Differences in Rate and Direction of Shifts between Phytoplankton Size Structure and Sea Surface Temperature
Differences in Rate and Direction of Shifts between Phytoplankton Size Structure and Sea Surface Temperature
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DOI：
10.3390/rs9030222
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发表时间：
2017-03
期刊：
影响因子：
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通讯作者：
Hisatomo Waga;T. Hirawake;A. Fujiwara;T. Kikuchi;S. Nishino;Koji Suzuki;S. Takao;S. Saitoh
中科院分区：
文献类型：
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作者：
Hisatomo Waga;T. Hirawake;A. Fujiwara;T. Kikuchi;S. Nishino;Koji Suzuki;S. Takao;S. Saitoh
物种分布正在以不同的速度和方向变化，以应对最近的全球变暖。海洋表面温度的速度(SST)被用来预测物种的迁移和持久性，作为物种如何跟踪其热生态位的预期；然而，一些研究发现，物种转移的证据与SST的速度背道而驰。这项研究调查了利用遥感数据估计浮游植物大小结构变化的速度是否有助于更好地预测物种变化。基于主成分分析方法，通过量化浮游植物群落的大小结构与浮游植物吸收系数的光谱特征(APH(λ))之间的关系，建立了一个叶绿素a大小分布模型。模型验证表明，成功地求出了描述浮游植物群落天气尺度结构的CSD指数(以下简称CSD斜率)，相对均方根误差为18.5%。横跨大洋的CSD坡面速度中值为485.2公里·十年−1，与CLA(531.5公里·十年−1)基本相似。这些值是SST的两倍，CSD斜率和Chla的移动方向与SST有很大的不同。由于Chla与浮游植物群落的大小结构通常是协变的，我们认为Chla的时空变化可以解释浮游植物大小结构的变化。浮游植物的大小结构与SST在变化的速度和方向上都有明显的差异，这表明浮游植物的大小结构的变化可以作为评估海洋物种分布变化的有力工具。我们的结果将有助于生成全球和区域地图，以预测物种因环境压力而发生的变化。
Species distributions are changing with various rates and directions in response to recent global warming. The velocity of sea surface temperature (SST) has been used to predict species migration and persistence as an expectation of how species track their thermal niches; however, several studies have found that evidence for species shifts has deviated from the velocity of SST. This study investigated whether estimation of the velocity of shifts in phytoplankton size structure using remote sensing data could contribute to better prediction of species shifts. A chlorophyll-a (Chla) size distribution (CSD) model was developed by quantifying the relationships between the size structure of the phytoplankton community and the spectral features of the phytoplankton absorption coefficient (aph(λ)), based on the principal component analysis approach. Model validation demonstrated that the exponent of CSD (hereafter, CSD slope), which can describe the synoptic size structure of a phytoplankton community, was derived successfully with a relative root mean square error of 18.5%. The median velocity of CSD slope across the ocean was 485.2 km·decade−1, broadly similar to Chla (531.5 km·decade−1). These values were twice the velocity of SST, and the directions of shifts in CSD slope and Chla were quite different from that of SST. Because Chla is generally covariant with the size structure of a phytoplankton community, we believe that spatiotemporal changes in Chla can explain the variations of phytoplankton size structure. Obvious differences in both rate and direction of shifts were found between the phytoplankton size structure and SST, implying that shifts of phytoplankton size structure could be a powerful tool for assessing the distributional shifts of marine species. Our results will contribute to generate global and regional maps of expected species shifts in response to environmental forcing.