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Reforestation to capture and store atmospheric carbon is increasingly championed as a climate change mitigation policy response. Reforestation plantings have the potential to provide conservation co-benefits when diverse mixtures of native species are planted, and there are growing attempts to monetise biodiversity benefits from carbon reforestation projects, particularly within emerging carbon markets. But what is meant by ‘biodiverse’ across different stakeholders and groups implementing and overseeing these projects and how do these perceptions compare with long-standing scientific definitions? Here, we discuss approaches to, and definitions of, biodiversity in the context of reforestation for carbon sequestration. Our aim is to review how the concept of biodiversity is defined and applied among stakeholders (e.g., governments, carbon certifiers and farmers) and rights holders (i.e., First Nations people) engaging in reforestation, and to identify best-practice methods for restoring biodiversity in these projects. We find that some stakeholders have a vague understanding of diversity across varying levels of biological organisation (genes to ecosystems). While most understand that biodiversity underpins ecosystem functions and services, many stakeholders may not appreciate the difficulties of restoring biodiversity akin to reference ecosystems. Consequently, biodiversity goals are rarely explicit, and project goals may never be achieved because the levels of restored biodiversity are inadequate to support functional ecosystems and desired ecosystem services. We suggest there is significant value in integrating biodiversity objectives into reforestation projects and setting specific restoration goals with transparent reporting outcomes will pave the way for ensuring reforestation projects have meaningful outcomes for biodiversity, and legitimate incentive payments for biodiversity and natural capital accounting.

Current literature suggests ecological niche differentiation between co-occurring Mucoromycotinian arbuscular mycorrhizal fungi (M-AMF) and Glomeromycotinian AMF (G-AMF), but experimental evidence is limited. We investigated the influence of soil age, water availability (wet and dry), and plant species (native Microlaena stipoides and exotic Trifolium subterraneum) on anatomical root colonisation and DNA profiles of M-AMF and G-AMF under glasshouse conditions. We grew seedlings of each species in soils collected from the four stages of a soil chronosequence, where pH decreases from the youngest to oldest stages, and phosphorus (P) is low in the youngest and oldest, but high in the intermediate stages. We scored the percentage of root length colonised and used DNA metabarcoding to profile fungal richness and community composition associated with treatment combinations. Soil age, water availability, and plant species were important influencers of root colonisation, although no M-AMF were visible following staining of M. stipoides roots. Soil age and host plant influenced fungal richness and community composition. However, response to soil age, potential host species, and water availability differed between M-AMF and G-AMF. Root colonisation of T. subterraneum by M-AMF and G-AMF was inversely correlated with soil P level. Community composition of M-AMF and G-AMF was structured by soil age and, to a lesser extent, plant species. Richness of M-AMF and G-AMF was negatively, and positively, correlated with available P, respectively. These findings are experimental evidence of ecological niche differentiation of M-AMF and G-AMF and invite further exploration into interactive effects of abiotic and biotic factors on their communities along successional trajectories.

Context To establish translocated populations of threatened plants with the genetic resources to adapt to changing environmental conditions, the source of propagation material is an important consideration. Aim We investigated the fitness consequences of genetic rescue and admixture for the threatened annual daisy Schoenia filifolia subsp. subulifolia, and the common S. filifolia subsp. filifolia, to inform seed-sourcing strategies for translocations of the threatened subspecies. Methods We evaluated genetic diversity of two populations of S. filifolia subsp. subulifolia and four populations of S. filifolia subsp. filifolia by using microsatellite markers. We grew seedlings from each study population and cross-pollinated inflorescences within and among populations of the same subspecies, and between subspecies. We evaluated the fitness consequences of each cross by using seed set, seed weight and seed viability. Key results There was a lower genetic diversity in the small (10 000 plants, Nar = 4.42, He = 0.51) population of S. filifolia subsp. subulifolia, although none of the measures was significantly different, and seed fitness was slightly, although not significantly, reduced in interpopulation crosses compared with the small population. Genetic diversity was similar between the threatened and widespread subspecies; however, the subspecies were genetically divergent (Fst = 0.242–0.294) and cross-pollination between subspecies produced negligible amounts of seeds (

Purpose Degraded ecosystems can be maintained by abiotic and biotic legacies long after initial disturbances, preventing recovery. These legacies can include changes in arbuscular mycorrhizal fungi (AMF). To inform potential restoration pathways, we aimed to elucidate differences in AMF between intact and degraded ecosystems, their responses to modified soils, and interactions with invasive plants. Methods We used a state-and-transition framework to characterise AMF communities, native and exotic plant cover, and soil physicochemical properties across little-modified reference states and degraded states, which were carbon (C) and nitrogen (N) -depleted, intermediate, and CN-enriched, in temperate eucalypt woodlands of south-eastern Australia. Results Most ground-layer states differed significantly in their AMF communities, with the CN-enriched states being most distinct. All states had unique taxa and characteristic indicator taxa, but intermediate and CN-enriched states harboured four-to-five times more indicator taxa than the reference state. Consistent with this, richness of AMF was higher in the intermediate and CN-enriched states than in reference states, driven by higher richness of Archaeosporaceae, Diversisporaceae, Glomeraceae, and Paraglomeraceae. Pathway analysis indicated that differences in AMF communities among states were strongly related to differences in native:exotic plant cover ratio, mediated by soil organic matter and nutrients. Conclusion Our results indicate that ecosystem degradation is associated with both loss of AMF taxa and introduction of ‘weedy’ AMF, which in turn potentially contribute to maintenance of degraded ecosystems. We argue that our state-and-transition approach to characterising AMF communities improved our understanding of the different pathways of degradation, elucidating possible constraints to ecosystem recovery.

