Scaling habitat loss and fragmentation of old forests on bird communities in boreal landscapes

北方景观中鸟类群落的栖息地丧失和老森林破碎化

• 批准号: RGPIN-2019-07075
• 负责人: Drapeau, Pierre
• 金额: $ 2.91万
• 依托单位: Université du Québec à Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=739295
• 关键词: Scaling; habitat; loss; fragmentation; old

Forests worldwide are undergoing major changes as a result of human activity. In the eastern boreal forest of Canada, the northern expansion of timber harvesting in the last 35 years has shifted the age-class distribution from a matrix formerly dominated by mature and old forest cover types to a matrix that is now dominated by young forests. This represents a major change for organisms that evolved and experienced high availability of closed canopy and keystone structures such as decaying and dead trees throughout the Holocene. This reduced proportion of old forests specifically affects species that are specialised on closed canopy (open-cup nesters) and on decaying and dead trees (cavity nesters). Landscape-scale sensitivity of birds to loss and fragmentation of old forest cover has usually been assessed in the neighbourhood of bird sampling stations (500 m to 2-km radius). Such approaches provide insightful knowledge on species responses at local scales. They are, however, limited for extrapolating how such patterns translate at the level of regional populations, across the entire forest mosaic. To do so large-scale bird surveys over biomes are required. Breeding Bird Atlas (BBA) projects, which have recently incorporated fine-grain scale surveys (point counts), now provide such opportunities for investigating bird populations' responses to habitat changes over large geographic regions. This proposal measures at the scale of Québec's commercial boreal forest the effects of shifting the forest age structure from an old to a young forest mosaic on the response of bird communities. We combine extensive (regional, BBA data) and intensive (local, field studies) approaches on open-cup and cavity nesters to: 1) assess the regional-scale effects of loss and fragmentation of old forests on populations of sensitive birds; 2) determine how the dynamics of regeneration in harvested landscapes enables the resilience of old forest bird communities; 3) measure how local habitat quality and connectivity of old forests are drivers in bird species nesting and foraging ecology. By scaling-up the response of bird populations and communities to old forest loss and fragmentation from local to regional effects, the proposed research program will contribute to groundbreaking advances in our understanding of the cumulative effects of timber-harvesting regimes on boreal biodiversity in human-modified landscapes. The use of a trait-based approach (open-cup and cavity nesters) in addition to traditional taxonomic diversity will provide an original perspective to pinpoint critical habitat drivers to which the functional diversity of boreal bird communities responds. From a conservation planning perspective, the proposed research will produce innovative science-based guidelines for developing policies in the Canadian boreal forest that better meet the long-term challenges of maintaining biodiversity and sustainable forest management in a rapidly changing world.

由于人类活动，世界范围内的森林正在发生重大变化。在加拿大东部的北方森林中，过去 35 年木材采伐的北部扩张改变了以前以成熟和古老森林覆盖为主的年龄分布。这代表了在整个全新世进化并经历了高可用性封闭树冠和关键结构（例如腐烂和枯死的树木）的生物体的重大变化。专门针对封闭式通常在鸟类采样站附近（500 m 至 2 km）评估鸟类对树冠（开杯筑巢者）和腐烂和死树（洞穴筑巢者）对旧森林覆盖损失和破碎的景观尺度敏感性。然而，这些方法提供了有关当地尺度物种反应的深入知识，但它们对于推断这些模式如何在整个森林镶嵌区域的水平上转化是有限的。生物群落繁殖地图集（BBA）项目最近纳入了细粒度调查（点计数），现在为调查大范围地理区域的鸟类种群对栖息地变化的反应提供了机会。魁北克商业性北方森林的森林年龄结构从古老的森林马赛克转变为年轻的森林马赛克对鸟类群落反应的影响我们将广泛的（区域、BBA 数据）和密集的（当地、实地研究）方法结合起来进行开杯研究。和空腔筑巢者：1) 评估老森林的丧失和破碎对敏感鸟类种群的区域规模影响；2) 确定收获景观的再生动态如何增强老森林鸟类群落的恢复力；3) 衡量当地栖息地的情况原始森林的质量和连通性是鸟类筑巢和觅食生态的驱动因素，通过扩大鸟类种群和群落对原始森林丧失和破碎化的反应，从地方到区域的影响，拟议的研究计划将有助于我们的突破性进展。了解累积效应除了传统的分类多样性之外，使用基于性状的方法（开杯和空穴筑巢者）将提供一个独特的视角来确定功能性栖息地的关键栖息地驱动因素。从保护规划的角度来看，拟议的研究将为加拿大北方森林制定政策提供创新的科学指南，以更好地应对快速变化的生物多样性维护和可持续森林管理的长期挑战。世界。