Climate-induced range shifts of mammals and reptiles: demography at range edges

气候引起的哺乳动物和爬行动物范围变化：范围边缘的人口统计

• 批准号: 312222-2012
• 负责人: Hodges, Karen
• 金额: $ 1.53万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2013
• 资助国家: 加拿大
• 起止时间: 2013-01-01 至 2014-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=526443
• 关键词: Climate; induced; range; shifts; mammals

Climate change is forecast to have serious and long-lasting impacts on Canada's wildlife species. Some species are likely to extend their ranges northward, while others may be driven extinct in Canada. Predicting how species will respond is of critical importance for Canada, so that appropriate management can be planned. At present, about half of Canada's mammal species and all of the reptiles have small geographic ranges at their northern range edges within Canada. The majority of these species are found in southern Canada, where human-caused habitat fragmentation threatens their populations. Many of these species are listed as Threatened or Endangered under the Species at Risk Act or are listed provincially. The dominant theory about range edges suggests that these populations occur at lower densities and with worse survival and reproduction than core populations. These ideas have been challenged recently as many northern range edge populations are rapidly expanding northwards as climate change makes new areas suitable. Recent theory suggests that range edge populations may in fact favour the evolution of high dispersal and reproductive rates. Further, range edge populations may be more tolerant of habitat fragmentation because conditions on the range edge are over-all worse than in the range core, thus favoring individuals able to tolerate poor habitats. The research I propose addresses how Canada's mammals and reptiles at their northern range limits will respond to climate change. Field-based projects on three species will test whether range edge and core populations are affected by habitat fragmentation in the same way. Analyses of densities, survival rates, and reproductive rates for mammals and reptiles across their geographic ranges will test how similar range core and range edge populations are in their demography. Finally, a statistical model for all Canadian mammals and reptiles will test whether species traits (e.g. body mass, diet, dispersal ability) affect their range edge dynamics. Collectively, these projects will contribute both to ecological theory about why ranges stop and to the management of Canadian species at their northern range edges.

据预测，气候变化将对加拿大的野生动物物种产生严重而持久的影响。一些物种可能会向北扩展它们的活动范围，而另一些物种可能会在加拿大灭绝。预测物种的反应对加拿大来说至关重要，这样才能制定适当的管理计划。目前，加拿大大约一半的哺乳动物和所有的爬行动物在加拿大境内的北部边缘都有很小的地理范围。这些物种中的大多数在加拿大南部被发现，在那里，人类造成的栖息地破碎威胁着它们的数量。根据《濒危物种法》，这些物种中有许多被列为受威胁或濒危物种，或者被列为省级物种。关于范围边缘的主流理论认为，这些种群密度较低，生存和繁殖能力比核心种群差。这些想法最近受到了挑战，因为气候变化使得新的地区适合居住，许多北部山脉边缘的人口正在迅速向北扩张。最近的理论表明，范围边缘种群实际上可能有利于高扩散率和繁殖率的进化。此外，边缘种群可能更能忍受栖息地破碎化，因为边缘的条件总体上比核心更差，因此有利于能够忍受恶劣栖息地的个体。我提出的研究是关于加拿大北部哺乳动物和爬行动物将如何应对气候变化。以三个物种为基础的实地项目将测试范围边缘和核心种群是否以同样的方式受到栖息地破碎化的影响。对哺乳动物和爬行动物在其地理范围内的密度、存活率和繁殖率进行分析，将测试范围核心种群和范围边缘种群在人口统计学上的相似程度。最后，加拿大所有哺乳动物和爬行动物的统计模型将测试物种特征（如体重、饮食、扩散能力）是否会影响它们的范围边缘动态。总的来说，这些项目将有助于生态学理论，解释为什么范围停止，以及加拿大物种在其北部边缘的管理。