Reproductive losses due to climate change-induced earlier flowering are not the primary threat to plant population viability in a perennial herb
Reproductive losses due to climate change-induced earlier flowering are not the primary threat to plant population viability in a perennial herb
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DOI：
10.1111/1365-2745.13146
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发表时间：
2019-07-01
影响因子：
5.5
通讯作者：
Miller, Tom E. X.
中科院分区：
文献类型：
--
作者：
Iler, Amy M.;Compagnoni, Aldo;Miller, Tom E. X.
尽管全球范围内的开花物候变化，以应对气候变化，这些变化的生殖后果知之甚少。此外，还不知道开花时间的改变是否会影响植物种群的生存能力。我们研究是否气候变化引起的提前开花的人口持续性的后果，将生殖损失从霜冻损害（提前开花的风险）到亚高山向日葵（Helianthella quinquenervis）的人口模型。使用跨越物种海拔范围（8-15年，取决于人口）的三个种群的长期人口统计数据，我们首先研究融雪日期如何影响植物生命率。为了验证生命率对融雪日期的反应，我们在一个人口中进行了除雪实验。最后，我们为每个种群构造了随机种群预测模型和生命表响应实验。我们发现，人口下降（λ（s）< 1）作为融雪日期变得更早。霜冻对花蕾的损害，是气候变化导致开花提前的结果，并没有对种群数量下降产生强烈影响。相反，我们发现的证据表明，对生存的负面影响，可能是由于在较长的生长季节增加干旱风险，驱动预计人口下降下较早的融雪日期。合成.开花物候的变化是生物对气候变化的反应的一个显著而重要的方面，但在这里，我们表明，生殖事件的物候可能是不可靠的措施，人口持续性的威胁，即使提前开花与大量的生殖损失。生殖物候变化的证据，沿着更少的证据表明这些变化实际上影响生殖成功，是有价值的，但可以描绘一个不完整的，甚至是误导的植物种群对气候变化的反应。
Despite a global footprint of shifts in flowering phenology in response to climate change, the reproductive consequences of these shifts are poorly understood. Furthermore, it is unknown whether altered flowering times affect plant population viability. We examine whether climate change-induced earlier flowering has consequences for population persistence by incorporating reproductive losses from frost damage (a risk of early flowering) into population models of a subalpine sunflower (Helianthella quinquenervis). Using long-term demographic data for three populations that span the species' elevation range (8-15 years, depending on the population), we first examine how snowmelt date affects plant vital rates. To verify vital rate responses to snowmelt date experimentally, we manipulate snowmelt date with a snow removal experiment at one population. Finally, we construct stochastic population projection models and Life Table Response Experiments for each population. We find that populations decline (lambda(s) < 1) as snowmelt dates become earlier. Frost damage to flower buds, a consequence of climate change-induced earlier flowering, does not contribute strongly to population declines. Instead, we find evidence that negative effects on survival, likely due to increased drought risk during longer growing seasons, drive projected population declines under earlier snowmelt dates. Synthesis. Shifts in flowering phenology are a conspicuous and important aspect of biological responses to climate change, but here we show that the phenology of reproductive events can be unreliable measures of threats to population persistence, even when earlier flowering is associated with substantial reproductive losses. Evidence for shifts in reproductive phenology, along with scarcer evidence that these shifts actually influence reproductive success, are valuable but can paint an incomplete and even misleading picture of plant population responses to climate change.