RAPID RESPONSE OF TREELINE VEGETATION AND LAKES TO PAST CLIMATE WARMING
RAPID RESPONSE OF TREELINE VEGETATION AND LAKES TO PAST CLIMATE WARMING
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DOI：
10.1038/361243a0
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发表时间：
1993-01-21
期刊：
影响因子：
64.8
通讯作者：
SMOL, JP
中科院分区：
文献类型：
--
作者：
MACDONALD, GM;EDWARDS, TWD;SMOL, JP
预计未来的温室效应在北方地区将特别明显，这些地区植被的变化可能反过来影响全球气候。因此，必须确定北方生态系统如何应对气候的迅速变化。在这里，我们提出了古生态证据的陆地植被和湖泊特征的变化，在5,000和4,000年前发生在加拿大中部的北方树线之间的气候变暖的插曲。最初的转变-从苔原到陆地上的森林苔原，与湖泊生产力、pH值和流入与蒸发的比率的增加相吻合-仅用了150年，这大致相当于在模拟北方森林对气候变暖的反应时经常使用的时间段5，6。树线推进的时间并不符合米兰科维奇理论7预测的高纬度夏季日照最大值，这表明北方加拿大经历了区域异步的全新世中晚期北极锋夏季位置的变化。这种全新世气候事件可能提供了一个更好的模拟未来全球变化对北方生态系统的影响，而不是从冰川到非冰川条件的过渡。
FUTURE greenhouse warming is expected to be particularly pronounced in boreal regions1, and consequent changes in vegetation in these regions may in turn affect global climate2-4. It is therefore important to establish how boreal ecosystems might respond to rapid changes in climate. Here we present palaeoecological evidence for changes in terrestrial vegetation and lake characteristics during an episode of climate warming that occurred between 5,000 and 4,000 years ago at the boreal treeline in central Canada. The initial transformation - from tundra to forest-tundra on land, which coincided with increases in lake productivity, pH and ratio of inflow to evaporation - took only 150 years, which is roughly equivalent to the time period often used in modelling the response of boreal forests to climate warming5,6. The timing of the treeline advance did not coincide with the maximum in high-latitude summer insolation predicted by Milankovitch theory7, suggesting that northern Canada experienced regionally asynchronous middle-to-late Holocene shifts in the summer position of the Arctic front. Such Holocene climate events may provide a better analogue for the impact of future global change on northern ecosystems than the transition from glacial to nonglacial conditions.