Native seed underpins the success of most terrestrial restoration efforts globally; however, the fragility of the native seed supply chain presents a key challenge to achieving global restoration goals. With the current heightened global focus on ecological restoration, seed supply chains are under unprecedented pressure worldwide. New and practical solutions are required to help the native seed industry move toward more sustainable and reliable supply, and in turn, facilitate more cost-effective, successful, seed-based restoration. Here we focus on species used in biodiverse mine site restoration in two regions of Western Australia as a test case for evaluating two key elements of the seed supply chain: seed quality and price. The study assessed seed quality in 185 species, then combined these results with seed price to determine the actual cost of pure live seeds (PLS) used in restoration. Average seed quality, expressed as a weight percentage of PLS, is 55%. The average price for a native seed batch across 129 species is $1,093 Australian dollars (AUD)/kg, and when adjusted for viability and purity is $2,600 (AUD)/ kg of PLS. We suggest replacing the traditional approach of pricing seed per unit weight ($/kg) with a new method that would reflect seed quality and unit number; price per thousand pure live seeds ($ TPLS). We posit that this new way of pricing native seeds would increase transparency and information flow in the marketing of native seeds, which will, in turn, enable seed users to more reliably plan for, and evaluate the cost-effectiveness of seed-based restoration projects.

1. Global interest in building healthy soils combined with new DNA sequencing technologies has led to the generation of a vast amount of soil microbial community (SMC) data. 2. SMC analysis is being adopted widely for monitoring ecological restoration trajectories. However, despite the large and growing quantity of soil microbial data, it remains unclear how these data inform and best guide restoration practice. 3. Here, we examine assumptions around SMC as a tool for guiding ecosystem restoration and evaluate the effectiveness of using species inventories of SMC as a benchmark for restoration success. 4. We investigate other approaches of assessing soil health, and conclude that we can significantly enhance the utility of species inventory data for ecological restoration by complementing it with the use of non-molecular approaches.

Substantial climate changes are evident across Australia, with declining rainfall and rising temperature in conjunction with frequent fires. Considerable species loss and range contractions have been predicted; however, our understanding of how genetic variation may promote adaptation in response to climate change remains uncertain. Here we characterized candidate genes associated with rainfall gradients, temperatures, and fire intervals through environmental association analysis. We found that overall population adaptive genetic variation was significantly affected by shortened fire intervals, whereas declining rainfall and rising temperature did not have a detectable influence. Candidate SNPs associated with rainfall and high temperature were diverse, whereas SNPs associated with specific fire intervals were mainly fixed in one allele. Gene annotation further revealed four genes with functions in stress tolerance, the regulation of stomatal opening and closure, energy use, and morphogenesis with adaptation to climate and fire intervals. B. attenuata may tolerate further changes in rainfall and temperature through evolutionary adaptations based on their adaptive genetic variation. However, the capacity to survive future climate change may be compromised by changes in the fire regime.

Trait divergence between populations is considered an adaptive response to different environments, but to what extent this response is accompanied by genetic differentiation is less clear since it may be phenotypic plasticity. In this study, we analyzed phenotypic variation between two Banksia attenuata growth forms, lignotuberous (shrub) and epicormic resprouting (tree), in fire-prone environments to identify the environmental factors that have driven this phenotypic divergence. We linked genotype with phenotype and traced candidate genes using differential gene expression analysis. Fire intervals determined the phenotypic divergence between growth forms in B. attenuata. A genome-wide association study identified 69 single nucleotide polymorphisms, putatively associated with growth form, whereas no growth form- or phenotype-specific genotypes were identified. Genomic differentiation between the two growth forms was low (F = 0.024). Differential gene expression analysis identified 37 genes/transcripts that were differentially expressed in the two growth forms. A small heat-shock protein gene, associated with lignotuber presence, was differentially expressed in the two forms. We conclude that different fire regimes induce phenotypic polymorphism in B. attenuata, whereas phenotypic trait divergence involves the differential expression of a small fraction of genes that interact strongly with the disturbance regime. Thus, phenotypic plasticity among resprouters is the general strategy for surviving varying fire regimes.

Purpose Biotic and abiotic properties of soils can hinder or facilitate ecological restoration, and management practices that impact edaphic factors can strongly influence plant growth and restoration outcomes. Salvaged topsoil is an invaluable resource for mine-site restoration, and a common practice is topsoil transfer from mined areas to restoration sites. However, direct transfer is often not feasible, necessitating storage in stockpiles. We evaluated the effects of topsoil stockpiling on plant performance across diverse ecosystems impacted by mining throughout Western Australia. Methods We conducted a bioassay experiment using a widespread native Acacia species to assess how topsoil storage might impact plant growth, physiology, and nodulation by N-fixing bacteria using soils from native reference vegetation and stockpiled soils from six mine sites across Western Australia. Results Plant responses varied across mine sites, but overall plants performed better in soils collected from native vegetation, exhibiting greater biomass, more root nodules, and higher water-use efficiency compared to those grown in stockpiled soils. Soil physiochemistry showed few and minor differences between native soils and stockpiles. Conclusion Results strongly suggest observed differences in plant performance were biotic in nature. This study highlights the negative effects of topsoil storage on the biological integrity of soil across diverse ecosystems, with important implications for mine-site restoration; our results show that topsoil management can strongly influence plant performance, and stockpiled soils are likely inferior to recently disturbed topsoil for restoration purposes. We also use this study to illustrate the utility of bioassays for assessing soil quality for ecological restoration.

