Energy flow and functional compensation in Great Basin small mammals under natural and anthropogenic environmental change
Energy flow and functional compensation in Great Basin small mammals under natural and anthropogenic environmental change
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DOI：
10.1073/pnas.1424315112
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发表时间：
2015-08-04
影响因子：
11.1
通讯作者：
Rowe, Rebecca J.
中科院分区：
文献类型：
--
作者：
Terry, Rebecca C.;Rowe, Rebecca J.
关于环境变化的生态影响的研究主要集中在物种水平上，而对生态系统水平上的属性（如能量流）的响应知之甚少。在无法直接观测的千年时间尺度上，情况尤其如此。在这里，我们研究如何在一个大盆地的小型哺乳动物社区的能量流响应气候驱动的环境变化在过去的12,800年，并使用此基线来评估在过去的世纪观察到的反应。我们的分析揭示了显着的稳定性，尽管在哺乳动物的身体大小和栖息地相关的功能群的分布急剧营业额在更新世末期的快速气候变暖过程中的能量流。功能组营业额与气候驱动的区域植被变化密切相关，气候和植被变化之前，在小型哺乳动物社区的精力充沛的转变。相比之下，在过去的世纪中，由于小型物种对封闭的草地栖息地的亲和力增加，能量流大幅减少。这表明，现代的土地覆盖变化所造成的人类活动，特别是非本地的一年生草地的蔓延，导致了能量流的补偿动力学的崩溃。因此，人类活动正在以不同于气候驱动预期的方式改变小型哺乳动物群落，从而产生了一个充满活力的新生态系统。我们的研究表明，需要整合跨生态和时间尺度的信息，为长期保护和管理提供强有力的见解。
Research on the ecological impacts of environmental change has primarily focused at the species level, leaving the responses of ecosystem-level properties like energy flow poorly understood. This is especially so over millennial timescales inaccessible to direct observation. Here we examine how energy flow within a Great Basin small mammal community responded to climate-driven environmental change during the past 12,800 y, and use this baseline to evaluate responses observed during the past century. Our analyses reveal marked stability in energy flow during rapid climatic warming at the terminal Pleistocene despite dramatic turnover in the distribution of mammalian body sizes and habitat-associated functional groups. Functional group turnover was strongly correlated with climate-driven changes in regional vegetation, with climate and vegetation change preceding energetic shifts in the small mammal community. In contrast, the past century has witnessed a substantial reduction in energy flow caused by an increase in energetic dominance of small-bodied species with an affinity for closed grass habitats. This suggests that modern changes in land cover caused by anthropogenic activities-particularly the spread of nonnative annual grasslands-has led to a breakdown in the compensatory dynamics of energy flow. Human activities are thus modifying the small mammal community in ways that differ from climate-driven expectations, resulting in an energetically novel ecosystem. Our study illustrates the need to integrate across ecological and temporal scales to provide robust insights for long-term conservation and management.