Seasonal variability of phytoplankton community structure in the subtropical western North Pacific
Seasonal variability of phytoplankton community structure in the subtropical western North Pacific
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DOI：
10.1007/s10872-015-0346-9
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发表时间：
2016-01
影响因子：
2.3
通讯作者：
T. Fujiki;K. Sasaoka;K. Matsumoto;M. Wakita;Y. Mino
中科院分区：
文献类型：
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作者：
T. Fujiki;K. Sasaoka;K. Matsumoto;M. Wakita;Y. Mino
在2010-2012年期间，在北太平洋副热带环流的西北部地区，我们研究了浮游植物群落的结构和光生理状态的季节性变化，使用化学分类程序CHEMTAX和快速重复率荧光法。在相对较深的垂直混合期（40-207 m），上层150 m的叶绿素a总现存量（ACTChla）在25.5 - 89.0 mg m− 2之间变化，但在分层期相当稳定（18.6-27.2 mg m−2）。Prymnesiophytes，绿藻，金藻，prasinophytes，和/或硅藻组成的主要部分的AMTChladuring混合期。硅藻在2011年2月成为最丰富的类群（29- 43%），当时观察到大型浮游植物水华，而原绿球藻是分层期间的主要成分（15- 46%）。在混合期间，表层沃茨中硝酸盐和亚硝酸盐（NO3+ NO2）浓度偶尔超过0.5 μmol kg− 1，而在真光层内，Fv/Fm（光系统II的光化学效率）的范围约为0.40-0.50。在层结期间，从表层到50-95 m，NO3+ NO2浓度很低（<0.1 μmol kg−1），混合层上部的Fv/Fm在0.25-0.40之间。该海域浮游植物群落结构的季节变化与深层沃茨的营养盐供应有关。此外，我们将我们的数据与位于NPSG东部地区的时间序列站ALOHA的公布值进行了比较。在Sta。在2011年的ALOHA中，叶绿素a几乎全年不变（19.5-26.4 mg m−2），并且一直由原绿球藻占主导地位（61- 81%）。这些结果表明，浮游植物群落在西北地区的NPSG的东部地区相比，是季节性变化和组成的多样性群体。
During 2010–2012 in the northwestern region of the North Pacific subtropical gyre, we examined seasonal variability of the phytoplankton community with respect to structure and photo-physiological status using the chemotaxonomy program CHEMTAX and fast-repetition-rate fluorometry. Total chlorophyllastanding stock in the upper 150 m (ʃTChla) varied from 25.5 to 89.0 mg m−2during periods of relatively deep vertical mixing (40–207 m), but was fairly constant (18.6–27.2 mg m−2) during stratification periods. Prymnesiophytes, chlorophytes, chrysophytes, prasinophytes, and/or diatoms comprised major portions of the ʃTChladuring mixing periods. Diatoms became the most abundant group (29–43 %) in February 2011, when large phytoplankton blooms were observed, whereasProchlorococcuswas the dominant component (15–46 %) during stratification periods. During mixing periods, nitrate and nitrite (NO3+ NO2) concentrations occasionally exceeded 0.5 μmol kg−1in surface waters, andFv/Fm(photochemical efficiency of photosystem II) ranged from approximately 0.40–0.50 within the euphotic zone. During stratification periods, however, NO3+ NO2concentrations were very low (<0.1 μmol kg−1) from the surface to 50–95 m, andFv/Fmwas in the range of 0.25–0.40 in the upper mixed layer. The seasonal variability of phytoplankton community structure in this region was related to the nutrient supply from deep waters. Additionally, we compared our data to published values at the time-series station ALOHA, located in the eastern region of the NPSG. At Sta. ALOHA in 2011, ʃTChlawas almost constant (19.5–26.4 mg m−2) throughout the year and was consistently dominated byProchlorococcus(61–81 %). These results suggest that the phytoplankton community in the northwestern region of the NPSG is seasonally variable and composed of diverse groups compared with the eastern region of the NPSG.