Ecological Implications of Germination Temperature on Native and Invasive <i>Rumex</i> Spp.

<i>Rumex alpinus</i> L. (<i>R. alpinus</i>) is a non-native invasive plant in Czech mountain regions, altering ecosystem structure and function in protected areas. <i>Rumex obtusifolius</i> L. (<i>R. obtusifolius</i>) is a native species and a problematic weed in Czech meadows, while <i>Rumex longifolius</i> DC. (<i>R. longifolius</i>) is characteristic of Fennoscandia and widespread in northern and central Europe. This study explores temperature-driven germination patterns in <i>R. alpinus</i>, <i>R. obtusifolius</i>, and <i>R. longifolius</i> and also focuses on potential differences across populations of <i>R. alpinus</i>. The hypothesis suggests that <i>R. alpinus</i> is not established in lowland areas due to temperature limitations during germination. A second experiment evaluates the influence of native and non-native localities on <i>R. alpinus</i> seed germination. The primary experiment was conducted at 6°C, 12°C, 18°C, 24°C, 29°C, and 35°C in a climate chamber, while the second experiment was performed at 24°C for 14 days. Contrary to expectations, <i>R. alpinus</i> exhibited the highest germination rate across all temperatures. In the second experiment, germination rates varied significantly, with a positive correlation between germination success and transition from Alpine to Czech localities. The highest and fastest germination was observed in seeds from the Krkonoše Mountains, where <i>R. alpinus</i> is an invasive plant species.