Highly diverse plant communities growing on nutrient-impoverished soils are test beds for theories on species coexistence. Here, neighbouring mycorrhizal and non-mycorrhizal plants compete for limited phosphorus. The impact of below-ground interactions on community dynamics is underexplored. We used an experimental approach to investigate effects of inoculation with arbuscular mycorrhizal (AM) fungi and a phosphorus supply gradient on competitive and facilitative interactions among mixed assemblages of woody plants in microcosms. The plant species, one cluster root-forming (CR) species and four AM species, are native to jarrah forest that grows on nutrient-impoverished soils in south-western Australia. We measured plant growth in microcosms, with and without inoculation with the AM fungus Rhizophagus irregularis, and across a gradient of P supply: 0, 9, 27 and 243 mg P per kg of soil. Our data show evidence of plant–plant facilitation at low P supply and competition at high P supply. Growth of the CR species, Hakea undulata, was highest in microcosms with 0P and without AM inoculation. One AM species, Bossiaea aquifolium, also performed better at lower P levels, possibly benefitting from P mobilised by H. undulata. The other three AM species, one strongly obligates, performed better at higher P levels. Data for Acacia celastrifolia suggested it was facultatively mycotropic, and because there was no correlation between AM colonisation and the relative inoculum effect, we suggest positive effects of AM inoculation at 9P might be due to benefits other than P acquisition, such as pathogen defence. Benefit of AM inoculation diminished for three of four mycorrhizal species at the highest P level as we had predicted. The fourth species, Eucalyptus marginata (jarrah), had higher growth in microcosms that were not inoculated with AM, perhaps because the species benefits more from ectomycorrhizas. Synthesis. Our experimental data suggest spatial heterogeneity of soil P, coupled with a diversity of nutrient-acquisition strategies, and plasticity among plant–plant and plant–AM fungi interactions, contributes to plant species coexistence in the nutrient-impoverished jarrah forest. Our research highlights the importance of below-ground mechanisms for understanding factors determining community structure including a potential role of AM fungi in plant pathogen defence.

The amount of nitrogen (N) derived from symbiotic N2 fixation by legumes in grasslands might be affected by anthropogenic N and phosphorus (P) inputs, but the underlying mechanisms are not known. Methods We evaluated symbiotic N2 fixation in 17 natural and semi-natural grasslands on four continents that are subjected to the same full-factorial N and P addition experiment, using the 15N natural abundance method. Results N as well as combined N and P (NP) addition reduced aboveground legume biomass by 65% and 45%, respectively, compared to the control, whereas P addition had no significant impact. Addition of N and/or P had no significant effect on the symbiotic N2 fixation per unit legume biomass. In consequence, the amount of N fixed annually per grassland area was less than half in the N addition treatments compared to control and P addition, irrespective of whether the dominant legumes were annuals or perennials. Conclusion Our results reveal that N addition mainly impacts symbiotic N2 fixation via reduced biomass of legumes rather than changes in N2 fixation per unit legume biomass. The results show that soil N enrichment by anthropogenic activities significantly reduces N 2 fixation in grasslands, and these effects cannot be reversed by additional P amendment. EEA Santa Cruz Fil: Vázquez, Eduardo. University of Bayreuth. Department of Soil Ecology. Bayreuth Center of Ecology and Environmental Research (BayCEER); Alemania Fil: Vázquez, Eduardo. Swedish University of Agricultural Sciences. Department of Soil and Environment; Suecia Fil: Schleuss, Per‑Marten. University of Bayreuth. Department of Soil Ecology. Bayreuth Center of Ecology and Environmental Research (BayCEER); Alemania Fil: Borer, Elizabeth T. University of Minnesota. Department of Ecology, Evolution, and Behavior; Estados Unidos Fil: Bugalho, Miguel N. University of Lisbon. Centre for Applied Ecology “Prof. Baeta Neves” (CEABN-InBIO). School of Agriculture; Portugal. Fil: Caldeira, Maria. C. University of Lisbon. Forest Research Centre. School of Agriculture; Portugal. Fil: Eisenhauer, Nico. German Centre for Integrative Biodiversity Research; Alemania Fil: Eisenhauer, Nico. Leipzig University. Institute of Biology; Alemania Fil: Eskelinen, Anu. German Centre for Integrative Biodiversity Research; Alemania Fil: Eskelinen, Anu. Physiological Diversity, Helmholtz Centrefor Environmental Research; Alemania Fil: Eskelinen, Anu. University of Oulu. Ecology & Genetics; Finlandia Fil: Fay, Philip A. Grassland Soil and Water Research Laboratory (USDA-ARS); Estados Unidos Fil: Haider, Sylvia. German Centre for Integrative Biodiversity Research; Alemania Fil: Haider, Sylvia. Martin Luther University. Institute of Biology. Geobotany and Botanical Garden; Alemania Fil: Jentsch, Anke. University of Bayreuth. Department of Soil Ecology. Bayreuth Center of Ecology and Environmental Research (BayCEER); Alemania Fil: Kirkman, Kevin P. University of KwaZulu-Natal. School of Life Sciences; Sudáfrica Fil: McCulley, Rebecca L. University of Kentucky. Department of Plant and Soil Sciences; Estados Unidos Fil: Peri, Pablo Luis. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina. Fil: Peri, Pablo Luis. Universidad Nacional de la Patagonia Austral; Argentina. Fil: Peri, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Fil: Price, Jodi. Charles Sturt University. Institute for Land, Water and Society; Australia. Fil: Richards, Anna E. CSIRO Land and Water. Northern Territory; Australia. Fil: Risch, Anita C. Swiss Federal Institute for Forest, Snow and Landscape Research WSL; Suiza Fil: Roscher, Christiane. German Centre for Integrative Biodiversity Research; Alemania Fil: Roscher, Christiane. Physiological Diversity, Helmholtz Centre for Environmental Research; Alemania Fil: Schütz, Martin. Swiss Federal Institute for Forest, Snow and Landscape Research WSL; Suiza Fil: Seabloom, Eric William. University of Minnesota. Dept. of Ecology, Evolution, and Behavior; Estados Unidos Fil: Standish, Rachel J. Murdoch University. Harry Butler Institute; Australia. Fil: Stevens, Carly J. Lancaster University. Lancaster Environment Centre; Reino Unido Fil: Tedder, Michelle J. University of KwaZulu-Natal. School of Life Sciences; Sudáfrica Fil: Virtanen, Risto. University of Oulu. Ecology & Genetics; Finlandia. Fil: Spohn, Marie. University of Bayreuth. Department of Soil Ecology. Bayreuth Center of Ecology and Environmental Research (BayCEER); Alemania Fil: Spohn, Marie. Swedish University of Agricultural Sciences. Department of Soil and Environment; Suecia

