Catastrophe, recovery and range limitation in NE Pacific kelp forests: a large-scale perspective
Catastrophe, recovery and range limitation in NE Pacific kelp forests: a large-scale perspective
复制标题
DOI：
10.3354/meps320079
复制
发表时间：
2006-01-01
影响因子：
2.5
通讯作者：
Estes, James A.
中科院分区：
文献类型：
--
作者：
Edwards, Matthew S.;Estes, James A.
1997-98年的厄尔尼诺现象是有记录以来最强烈的一次，导致北美西海岸沿着的巨型海带Macrocystis pyrifera（Agardh）大面积消失。利用丰富的研究历史，显示异常大的波浪和温暖的营养贫乏的水与厄尔尼诺现象产生负面影响的巨型海带种群在南部和下加利福尼亚的一些地方，我们研究（1）如何扩大这些影响时，考虑到整个物种的地理范围在东北太平洋和（2）如果这些影响是概括在广泛的空间尺度。工作在56个地点在14个研究地点在3年期间（1997年至2000年），我们研究了如何巨大的海带种群的影响，并恢复了1997-98年厄尔尼诺超过类似的1500公里的跨度沿着北美西海岸。我们的研究结果表明，虽然几乎所有的巨型海带消失了南部三分之一的物种的范围沿着下加利福尼亚州，墨西哥海岸，和严重的损失发生在整个中部三分之一的物种的范围在美国加州州南部，只有轻微的影响，观察到整个北方三分之一的物种的范围在加州州中部。此外，虽然各区域之间差异很大，但这些影响在每个区域内的地点之间是相似和普遍的。我们的研究结果还表明，正如在局部尺度研究中所观察到的那样，巨型海带死亡率的这种大尺度变化是由海洋温度（营养浓度）和波浪强度的大尺度模式驱动的。恢复厄尔尼诺现象后，相反，是可变的，在多个空间尺度，虽然没有直接测试这里，可能受到许多因素的影响，如接近涌升区，与其他藻类的竞争，放牧，繁殖可用性。此外，不同地点之间的恢复率的变化导致了整个下加利福尼亚大部分地区的巨型海带恢复普遍缓慢，厄尔尼诺现象结束后2年，厄尔尼诺现象的残余大规模影响仍然很明显。由于全球气候变化可能导致厄尔尼诺现象的频率和强度增加，我们的研究结果对生态系统可能对它们做出反应的方式具有广泛的影响，并提供了一种措施，可以在事件之间比较它们对巨型海带生态系统的影响。
The 1997-98 El Nino was one of the strongest on record and resulted in widespread losses of the giant kelp Macrocystis pyrifera (Agardh) along the west coast of North America. Drawing on a rich history of studies that have shown abnormally large waves and warm nutrient-poor water associated with El Ninos to negatively impact giant kelp populations at some locations in southern and Baja California, we examined (1) how these impacts scale up when considered across the species' geographic range in the NE Pacific Ocean and (2) if these impacts are generalizable over broad spatial scales. Working at 56 sites in 14 study locations over a 3 yr period (1997 to 2000), we examined how giant kelp populations were impacted by and recovered following the 1997-98 El Niho over a similar to 1500 km span along the west coast of North America. Our results indicate that while nearly all giant kelp disappeared from the southern one-third of the species' range along the coast of Baja California, Mexico, and heavy losses occurred throughout the central one-third of the species' range in southern California, USA, only minor impacts were observed throughout the northern one-third of the species' range in central California. Further, although highly variable among regions, these impacts were similar and generalizable among locations within each region. Our results also suggest that, as has been observed in local-scale studies, this large-scale variability in giant kelp mortality was driven by large-scale patterns in ocean temperature (nutrient concentration) and wave intensity. Recovery following El Niho, in contrast, was variable at multiple spatial scales and although not directly tested here, presumably influenced by numerous factors such as proximity to upwelling areas, competition with other algae, grazing, and propagule availability. Further, variability in the rates of recovery among locations resulted in a generally slow recovery of giant kelp throughout most of Baja California, and residual large-scale impacts of the El Niho were still evident 2 yr after the El Niho ended. As global climate change may lead to increases in the frequency and intensity of El Ninos, our findings have broad implications for the ways in which ecosystems might be expected to respond to them and provide a measure by which their impacts to giant kelp ecosystems may be compared among events.