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THERE AND BACK AGAIN – UNRAVELING MECHANISMS OF MICROBIAL BIOGEOGRAPHY IN THE NORTH PACIFIC SUBTROPICAL GYRE TO AND FROM STATION ALOHA

Marine microbes cycle energy and matter essential for all organisms. Yet, mechanisms shaping microbial biogeography among free-living, particle-attached and different taxa within communities remain unknown. We sequenced 16S rRNA amplicons from size fractionated DNA, sampled underway between Honolulu and station ALOHA in the North Pacific Subtropical Gyre to elucidate microbial metacommunity and metapopulation dynamics. Communities were structured following the neutral model and patch dynamics, i.e. stochastic and dispersal-driven processes. However, species sorting and mass effects, i.e. local environmental conditions and dispersal-driven processes, structured Prochlorococcus and Synechococcus populations (delineated at 99% 16S rRNA gene identity). For the total and free-living community most populations occupied a single site and the number of populations occupying different number of sites followed a significant bimodal pattern with several populations occupying all sites. Such bimodal patterns were coupled with quadratic colonization and extinction rates for the overall community and most taxa, thus following core and satellite metapopulation dynamics. In contrast, particle-attached communities exhibited unimodal patterns and linear colonization and extinction rates. Our findings highlight the importance of positive feedbacks between local abundance and occupancy of populations in structuring microbial communities. Nevertheless, pooling all populations into a single distribution model will mask important differences in assembly processes, critical for our understanding of microbial biogeography and in predicting the structure and function of marine ecosystems.

Authors

Lindh, M. V., University of Hawaii, USA, markusvlindh@gmail.com

Church, M. J., University of Hawaii, USA, mjchurch@hawaii.edu

Details

Poster presentation

Session #:040
Date: 03/01/2017
Time: 15:30 - 16:30
Location: Poster/Exhibit Hall

Presentation is given by student: No

PosterID: 349