The evolutionary ecology of geographic ranges in western North American Mimulus

在一个快速环境变化的时代，对物种范围的生态和进化控制的理解落后于预测未来范围的需要。主要问题包括a)地理范围边缘与生态位限制何时何地一致，b)为什么生态位进化可能在范围边缘失败，c)广布和特有物种的范围限制过程有何不同，以及d)范围将如何随着气候变化而变化。缺乏答案阻碍了有关稀有物种和周边种群的管理决策。这在加拿大尤其重要，那里许多濒危物种达到了它们的北方极限。这项研究计划的总体目标是发展对物种地理范围的生态学、进化和保护的综合理解。近期研究目标和计划如下：(1)量化不同范围边缘和范围大小不同的物种限制生态因素的相对重要性。我们将进行环境控制和种子引进，以评估非生物、生物和传播限制的强度。我们还将比较广布种和狭义特有种的生理生态位宽度。(2)考察在范围边缘和范围大小不同的物种的生态位进化的限制。我们将进行人工选择，以确定边缘种群是否缺乏扩大范围的遗传变异。为了验证淹没基因流动导致范围边缘适应不良的假设，我们将从范围内部模拟不同程度的基因流动。我们还将研究分布广泛和稀有物种范围内的生态位进化模式。(3)气候变化引起的距离漂移预报精细化试验方法。我们将使用上面的实验结果来帮助将分布模型参数化，该模型评估扩散限制、生理可塑性、生物相互作用和进化变化对潜在射程移动的影响。通过这项研究培养的高素质人才包括四名博士、两名硕士和几名本科生。

Understanding of the ecological and evolutionary controls over species' ranges lags behind the need to forecast future ranges in an era of rapid environmental change. Major questions include a) when and where geographic range edges are concordant with limits to the ecological niche, b) why niche evolution might fail at range margins, c) how range-limiting processes differ for widespread and endemic species, and d) how ranges will move in response to climate change. A lack of answers hinders management decisions concerning rare species and peripheral populations. This is of particular relevance in Canada, where many species at risk reach their northern limits. The overall goal of this research program is to develop a synthetic understanding of the ecology, evolution and conservation of species' geographic ranges. Near-term research objectives and plans are as follows: (1) Quantify the relative importance of limiting ecological factors across different range edges and for species with contrasting range sizes. We will conduct environmental manipulations and seed introductions to assess the strength of abiotic, biotic, and dispersal limitations. We will also compare physiological niche breadth of widespread and narrowly endemic species. (2) Examine constraints on niche evolution at range margins and for species with contrasting range sizes. We will conduct artificial selection to determine if edge populations lack genetic variation for range expansion. To test the hypothesis that swamping gene flow causes maladaptation at the range edge, we will simulate varying degrees of gene flow from the range interior. We will also examine patterns of niche evolution across the ranges of widespread and rare species. (3) Test methods for refining forecasts of range shifts driven by climate change. We will use experimental results from the above to help parameterize distribution models that evaluate the effects of dispersal limitation, physiological plasticity, biotic interactions, and evolutionary change on potential range shifts. Highly qualified personnel to be trained through this research include four PhD, two MS, and several undergraduate students.