Restoration of old fields in agricultural landscapes has become increasingly important for conservation of species and their habitats owing to habitat destruction and rapid environmental change. Studies examining the outcomes of old field restoration predominantly focus on plant, and sometimes, vertebrate communities. Fewer studies have systematically investigated the effects of restoration efforts on soil properties or ground‐dwelling invertebrates and there is limited synthesis of these data. We conducted a global meta‐analysis of published studies to assess the effects of old field restoration on soil properties and soil invertebrate abundance and richness. We anticipated increased vegetation cover would improve soil properties towards reference condition and in turn, this would promote invertebrate abundance and richness. Studies were included if field sites had a history of cropping or livestock grazing. We identified 42 studies (1994–2019) from 16 countries that met our criteria. More studies assessed passive restoration methods than active planting, and native species were more commonly planted than exotic species. Results showed that restoration improved soil conditions with respect to total nitrogen, magnesium, soil carbon, bulk density and porosity when compared to controls; however, conditions similar to those in reference ecosystems were generally not achieved, even 50+ years after restoration had been initiated. Moderator analyses showed few significant tends, however, bulk density improved with age, and in passively restored versus reference ecosystems. Outcomes for soil carbon and bulk density were most predominant in the top soil when compared to the degraded ecosystem. We detected no consistent trends for the effect of restoration on soil invertebrate richness and abundance compared to the control or reference ecosystems. Synthesis and applications. Our global meta‐analysis found strong evidence that old field restoration in agricultural landscapes had positive effects on soil condition but did not lead to full recovery when compared to a reference ecosystem. We detected few and idiosyncratic effects for invertebrates. Further research is needed to understand effects of restoration on soil invertebrate functional groups and to develop management interventions that accelerate the restoration of soil condition.

Global assessments show biodiversity has already declined beyond ‘safe limits’ across most biomes, calling for large‐scale conservation and restoration interventions. At the same time, the potential and emerging catastrophic impacts of accelerated climate change have led to increasing investment in climate change mitigation efforts through maintaining or sequestering carbon in vegetation biomass, particularly woodlands and forests. This raises the challenge of whether these climate change mitigation investments can concurrently contribute to ameliorating the biodiversity crisis. However, the assumption of industry observers is that tree monocultures will sequester more carbon than biodiverse plantings, that is, there is a carbon‐biodiversity trade‐off. Here, we review experimental and observational evidence to examine whether a biodiversity trade‐off is necessary to maximise carbon credits. We apply the findings to the four types of Australian vegetation projects that have been registered with the Australian Government’s Emissions Reduction Fund since 2012: avoided deforestation, managed regeneration, farm forestry and tree planting. We find limited evidence in the biodiversity‐ecosystem function literature for a trade‐off between biodiversity and carbon stored in above‐ground vegetation biomass; rather we find evidence for neutral or positive relationships. Further, additional benefits of plant diversity to carbon storage, rarely accounted for in vegetation projects, include increased soil carbon storage, stability and ecological resilience to disturbances. Our findings suggest opportunities for enhancing biodiversity in vegetation projects, for example through more diverse plantings, or manipulation of herbivores or plant propagules in avoided deforestation and managed regeneration projects. More research is needed to understand the contribution of faunal diversity to ecosystem functions and to manage fire in vegetation projects. We conclude that vegetation projects can aim to benefit biodiversity without compromising carbon credits.

Professor Richard Hobbs has had a profound influence on the development of the discipline of restoration ecology. With more than 300 publications spanning a broad scope of applied ecological sciences, he has collaborated with hundreds of researchers. His sometimes‐provocative insights, balanced by extensive empirical research, will have a lasting impact by encouraging people to think more broadly about the science and practice of ecological restoration. Here, on the eve of his retirement, some of his staff and students, past and present, take a retrospective look at his contributions to restoration ecology both as a scientist and as a mentor.

Globally, agricultural land-use negatively affects soil biota that contribute to ecosystem functions such as nutrient cycling, yet arbuscular mycorrhizal fungi (AMF) are promoted as essential components of agroecosystems. Arbuscular mycorrhizal fungi include Glomeromycotinian AMF (G-AMF) and the arbuscule-producing fine root endophytes, recently re-classified into the Endogonales order within Mucoromycotina. The correct classification of Mucoromycotinian AMF (M-AMF) and the availability of new molecular tools can guide research to better the understanding of their diversity and ecology. To investigate the impact on G-AMF and M-AMF of agricultural land-use at a continental scale, we sampled DNA from paired farm and native sites across 10 Australian biomes. Glomeromycotinian AMF were present in both native and farm sites in all biomes. Putative M-AMF were favoured by farm sites, rare or absent in native sites, and almost entirely absent in tropical biomes. Temperature, rainfall, and soil pH were strong drivers of richness and community composition of both groups, and plant richness was an important mediator. Both fungal groups occupy different, but overlapping, ecological niches, with M-AMF thriving in temperate agricultural landscapes. Our findings invite exploration of the origin and spread of M-AMF and continued efforts to resolve the phylogeny of this newly reclassified group of AMF.

Background and aims:The amount of nitrogen (N) derived from symbiotic N2 fixation by legumes in grasslands might be affected by anthropogenic N and phosphorus (P) inputs, but the underlying mechanisms are not known. Methods:We evaluated symbiotic N2 fixation in 17 grasslands on four continents that are subjected to the same full-factorial N and P addition experiment, using the 15N natural abundance method.Results:N as well as combined N and P (NP) addition reduced legume biomass by 65% and 45%, respectively, compared to the control, whereas P addition had no significant impact. Element addition had no significant effect on the symbiotic N2 fixation per unit legume biomass. In consequence, the amount of N fixed annually per grassland area was less than half in the N addition treatments compared to control and P addition, irrespective of whether the dominant legumes were annuals or perennials. Conclusion:Our results reveal that N addition mainly impacts symbiotic N2 fixation via reduced biomass of legumes rather than changes in N2 fixation per unit legume biomass. The results show that soil N enrichment by anthropogenic activities significantly reduces N2 fixation in the world’s grasslands, and these effects cannot be reversed by additional P amendment.

