Climate and rapid local adaptation as drivers of germination and seed bank dynamics of Alliaria petiolata (garlic mustard) in North America

Local differences in climate conditions may facilitate rapid evolutionary changes in introduced plants to optimize timing of germination or ability to survive in seed banks, which may constitute beneficial demographic adaptations during range expansions. Understanding differences in germination requirements and emergence patterns across a species’ range is critical for demographic modelling and potential invasive species control efforts.
We assessed germination responses of Alliaria petiolata using seeds collected from 10 populations spanning much of the North American distribution of the species. We compared germination responses under different stratification regimes in a growth chamber over 2·5 years, and evaluated seedling emergence in a common garden in Ithaca, New York over 13 years. We further evaluated how climate overlap between Ithaca and original collection sites influenced emergence patterns.
In the laboratory, germination of all populations was similar and highest at 4 °C...

局地气候条件的差异，可促使外来植物发生快速演化，以优化其萌发时机或种子库存活能力，此类演化在物种分布范围扩张过程中或可构成有益的种群统计学适应性。
阐明物种分布范围内萌发需求与出苗模式的差异，对于种群统计学建模以及潜在的入侵物种防控工作至关重要。
本研究以采集自大蒜芥（Alliaria petiolata）北美分布区绝大多数区域的10个种群的种子为材料，对其萌发响应进行了评估。我们在生长箱中设置不同层积（stratification）处理条件，于2.5年的周期内比较了各群体的萌发响应；同时在纽约州伊萨卡的同质园内开展了为期13年的试验，评估幼苗出苗情况。我们进一步探究了伊萨卡与原始采集位点之间的气候重叠度如何影响出苗模式。
实验室条件下，所有种群的萌发率均较为相近，且在4 ℃时达到最高值……