Stability And Change In Canada's Forested Landscapes: A Conceptual Model For Understanding Dynamic Connectivity Patterns Across Decades

加拿大森林景观的稳定性和变化：理解数十年来动态连通模式的概念模型

• 批准号: RGPIN-2016-05893
• 负责人: Cardille, Jeffrey
• 金额: $ 2.04万
• 依托单位: McGill University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=631640
• 关键词: Stability; Change; Canada; Forested; Landscapes

As Canada experiences climate change in coming decades, animals will be on the move. Whether encountering new neighbors venturing from the south or trying to travel into newly suitable habitat, many organisms will see their fitness linked to the paths they choose. Dispersers through forests, for example, will move through and within landscapes reflecting many historical factors including the size of past disturbances, the time since they occurred, and the forest recovery rate. Understanding the context of a landscape’s connectivity will help managers to forecast and manage land to aid the long-term persistence of species in Canada. But because of the complex effects of the history of disturbance on landscapes, a fuller understanding of landscape patterns—particularly as they affect functional connectivity for organisms—requires careful study beyond a single snapshot of land cover. An effective new perspective for modeling connectivity treats landscapes like electrical circuits, with each land-cover type presenting a certain resistance to movement of a given organism. Recent work in my lab has extended this model to allow tiling of circuit-based maps across arbitrarily large areas. Yet although we can map compelling connectivity surfaces with circuit theory, it is not clear if connectivity patterns are stable or changing through time. The goal of this research is to develop and test a new conceptual model of the stability of landscape connectivity through time and across space. Over the next five years my research team of undergraduates, Master’s students, PhD students, and postdocs will study the relationship between disturbance and connectivity in forested landscapes, explore the history of thousands of landscapes of Canada using satellite observations over the last three decades, and consider landscapes from a variety of organisms’ perspectives. My long-term program has three medium-term objectives: (1) define measures of stability for connectivity through time in circuit-based analyses; (2) build and test a new conceptual model of dynamic landscape connectivity as a function of disturbance frequency and size; and (3) incorporate a multi-species perspective of changes in landscape connectivity through time. Our proposed model extends an influential early conceptual framework of landscape equilibrium. That model hypothesized regions of landscape stability and instability as a function of disturbance frequency and size, but did not explicitly consider the spatial patterns produced by disturbance and recovery. This work will expand that vision of equilibrium and give it spatial context, by tracing when and how a changing landscape pattern affects functional connectivity through time. The conceptual model, the new methods to support it, and the data created to test it will be an asset for the scientific community that will open long-term research avenues for ourselves and others.

随着加拿大在未来几十年经历气候变化，动物将会迁徙。无论是遇到冒险从南方来的新邻居，还是试图进入新的适宜栖息地，许多生物都会发现它们的适应性与它们选择的路径有关。例如，通过森林的散布者将穿过和在反映许多历史因素的景观中移动，包括过去干扰的大小、发生后的时间和森林恢复速度。了解景观连通性的背景将有助于管理者预测和管理土地，以帮助加拿大物种的长期持久性。但是，由于干扰历史对景观的复杂影响，更全面地了解景观模式——特别是当它们影响生物的功能连通性时——需要仔细研究，而不仅仅是对土地覆盖的单一快照。建模连通性的一个有效的新视角是将景观视为电路，每种土地覆盖类型都对给定生物的运动表现出一定的阻力。我的实验室最近的工作扩展了这个模型，允许在任意大的区域上平铺基于电路的地图。然而，尽管我们可以用电路理论绘制出引人注目的连接面，但连接模式是稳定的还是随时间变化的尚不清楚。本研究的目的是开发和测试景观连通性在时间和空间上稳定性的新概念模型。在接下来的五年里，我的研究团队包括本科生、硕士生、博士生和博士后，他们将研究森林景观中干扰与连通性之间的关系，探索过去三十年来加拿大数千个景观的历史，并从各种生物的角度考虑景观。我的长期计划有三个中期目标：(1)在基于电路的分析中定义连接随时间变化的稳定性措施；(2)构建并验证了动态景观连通性作为干扰频率和大小函数的新概念模型；(3)结合多物种视角研究景观连通性随时间的变化。我们提出的模型扩展了一个有影响力的早期景观平衡概念框架。该模型假设景观稳定和不稳定区域是干扰频率和大小的函数，但没有明确考虑干扰和恢复所产生的空间格局。这项工作将通过追踪变化的景观模式何时以及如何影响功能连接来扩展平衡的视野，并赋予其空间背景。概念模型，支持它的新方法，以及为测试它而创建的数据将成为科学界的一笔财富，为我们自己和他人开辟长期研究途径。