Browsing by Author "Koot EM"

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    Climate change and alpine-adapted insects: modelling environmental envelopes of a grasshopper radiation
    (The Royal Society, 2022-03-02) Koot EM; Morgan-Richards M; Trewick SA
    Mountains create steep environmental gradients that are sensitive barometers of climate change. We calibrated 10 statistical models to formulate ensemble ecological niche models for 12 predominantly alpine, flightless grasshopper species in Aotearoa New Zealand, using their current distributions and current conditions. Niche models were then projected for two future global climate scenarios: representative concentration pathway (RCP) 2.6 (1.0°C rise) and RCP8.5 (3.7°C rise). Results were species specific, with two-thirds of our models suggesting a reduction in potential range for nine species by 2070, but surprisingly, for six species, we predict an increase in potential suitable habitat under mild (+1.0°C) or severe global warming (+3.7°C). However, when the limited dispersal ability of these flightless grasshoppers is taken into account, all 12 species studied are predicted to suffer extreme reductions in range, with a quarter likely to go extinct due to a 96-100% reduction in suitable habitat. Habitat loss is associated with habitat fragmentation that is likely to escalate stochastic vulnerability of remaining populations. Here, we present the predicted outcomes for an endemic radiation of alpine taxa as an exemplar of the challenges that alpine species, both in New Zealand and internationally, are subject to by anthropogenic climate change.
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    Global warming leads to habitat loss and genetic erosion of alpine biodiversity
    (John Wiley and Sons Ltd, 2023-03-11) Meza-Joya FL; Morgan-Richards M; Koot EM; Trewick SA; Parmakelis A
    Aim Species living on steep environmental gradients are expected to be especially sensitive to global climate change, but little is known about the factors influencing their responses to contemporary warming. Here, we investigate the influence of climate on the biogeography of three alpine species with overlapping ranges. Location Te Waipounamu (South Island) Aotearoa–New Zealand. Taxon Endemic alpine adapted Catantopinae grasshoppers. Methods We used niche modelling to estimate and project the potential niche of three focal species under past and future climate scenarios. Vulnerability assessments were performed using niche factor analyses. Demographic trends and phylogeographic structure were investigated using samples from 15 mountain tops to generate mitochondrial DNA haplotype networks and population genetic statistics. Results Niche models and genetic data suggest suitable habitat for all three alpine species was more widespread and contiguous in the past than today. Demographic analyses indicate in situ survival rather than post-Pleistocene colonisation of current habitat. Population structuring and genetic divergence suggest that mountain uplift during the Pliocene and environmental barriers during Pleistocene glacial and interglacial stages shaped contemporary population structure of each species. Although geographically overlapping, niche analyses suggest these alpine species are not ecologically identical, each showing distinct responses to environmental change, but all will lose intraspecific diversity through population extinction. Main Conclusions Climatic, biological and geophysical factors controlled population structuring of three cold-adapted species during the Pleistocene with a legacy of spatially separate intraspecific lineages. Ecological niche models for each species emphasise distinct combinations of environmental proxies, but all are expected to experience severe habitat reduction during climate warming. Increased global temperatures drive available habitat to higher elevation resulting in population contractions, range shifts, habitat fragmentation, local extinctions and genetic impoverishment. Despite alpine species not being ecologically identical, we predict all mountain biota will lose significant genetic diversity due to global warming.
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    Ngāokeoke Aotearoa: The Peripatoides Onychophora of New Zealand
    (MDPI (Basel, Switzerland), 2024-04-04) Trewick SA; Koot EM; Morgan-Richards M; Allegrucci G
    (1) Background: Originally described as a single taxon, Peripatoides novaezealandiae (Hutton, 1876) are distributed across both main islands of New Zealand; the existence of multiple distinct lineages of live-bearing Onychophora across this spatial range has gradually emerged. Morphological conservatism obscured the true endemic diversity, and the inclusion of molecular tools has been instrumental in revealing these cryptic taxa. (2) Methods: Here, we review the diversity of the ovoviviparous Onychophora of New Zealand through a re-analysis of allozyme genotype data, mitochondrial DNA cytochrome oxidase subunit I sequences, geographic information and morphology. (3) Results: New analysis of the multilocus biallelic nuclear data using methods that do not require a priori assumptions of population assignment support at least six lineages of ovoviviparous Peripatoides in northern New Zealand, and mtDNA sequence variation is consistent with these divisions. Expansion of mitochondrial DNA sequence data, including representation of all existing taxa and additional populations extends our knowledge of the scale of sympatry among taxa and shows that three other lineages from southern South Island can be added to the Peripatoides list, and names are proposed here. In total, 10 species of Peripatoides can be recognised with current data.
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    The future of molecular ecology in Aotearoa New Zealand: an early career perspective
    (Taylor and Francis Group on behalf of the Royal Society of New Zealand, 2022-07-14) Liggins L; Arranz V; Braid HE; Carmelet-Rescan D; Elleouet J; Egorova E; Gemmell MR; Hills SFK; Holland LP; Koot EM; Lischka A; Maxwell KH; McCartney LJ; Nguyen HTT; Noble C; Olmedo Rojas P; Parvizi E; Pearman WS; Sweatman JAN; Kaihoro TR; Walton K; Aguirre JD; Stewart LC; Moss S
    The skills, insights, and genetic data gathered by molecular ecologists are pivotal to addressing many contemporary biodiversity, environmental, cultural, and societal challenges. Concurrently, the field of molecular ecology is being revolutionised by rapid technological development and diversification in the scope of its applications. Hence, it is timely to review the future opportunities of molecular ecological research in Aotearoa New Zealand, and to reconcile them with philosophies of open science and the implications for Indigenous data sovereignty and benefit sharing. Future molecular ecologists need to be interdisciplinary, equipped to embrace innovation, and informed about the broader societal relevance of their research, as well as advocates of best practice. Here, we present an ideal future for molecular ecology in Aotearoa, based on the perspectives of 23 early career researchers from tertiary institutions, Crown Research Institutes, research consultancies, and government agencies. Our article provides: a guide for molecular ecologists embarking on genetic research in Aotearoa, and a primer for individuals in a position to support early career molecular ecologists in Aotearoa. We outline our goals and highlight specific considerations–for molecular ecology and the scientific community in Aotearoa–based on our own experience and aspirations, and invite other researchers to join this dialogue.