Pleistocene Divergence and Long-Term Population Decline in Three Endemic Euphorbia Species of High Conservation Concern From the South-Western Alps and the Mountains of Corsica and Sardinia

IF 4.2 2区环境科学与生态学 Q1 BIODIVERSITY CONSERVATION

Diversity and Distributions Pub Date : 2026-03-31 DOI:10.1111/ddi.70177

Valentin Heimer, Božo Frajman

{"title":"Pleistocene Divergence and Long-Term Population Decline in Three Endemic Euphorbia Species of High Conservation Concern From the South-Western Alps and the Mountains of Corsica and Sardinia","authors":"Valentin Heimer, Božo Frajman","doi":"10.1111/ddi.70177","DOIUrl":null,"url":null,"abstract":"<div>\n \n \n <section>\n \n <h3> Aim</h3>\n \n <p>Understanding the evolutionary history and demographic dynamics of narrow-ranged endemics is essential for predicting their future under climate change. We investigated the origins, population trajectories, and conservation outlook of three endemic spurges (<i>Euphorbia gayi</i>, <i>E. valliniana</i>, <i>E. variabilis</i>) restricted to the south-western Alps, Corsica, and Sardinia.</p>\n </section>\n \n <section>\n \n <h3> Location</h3>\n \n <p>South-western Alps, Corsica, Sardinia.</p>\n </section>\n \n <section>\n \n <h3> Methods</h3>\n \n <p>We used restriction site-associated DNA (RAD) sequencing data to infer phylogenetic relationships, population structure, and long-term effective population size (<i>N</i><sub><i>e</i></sub>) dynamics through demographic modelling. To assess vulnerability under climate change, we combined genomic insights with species distribution modelling (SDM) across past (Last Glacial Maximum), present, and future (ssp126, ssp370, ssp585) climate scenarios.</p>\n </section>\n \n <section>\n \n <h3> Results</h3>\n \n <p>Genomic analyses revealed mid-Pleistocene divergence of <i>E. gayi</i> and evidence of long-distance dispersal underlying the origin of <i>E. variabilis</i>. All three species showed strong genetic structure and limited connectivity among populations, alongside a long-term decline in <i>N</i><sub><i>e</i></sub>. SDMs predicted substantial range contractions under future warming, with losses of up to 98% of suitable habitat by 2100 under the ssp585 scenario. Even under optimistic projections (ssp126), range reduction was pronounced, particularly for the small and isolated Corsican and Sardinian populations of <i>E. gayi</i>.</p>\n </section>\n \n <section>\n \n <h3> Main Conclusions</h3>\n \n <p>Our integrative genomic and ecological modelling approach highlights the vulnerability of three narrow-ranged alpine and montane endemics to ongoing climate change. Persistent demographic decline, limited population connectivity, and severe habitat loss together place these taxa at high risk of local or complete extinction. These findings emphasise the need for urgent conservation measures to safeguard endemic Mediterranean mountain plants under future climate change.</p>\n </section>\n </div>","PeriodicalId":51018,"journal":{"name":"Diversity and Distributions","volume":"32 3","pages":""},"PeriodicalIF":4.2000,"publicationDate":"2026-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/ddi.70177","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Diversity and Distributions","FirstCategoryId":"93","ListUrlMain":"https://onlinelibrary.wiley.com/doi/10.1111/ddi.70177","RegionNum":2,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"BIODIVERSITY CONSERVATION","Score":null,"Total":0}

引用次数: 0

Abstract

Aim

Understanding the evolutionary history and demographic dynamics of narrow-ranged endemics is essential for predicting their future under climate change. We investigated the origins, population trajectories, and conservation outlook of three endemic spurges (Euphorbia gayi, E. valliniana, E. variabilis) restricted to the south-western Alps, Corsica, and Sardinia.

Location

South-western Alps, Corsica, Sardinia.

Methods

We used restriction site-associated DNA (RAD) sequencing data to infer phylogenetic relationships, population structure, and long-term effective population size (N_e) dynamics through demographic modelling. To assess vulnerability under climate change, we combined genomic insights with species distribution modelling (SDM) across past (Last Glacial Maximum), present, and future (ssp126, ssp370, ssp585) climate scenarios.

Results

Genomic analyses revealed mid-Pleistocene divergence of E. gayi and evidence of long-distance dispersal underlying the origin of E. variabilis. All three species showed strong genetic structure and limited connectivity among populations, alongside a long-term decline in N_e. SDMs predicted substantial range contractions under future warming, with losses of up to 98% of suitable habitat by 2100 under the ssp585 scenario. Even under optimistic projections (ssp126), range reduction was pronounced, particularly for the small and isolated Corsican and Sardinian populations of E. gayi.

Main Conclusions

Our integrative genomic and ecological modelling approach highlights the vulnerability of three narrow-ranged alpine and montane endemics to ongoing climate change. Persistent demographic decline, limited population connectivity, and severe habitat loss together place these taxa at high risk of local or complete extinction. These findings emphasise the need for urgent conservation measures to safeguard endemic Mediterranean mountain plants under future climate change.

Abstract Image

查看原文本刊更多论文

西南阿尔卑斯及科西嘉和撒丁岛三种高度保护的大大麻特有物种的更新世分化和长期种群下降

目的了解小范围地方性昆虫的进化历史和种群动态对预测它们在气候变化下的未来至关重要。本文研究了分布于阿尔卑斯山西南部、科西嘉岛和撒丁岛的三种地方性刺虫（Euphorbia gayi， E. valliniana， E. variabilis）的起源、种群轨迹和保护前景。位置西南阿尔卑斯山，科西嘉岛，撒丁岛。方法利用限制性内切位点相关DNA （RAD）测序数据，通过人口统计学模型推断系统发育关系、种群结构和长期有效种群大小（Ne）动态。为了评估气候变化下的脆弱性，我们将基因组学见解与物种分布模型（SDM）结合起来，跨越过去（末次盛冰期）、现在和未来（ssp126、ssp370、ssp585）气候情景。结果基因组分析显示，在更新世中期，盖伊古猿出现了分化，并为变异古猿的起源提供了远距离传播的证据。这三个物种均表现出较强的遗传结构和种群间有限的连通性，同时它们的种群数量也在长期下降。SDMs预测，在未来变暖的情况下，范围将大幅缩小，在ssp585情景下，到2100年将失去高达98%的适宜栖息地。即使在乐观的预测（ssp126）下，分布范围也明显缩小，特别是对于小而孤立的科西嘉和撒丁岛的大背蝗种群。我们的综合基因组和生态建模方法强调了三种窄范围高山和山地特有物种对持续气候变化的脆弱性。持续的人口下降、有限的种群连通性和严重的栖息地丧失共同使这些分类群面临着局部或完全灭绝的高风险。这些发现强调了在未来气候变化下，迫切需要采取保护措施来保护地中海特有山地植物。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

求助全文

约1分钟内获得全文求助全文

来源期刊

Diversity and Distributions 环境科学-生态学

CiteScore

8.90

自引率

4.30%

发文量

195

审稿时长

8-16 weeks

期刊介绍： Diversity and Distributions is a journal of conservation biogeography. We publish papers that deal with the application of biogeographical principles, theories, and analyses (being those concerned with the distributional dynamics of taxa and assemblages) to problems concerning the conservation of biodiversity. We no longer consider papers the sole aim of which is to describe or analyze patterns of biodiversity or to elucidate processes that generate biodiversity.