Phenotypic plasticity and genetic adaptation in arctic plants in a warming climate: response to long-term experimental and observed climate change

物种有三种选择来应对气候变化：适应、迁徙或灭绝。虽然地球的气候在过去经历了重大变化，但变化相对缓慢，这使得具有正确遗传特征的生物能够适应和生存。然而，由于温室气体排放的增加，目前的变暖正在以前所未有的速度发生，特别是在北极。在过去的50年里，北极的气候已经变暖了1摄氏度以上。我们不知道苔原植物物种是否有能力适应快速变暖。我们知道，苔原植物在实验中变暖或在过去20-30年里随着气候变暖而进行测量时，会做出预测的反应。大多数植物在温暖的环境中开花更早，生长更快，结出更大更好的种子。我们需要知道的是，温暖的植物中的这些变化是否是永久性的，以及温暖的地块中的植物是否会继续变大并结出更好的种子，即使它们是在温暖的地块之外生长的。我们将在北极高地埃尔斯米尔岛的一个地点进行一系列变暖实验，从我们自1992年以来一直跟踪的主要苔原植物物种中收集种子。我们将在耶洛奈夫以北的低北极地区的另一个试验场进行同样的实验。这些种子将在不列颠哥伦比亚大学的气候控制室中发芽和生长，在那里它们将被允许开花和产生种子。这些第二代种子的幼苗将被种植到研究地点温暖和未温暖的地块中。如果来自温暖植物的种子的植物继续比来自未温暖地块的植物更早开花，有更大的叶子，更大和更好的种子，那么我们将有非常有力的证据表明，在19-20年的实验中，植物已经能够适应温暖的条件。如果植物之间没有差异，那么我们可以得出结论，(目前)还没有发生对变暖的遗传适应。这种类型的研究对于理解和预测变暖世界中苔原生态系统的未来至关重要。

Species have three options to deal with the changes in climate: adapt, migrate or go extinct. While the climate of the planet has gone through major changes in the past, the changes were relatively slow which allowed organisms with the right mix of genetic traits, to adapt and survive. However, the current warming, due to the increased emissions of greenhouse gases, is happening at a rate that has never been seen before, especially in the Arctic. The climate of the Arctic has already warmed by more than 1°C in the past 50 years. We do not know if tundra plant species have the ability to adapt to the rapid warming. We know that tundra plants responded as predicted when warmed in experiments or when measured over the past 20-30 years as the climate has warmed. Most plants flowered earlier, increased in growth and produced larger and better seeds in warmed environments. What we need to know is whether these changes in warmed plants are permanent, and if the plants in warmed plots continue to grow larger and produce better seeds even when they are grown outside the warmed plots. We will collect seeds from the major tundra plant species we have been following since 1992 in a set of warming experiments at a site on Ellesmere Island in the High Arctic. We will do the same at another experimental site in the Low Arctic, north of Yellowknife. The seeds will be germinated and seedlings grown in climate controlled chambers at the University of British Columbia where they will be allowed to flower and produce seeds. Seedlings from these second generation seeds will be planted into warmed and unwarmed plots at the research sites. If the plants from seeds that originally came from warmed plants continue to flower earlier, have larger leaves, and larger and better seeds than the plants from the unwarmed plots, then we will have very strong evidence that the plants have been able to adapt to the warmed conditions over the 19-20 years of the experiment. If there is no difference between the plants, then we can conclude that genetic adaptation to the warming has not (yet) occurred. This type of research is critical to understand and predict the future of tundra ecosystems in a warmer world.