Banksia is a significant element in vegetation of southwestern Australia, a biodiversity hotspot with global significance. In particular, Banksia hookeriana represents a species with significant economic and ecological importance in the region. For better conservation and management, we reported an overview of transcriptome of B. hookeriana using RNA-seq and de novo assembly. We have generated a total of 202.7 million reads (18.91 billion of nucleotides) from four leaf samples in four plants of B. hookeriana, and assembled 59,063 unigenes (average size = 1098 bp) through de novotranscriptome assembly. Among them, 39,686 unigenes were annotated against the Swiss-Prot, Clusters of Orthologous Groups (COG), and NCBI non-redundant (NR) protein databases. We showed that there was approximately one single nucleotide polymorphism (SNP) per 5.6–7.1 kb in the transcriptome, and the ratio of transitional to transversional polymorphisms was approximately 1.82. We compared unigenes of B. hookeriana to those of Arabidopsis thaliana and Nelumbo nucifera through sequence homology, Gene Ontology (GO) annotation, and KEGG pathway analyses. The comparative analysis revealed that unigenes of B. hookeriana were closely related to those of N. nucifera. B. hookeriana, N. nucifera, and A. thaliana shared similar GO annotations but different distributions in KEGG pathways, indicating that B. hookeriana has adapted to dry-Mediterranean type shrublands via regulating expression of specific genes. In total 1927 potential simple sequence repeat (SSR) markers were discovered, which could be used in the genotype and genetic diversity studies of the Banksia genus. Our results provide valuable sequence resource for further study in Banksia.

Salvaged native topsoil is a scarce, highly valuable resource in post-mining restoration, being the main source of organic matter and nutrients and a major repository of plant propagules and soil microbes. During the mining process, topsoil is often stockpiled, and factors such as stockpile depth, season of stripping, and storage time can adversely affect topsoil functionality. We aimed to determine if soil functionality differs between undisturbed native reference topsoils and stockpiled topsoils of various age and origin, and whether measures of soil microbial community composition, soil respiration, and plant growth provide comparable assessments of soil functionality. We investigated this using select biological assessments of undisturbed native reference topsoils and stockpiled topsoils collected from seven mine sites representing a range of climate, soil, commodity, and vegetation types across the major mining province of Western Australia. Biotic properties of stored topsoil were idiosyncratic and variable across mine sites, and results differed based on the biotic measure being assessed. Biomass was generally lower for plants grown in stockpiled topsoils than for plants grown in native reference topsoils across mine sites. However, no single biotic measure provided an accurate assessment of soil functionality as reflected in plant growth responses. Overall, stockpiling adversely affected soil functionality and further research is needed to improve topsoil management procedures that may be site-and biome-specific.

Abstract. Mining can cause severe disturbances to the soil, which underpins the viability of terrestrial ecosystems. Post-mining rehabilitation relies on measuring soil properties that are critical indicators of soil health. Soil visible–near-infrared (vis–NIR) spectroscopy is rapid, accurate, and cost-effective for estimating a range of soil properties. Recent advances in infrared detectors and microelectromechanical systems (MEMSs) have produced miniaturised, relatively inexpensive spectrometers. Here, we evaluate the spectra from four miniaturised visible and NIR spectrometers, some combinations, and a full-range vis–NIR spectrometer for modelling 29 soil physical, chemical, and biological properties used to assess soil health at mine sites. We collected topsoil samples from reference, undisturbed native vegetation, and stockpiles from seven mines in Western Australia. We evaluated the spectrometers' repeatability and the accuracy of spectroscopic models built with seven statistical and machine learning algorithms. The spectra from the visible spectrometer could estimate sand, silt, and clay with similar or better accuracy than the NIR spectrometers. However, the spectra from the NIR spectrometers produced better estimates of soil chemical and biological properties. By combining the miniaturised visible and NIR spectrometers, we improved the accuracy of their soil property estimates, which were similar to those from the full-range spectrometer. The miniaturised spectrometers and combinations predicted 24 of the 29 soil properties with moderate or greater accuracy (Lin's concordance correlation, ρc≥0.65). The repeatability of the NIR spectrometers was similar to that of the full-range, portable spectrometer. The miniaturised NIR spectrometers produced comparably accurate soil property estimates to the full-range portable system which is an order of magnitude more expensive, particularly when combined with the visible range sensor. Thus, the miniaturised spectrometers could form the basis for a rapid, cost-effective soil diagnostic capacity to support mine site rehabilitation and deliver significant positive economic and environmental outcomes.