Global climate change poses a significant threat to natural communities around the world, with many plant species showing signs of climate stress. Grassland ecosystems are not an exception, with climate change compounding contemporary pressures such as habitat loss and fragmentation. In this study, we assess the climate resilience of Themeda triandra, a foundational species and the most widespread plant in Australia, by assessing the relative contributions of spatial, environmental and ploidy factors to contemporary genomic variation. Reduced‐representation genome sequencing on 472 samples from 52 locations was used to test how the distribution of genomic variation, including ploidy polymorphism, supports adaptation to hotter and drier climates. We explicitly quantified isolation by distance (IBD) and isolation by environment (IBE) and predicted genomic vulnerability of populations to future climates based on expected deviation from current genomic composition. We found that a majority (54%) of genomic variation could be attributed to IBD, while an additional 22% (27% when including ploidy information) could be explained by two temperature and two precipitation climate variables demonstrating IBE. Ploidy polymorphisms were common within populations (31/52 populations), indicating that ploidy mixing is characteristic of T. triandra populations. Genomic vulnerabilities were found to be heterogeneously distributed throughout the landscape, and our analysis suggested that ploidy polymorphism, along with other factors linked to polyploidy, reduced vulnerability to future climates by 60% (0.25–0.10). Our data suggests that polyploidy may facilitate adaptation to hotter climates and highlight the importance of incorporating ploidy in adaptive management strategies to promote the resilience of this and other foundation species.

中文翻译：

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空间，气候和倍性因素驱动着广泛分布的特提达草中的基因组多样性和适应力。

全球气候变化对世界各地的自然社区构成了重大威胁，许多植物物种都表现出气候压力的迹象。草原生态系统也不例外，气候变化加剧了当代压力，例如生境丧失和破碎化。在这项研究中，我们评估了Themeda triandra的气候适应能力通过评估空间，环境和倍性因子对当代基因组变异的相对贡献，是澳大利亚的基础物种和最广泛的植物。使用来自52个位置的472个样本的减少代表性的基因组测序来测试基因组变异的分布（包括倍性多态性）如何支持适应更热和更干燥的气候。我们明确量化了距离隔离（IBD）和环境隔离（IBE），并根据与当前基因组组成的预期偏差，预测了人口对未来气候的基因组脆弱性。我们发现，大多数（54％）的基因组变异可归因于IBD，而另外22％（包括倍性信息时为27％）可以用两个温度和两个降水气候变量来说明IBE来解释。倍性多态性在种群（31/52种群）中很常见，表明倍性混合是T. triandra种群。发现基因组脆弱性在整个景观中分布不均，我们的分析表明，倍性多态性以及与多倍性相关的其他因素使对未来气候的脆弱性降低了60％（0.25–0.10）。我们的数据表明，多倍体可能有助于适应较热的气候，并强调了将倍性纳入适应性管理策略中以提高该物种和其他基础物种的适应力的重要性。