We evaluated how climate change and variable rates of moose browsing intensity, as they relate to wolf predation, might affect the forests of Isle Royale National Park, Michigan, United States by conducting a modeling experiment. The experiment consisted of contrasting three different scenarios of wolf management and with a static (current conditions) and changing climate (high emissions). Our results indicate that the interactive effects of wolf predation and climate change are likely to be temporally variable and dependent on biogeographic and forest successional processes. During the first 50 years of 120-year simulations, when the effects of climate change were less impactful, higher simulated rates of predation by wolves reduced moose population densities, resulting in greater forest biomass and higher carrying capacities for moose. However, over the longer term, early successional and highly palatable aspen and birch forests transitioned to late successional spruce and fir forests, regardless of climate or predation intensity. After 50 years, the effects of climate change and predation were driven by effects on balsam fir, a late successional conifer species that is fed on by moose. High-intensity predation of moose allowed balsam fir to persist over the long term but only under the static climate scenario. The climate change scenario caused a reduction in balsam fir and the other boreal species that moose currently feed on, and the few temperate species found on this isolated island were unable to compensate for such reductions, causing strong declines in total forest biomass. The direct effects of moose population management via reintroduction of wolves may become increasingly ineffective as the climate continues to warm because the productivity of boreal plant species may not be sufficient to support a moose population, and the isolation of the island from mainland temperate tree species may reduce the likelihood of compensatory species migrations.

中文翻译：

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气候变化可能会改变美国皇家岛国家公园的狼-驼鹿-森林相互作用

我们通过进行建模实验评估了气候变化和驼鹿浏览强度的可变速率（因为它们与狼捕食有关）可能如何影响美国密歇根州皇家岛国家公园的森林。该实验包括对比三种不同的狼管理情景以及静态（当前条件）和不断变化的气候（高排放）。我们的研究结果表明，狼捕食和气候变化的交互作用可能随时间变化并取决于生物地理和森林演替过程。在 120 年模拟的前 50 年中，当气候变化的影响较小时，更高的狼捕食率模拟降低了驼鹿的种群密度，从而导致更大的森林生物量和更高的驼鹿承载能力。然而，从长远来看，无论气候或捕食强度如何，早期演替和高度适口的白杨林和桦木林过渡到后期演替云杉和冷杉林。50 年后，气候变化和捕食的影响是由对香脂冷杉的影响驱动的，香脂冷杉是一种以驼鹿为食的晚期演替针叶树物种。对驼鹿的高强度捕食使香脂冷杉能够长期存在，但仅限于静态气候情景。气候变化情景导致香脂冷杉和驼鹿目前以其他北方物种为食的数量减少，而在这个孤岛上发现的少数温带物种无法弥补这种减少，导致森林总生物量大幅下降。