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

这项建议涉及研究食物链是如何构成的，将安大略的北方北方倡议（一个发展前沿）地区的食草动物觅食和行为与纽芬兰地区的食草动物觅食和行为进行对比，前者狼占主导地位，后者没有狼，郊狼是最近才到达的。 选择研究的草食动物，驼鹿和海狸，在北方森林生态系统中占主导地位，也具有文化意义，例如，作为狩猎和诱捕资源。 本研究强调的问题的情况下，自上而下（捕食者）的影响，在北方森林中，自然和人为干扰的作用，在改变捕食者-猎物动态，持久的自上而下的影响明显的植被和土壤。 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有效性，间接限制了植物的生长，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。 食肉动物的存在调节了这种影响，而驼鹿和海狸则通过改变栖息地成为长期的间接竞争对手。 对这些假设的检验有可能通过区域间的比较填补资源管理方面的知识空白。这项研究建议让四名学生参与土壤调查、植被调查、无线电跟踪和现有全球定位系统遥测数据的分析以及基本发现问题。 这一建议的一个基本前提是，特征介导的捕食者和食草动物之间的相互作用是足够的，但未充分探讨的潜在自上而下的陆地生态系统的影响。 这种相互作用将包括在捕食者存在的情况下觅食行为的变化，这些捕食者的进化使得食草动物的密度低于如果捕食单独限制种群的情况。 本研究还对比了捕食，诱捕和森林干扰的相对影响，在特定地区的持久性和人口动态的海狸殖民地将进行探讨。

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.