Aims Fertiliser is often used to kick-start ecological restoration despite growing evidence of the potentially negative impacts on plant diversity. Jarrah (Eucalyptus marginata) forest species growing on nutrient (especially phosphorus) impoverished soils in southwestern Australia have a suite of adaptations for phosphorus (P) acquisition, including the formation of cluster roots, and associations with mycorrhizal fungi. Here we investigated how escalating P supply, along with a stoichiometric adjustment of nitrogen (N) supply, impacted the growth and nutrition of a wide range of jarrah forest seedlings. Methods In a pot experiment, we measured seedling biomass and nutritional responses of 12 jarrah forest species to a gradient of P supply in relation to N supply, and for the mycorrhizal species, inoculation with arbuscular mycorrhizal fungi. Results Three cluster-root forming species did not respond to increasing P, probably because they were reliant on seed P. Generally, mycorrhizal species showed a positive biomass response to increasing P when N was available. Mycorrhizas benefited seedling growth at low P (9 mg P added per kg of jarrah forest soil) when N was also available, and were parasitic to seedling growth at high P (243 mg P/ kg soil) without additional N. Conclusions These results highlight importance of P and N supply in determining the nature of the symbiosis between plants and mycorrhizal fungi. Since P supply has the potential to reduce plant growth, for a range of species, our results suggest careful consideration of fertiliser amounts for ecological restoration of ecosystems adapted to nutrient poor soils.

Food systems are primary drivers of human and environmental health, but the understanding of their diverse and dynamic co-transformation remains limited. We use a data-driven approach to disentangle different development pathways of national food systems (i.e. ‘transformation archetypes’) based on historical, intertwined trends of food system structure (agricultural inputs and outputs and food trade), and social and environmental outcomes (malnutrition, biosphere integrity, and greenhouse gases emissions) for 161 countries, from 1995 to 2015. We found that whilst agricultural total factor productivity has consistently increased globally, a closer analysis suggests a typology of three transformation archetypes across countries: rapidly expansionist, expansionist, and consolidative. Expansionist and rapidly expansionist archetypes increased in agricultural area, synthetic fertilizer use, and gross agricultural output, which was accompanied by malnutrition, environmental pressures, and lasting socioeconomic disadvantages. The lowest rates of change in key structure metrics were found in the consolidative archetype. Across all transformation archetypes, agricultural greenhouse gases emissions, synthetic fertilizer use, and ecological footprint of consumption increased faster than the expansion of agricultural area, and obesity levels increased more rapidly than undernourishment decreased. The persistence of these unsustainable trajectories occurred independently of improvements in productivity. Our results underscore the importance of quantifying the multiple human and environmental dimensions of food systems transformations and can serve as a starting point to identify potential leverage points for sustainability transformations. More attention is thus warranted to alternative development pathways able of delivering equitable benefits to both productivity and to human and environmental health.

Biotic and abiotic factors interact with dominant plants—the locally most frequent or with the largest coverage—and nondominant plants differently, partially because dominant plants modify the environment where nondominant plants grow. For instance, if dominant plants compete strongly, they will deplete most resources, forcing nondominant plants into a narrower niche space. Conversely, if dominant plants are constrained by the environment, they might not exhaust available resources but instead may ameliorate environmental stressors that usually limit nondominants. Hence, the nature of interactions among nondominant species could be modified by dominant species. Furthermore, these differences could translate into a disparity in the phylogenetic relatedness among dominants compared to the relatedness among nondominants. By estimating phylogenetic dispersion in 78 grasslands across five continents, we found that dominant species were clustered (e.g., co‐dominant grasses), suggesting dominant species are likely organized by environmental filtering, and that nondominant species were either randomly assembled or overdispersed. Traits showed similar trends for those sites (, We found a prevalent disparity between the dominant and nondominant species (measured as the standardized effect size of the mean nearest taxonomic distance), with the former more clustered than the latter, suggesting a disparity in the mechanisms organizing both groups. We also found several clades more likely to have nondominant species than dominant species, measured as the probability of finding a species of a given clade among the third less abundant species in the sites where that clade occurred. Unexpectedly, many nondominant clades have a large number of species, mainly were comprised of nonwoody species, and often appeared in the phylogeny. Together, these findings suggest dominance and nondominance are conserved and that their differences have ecological consequences.

Understanding constraints to ecological restoration on former agricultural land has become increasingly important due to agricultural land degradation in the developed world, and growing evidence for enduring agricultural legacies that limit native species recovery. In particular, the removal of native plant biomass and subsequent disturbance of soil properties through farming activities can alter soil ecosystem processes. Planting of native plant species is a common approach to restoring native vegetation on agricultural land and is assumed to benefit soil ecosystem processes, but the degree to which altered soil chemical processes recover is poorly documented. We investigated recovery of soil chemical properties after restoration in semiarid Western Australia, hypothesizing that elevated nutrient concentrations would gradually decline post planting, but available phosphorus (P) concentrations would remain higher than reference conditions. We used a space-for-time substitution approach, comparing 10 planted old field plots with matched fallow cropland and reference woodlands. Sampling on planted old fields and reference woodland plots was stratified into open patches and under tree canopy to account for consistent differences between these areas. The most prominent legacy of cropping was significantly and substantially higher concentrations of soil available P in fallow croplands and restored old fields compared with reference woodlands. Soil mineral nitrogen (N) concentrations were elevated in fallow croplands compared to open patches in reference woodlands (ammonium and nitrate) and under the tree canopy (ammonium). However, in restored old fields, mineral N concentrations were similar to woodland sites, providing evidence for amelioration over time. No significant differences in nutrient concentrations under tree canopies compared with open patches had developed in the planted old fields, despite a distinction between open patches and he under ttree canopy in reference woodlands for total N. We conclude that soil P legacies in old fields may inhibit the recolonization of native species that are sensitive to, or uncompetitive at, elevated P concentrations. To achieve full recovery, further research is required to test restoration practices aimed at reducing soil P concentrations to facilitate native plant establishment and persistence.

