Phylogenetics of the skyhoppers (Kosciuscola) of the Australian Alps : evolutionary and conservation implications

The true biodiversity of Australia's alpine and subalpine endemics is unknown. Genetic studies to date have focused on sub-regions and restricted taxa, but even so, indicate deep divergences across small geographic scales and therefore that the bulk of biodiversity remains to be discovered. We aimed to study the phylogeography of the Australian Alps by focusing on the skyhoppers (Kosciuscola), a genus of five species of flightless grasshoppers whose combined distributions both span the region and are almost exclusively contained within it. Our sampling covered 650 km on the mainland and several sites in Tasmania with total of 260 specimens used to reconstruct a robust phylogeny of Koscisucola. Phylogenies were based on single nucleotide polymorphism data generated from double-digested restriction-associated DNA sequencing. Skyhoppers diverged around 2 million years ago and have since undergone complex diversification seemingly driven by climatic oscillations throughout the Pleistocene. We recovered not 5 but 14 clades indicating the presence of many unknown species. Our results support conspicuous geographic features as genetic breaks; e.g. the Murray Valley, and inconspicuous ones; e.g. between the Bogong High Plains and Mt Hotham. Climate change is progressing quickly in the region and its impact, particularly on snow, could have severe consequences for the skyhoppers' overwinter survival. The true diversity of skyhoppers highlights that biodiversity loss in the Alps as a result of climate change is likely to be far greater than what can be estimated based on current species numbers and that management including small geographical scales is key

Predicting species and community responses to global change using structured expert judgement : an Australian mountain ecosystems case study

Conservation managers are under increasing pressure to make decisions about the allocation of finite resources to protect biodiversity under a changing climate. However, the impacts of climate and global change drivers on species are outpacing our capacity to collect the empirical data necessary to inform these decisions. This is particularly the case in the Australian Alps which has already undergone recent changes in climate and experienced more frequent large-scale bushfires. In lieu of empirical data, we used a structured expert elicitation method (the IDEA protocol) to estimate the abundance and distribution of nine vegetation groups and 89 Australian alpine and subalpine species by the year 2050. Experts predicted that most alpine vegetation communities would decline in extent by 2050; only woodlands and heathlands are predicted to increase in extent. Predicted species-level responses for alpine plants and animals were highly variable and uncertain. In general, alpine plants spanned the range of possible responses, with some expected to increase, decrease or not change in cover. By contrast, almost all animal species are predicted to decline or not change in abundance or elevation range; more species with water-centric life-cycles are expected to decline in abundance than other species. While long-term ecological data will always be the gold-standard in informing the future of biodiversity, the method and outcomes outlined here provide a pragmatic and coherent basis upon which to start informing conservation policy and management in the face of rapid change and paucity of data

Physiological Limits along an Elevational Gradient in a Radiation of Montane Ground Beetles

<div><p>A central challenge in ecology and biogeography is to determine the extent to which physiological constraints govern the geographic ranges of species along environmental gradients. This study tests the hypothesis that temperature and desiccation tolerance are associated with the elevational ranges of 12 ground beetle species (genus <i>Nebria</i>) occurring on Mt. Rainier, Washington, U.S.A. Species from higher elevations did not have greater cold tolerance limits than lower-elevation species (all species ranged from -3.5 to -4.1°C), despite a steep decline in minimum temperature with elevation. Although heat tolerance limits varied among species (from 32.0 to 37.0°C), this variation was not generally associated with the relative elevational range of a species. Temperature gradients and acute thermal tolerance do not support the hypothesis that physiological constraints drive species turnover with elevation. Measurements of intraspecific variation in thermal tolerance limits were not significant for individuals taken at different elevations on Mt. Rainier, or from other mountains in Washington and Oregon. Desiccation resistance was also not associated with a species’ elevational distribution. Our combined results contrast with previously-detected latitudinal gradients in acute physiological limits among insects and suggest that other processes such as chronic thermal stress or biotic interactions might be more important in constraining elevational distributions in this system.</p></div

Intraspecific variation in thermal tolerance among five species of <i>Nebria</i>.

<p>(A) Cold tolerance and (B) heat tolerance. Different symbols correspond to population trait means (± s.d.) on different mountains (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0151959#pone.0151959.t002" target="_blank">Table 2</a> for details); for <i>N</i>. <i>paradisi</i> and <i>N</i>. <i>vandykei</i>, filled squares correspond to the low-elevation population on Mt. Rainier (Site 2) and open squares correspond to the high-elevation population on Mt. Rainier (Site 1).</p

Elevational ranges and sampling elevations for study species.

<p>Approximate elevational ranges for the 12 <i>Nebria</i> species on Mt. Rainier, Washington. Range edges were derived from Kavanaugh [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0151959#pone.0151959.ref021" target="_blank">21</a>] and our own transect surveys. Horizontal lines indicate the elevation of the population used in the study.</p

Microclimate temperature variation on Mt. Rainier.

<p>Mean (± s.d.) temperature variation among four <i>Nebria</i> collection sites on Mt. Rainier. Temperatures were recorded every 30 minutes for 44 days from June 20^th to August 2^nd, 2014, with DS1922L iButtons. Mean nightly maximum (filled circles) and minimum (open squares) were calculated for each site using temperatures between the hours of sunset and sunrise.</p

Population details for intraspecific comparisons.

<p>Population details for intraspecific comparisons.</p

Associations between physiological traits and elevational range among 12 <i>Nebria</i> species from Mt. Rainier.

<p>(A) Cold tolerance and the high-elevation range edge (all <i>n</i> = 10); (B) heat tolerance and the low-elevation range edge (all <i>n</i> = 10); and (C) desiccation resistance and the high-elevation range edge (all <i>n</i> = 5; filled circles represent water loss rates at 5°C, while open squares are water loss rates at 10°C, measured over 24 h). In (B), three species have their lower elevation limit at 600 m, and two at 1100 m and have been repositioned for graphical purposes only; trait means for each species are also provided in Table C in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0151959#pone.0151959.s002" target="_blank">S2 Appendix</a>. Error bars are ± s.d.</p