To predict the responses of plant communities to the control of bridal creeper, a prerelease baseline of the impacts of bridal creeper on native plant communities was undertaken. Plant assemblages in areas invaded by bridal creeper were compared with reference areas that contained little or no bridal creeper. Areas invaded by bridal creeper contained 52% fewer native plant species when compared with nearby reference areas. However, there was no difference in the number of other exotic plant species between areas. Similar trends were found for the germinable seed bank. Although a greater number of exotic species were present in the seed bank compared with the vegetation surveys, there was still no difference between areas with and without bridal creeper. In a glasshouse trial, exotic species germinated more frequently compared with native species. This could indicate that as bridal creeper density decreases following control, exotic species have an advantage over native species when colonizing areas left vacant by bridal creeper. Second, as bridal creeper areas contained reduced native species richness and cover, they may be susceptible to further weed invasion after bridal creeper is removed. Therefore, simply reducing the presence of bridal creeper may not guarantee successful restoration of invaded areas and additional restoration efforts will be needed to ensure the ultimate goal of protecting native biodiversity is reached. [ABSTRACT FROM AUTHOR]

Human induced alterations to rivers and steams have resulted in significant changes to the structure and diversity of riparian and aquatic plant communities. These changes will impact on the dynamics of riverine carbon cycles and food web structure and function. Here we investigate the principal sources of organic carbon supporting local shredder communities across a gradient in different levels of anthropogenic development along riverine reaches, in South Australia. In forested/wooded reaches with minimum to limited development, semi-emergent macrophytes were the principal sources of organic carbon supporting the local shredder communities. However, in developed reaches, course particulate organic matter and filamentous algae were the principal food sources. The C:N ratios of the food sources in developed reaches were higher than those of their consumers indicating a stoichiometric mismatch. This imbalanced consumer-resource nutrient ratio in those developed reaches is likely to impose constraints on the growth and reproduction of their aquatic shredder communities with probable knock-on effects to higher trophic levels. [ABSTRACT FROM AUTHOR]

Various models of the species-abundance distribution (SAD) have been proposed to fit empirically derived data however there is no general consensus as to which model provides the best fit. Further, the zero-sum multinomial SAD model (ZSM) was proposed as a metacommunity model, yet it has not previously been fitted at the metacommunity scale. We note that SAD models based on compound lognormal distributions (such as the Poisson-lognormal, PLN, and the negative binomial-lognormal models, NBLN) can also be thought of as metacommunity models, and we compare these with the ZSM when fitted as metacommunity models to SADs of related communities. We collected five datasets in the Sydney Basin, eastern Australia, representing five different types of subtropical/temperate plant communities ranging from closed warm-temperate rainforest to open wet sclerophyll forest to dry sclerophyll woodland. For each type of plant community, five local communities were identified across the Sydney Basin, and SAD data collected in five randomly placed 0.2-ha quadrats at each local community. Analysis was performed at two levels: all abundance data from each local community were pooled across each metacommunity and analysed as a single pooled community; and a metacommunity model was fitted to all five local communities of a community type, simultaneously. For the pooled data, we considered the negative-binomial (NB) and the log-series (LS) models in addition to ZSM, PLN and NBLN. All five models performed similarly, however the LS had a better fit to three pooled communities and the ZSM and PLN to the remaining two communities. By contrast, the ZSM performed statistically better against the PLN and NBLN when considered as a metacommunity model. We conclude that the ZSM generally provides a more reliable null model for metacommunity abundance data than the lognormal model. [ABSTRACT FROM AUTHOR]