School of Forest Resources and Environmental Science, 1400 Townsend Drive, Michigan Technological University, Houghton, Michigan 49931, USA.
Ecology. 2009 Nov;90(11):3159-67. doi: 10.1890/09-0292.1.
Mechanistic links between top terrestrial predators and biogeochemical processes remain poorly understood. Here we demonstrate that large carnivores configure landscape heterogeneity through prey carcass distribution. A 50-year record composed of > 3600 moose carcasses from Isle Royale National Park, Michigan, USA, showed that wolves modulate heterogeneity in soil nutrients, soil microbes, and plant quality by clustering prey carcasses over space. Despite being well utilized by predators, moose carcasses resulted in elevated soil macronutrients and microbial biomass, shifts in soil microbial composition, and elevated leaf nitrogen for at least 2-3 years at kill sites. Wolf-killed moose were deposited in some regions of the study landscape at up to 12x the rate of deposition in other regions. Carcass density also varied temporally, changing as much as 19-fold in some locations during the 50-year study period. This variation arises, in part, directly from variation in wolf hunting behavior. This study identifies a top terrestrial predator as a mechanism generating landscape heterogeneity, demonstrating reciprocal links between large carnivore behavior and ecosystem function.
陆地顶级捕食者与生物地球化学过程之间的机制联系仍知之甚少。本研究表明,大型食肉动物通过猎物尸体的分布来构建景观异质性。从美国密歇根州的皇家岛国家公园收集的超过 3600 具驼鹿尸体组成的 50 年记录表明,狼群通过在空间上聚集猎物尸体来调节土壤养分、土壤微生物和植物质量的异质性。尽管被捕食者很好地利用,但驼鹿尸体导致土壤大量营养素和微生物生物量增加,土壤微生物组成发生变化,在杀死地点,叶片氮含量至少升高 2-3 年。在研究景观的某些区域,狼杀死的驼鹿的沉积速度高达其他区域的 12 倍。尸体密度也随时间变化而变化,在 50 年的研究期间,某些地点的变化高达 19 倍。这种变化部分直接源于狼的狩猎行为的变化。本研究确定了一种陆地顶级捕食者作为产生景观异质性的机制,证明了大型食肉动物行为与生态系统功能之间的相互联系。