Ensuring ecosystem resilience is an intuitive approach to safeguard the functioning of ecosystems and hence the future provisioning of ecosystem services (ES). However, resilience is a multi-faceted concept that is difficult to operationalize. Focusing on resilience mechanisms, such as diversity, network architectures or adaptive capacity, has recently been suggested as means to operationalize resilience. Still, the focus on mechanisms is not specific enough. We suggest a conceptual framework, resilience trinity, to facilitate management based on resilience mechanisms in three distinctive decision contexts and time-horizons: i) reactive, when there is an imminent threat to ES resilience and a high pressure to act, ii) adjustive, when the threat is known in general but there is still time to adapt management, and iii) provident, when time horizons are very long and the nature of the threats is uncertain, leading to a low willingness to act. Resilience has different interpretations and implications at these different time horizons, which also prevail in different disciplines. Social ecology, ecology, and engineering are often implicitly focussing on provident, adjustive, or reactive resilience, respectively, but these different notions and of resilience and their corresponding social, ecological, and economic trade-offs need to be reconciled. Otherwise, we keep risking unintended consequences of reactive actions, or shying away from provident action because of uncertainties that cannot be reduced. The suggested trinity of time horizons and their decision contexts could help ensuring that longer-term management actions are not missed while urgent threats to ES are given priority.

Restoring nutrients lost in the mining process and re-establishing nutrient-cycling are often key goals of mine restoration. One common strategy to facilitate these goals is to seed fast-growing legumes combined with one application of P-fertiliser to maximise legume growth and increase soil-N. However, the longer term effects of this strategy have received little attention. Here we report the results of a 15-year-old experiment that was established to test the effects of fertiliser-P application and seeding large understorey legumes, both singly and in combination, on jarrah forest restoration after bauxite mining. Fifteen years after the establishment of this experiment, the majority of the seeded legumes had senesced, with total legume cover having declined significantly compared with results of the same experiment at 5-years-of-age. Yet, despite the legumes having senesced there were still negative effects of both large legumes and P-fertiliser on species richness and abundance of non-leguminous understorey species. These negative effects may be mediated by the persistent effects of legume competition that was evident at 5 years and the accumulation of significant quantities of leaf litter and fine woody debris in the large legume × P-addition treatments. Compared with the 0 kg P ha−1 treatment, application of 20 kg P ha−1 significantly increased jarrah tree growth, but there was no additional benefit of 80 kg P ha−1. These data suggest that moderation of P-fertiliser and large understorey legumes could maximise understorey cover, tree growth and understorey species richness, and therefore simultaneously address multiple key restoration goals.

Anthropogenic nutrient enrichment is driving global biodiversity decline and modifying ecosystem functions. Theory suggests that plant functional types that fix atmospheric nitrogen have a competitive advantage in nitrogen-poor soils, but lose this advantage with increasing nitrogen supply. By contrast, the addition of phosphorus, potassium, and other nutrients may benefit such species in low-nutrient environments by enhancing their nitrogen-fixing capacity. We present a global-scale experiment confirming these predictions for nitrogen-fixing legumes (Fabaceae) across 45 grasslands on six continents. Nitrogen addition reduced legume cover, richness, and biomass, particularly in nitrogen-poor soils, while cover of non-nitrogen-fixing plants increased. The addition of phosphorous, potassium, and other nutrients enhanced legume abundance, but did not mitigate the negative effects of nitrogen addition. Increasing nitrogen supply thus has the potential to decrease the diversity and abundance of grassland legumes worldwide regardless of the availability of other nutrients, with consequences for biodiversity, food webs, ecosystem resilience, and genetic improvement of protein-rich agricultural plant species.

Aim The importance of restoring ecosystem functions to native systems that have been degraded, damaged or destroyed is increasingly recognised. Yet few studies have measured the effect of restoration efforts on ecosystem functioning or the functional diversity (FD) that underpins it. Here we assessed change in FD of restored assemblages one to 25 years after the onset of post-mine restoration. Location Northern Jarrah (Eucalyptus marginata Donn ex Sm.) Forest bioregion of southwestern Australia. Methods Functional richness, evenness, divergence and dispersion were derived from five plant functional traits relevant to community reassembly. Effects of three explanatory variables (i.e. age, year restoration was initiated, and time since fire) on six response variables (i.e. four FD indices, species richness, and compositional similarity to nearby reference forest) were analysed using linear mixed models for a data set with repeated measures of plots through time (n = 810 plots), and linear models for a subset of one-time measures of different aged assemblages (i.e. space-for-time approach; n = 490 plots). Results Functional evenness and functional dispersion increased with age, while functional divergence and functional richness decreased with age. Functional dispersion increased with time since fire, while functional richness decreased with time since fire. Species richness decreased with age, but at 25 years, species richness was comparable to that observed in reference forest. In contrast, similarity showed no relationship with age of restored forest, and at 25 years, similarity of restored forest to reference was low compared with similarity of reference forest to itself. Three of four FD indices had not reached those of reference jarrah forest 25 years after restoration had been initiated. Conclusions Reassembly of FD suggests importance of environmental filtering and high functional redundancy. A longer time frame may be needed to assess FD of restored assemblages, and in the meantime, species richness is not an adequate surrogate of FD.

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.

