Circumpolar synchrony in big river bacterioplankton
Publication Type:
Journal ArticleSource:
Proceedings of the National Academy of Sciences of the United States of America, Volume 106, Issue 50, Number 50, p.21208-21212 (2009)ISBN:
0027-8424Keywords:
16s, 16s ribosomal-rna, assemblages, bacterial communities, dgge, diversity, gradient gel-electrophoresis, LAKES, microbial diversity, OCEAN, population-dynamics, seasonality, SUCCESSION, time-series, WATERAbstract:
Natural bacterial communities are extremely diverse and highly dynamic, but evidence is mounting that the compositions of these communities follow predictable temporal patterns. We investigated these patterns with a 3-year, circumpolar study of bacterio-plankton communities in the six largest rivers of the pan-arctic watershed (Ob', Yenisey, Lena, Kolyma, Yukon, and Mackenzie), five of which are among Earth's 25 largest rivers. Communities in the six rivers shifted synchronously over time, correlating with seasonal shifts in hydrology and biogeochemistry and clustering into three groups: winter/spring, spring freshet, and summer/fall. This synchrony indicates that hemisphere-scale variation in seasonal climate sets the pace of variation in microbial diversity. Moreover, these seasonal communities reassembled each year in all six rivers, suggesting a long-term, predictable succession in the composition of big river bacterioplankton communities.