Global nutrient transport in a world of giants
Global nutrient transport in a world of giants
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DOI：
10.1073/pnas.1502549112
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发表时间：
2016-01-26
影响因子：
11.1
通讯作者：
Svenning, Jens-Christian
中科院分区：
文献类型：
--
作者：
Doughty, Christopher E.;Roman, Joe;Svenning, Jens-Christian
过去是一个巨人的世界，海洋中有大量的鲸鱼，大型动物在陆地上漫游。然而，在过去的几个世纪里，随着大规模的晚第四纪巨型动物在陆地上的灭绝和大鲸鱼种群的普遍减少，这个世界结束了。这些损失很可能对大规模的营养循环产生了重要影响，因为最近的文献表明，大型动物不成比例地推动营养运动。我们估计，动物将营养物质从集中斑块转移的能力已经下降到陆地上灭绝前值的8%左右，海洋中历史值的5%左右。对于磷（P），一种关键的营养物质，海洋哺乳动物在海洋中的向上移动约为以前容量的23%（以前每年约3.4亿公斤P）。海鸟和溯河产卵鱼类的运动提供了重要的营养物质从海洋到陆地的转移，过去全球每年的磷总量约为1.5亿公斤，由于海鸟种群和溯河产卵鱼类种群的大量减少，这种转移已经下降到不到这个值的4%。我们认为，在过去，海洋哺乳动物，海鸟，溯河产卵的鱼类和陆生动物可能形成了一个相互联系的系统，从海洋深处的大陆内部回收营养物质，海洋哺乳动物从深海到表面沃茨的营养物质，海鸟和溯河产卵的鱼类从海洋到陆地的营养物质，大型动物从热点到大陆内部的营养物质。
The past was a world of giants, with abundant whales in the sea and large animals roaming the land. However, that world came to an end following massive late-Quaternary megafauna extinctions on land and widespread population reductions in great whale populations over the past few centuries. These losses are likely to have had important consequences for broad-scale nutrient cycling, because recent literature suggests that large animals disproportionately drive nutrient movement. We estimate that the capacity of animals to move nutrients away from concentration patches has decreased to about 8% of the preextinction value on land and about 5% of historic values in oceans. For phosphorus (P), a key nutrient, upward movement in the ocean by marine mammals is about 23% of its former capacity (previously about 340 million kg of P per year). Movements by seabirds and anadromous fish provide important transfer of nutrients from the sea to land, totalling similar to 150 million kg of P per year globally in the past, a transfer that has declined to less than 4% of this value as a result of the decimation of seabird colonies and anadromous fish populations. We propose that in the past, marine mammals, seabirds, anadromous fish, and terrestrial animals likely formed an interlinked system recycling nutrients from the ocean depths to the continental interiors, with marine mammals moving nutrients from the deep sea to surface waters, seabirds and anadromous fish moving nutrients from the ocean to land, and large animals moving nutrients away from hotspots into the continental interior.