Using range-edge ecology to inform conservation of Canada's rare plants

利用范围边缘生态学为加拿大稀有植物的保护提供信息

• 批准号: 571462-2021
• 负责人: Hargreaves, AnnaAL
• 金额: $ 3.28万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Alliance Grants
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=745282
• 关键词: Using; range; edge; ecology; inform

Most species considered imperilled in Canada only occur here at the northern edge of their geographic range. Species conservation in Canada is therefore inextricably tied to the ecology of range-edge populations. Yet little of the extensive ecological theory about edge populations or field techniques for studying them have been applied to Canada's species-at-risk to guide their conservation. For example, theory predicts that species' northern ranges are often limited by cold. If so, recent climate warming should be creating new habitat for many range-edge species, yet species-at-risk policy is focused on preventing loss of existing populations rather than helping species keep pace with climate change. We propose to combine our expertise on biogeography (AH), field experiments with range-edge populations (AH, MV), and Canadian plants at risk (JM) to help shift conservation of rare plants from simply preventing loss to promoting recovery. Questions: Using at-risk plants whose Canadian range is limited to southern Ontario and/or Quebec, we will ask two fundamental questions about edge populations that bear directly on their long-term conservation. 1) Is their northern range edge determined by ecological factors or dispersal? Dispersal limitation would mean their range could be bolstered by founding new populations; limitation by ecological factors (e.g. snow depth) would suggest mitigation strategies to bolster the size of existing populations (e.g. snow traps). 2) Is climate warming creating newly-suitable habitat north of species' current ranges? None of our candidate species' ranges have expanded despite five decades of warming; if new habitat exists they will need help getting there. Approach: First, we will use species distribution models to generate predictions about the ranges of 90+ rare species' in ON/QU. JM has successfully used distribution models to identify suitable habitat within species' ranges; we will increase models' geographic extent to identify potential habitat beyond them. We predict that species whose distributions are best predicted by temperature will be most likely to have suitable habitat beyond their range due to warming. Second, we will test model predictions using transplant experiments for 3 provincially-rare herbs. We will transplant seeds and cuttings to beyond-range sites that our models predict to be highly-suitable (treatment1) and moderately-suitable (treatment2) under current climates, monitoring to compare performance to control transplants within the range (treatment3). If plants perform well beyond their range, it suggests their distribution is dispersal limited; if transplants perform poorly, monitoring will reveal which ecological factors limit fitness. Better performance in treatment1 than treatment2 will validate models' ability to predict habitat; exceptions will reveal which models need refining. Third, we will re-run distribution models using future climate projections to predict where species' suitable climate will move. We will transplant plants to these 'future sites', surrounding half with experimental warming chambers to test whether plants could survive there given warming, or whether non-temperature factors will prevent warming-driven expansions.Impact: Canada's future biodiversity will be strongly shaped by dynamics of species range-edges. This project would help establish a scientific foundation for predicting such changes and identify effective recovery strategies for Canada's rare plants.

在加拿大被认为危害的大多数物种仅发生在其地理范围的北边缘。因此，加拿大的物种保护与范围边缘人群的生态密不可分。然而，关于研究它们的边缘种群或现场技术的广泛生态理论几乎没有应用于加拿大风险的物种，以指导其保护。例如，理论预测物种的北部范围通常受到寒冷的限制。如果是这样，最近的气候变暖应该为许多范围边缘物种创造新的栖息地，但是风险的物种政策旨在防止现有人群丧失，而不是帮助物种保持与气候变化的速度。我们建议将我们的生物地理学专业知识（AH），现场实验与范围边缘人群（AH，MV）和有风险的加拿大植物（JM）结合在一起，以帮助将稀有植物的保护从简单地防止损失转向促进恢复。问题：使用加拿大范围仅限于安大略省和/或魁北克的高危植物，我们将询问有关直接在其长期保护的边缘种群的两个基本问题。 1）他们的北范围边缘是由生态因素还是分散确定的？分散限制将意味着他们的范围可以通过成立新的人群来加强；生态因素的限制（例如，积雪深度）将提出缓解策略来加强现有人群的规模（例如雪陷阱）。 2）气候变暖是否会在物种当前范围以北的新型适合栖息地？尽管有五十年的变暖，但我们候选物种的范围都没有扩大。如果存在新的栖息地，他们将需要帮助到达那里。方法：首先，我们将使用物种分布模型来产生有关ON/QU中90多种稀有物种范围的预测。 JM已成功使用分布模型来识别物种范围内的合适栖息地。我们将增加模型的地理范围，以确定超越它们的潜在栖息地。我们预测，由于变暖，其最有可能在其范围之外的适当栖息地预测其分布的物种。其次，我们将使用3种省稀有草药的移植实验测试模型预测。我们将在当前气候下将种子和插条移植到超越范围的位点（治疗1）和适度的（处理2），并将其监测以比较性能与控制范围内的性能（处理3）。如果植物的表现远远超出其范围，则表明它们的分布受到限制；如果移植术的表现较差，则监测将揭示哪些生态因素限制适应性。治疗中的表现比治疗2更好，将验证模型预测栖息地的能力；例外将揭示哪些模型需要精炼。第三，我们将使用未来的气候预测重新运行分配模型，以预测物种适当的气候将在哪里移动。我们将将植物移植到这些“未来地点”，一半围绕一半的实验变暖室，以测试植物是否可以在那里升温，或者非温度因素是否会阻止变暖驱动的扩张。Impact：加拿大的未来生物多样性将被强烈影响。物种范围的动力学。该项目将有助于建立科学基础，以预测这种变化并确定加拿大稀有植物的有效恢复策略。