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.

Assisted migration can aid in the conservation of narrowly endemic species affected by habitat loss, fragmentation and climate change. Here, we employ a multidisciplinary approach by examining the population genetic structure of a threatened, dioecious rainforest tree of the subtropical notophyll vine forests of eastern Australia, Fontainea rostrata, and its potential requirements for population enhancement and translocation to withstand the effects of anthropogenic fragmentation and climate change. We used microsatellite markers to gain an understanding of the way genetic diversity is partitioned within and among the nine extant populations of F. rostrata identified in this study. We combined the results with species distribution modelling to identify populations vulnerable to possible future range shifts based on climate change projections. We found regional differences between the species’ main distribution in the south and a disjunct northern population cluster (FRT = 0.074, FSR = 0.088, FST = 0.155), in mean allelic richness (AR = 2.77 vs 2.33, p < 0.05), expected heterozygosity (HE = 0.376 vs 0.328), and inbreeding (F = 0.116 vs 0.219). Species distribution models predicted that while southern populations of F. rostrata are likely to persist for the next 50 years under the RCP6.0 climate change scenario, with potential for a small-scale expansion to the south-east, the more highly inbred and less genetically diverse northern populations will come under increasing pressure to expand southwards as habitat suitability declines. Given the species’ genetic structure and with the aim to enhance genetic diversity and maximise the likelihood of reproductive success, we recommend that plant reintroductions to supplement existing populations should be prioritised over translocation of the species to new sites. However, future conservation efforts should be directed at translocation to establish new sites to increase population connectivity, focussing particularly on habitat areas identified as persisting under conditions of climate change.

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Habitat fragmentation is affecting greater numbers of species as human land use requirements increase. Melaleuca irbyana R.T.Baker (Myrtaceae) is an endangered tea tree which dominates critically endangered, south-east Queensland swamp tea tree forest. It is restricted to isolated populations in south-east Queensland. New disjunct populations have recently been found adjacent to gas pipeline developments in the Brigalow Belt in central Queensland. A population genetics study was undertaken on the species to investigate its diversity to advise conservation and restoration. Primers for microsatellite markers were developed and used to provide the genetic information for the study. M. irbyana was found to possess moderate levels of genetic diversity within populations but this was not correlated with patch size or isolation. However, inbreeding levels were moderately high in all populations, suggesting individuals may be self-fertilised as there was no evidence of clonality detected in this species despite evidence of resprouting. The disjunct populations in central Queensland were genetically distinct, which highlights their importance for conservation of the species. The northern NSW populations are potentially at risk as they are depauperate and genetically distinct. There is differentiation among populations between the geographic regions so care should be taken to consider local provenance in restoration plantings.

Little remains of the Brigalow (Acacia harpophylla F.Muell. ex Benth.) woodlands of Australia, primarily due to land clearing for grazing and agriculture. Many threatened species in this region are poorly studied, and the life history traits of some herbaceous species such as ephemeral shoot systems, mean that conservation assessments are difficult. Recent gas pipeline developments have led to an increased need to understand the ecology and genetics of such taxa, in order to advise offset and translocation activities. Xerothamnella herbacea R.Baker is an endangered ephemeral herbaceous species from the Brigalow Belt region, which dies back during prolonged dry conditions. The aim of this study was to map the extent of potentially suitable habitat of this species, including determination of population extent within existing protected area estate. The species population sizes, reproductive activity and evidence of clonal spread, as well as the levels of genetic diversity and inbreeding, across the species range were also assessed to provide guidance for potential translocation and offsetting programs. The genetic results were related to the species suitable habitat distribution to test whether historic or recent habitat fragmentation most explains genetic patterns in this species. Most of the populations of this species were found to be small with less than 100 plants. The species appears not to be limited by its reproductive output, suggesting other factors may limit its abundance. The species populations have moderate to low genetic diversity suggesting the species is genetically viable in the medium term but are inbred which may be partially due to vegetative spread. Geographic proximity does not predict genetic similarity of populations and diversity is not correlated with population size. The results indicate potential translocation or offsetting programs need to account for genetic relationships in their planning. Resprouting ability has potentially assisted the species to slow the pace of genetic diversity loss due to anthropogenic fragmentation.