The Aftermath of Megafaunal Extinction: Ecosystem Transformation in Pleistocene Australia
The Aftermath of Megafaunal Extinction: Ecosystem Transformation in Pleistocene Australia
复制标题
巨型动物灭绝的后果：澳大利亚更新世的生态系统转变
DOI：
10.1126/science.1214261
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发表时间：
2012
期刊：
影响因子：
56.9
通讯作者：
Christopher N. Johnson
中科院分区：
文献类型：
--
作者：
S. Rule;B. Brook;S. Haberle;C. Turney;A. Kershaw;Christopher N. Johnson
人类影响？ 40至5万年前人类抵达澳大利亚后，许多大型脊椎动物物种迅速灭绝。通过分析澳大利亚东北部某个地点的沉积物岩心，Rule 等人。 （第 1483 页；参见 McGlone 的《观点》）表明，澳大利亚巨型动物群的灭绝导致了重要的生态系统转变。其中最突出的是从雨林植被向硬叶植被的转变以及火灾发生率的持续增加。这些岩芯还提供了澳大利亚巨型动物灭绝原因的证据，排除了气候和人为火灾的可能原因，同时证实了灭绝是在人类到来之后发生的。这些发现表明，早期人类的间接影响有时会从根本上改变地貌，这强调了史前人类社会对自然系统的影响。四万年前人类到来后，巨型动物灭绝，导致植被和火灾状况发生重大变化。巨型脊椎动物在许多更新世生态系统中占主导地位。许多是食草动物，它们在史前时期的突然灭绝可能会产生巨大的生态影响。我们使用 13 万年的高分辨率环境记录来帮助解决澳大利亚巨型动物灭绝的原因并重建其生态后果。我们的研究结果表明，人类的到来而不是气候导致了巨型动物的灭绝，然后通过草食动物压力放松和景观中火灾增加对植被的直接影响，引发了硬叶植物取代混合雨林。这种生态系统的转变与上一个冰川周期气候变化的影响一样大，并表明世界其他地方巨型动物灭绝后可能发生的变化的严重程度。
Human Impact? Following the arrival of humans in Australia 40- to 50,000 years ago, many species of large vertebrates rapidly became extinct. By analyzing sediment cores from a site in northeastern Australia, Rule et al. (p. 1483; see the Perspective by McGlone) show that the extinction of the Australian megafauna caused important ecosystem shifts. Prominent among these were a shift from rainforest vegetation to sclerophyllous vegetation and a sustained increase in the incidence of fire. The cores also provide evidence of the cause of megafaunal extinction in Australia, ruling out climate and anthropogenic fire as possible causes while confirming that the extinctions closely followed human arrival. These findings show how landscapes sometimes have been fundamentally changed by the indirect effects of early humans—which underscores the impact that even prehistoric human societies had on natural systems. The extinction of megafauna 40,000 years ago after the arrival of humans led to major changes in vegetation and fire regimes. Giant vertebrates dominated many Pleistocene ecosystems. Many were herbivores, and their sudden extinction in prehistory could have had large ecological impacts. We used a high-resolution 130,000-year environmental record to help resolve the cause and reconstruct the ecological consequences of extinction of Australia’s megafauna. Our results suggest that human arrival rather than climate caused megafaunal extinction, which then triggered replacement of mixed rainforest by sclerophyll vegetation through a combination of direct effects on vegetation of relaxed herbivore pressure and increased fire in the landscape. This ecosystem shift was as large as any effect of climate change over the last glacial cycle, and indicates the magnitude of changes that may have followed megafaunal extinction elsewhere in the world.