Plant population and community responses to environmental change

植物生命中每年发生的事件，如叶子或花的出现，对这些植物的表现以及它们与其他种群和其他物种的互动有着重要的影响。由于这类事件的发生时间(“物候”)对气候条件很敏感，我们预计气候变化可能会通过物候作用产生重要的生态后果。然而，测试涉及年复一年气候波动的假设气候需要长期数据，这在生态学中是罕见的。我的中心目标是测试关于气候、物候、植物适合度和物种相互作用之间因果联系的假设。在接下来的5年里，植物开花的长期监测点和植物物候的自动摄像机网络将分别延长到15年和10年。对这些数据的分析，以及操纵假设的因果因素的有针对性的实验，将允许从机械上理解植物物候的原因和结果。其结果将是基本生态理解方面的重大进展，通过改进预测气候变化的生态后果的基础，对科学和加拿大都有好处。这项研究在魁北克国家公园的Mégantic山进行，那里的低海拔温度落叶林以糖枫为主，高海拔北方森林以香脂冷杉和红云杉为主。重点主要放在早春出现的林下植物上，这些植物在树冠树叶展开之前，利用4到5周的强光。全文共分三个研究主题。主题1侧重于开花物候，并将首先测试以下假设：(I)开花时间对积雪融化最敏感，(Ii)气候变暖将导致不同海拔种群之间基因流动的可能性降低，以及(Iii)气候变暖与同时开花的植物物种的新颖组合有关。随后的实验研究将测试物候变化的潜在后果(例如，植物与传粉者的相互作用)。主题2侧重于营养(叶)物候，并将首先测试春季林下植物高光期的持续时间将随着气候变暖而增加的假设。主题3将使用操控实验来测试因果因素(例如，积雪融化、温度、日长)，这些因素可能是田间观察到的开花和营养物候模式的基础。拟议的研究计划涉及制作具有里程碑意义的植物物候长期数据，结合了高时间分辨率、关于花或植物数量和大小的详细数据(而不仅仅是存在)以及覆盖陡峭气候(海拔)梯度的独特组合。结合有针对性的实验研究，这些结果将使重大科学进步成为可能。

The timing of yearly events in a plant's life, such as the emergence of leaves or flowers, has important consequences for how those plants perform and how they interact with other populations and other species. Since the timing of such events ("phenology") is sensitive to climatic conditions, we expect potentially important ecological consequences of climate change acting through phenology. However, testing hypotheses involving year-to-year climate fluctuations climate requires long-term data, which is rare in ecology. My central objective is to test hypotheses concerning causal links between climate, phenology, plant fitness, and species interactions. Over the next 5 years, long-term monitoring plots for plant flowering and a network of automated cameras for vegetative phenology will be extended to durations of 15 and 10 years, respectively. Analyses of these data, along with targeted experiments manipulating hypothesized causal factors, will permit mechanistic understanding of the causes and consequences of plant phenology. The outcome will be major advances in fundamental ecological understanding, with benefits both to science and to Canada via an improved basis for forecasting the ecological consequences of climate change. The research takes place in Parc national du Mont Mégantic, Québec, where low-elevation temperature deciduous forest is dominated by sugar maple, and high-elevation boreal forest is dominated by balsam fir and red spruce. The focus is largely on understory plants that emerge in early spring and that take advantage of a 4 to 5-week period of high light, prior to the expansion of canopy tree leaves. There are 3 research themes. Theme 1 focuses on flowering phenology and will first test the hypotheses that (i) flowering time is most sensitive to snowmelt, (ii) climate warming will cause reduced potential for gene flow across populations at different elevations, and (iii) climate warming is associated with novel combinations of plant species that flower simultaneously. Subsequent experimental studies will test for potential consequences of altered phenology (e.g., for plant-pollinator interactions). Theme 2 focuses on vegetative (leaf) phenology and will first test the hypothesis that the duration of the high-light period for spring understory plants will increase with climate warming. Theme 3 will use manipulative experiments to test causal factors (e.g., snowmelt, temperature, day length) that potentially underlie patterns observed in the field for both flowering and vegetative phenology. The proposed research program involves production of a landmark long-term data on plant phenology, with a unique combination of high temporal resolution, detailed data on flower or plant numbers and sizes (rather than only presence), and coverage of a steep climatic (elevational) gradient. Combined with the targeted experimental studies, the results will permit major scientific advances.