Comparative studies of seed germination of closely related taxa can help increase our understanding of the ecological limitations of cold-adapted plants and forecast how they might respond to global warming. No studies exist on the relationship between thermoclimatic belts that classify mountain life zones according to bioclimatic criteria and the germination strategy of alpine plants. The aim of this study was to assess this relationship using two closely related species growing in different thermotypes and to test whether their germination responses were related to the climate at natural sites. Fresh Rhaponticum bicknellii and R. scariosum seeds were cold stratified for 0, 30, 60 and 90 days and tested for germination at 10, 15 and 20 °C. At the same time, seed burial experiments were run in the field and in the plant nursery. A GLM analysis showed that the length of cold stratification affected significantly only the germination of R. bicknellii seeds, while increasing temperatures prompted germination in both species. We found that R. bicknellii adopts a drought-avoiding germination strategy, while R. scariosum germination is favoured by warm temperatures. Our findings support the general view that alpine plants do not share common germination requirements and that any conclusions should be interpreted from a biogeographical and bioclimatic perspective. Therefore, seed germination and seedling establishment of endemic alpine species can also be predicted by looking at the bioclimate of the species’ range.

中文翻译：

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利古里亚和海洋阿尔卑斯山（意大利皮埃蒙特）不同气候区的两种地方性根瘤菌（菊科）的比较发芽生态。

密切相关的分类单元的种子发芽的比较研究可以帮助我们加深对冷适应植物的生态限制的了解，并预测它们对全球变暖的反应。关于根据生物气候标准对山区生活区进行分类的热气候带与高山植物的萌发策略之间的关系尚无研究。这项研究的目的是使用两种在不同热型下密切相关的物种评估这种关系，并测试它们的发芽反应是否与自然地点的气候有关。新鲜的Rhaponticum bicknellii和R.scariosum将种子冷分层0、30、60和90天，并在10、15和20°C下测试发芽率。同时，在田间和植物苗圃进行了种子埋葬实验。GLM分析表明，冷分层的长度仅显着影响比克尼利罗非鱼种子的发芽，而温度升高则促使两个物种发芽。我们发现R. bicknellii采用了避免干旱的发芽策略，而R. scariosum温暖的温度有利于发芽。我们的发现支持普遍的观点，即高山植物没有共同的发芽要求，任何结论都应从生物地理和生物气候的角度进行解释。因此，也可以通过观察该物种范围的生物气候来预测特有高山物种的种子发芽和幼苗生长。