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Threatened species in rainforests may be vulnerable to climate change, because of their potentially narrow thermal tolerances, small population sizes, restricted distributions and limited dispersal. We investigated the relative influence of potential climate change on the population viability of Triunia robusta (Proteaceae), an endangered rainforest shrub endemic to southeast Queensland, Australia. A spatially explicit, stochastic population model with seven stage classes was developed and linked with the species distribution model (SDM) to explore a variety of hypothetical climate change simulations over a 90‐year period from 2010 to 2100: (1) constant population dynamics, (2) changes in habitat distributions as trend in carrying capacity and (3) changes in habitat distributions, precipitation and temperature regime as relative change in seedling survival and fecundity. The results revealed high vulnerability of small populations to local extinction regardless of geographical location or climatic stressors, while some larger populations located in the southern end of the species distribution range showed persistence in‐situ. Triunia robusta was found to be sensitive to reduced precipitation and increased temperature, limiting the species reproductive activities and seedling establishment and reducing the overall abundance consequently. Integration of population models and SDM allowed for the evaluation of multiple climatic stressors that may affect habitat distributions and population dynamics of T. robusta and ultimately suggest potential implications for future conservation and management planning with respect to climate change. [ABSTRACT FROM AUTHOR]

Background and aims: Proteaceae species strongly acidify their rhizosphere to increase soil phosphorus (P) availability, which also inadvertently increases the availability of other elements, such as manganese and rare earth elements (REE). This study aimed to investigate REE (hyper) accumulation in the Proteaceae genus Helicia from Queensland, Australia, from a systematic assessment of REE concentrations in herbarium specimens and verification with field collected samples. Methods: Herbarium X-ray fluorescence (XRF) scanning (using yttrium as a proxy for REEs) was undertaken on selected Helicia species (Proteaceae) at the Queensland Herbarium, followed by Inductively coupled plasma atomic emission spectroscopy (ICP-AES) analysis and field collection of H. glabriflora samples to confirm the XRF findings. Results: The herbarium XRF analysis revealed highly anomalous REE concentrations in some Helicia species, reaching ~ 1300 µg Y g-1 in H. australasica and H. glabriflora. The ICP-AES analysis of the herbarium specimens revealed total REE concentrations (REE) of up to 2300 µg g-1 in H. australasica and H. glabriflora, with relatively higher light REEs (~ 70%) and yttrium (~ 20%) concentrations, compared to heavy REEs (~ 10%). The field collected H. glabriflora material had relatively higher total REE concentrations in the mature leaves (~ 850 µg REE g-1) and stems (~ 675 µg REE g-1), compared to young leaves (~ 130 µg REE g-1), roots (~ 220 µg REE g-1) and soil (~ 90 µg REE g-1). Conclusion: The discovery of REE (hyper)accumulation in these Helicia species suggests that the Proteaceae family may host several other REE hyperaccumulators that are hitherto undiscovered. This calls for systematic assessment of the Proteaceae using the same approach as used in this study. The findings have potential implications for (i) discovery of REE hyperaccumulator plants, (ii) investigation of REE uptake and accumulation in plants and (iii) biogeochemical exploration of buried REE ore deposits. [ABSTRACT FROM AUTHOR]

Identifying the geographic origins of crops is important for the conservation and utilization of novel genetic variation. Even so, the origins of many food crops remain elusive. The tree nut crop macadamia has a remarkable domestication history, from subtropical rain forests in Australia through Hawaii to global cultivation all within the last century. The industry is based primarily on Macadamia integrifolia and M. integrifolia–M. tetraphylla hybrid cultivars with Hawaiian cultivars the main contributors to world production. Sequence data from the chloroplast genome assembled using a genome skimming strategy was used to determine population structure among remnant populations of the main progenitor species, M. integrifolia. Phylogenetic analysis of a 506 bp chloroplast SNP alignment from 64 wild and cultivated accessions identified phylogeographic structure and deep divergences between clades providing evidence for historical barriers to seed dispersal. High levels of variation were detected among wild accessions. Most Hawaiian cultivars, however, shared a single chlorotype that was also present at two wild sites at Mooloo and Mt Bauple from the northernmost distribution of the species in south-east Queensland. Our results provide evidence for a maternal genetic bottleneck during early macadamia domestication, and pinpoint the likely source of seed used to develop the Hawaiian cultivars. The extensive variability and structuring of M. integrifolia chloroplast genomic variation detected in this study suggests much unexploited genetic diversity is available for improvement of this recently domesticated crop. [ABSTRACT FROM AUTHOR]

Specimens of all known taxa and putative entities belonging to the Banksia spinulosa complex were collected from Kuranda in northern Queensland, western to central Queensland and down the eastern coast of Australia to Wilsons Promontory in southern Victoria. These specimens were used to investigate morphological variation in habit, stems, leaves, inflorescences, fruits and seeds in the complex. Phenetic analysis (unweighted pair-group method with arithmetic mean, UPGMA, clustering and semi-strong hybrid multi-dimensional scaling, SSH–MDS, ordination) was performed on the full dataset of 233 entities using 33 characters (18 quantitative, two binary and 13 multistate). To facilitate visualisation of patterns in both clustering and ordination, we also analysed subgroups based on the results of the phenogram from the full dataset. The results showed that the five known and described taxa are phenetically distinct, viz. B. collina sens. str., B. cunninghamii sens. str., B. neoanglica, B. spinulosa and B. vincentia, and provided support for a further 12 morphometrically diagnosable entities, four of which could not be diagnosed with simple combinations of character states and require further investigation. The present study has highlighted that there is much more hidden morphological diversity in the B. spinulosa complex than has previously been recognised in any of the current competing taxonomies. [ABSTRACT FROM AUTHOR]

Threatened species in rainforests may be vulnerable to climate change, because of their potentially narrow thermal tolerances, small population sizes and restricted distributions. This study modelled climate induced changes on the habitat distribution of the endangered rainforest plant Triunia robusta, endemic to southeast Queensland, Australia. Species distribution models were developed for eastern Australia at 250 m grids and southeast Queensland at 25 m grids using ground-truthed presence records and environmental predictor data. The species' habitat distribution under the current climate was modelled, and the future potential habitat distributions were projected for the epochs 2030, 2050 and 2070. The eastern Australia model identified several spatially disjunct, broad habitat areas of coastal eastern Australia consistent with the current distribution of rainforests, and projected a southward and upslope contraction driven mainly by average temperatures exceeding current range limits. The southeast Queensland models suggest a dramatic upslope contraction toward locations where the majority of known populations are found. Populations located in the Sunshine Coast hinterland, consistent with past rainforest refugia, are likely to persist long-term. Upgrading the level of protection for less formal nature reserves containing viable populations is a high priority to better protect refugial T. robusta populations with respect to climate change.