Predation risk and habitat selection in culturally significant herbivores of the boreal forest

北方森林具有重要文化意义的食草动物的捕食风险和栖息地选择

• 批准号: 312860-2006
• 负责人: McLaren, Brian
• 金额: $ 1.4万
• 依托单位: Lakehead University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2007
• 资助国家: 加拿大
• 起止时间: 2007-01-01 至 2008-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=366029
• 关键词: Predation; risk; habitat; selection; culturally

This proposal involves a study of how food chains are structured, by contrasting herbivore foraging and behaviour in areas of the Northern Boreal Initiative (a development frontier) in Ontario, where wolves dominate, to areas of Newfoundland, where wolves are absent and coyotes are recent arrivals.  The herbivores chosen for study, moose and beaver, are dominants in the boreal forest ecosystem and also culturally significant, for example, as hunting and trapping resources.  This study emphasizes questions of the case for top-down (predator) effects in the boreal forest, the role for natural and anthropogenic disturbances in changing predator-prey dynamics, and enduring top-down effects evident in vegetation and in soils.  A key hypothesis, for example, is that selective foraging by beavers and moose alters soil nutrient availability, indirectly limiting plant growth, and that in the absence of other disturbances and especially in the absence of predators, this indirect effect becomes limiting to the herbivores themselves via changes to soil processes.  The presence of predators regulates this effect, while moose and beavers are indirect competitors over the long term via changes to habitat.  Testing these hypotheses potentially fills a knowledge gap in resource management through comparisons among regions. This study proposes to engage four students in soil survey, vegetation survey, analysis of radio-tracking and existing GPS telemetry data, as well as in questions of fundamental discovery.  A basic premise of this proposal is that trait-mediated interactions among predators and herbivores are sufficient yet under-explored as potential top-down terrestrial ecosystem effects.  Such interactions would include changes in foraging behaviour in the presence of predators that evolve such that herbivore density is lower than it would be if predation alone were limiting populations.  This study also contrasts the relative effects of predation, trapping and forest disturbances in specific areas where persistence and population dynamics of beaver colonies will be explored.

这项提案涉及到对食物链结构的研究，通过对比在安大略省北部北方倡议（一个开发前沿）地区的食草动物觅食和行为，在那里狼占主导地位，纽芬兰地区，那里没有狼，土狼是最近到来的。研究中选择的食草动物，驼鹿和海狸，在北方森林生态系统中占主导地位，也具有重要的文化意义，例如，作为狩猎和诱捕资源。本研究强调了北方森林自上而下（捕食者）效应的问题，自然和人为干扰在改变捕食者-猎物动态中的作用，以及在植被和土壤中明显的持续自上而下的影响。例如，一个关键的假设是，海狸和驼鹿的选择性觅食改变了土壤养分的可用性，间接地限制了植物的生长，并且在没有其他干扰的情况下，特别是在没有捕食者的情况下，这种间接影响通过改变土壤过程而限制了食草动物本身。掠食者的存在调节了这种影响，而驼鹿和海狸则通过栖息地的变化成为长期的间接竞争对手。检验这些假设可能会通过区域间的比较填补资源管理方面的知识空白。本研究拟安排4名学生参与土壤调查、植被调查、无线电跟踪和现有GPS遥测数据分析，以及基础发现问题。该建议的一个基本前提是，捕食者和食草动物之间的性状介导的相互作用是充分的，但作为潜在的自上而下的陆地生态系统效应尚未得到充分的探索。这种相互作用包括在捕食者存在的情况下觅食行为的变化，这种变化使得食草动物的密度低于单独捕食限制种群数量的情况。本研究还对比了捕食、诱捕和森林干扰在特定地区的相对影响，这些地区将探索海狸种群的持久性和种群动态。