1. Ecological restoration increasingly aims at improving ecosystem multifunctionality and making landscapes resilient to future threats, especially in biodiversity hotspots such as Mediterranean-type ecosystems. Plants and their traits play a major role in the functioning of an ecosystem. Therefore, successful restoration towards long-term multifunctionality requires a fundamental mechanistic understanding of this link under changing climate. An integrated approach of empirical research and simulation modelling with a focus on plant traits can allow this understanding. 2. Based on empirical data from a large-scale restoration project in a Mediterranean-type ecosystem in Western Australia, we developed and validated the spatially explicit simulation model Modelling Ecosystem Functions and Services based on Traits (ModEST), which calculates coupled dynamics of nutrients, water and individual plants characterised by functional traits. We then simulated all possible combinations of eight plant species with different levels of diversity to assess the role of plant diversity and traits on multifunctionality, the provision of six ecosystem functions that can be linked to ecosystem services, as well as trade-offs and synergies among the functions under current and future climatic conditions. 3. Our results show that multifunctionality cannot fully be achieved because of trade-offs among functions that are attributable to sets of traits that affect functions differently. Our measure of multifunctionality was increased by higher levels of planted species richness under current, but not future climatic conditions. In contrast, single functions were differently impacted by increased plant diversity and thus the choice and weighting of these functions affected multifunctionality. In addition, we found that trade-offs and synergies among functions shifted with climate change due to different direct and indirect (mediated via community trait changes) effects of climate change on functions. 4. Synthesis and application. With our simulation model Modelling Ecosystem Functions and Services based on Traits (ModEST), we show that restoration towards multifunctionality might be challenging not only under current conditions but also in the long-term. However, once ModEST is parameterised and validated for a specific restoration site, managers can assess which target goals can be achieved given the set of available plant species and site-specific conditions. It can also highlight which species combinations can best achieve long-term improved multifunctionality due to their trait diversity.

Ecological restoration increasingly aims at improving ecosystem multifunctionality and making landscapes resilient to future threats, especially in biodiversity hotspots such as Mediterranean-type ecosystems. Successful realisation of such a strategy requires a fundamental mechanistic understanding of the link between ecosystem plant composition, plant traits and related ecosystem functions and services, as well as how climate change affects these relationships. An integrated approach of empirical research and simulation modelling with focus on plant traits can allow this understanding.Based on empirical data from a large-scale restoration project in a Mediterranean-type climate in Western Australia, we developed and validated the spatially explicit simulation model ModEST, which calculates coupled dynamics of nutrients, water and individual plants characterised by traits. We then simulated all possible combinations of eight plant species with different levels of diversity to assess the role of plant diversity and traits on multifunctionality, the provision of six ecosystem functions (covering three ecosystem services), as well as trade-offs and synergies among the functions under current and future climatic conditions.Our results show that multifunctionality cannot fully be achieved because of trade-offs among functions that are attributable to sets of traits that affect functions differently. Our measure of multifunctionality was increased by higher levels of planted species richness under current, but not future climatic conditions. In contrast, single functions were differently impacted by increased plant diversity. In addition, we found that trade-offs and synergies among functions shifted with climate change.Synthesis and application. Our results imply that restoration ecologists will face a clear challenge to achieve their targets with respect to multifunctionality not only under current conditions, but also in the long-term. However, once ModEST is parameterized and validated for a specific restoration site, managers can assess which target goals can be achieved given the set of available plant species and site-specific conditions. It can also highlight which species combinations can best achieve long-term improved multifunctionality due to their trait diversity.

Questions Globally, ecological restoration is required to restore degraded landscapes and to contribute to biodiversity conservation. Ecological theory suggests that manipulating dispersal, abiotic and biotic filters limiting plant re‐establishment will improve restoration outcomes. Here, we manipulated spread depth of soil containing a salvaged soil seedbank (dispersal filter), soil compaction (abiotic filter) and herbivore grazing (biotic filter) in a topsoil transfer experiment to test their effects on restoration success. Location Banksia woodland of the Swan Coastal Plain, Western Australia. Methods Topsoil (upper ~7 cm) with its seedbank was removed from a donor site (20 ha) of recently cleared native vegetation and transferred to six recipient restoration sites (16 ha). Deep (10 cm thick) and shallow (5 cm thick) layers of topsoil were applied in a fully factorial experiment, with and without soil ripping and fencing, respectively. We analysed emergence, survival and functional types (alien/native, life form, fire response) of all vascular plant species for two consecutive years after topsoil transfer. Results The most successful restoration treatment was deep topsoil with a mean density of 14.3 m−2 native perennial germinants in year one and 7.3 m−2 in year two. Application of deep topsoil increased native seedling emergence by 34% and decreased weed density by 21% compared with shallow topsoil. Overall seedling survival across the two‐year period was unaffected by filter treatments (range 0.6%–5%). After two years, the resulting plant community was 6%–38% weed species and of native perennial species, 12%–48% were capable of resprouting. Conclusions Manipulation of the dispersal filter alone, that is deep topsoil application, can lead to near‐equivalent native species number emerging on restoration sites as compared to pre‐cleared woodland. However, more research is required to test additional restoration tools to improve survival of biodiverse plant communities. For example, targeted herbicide application coupled with soil ripping to improve weed management and native seedling establishment.

Human activities can disrupt the insect pollination process, which can trigger a decline in pollination and plant reproductive output. Floral visitors are not equally effective pollinators, and it is unknown how multiple changes to an environment further change the effectiveness of insect pollination for native plants. We investigated how herbicide treatment, the presence of non‐native plants and addition of nitrogen fertiliser change the relative importance of different species of floral visitors to four native plant species: Callistemon phoeniceus, Calothamnus quadrifidus, Hakea lissocarpha and Banksia sessilis. Our field site was a large‐scale revegetation site in south‐west Western Australia in which the presence of non‐native plants and nitrogen deposition were experimentally manipulated. Experimental exclusion of floral visitors revealed pollinators were likely required for the seed set of three of the native species, and none of the four plant species were pollen‐limited. We observed 8936 floral visitors of 249 morphospecies from 14 insect orders on four native and two non‐native plant species. From PIV calculations, 57% of floral visitors were potential pollinators, with the remainder considered just visitors due to their low Pollinator Importance Value (PIV). The introduced Apis mellifera (European honey bee, Apidae) was the most frequent floral visitor and the most effective pollinator of all four native plant species. The presence of two non‐native plant species and addition of nitrogen fertiliser did not affect the effectiveness of the potential pollinators, or the viable seeds produced by the four native plant species.

