Picophytoplankton Niche Partitioning in the Warmest Oligotrophic Sea
Picophytoplankton Niche Partitioning in the Warmest Oligotrophic Sea
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DOI：
10.3389/fmars.2021.651877
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发表时间：
2021-04-29
影响因子：
3.7
通讯作者：
Agusti, Susana
中科院分区：
文献类型：
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作者：
Coello-Camba, Alexandra;Agusti, Susana
微微大小的聚球藻、原绿球藻和真核生物是海洋中广阔的温暖和贫营养区域中占主导地位的光合生物。在本文中，我们的目标是实现生态位的picophytoastononic社区居住在红海，最温暖的贫营养海，这被认为是未来的海洋模式。我们量化的人口丰度和环境变量在几个海洋调查，并使用逐步回归，主成分分析（PCA），和成分数据分析，以确定实现的生态位的三个picophytoacetontic组。在上层200米水柱内，水温从21.4摄氏度到32.4摄氏度不等，最温暖的沃茨位于南部，那里的营养物质增加。聚球藻占主导地位的生物量，占总微微型浮游植物生物量的47.6%，其次是微微型真核生物（26.4%）和原绿球藻（25.9%），其比例显着对比亚热带海洋，其中原绿球藻占主导地位。温度和三个种群之间存在显著的正相关关系，但原绿球藻的相关性较弱（R-2 = 0.08），聚球藻的相关性较强且较陡（R-2 = 0.57）。这三个人口集中在类似的低营养值的最大丰度（洛伦兹拟合）。聚球藻集中在接近表面的光合有效辐射（PAR）的约77%和约30.6摄氏度。微真核生物集中在较低的光（约6.4%的表面PAR）和温暖的沃茨（约30摄氏度）。原绿球藻从表面沃茨中分离出来，并在弱光（约3.2%的表面PAR）下集中在深处。光照和温度是决定群落组成的最具影响力的因素，聚球藻占主导地位，在最温暖的（>30摄氏度）沃茨的微型浮游植物生物量的74%。在温暖和中营养的红海南部，中等丰度的picoeukaryotes和Synechococcus表明增加与纳米和微型浮游植物的竞争。我们的观察结果同意预测的增加垂直分离的picophytoplankton社区与未来的变暖，并揭示聚球藻的显着能力，以适应气候变暖。
Pico-sized Synechococcus, Prochlorococcus, and eukaryotes are the dominant photosynthetic organisms in the vast warm and oligotrophic regions of the ocean. In this paper, we aim to characterize the realized niches of the picophytoplanktonic community inhabiting the Red Sea, the warmest oligotrophic sea, which is considered to be a model for the future ocean. We quantify population abundances and environmental variables over several oceanographic surveys, and use stepwise regression, principal-component analysis (PCA), and compositional-data analysis to identify the realized niches of the three picophytoplanktonic groups. Water temperature varied from 21.4 to 32.4 degrees C within the upper 200-m water column, with the warmest waters being found in the South, where nutrients increased. Synechococcus dominated the biomass, contributing 47.6% to the total picophytoplankton biomass, followed by picoeukaryotes (26.4%) and Prochlorococcus (25.9%), whose proportions contrast significantly with those reported in the subtropical ocean, where Prochlorococcus prevails. There were positive and significant relationships between temperature and the three populations, although these were weak for Prochlorococcus (R-2 = 0.08) and stronger and steeper for Synechococcus (R-2 = 0.57). The three populations centered their maximum abundances (Lorentzian fits) at similar low nutrient values. Synechococcus were centered close to the surface at approximate to 77% of surface photosynthetically active radiation (PAR) and approximate to 30.6 degrees C. The picoeukaryotes were centered at lower light (approximate to 6.4% surface PAR) and warm waters (approximate to 30 degrees C). Prochlorococcus was segregated from the surface waters and centered deep at low light (approximate to 3.2% surface PAR). Light and temperature were the most influential factors determining the community composition, with Synechococcus dominating similar to 74% of the picophytoplankton biovolume in the warmest (>30 degrees C) waters. In the warm and mesotrophic southern Red Sea, the moderate abundances of picoeukaryotes and Synechococcus suggest increasing competition with nano and microphytoplankton. Our observations agree with predictions of increasing vertical segregation of picophytoplankton communities with future warming and reveal Synechococcus's significant capacity to adapt to warming.