Disentangling the Ecological Processes Shaping the Latitudinal Pattern of Phytoplankton Communities in the Pacific Ocean

mSystems

Hisashi Endo¹  Bingzhang Chen²  Ngai Hei Ernest Ho³  Shunyan Cheung³  Koji Suzuki⁴  Xiaomin Xia⁵  Zhimeng Xu⁶  Meng Li⁶  Wenxue Wu⁷  Hongbin Liu⁸ 

[1] Bioinformatics Center, Institute for Chemical Research, Kyoto University, Kyoto, Japan;Department of Mathematics and Statistics, University of Strathclyde, Glasgow, United Kingdom;Department of Ocean Science, The Hong Kong University of Science and Technology, Hong Kong, China;Graduate School of Environmental Science, and Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Hokkaido, Japan;Key Laboratory of Tropical Marine Bio‐resources and Ecology, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, China;SZU-HKUST Joint PhD Program in Marine Environmental Science, Shenzhen University, Shenzhen, China;School of Marine Sciences, Sun Yat-sen University, Zhuhai, China;Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China;

关键词: Pacific Ocean;    ecological process;    latitudinal biogeography;    phytoplankton community;    spatial scale;   

DOI  :  10.1128/msystems.01203-21

来源: DOAJ

【 摘 要 】

ABSTRACT Phytoplankton diversity and community compositions vary across spaces and are fundamentally affected by several deterministic (e.g., environmental selection) and stochastic (e.g., ecological drift) processes. How this suite of different processes regulates the biogeography of phytoplankton remains to be comprehensively explored. Using high-throughput sequencing data and null model analysis, we revealed the ecological processes shaping the latitudinal community structure of three major phytoplankton groups (i.e., diatoms, Synechococcus, and haptophytes) across the Pacific Ocean (70°N, 170°W to 35°S, 170°W). At the basin scale, heterogeneous selection (selection under heterogeneous environmental conditions) dominated the assembly processes of all phytoplankton groups; however, its relative importance varied greatly at the climatic zonal scale, explaining the distinct latitudinal α- and β-diversity among phytoplankton groups. Assembly processes in Synechococcus and haptophyte communities were mainly controlled by physical and nutrient factors, respectively. High temperature drove Synechococcus communities to be more deterministic with higher diversity, while haptophyte communities were less environmentally selected at low latitudes due to their wide niche breadth and mixotrophic lifestyle. Diatom communities were overwhelmingly dominated by the selection process but with low correlation of measured environmental factors to their community compositions. This could be attributed to the high growth rate of diatoms, as indicated by their lower site occupation frequency than predicted in the neutral community model. Our study showed that heterogeneous selection is the main force that shaped the biogeography of three key phytoplankton groups in the Pacific Ocean, with a latitudinal variation of relative importance due to the distinct traits among phytoplankton. IMPORTANCE Phytoplankton are diverse and abundant as primary producers in the ocean, with diversity and community compositions varying spatially. How fundamental processes (e.g., selection, dispersal, and drift) regulate their global biogeography remains to be comprehensively explored. In this study, we disentangled the ecological processes of three key phytoplankton groups (i.e., diatoms, Synechococcus, and haptophytes) along the same latitudinal gradients in the Pacific Ocean. Heterogeneous selection, by promoting species richness and reducing similarity between communities, was the dominant process shaping the communities of each phytoplankton group at the basin scale. However, its relative importance varied greatly among different phytoplankton groups in different climate zones, explaining the uneven latitudinal α- and β-diversity. We also highlight the importance of identifying key factors mediating the relative importance of assembly processes in phytoplankton communities, which will enhance our understanding of their biogeography in the ocean and future patterns under climate changes.

【 授权许可】

Unknown