Microbial processing of aggregate-unprotected organic matter inputs is key for soil fertility, long-term ecosystem carbon and nutrient sequestration and sustainable agriculture. We investigated the effects of adding multiple nutrients (nitrogen, phosphorus and potassium plus nine essential macro- and micro-nutrients) on decomposition and biochemical transformation of standard plant materials buried in 21 grasslands from four continents. Addition of multiple nutrients weakly but consistently increased decomposition and biochemical transformation of plant remains during the peak-season, concurrent with changes in microbial exoenzymatic activity. Higher mean annual precipitation and lower mean annual temperature were the main climatic drivers of higher decomposition rates, while biochemical transformation of plant remains was negatively related to temperature of the wettest quarter. Nutrients enhanced decomposition most at cool, high rainfall sites, indicating that in a warmer and drier future fertilized grassland soils will have an even more limited potential for microbial processing of plant remains. Fil: Ochoa Hueso, Raúl. Universidad de Cádiz; España Fil: Borer, Elizabeth. University of Minnesota; Estados Unidos Fil: Seabloom, Eric. University of Minnesota; Estados Unidos Fil: Hobbie, Sarah E.. University of Minnesota; Estados Unidos Fil: Risch, Anita C.. Swiss Federal Institute for Forest, Snow and Landscape Research; Suiza Fil: Collins, Scott L.. University of New Mexico; Estados Unidos Fil: Alberti, Juan. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Bahamonde, Héctor Alejandro. Universidad Nacional de la Patagonia Austral; Argentina. Instituto Nacional de Tecnología Agropecuaria; Argentina Fil: Brown, Cynthia S.. State University of Colorado - Fort Collins; Estados Unidos Fil: Caldeira, Maria C.. Universidade Nova de Lisboa; Portugal Fil: Daleo, Pedro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentina Fil: Dickman, Chris R.. University of Sydney; Australia Fil: Ebeling, Anne. Universitat Jena; Alemania Fil: Eisenhauer, Nico. German Centre for Integrative Biodiversity Research; Alemania. Universitat Leipzig; Alemania Fil: Esch, Ellen H.. University Of Guelph. Department Of Integrative Biology.; Canadá Fil: Eskelinen, Anu. German Centre for Integrative Biodiversity Research; Alemania. Helmholtz Centre for Environmental Research; Alemania. University of Oulu; Finlandia Fil: Fernández, Victoria. Universidad Politécnica de Madrid; España Fil: Güsewell, Sabine. Institute of Integrative Biology; Suiza Fil: Gutierrez Larruga, Blanca. Universidad Autónoma de Madrid; España Fil: Hofmockel, Kirsten. Pacific Northwest National Laboratory; Estados Unidos. University of Iowa; Estados Unidos Fil: Laungani, Ramesh. Doane University; Estados Unidos Fil: Lind, Eric. University of Minnesota; Estados Unidos Fil: López, Andrea. University of New Mexico; Estados Unidos Fil: McCulley, Rebecca L.. University of Kentucky; Estados Unidos Fil: Moore, Joslin L.. Monash University; Australia Fil: Peri, Pablo Luis. Instituto Nacional de Tecnología Agropecuaria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Santa Cruz. Universidad Tecnológica Nacional. Facultad Regional Santa Cruz. Centro de Investigaciones y Transferencia de Santa Cruz. Universidad Nacional de la Patagonia Austral. Centro de Investigaciones y Transferencia de Santa Cruz; Argentina Fil: Power, Sally A.. University of Western Sydney; Australia Fil: Price, Jodi N.. Charles Sturt University; Australia Fil: Prober, Suzanne M.. Csiro National Collections And Marine Infrastructure; Australia Fil: Roscher, Christiane. German Centre for Integrative Biodiversity Research; Alemania. University of Oulu; Finlandia Fil: Velasco Ayuso, Sergio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura. Universidad de Buenos Aires. Facultad de Agronomía. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; Argentina

Fine root endophytes (FRE) were traditionally considered a morphotype of arbuscular mycorrhizal fungi (AMF), but recent genetic studies demonstrate that FRE belong within the subphylum Mucoromycotina, rather than in the subphylum Glomeromycotina with the AMF. These findings prompt enquiry into the fundamental ecology of FRE and AMF. We sampled FRE and AMF in roots of Trifolium subterraneum from 58 sites across temperate southern Australia. We investigated the environmental drivers of composition, richness, and root colonization of FRE and AMF by using structural equation modelling and canonical correspondence analyses. Root colonization by FRE increased with increasing temperature and rainfall but decreased with increasing phosphorus (P). Root colonization by AMF increased with increasing soil organic carbon but decreased with increasing P. Richness of FRE decreased with increasing temperature and soil pH. Richness of AMF increased with increasing temperature and rainfall but decreased with increasing soil aluminium (Al) and pH. Aluminium, soil pH, and rainfall were, in decreasing order, the strongest drivers of community composition of FRE; they were also important drivers of community composition of AMF, along with temperature, in decreasing order: rainfall, Al, temperature, and soil pH. Thus, FRE and AMF showed the same responses to some (e.g. soil P, soil pH) and different responses to other (e.g. temperature) key environmental factors. Overall, our data are evidence for niche differentiation among these co-occurring mycorrhizal associates.

In many mining-intensive areas around the world, knowledge-sharing among companies is critical to advance best-practices in mine rehabilitation and closure. The academic literature documents innovative, best-practices options, yet these are often not accessible to field practitioners. Published mine closure plans provide relevant examples of standards accepted by regulators, however, regulations vary with jurisdiction and can change over time, limiting the utility of these plans. There is, therefore, a need for greater transparency and accessibility of practical knowledge to inform the definition of achievable completion criteria. The purpose of this study is to provide an overview of best-practices for the purpose of defining mine completion criteria. The methods comprise: i) a qualitative meta-analysis of the global peer-reviewed literature; and ii) three in-depth case studies in Western Australia. The research identifies ten key best-practices that could be potentially applied by mining proponents to guide the definition of successful completion criteria. These include: multiple references, monitoring and corrective actions, science-informed completion criteria, holistic rehabilitation, dynamic targets, leading indicators, integration of rehabilitation with mine operations, innovation-guided completion criteria, specific objectives and indicators and risk-based completion criteria. These best-practices are further examined through recent mine rehabilitation and closure programs of mid-to-large mining operators in Western Australia. Our findings provide the first comprehensive review of best-practices towards the definition of mine completion criteria, which are relevant to industries requiring rehabilitation of disturbed lands across Australian and international jurisdictions.

