Shryock Daniel F, Washburn Loraine K, DeFalco Lesley A, Esque Todd C
U.S. Geological Survey, Western Ecological Research Center, Henderson, NV, USA.
California Botanic Garden, Claremont, CA, USA.
Mol Ecol. 2021 Feb;30(3):698-717. doi: 10.1111/mec.15672. Epub 2021 Jan 2.
Local adaptation features critically in shaping species responses to changing environments, complicating efforts to revegetate degraded areas. Rapid climate change poses an additional challenge that could reduce fitness of even locally sourced seeds in restoration. Predictive restoration strategies that apply seeds with favourable adaptations to future climate may promote long-term resilience. Landscape genomics is increasingly used to assess spatial patterns in local adaption and may represent a cost-efficient approach for identifying future-adapted genotypes. To demonstrate such an approach, we genotyped 760 plants from 64 Mojave Desert populations of the desert annual Plantago ovata. Genome scans on 5,960 SNPs identified 184 potentially adaptive loci related to climate and satellite vegetation metrics. Causal modelling indicated that variation in potentially adaptive loci was not confounded by isolation by distance or isolation by habitat resistance. A generalized dissimilarity model (GDM) attributed spatial turnover in potentially adaptive loci to temperature, precipitation and NDVI amplitude, a measure of vegetation green-up potential. By integrating a species distribution model (SDM), we find evidence that summer maximum temperature may both constrain the range of P. ovata and drive adaptive divergence in populations exposed to higher temperatures. Within the species' current range, warm-adapted genotypes are predicted to experience a fivefold expansion in climate niche by midcentury and could harbour key adaptations to cope with future climate. We recommend eight seed transfer zones and project each zone into its relative position in future climate. Prioritizing seed collection efforts on genotypes with expanding future habitat represents a promising strategy for restoration practitioners to address rapidly changing climates.
局部适应性在塑造物种对变化环境的反应中起着关键作用，这使得恢复退化地区植被的努力变得复杂。快速的气候变化带来了额外的挑战，甚至可能降低恢复中即使是本地来源种子的适应性。应用具有适应未来气候良好适应性种子的预测性恢复策略可能会促进长期恢复力。景观基因组学越来越多地用于评估局部适应性的空间模式，可能是识别适应未来基因型的一种经济有效的方法。为了展示这种方法，我们对来自沙漠一年生植物卵叶车前64个莫哈韦沙漠种群的760株植物进行了基因分型。对5960个单核苷酸多态性（SNP）进行的基因组扫描确定了184个与气候和卫星植被指标相关的潜在适应性位点。因果模型表明，潜在适应性位点的变异不受距离隔离或栖息地抗性隔离的混淆。广义差异模型（GDM）将潜在适应性位点的空间周转率归因于温度、降水和归一化植被指数（NDVI）幅度，这是一种衡量植被返青潜力的指标。通过整合物种分布模型（SDM），我们发现有证据表明夏季最高温度可能既限制了卵叶车前的分布范围，又驱动了暴露于较高温度下种群的适应性分化。在该物种目前的分布范围内，预计到本世纪中叶，适应温暖环境的基因型的气候生态位将扩大五倍，并可能拥有应对未来气候的关键适应性特征。我们推荐了八个种子转移区，并将每个区投射到其在未来气候中的相对位置。优先收集未来栖息地不断扩大的基因型的种子，对于恢复从业者应对快速变化的气候来说是一种很有前景的策略。
