Variation in the seasonal germination niche across an elevational gradient: the role of germination cueing in current and future climates
Variation in the seasonal germination niche across an elevational gradient: the role of germination cueing in current and future climates
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DOI：
10.1002/ajb2.1425
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发表时间：
2020-02-13
影响因子：
3
通讯作者：
Schmitt, Johanna
中科院分区：
文献类型：
--
作者：
Gremer, Jennifer R.;Chiono, Alec;Schmitt, Johanna
种子萌发的时间对适合度、种群动态和物种范围有着深远的影响。许多植物已经进化出对季节性环境线索的响应，以在有利条件下萌发;这些响应与当地气候的时间变化相互作用，以驱动季节性气候生态位，并可能反映当地的适应。在这里，我们研究了不同海拔梯度的扭枝链霉菌种群对温度线索的萌发反应。方法使用普通花园实验，我们评估了种群之间对冷层积（寒冷）和萌发温度反应的差异，并将其与田间观察到的萌发物候相关联。然后，我们探讨了这些反应与过去的气候在每个网站和这些模式下的未来气候changes.Results的影响，从高海拔地区的人口有较强的分层要求发芽和较窄的温度范围内发芽没有分层。发芽反应的差异与海拔和季节性温度和降水的变化在人群中。此外，它们对应于在该领域的发芽物候;低海拔人口在没有寒冷的秋季发芽，而高海拔人口在春季和夏季的冬季寒冷和融雪后发芽。气候变化预测表明，气温升高和积雪减少，这可能会改变发芽线索和时间，特别是高海拔种群。tortuosus受温度的影响很大，并在海拔梯度上变化。气候变化可能会影响发芽时间，这可能会级联影响性状表达，健身和人口的持久性。
Premise The timing of germination has profound impacts on fitness, population dynamics, and species ranges. Many plants have evolved responses to seasonal environmental cues to time germination with favorable conditions; these responses interact with temporal variation in local climate to drive the seasonal climate niche and may reflect local adaptation. Here, we examined germination responses to temperature cues in Streptanthus tortuosus populations across an elevational gradient.Methods Using common garden experiments, we evaluated differences among populations in response to cold stratification (chilling) and germination temperature and related them to observed germination phenology in the field. We then explored how these responses relate to past climate at each site and the implications of those patterns under future climate change.Results Populations from high elevations had stronger stratification requirements for germination and narrower temperature ranges for germination without stratification. Differences in germination responses corresponded with elevation and variability in seasonal temperature and precipitation across populations. Further, they corresponded with germination phenology in the field; low-elevation populations germinated in the fall without chilling, whereas high-elevation populations germinated after winter chilling and snowmelt in spring and summer. Climate-change forecasts indicate increasing temperatures and decreasing snowpack, which will likely alter germination cues and timing, particularly for high-elevation populations.Conclusions The seasonal germination niche for S. tortuosus is highly influenced by temperature and varies across the elevational gradient. Climate change will likely affect germination timing, which may cascade to influence trait expression, fitness, and population persistence.