The mining industry is a major contributor to Australia's economy. However, such returns may come at high environmental and social costs, including loss of biodiversity or heritage values. Thus, companies worldwide are required to rehabilitate mine sites to a state that is safe, non-polluting and capable of supporting an agreed post-mining land use. While national and international guidelines on mine rehabilitation and closure exist, there is a lack of guidance on how to define achievable and measurable criteria that reflect rehabilitation success. This often leads to discrepancies between proponents and regulators, which hinder progression towards mine closure and relinquishment. The purpose of this study was to develop a systematic framework for the definition of completion criteria for mine closure and rehabilitation. The study was informed by a global review of the literature and collaborative research with mining stakeholders from Western Australia. The proposed framework consists of six fundamental steps: 1) selection of post mining land use; 2) definition of aspects and closure objectives; 3) selection of reference(s); 4) selection of attributes; 5) definition of completion criteria; and 6) evaluation of performance. This framework is the first to provide a step-by-step guide for defining site-specific completion criteria and applying a risk-based monitoring approach throughout the life of mine. The framework is applicable across jurisdictions and industries, in Australia and internationally, that require similar rehabilitation of disturbed lands.

Directional climate change can potentially cause a nested pattern of species occurrences as species move or go extinct. That is, species-poor communities may become a nested subset of species-rich communities. There is a precedent for understanding these patterns in the context of historical climate change but few researchers have studied these patterns in the context of recent changes to climate. Here we show the value of nestedness analyses for understanding plant community responses to reduced annual rainfall using data on seedling establishment in restored jarrah forest between the years of 1992 and 2010. Specifically, we recorded the annual seedling establishment of species assemblages in plots 15 months after restoration. We tested to what extent jarrah-forest assemblages that established in low ( 1200 mm) rainfall, and whether assemblages established following lower standard restoration practice were nested subsets of those following higher standard practices. We also tested how both types of nestedness patterns varied among trait groups defined by status (i.e., native or non-native), life-form and seed size. We found high support for species and trait assemblages that established in dry years being a nested subset of assemblages that established in years of moderate rainfall, and consistently low support for nestedness of high in low, and moderate in low, rainfall years. Nestedness patterns associated with restoration practice were as we predicted. Recruitment failure in low rainfall years was the most parsimonious explanation for nestedness patterns associated with rainfall (i.e., selective environmental tolerance). Nestedness patterns associated with restoration practice were explained by differential seed dispersal of species via topsoil and their tolerance of inferior restoration practice. Taken together, we demonstrate the application of the nestedness approach for understanding community responses to climate change in a restoration context. Indeed, generalising species responses to climate change by linking these to ecological processes and traits will help to meet the current global demand for forest restoration. Therefore, we anticipate our findings will interest practitioners working to restore the world’s forests under climate change.

Landscape-scale restoration requires stakeholder collaboration and recognition of diverse social and ecological motivations to achieve multiple benefits. Yet few landscape restoration projects have set and achieved shared social and ecological goals. Mechanisms to integrate social and ecological motivations will differ in different landscapes. We provide examples from urban, agricultural, and mined landscapes to highlight how integration can achieve multiple benefits and help incentivize restoration. Better communication of ecological and especially social benefits of restoration could increase motivation. Social and economic incentives from carbon markets are evident in agricultural landscapes, biodiversity offset schemes are unlikely to motivate restoration without proof-of-concept, and framing restoration in terms of ecosystem services shows promise. Synthesis and applications. When setting restoration goals, it is important to recognize the diverse motivations that influence them. In doing so, and by evaluating both social and ecological benefits, we can better achieve desired restoration outcomes. Customizing incentives to cater for diverse stakeholder motivations could therefore encourage restoration projects.

The majority of terrestrial plants form mutualistic associations with arbuscular mycorrhizal fungi (AMF) and rhizobia (i.e., nitrogen-fixing bacteria). Understanding these associations has important implications for ecological theory and for restoration practice. Here, we tested whether the presence of AMF and rhizobia influences the performance of native woody plants invaded by a non-native grass in experimental microcosms. We planted eight plant species (i.e., Acacia acuminata, A. microbotrya, Eucalyptus loxophleba subsp. loxophleba, E. astringens, Calothamnus quadrifidus, Callistemon phoeniceus, Hakea lissocarpha and H. prostrata) in microcosms of field-conditioned soil with and without addition of AMF and rhizobia in a fully factorial experimental design. After seedling establishment, we seeded half the microcosms with an invasive grass Bromus diandrus. We measured shoot and root biomass of native plants and Bromus, and on roots, the percentage colonization by AMF, number of rhizobia-forming nodules and number of proteaceous root clusters. We found no effect of plant root symbionts or Bromus addition on performance of myrtaceous, and as predicted, proteaceous species as they rely little or not at all on AMF and rhizobia. Soil treatments with AMF and rhizobia had a strong positive effect (i.e., larger biomass) on native legumes (A. microbotrya and A. acuminata). However, the beneficial effect of root symbionts on legumes became negative (i.e., lower biomass and less nodules) if Bromus was present, especially for one legume, i.e., A. acuminata, suggesting a disruptive effect of the invader on the mutualism. We also found a stimulating effect of Bromus on root nodule production in A. microbotrya and AMF colonization in A. acuminata which could be indicative of legumes’ increased resource acquisition requirement, i.e., for nitrogen and phosphorus, respectively, in response to the Bromus addition. We have demonstrated the importance of measuring belowground effects because the aboveground effects gave limited indication of the effects occurring belowground.