Plant colonisation in the hight Arctic, a seed for change

快速变化的北极环境将改变实际的生态平衡(例如，植物-草食关系)，并促进植被转移。在稀疏的高北极植被中，繁殖产量预计将改善，植物建立预计将增加。然而，物种对变化的反应也将取决于所涉及的生物相互作用，这些相互作用可以促进或阻止植物的生长和建立。我最近的工作表明，促进在高北极的垫状植物(主要是草本)和生物土壤结皮(草本和灌木)中增加植物的建立。然而，气候变暖可能会导致干旱加剧，竞争限制了幼苗的建立。占主导地位的灌木物种在开阔土地上进行殖民活动是罕见的，但要想实现大规模的北方绿化，这是必不可少的。我自1989年以来一直活跃在北极，我的长期目标是为植被动力学的生态学理论做出贡献。我的短期目标是启动第一个大规模的种子添加实验，用生物去除土壤结皮来测试：1)种子短缺和安全地点限制的相对重要性；2)在高北极两个截然不同的护士-门徒系统中，竞争和促进植物定居之间的平衡。这些田间实验将包括变暖和浇水处理，并解决以下问题：是什么阻止了优势维管束物种(例如灌木)的建立？全球变化将促进还是减少它们的招募？我的工作发生在比洛特岛研究营地(北纬73°，西经80°)附近的Pond Inlet(NU)附近。我加入这个研究小组大大降低了后勤成本，改善了科学互动。我计划用这个项目培训1名博士、2名硕士和至少4名理科学生。*我们将向当地社区提交我们研究活动的年度报告，并在5年协调一次冬季访问，以便就我们的成果进行更彻底的交流。首先解决这一系统中的理论和实践问题，这项工作将对理解、保护和未来管理加拿大最北端的生物群做出重大贡献。

The rapidly changing arctic environment will alter the actual ecological balance (e.g. plant-herbivore relationships) and promote vegetation shifts.  In sparse high arctic vegetation, reproductive output is predicted to improve and increased plant establishment is expected. However, species response to change will also depend on the biotic interactions involved that can promote or prohibit plant growth and establishment.  My recent work revealed that facilitation increases plant establishment in cushion plants (mostly herbs) and biological soil crusts (herbs and shrubs) in the High Arctic. However, warming may lead to increased drought and competition limiting seedling establishment. Colonisation of open grounds by dominant shrub species is rare, yet it is essential for a substantial 'greening of the North' to take place.        Active in the Arctic since 1989, my long-term objective is to contribute to the ecological theory of vegetation dynamics. My short term objectives are to initiate the first large scale seed addition experiments with biological soil crust removal to test: 1) the relative importance of seed shortage and safe site limitation; and 2) the balance between competition and facilitation in plant colonisation in two contrasting nurse-protégé systems of the High Arctic.  These field experiments will include warming and watering treatments and address questions such as:  What prevent dominant vascular species (e.g. shrubs) establishment?  Will global change promote or decrease their recruitment? My work takes place near Pond Inlet (NU) around the Bylot Island research camp (73°N, 80°W).  My participation to this research group significantly reduces logistical costs and improves scientific interactions.  I plan to train 1 PhD, 2 MSc and a minimum of 4 BSc students with this project.  We will present annual reports on our research activities to the local communities and coordinate a winter visit in Yr 5 to allow more thorough exchanges on our results. First to address such theoretical and practical questions in this system, this work will be a significant contribution to the understanding, conservation and future management of Canada's northernmost biome.