Arctic Research Centre, Aarhus University, 8000 Aarhus C, Denmark.
Proc Biol Sci. 2012 Nov 7;279(1746):4417-22. doi: 10.1098/rspb.2012.1490. Epub 2012 Sep 12.
Alpine and arctic lemming populations appear to be highly sensitive to climate change, and when faced with warmer and shorter winters, their well-known high-amplitude population cycles may collapse. Being keystone species in tundra ecosystems, changed lemming dynamics may convey significant knock-on effects on trophically linked species. Here, we analyse long-term (1988-2010), community-wide monitoring data from two sites in high-arctic Greenland and document how a collapse in collared lemming cyclicity affects the population dynamics of the predator guild. Dramatic changes were observed in two highly specialized lemming predators: snowy owl and stoat. Following the lemming cycle collapse, snowy owl fledgling production declined by 98 per cent, and there was indication of a severe population decline of stoats at one site. The less specialized long-tailed skua and the generalist arctic fox were more loosely coupled to the lemming dynamics. Still, the lemming collapse had noticeable effects on their reproductive performance. Predator responses differed somewhat between sites in all species and could arise from site-specific differences in lemming dynamics, intra-guild interactions or subsidies from other resources. Nevertheless, population extinctions and community restructuring of this arctic endemic predator guild are likely if the lemming dynamics are maintained at the current non-cyclic, low-density state.
高山和北极旅鼠种群对气候变化似乎非常敏感，当面临更温暖和更短的冬季时，它们众所周知的高振幅种群周期可能会崩溃。作为冻原生态系统的关键物种，旅鼠动态的变化可能会对与它们有营养联系的物种产生重大的连锁反应。在这里，我们分析了来自格陵兰高北极两个地点的长期（1988-2010 年）、全社区监测数据，并记录了环斑旅鼠周期性崩溃如何影响捕食者群体的种群动态。在两种高度专业化的旅鼠捕食者中观察到了显著的变化：雪鸮和白鼬。在旅鼠周期崩溃后，雪鸮雏鸟的产量下降了 98%，而且在一个地点，白鼬的种群数量明显下降。不太专业化的长尾贼鸥和普通的北极狐与旅鼠动态的联系较为松散。尽管如此，旅鼠的崩溃对它们的繁殖表现还是有明显的影响。在所有物种中，捕食者的反应在不同地点略有不同，这可能是由于特定地点的旅鼠动态、种内相互作用或来自其他资源的补贴的差异所致。然而，如果旅鼠的动态保持在当前非周期性的低密度状态，那么这种北极特有捕食者群体的灭绝和群落重构很可能发生。
