Ecology & Evolution of Species Range Limits

生态

• 批准号: RGPIN-2020-04831
• 负责人: Eckert, Christopher
• 金额: $ 4.74万
• 依托单位: Queen's University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 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=745688
• 关键词: Ecology; Evolution; Species; Range; Limits

All organisms are limited in geographic distribution, but how & why range limits occur are still poorly understood. This prevents realistic forecasting of whether species will shift ranges or go extinct during climate change and weakens effective conservation of Canadian species at risk most of which are at their northern limits in southern Canada. The goal of my research is to better understand the ecological and evolutionary processes that impose range limits over the short-term and prevent range expansion over the long term. My students and I will address this goal by filling 4 knowledge gaps described below, each of which is a missing piece of the range-limit puzzle. (1) A range limit is thought to occur where the environment reduces survival and reproduction sufficiently that populations are not self-replacing. Although species transplanted beyond their range often suffer, their reduced performance is often insufficient to limit the distribution. In such cases, dispersal may be limiting but how this occurs is unknown. A likely but untested hypothesis is that the range limit occurs where a species' dispersal into unoccupied habitat patches fails to keep pace with its extinction from occupied patches. (2) Across its range, a species may occur in a variety of habitats and the range of habitats occupied may narrow towards range limits. This may, in turn, reduce successful dispersal between habitat patches required for species persistence. However, whether habitat breadth changes at range edges has rarely been studied and underlying mechanisms are not understood. (3) Stable range limits are thought to occur where adaptation fails. Recent experiments have failed to reveal the necessary constraints on adaptation, but none have examined adaptation over multiple generations under natural conditions. (4) The capacity of peripheral populations to adapt to conditions beyond the range will be strongly influenced by reproductive mode. Plants often shift reproductive modes towards range limits, but whether this inhibits or facilitates geographic spread is unknown. We address these objectives using large-scale geographic surveys, manipulative transplant experiments and genomic analyses with plants species proven to be excellent experimental systems. This research will help answer fundamental questions at the forefront of biology and contribute to the conservation of species-at-risk, the management of exotic invaders, and better forecasting of species' responses to climate change; key environmental problems threatening Canadian biodiversity. My lab is an inclusive environment where diverse trainees at all levels learn highly transferable technical skills suited to their interests and long-term career goals in academia, resource management and industry. Ongoing partnerships with resource-management agencies broaden training and facilitate the transfer of information and skills between university researchers, government scientists and policy-makers.

所有生物体的地理分布都受到限制，但是如何以及为什么发生范围限制的方式仍然很差。这样可以防止对物种在气候变化期间是否会改变范围或灭绝的现实预测，并削弱对处于危险的加拿大物种的有效保护，其中大多数处于加拿大南部的北部极限。我的研究的目的是更好地了解短期内施加范围限制的生态和进化过程，并在长期内防止范围扩展。我和我的学生将通过填补下面描述的4个知识差距来解决这个目标，每个知识差距是范围限制的难题中缺少的一部分。 （1）范围限制被认为是在环境减少生存和繁殖的情况下，人口不是自我替代的。尽管移植到其范围之外的物种经常受到影响，但其性能降低通常不足以限制分布。在这种情况下，分散可能是限制的，但是这种情况的发生方式尚不清楚。一个可能但未经测试的假设是，范围极限发生在物种散布在空地的栖息地斑块中的情况下，无法与其在被占用斑块中灭绝的步伐保持同步。 （2）在其范围内，一个物种可能发生在各种栖息地中，而所栖息地的范围可能会缩小范围限制。反过来，这可能减少了物种持久性所需的栖息地斑块之间的成功分散。但是，很少研究范围边缘的栖息地宽度变化，并且尚不清楚潜在的机制。 （3）在适应失败的情况下，人们认为稳定范围限制发生。最近的实验未能揭示适应的必要限制，但是在自然条件下，没有人检查过多代的适应。 （4）外围人群适应超出该范围的条件的能力将受到生殖模式的强烈影响。植物经常将生殖模式转移到范围限制上，但是无论是抑制还是促进地理扩散是尚不清楚的。我们使用大规模的地理调查，操纵移植实验和植物物种的基因组分析来解决这些目标，被证明是出色的实验系统。这项研究将有助于在生物学的最前沿回答基本问题，并有助于保护物种风险，外来入侵者的管理以及更好地预测物种对气候变化的反应；威胁加拿大生物多样性的关键环境问题。我的实验室是一个包容性的环境，各个层面的不同学员都学会了适合他们的利益以及在学术界，资源管理和行业的长期职业目标的高度可转移的技术技能。与资源管理机构的持续合作伙伴关系扩大了培训，并促进了大学研究人员，政府科学家和政策制定者之间信息和技能的转移。