New research on bacterial communities throughout six
large Arctic river ecosystems reveals predictable temporal
patterns, suggesting that scientists could use these communities
as markers for monitoring climate change in the polar regions.
The study, published in the Proceedings of the National Academy
of Sciences, shows that bacterial communities in the six rivers
shifted synchronously over time, correlating with seasonal shifts
in hydrology and biogeochemistry. The research team documents
these patterns through a three-year, circumpolar study of planktonic bacterial communities in the six largest rivers of
the pan-arctic watershed: the Ob', Yenisey, Lena, Kolyma,
Yukon and Mackenzie rivers.
"Our results demonstrate that synchrony,
seasonality and annual reassembly in planktonic bacterial
communities occur on global scales," said lead author Dr.
Byron Crump of the University of Maryland Center for
Environmental Science Horn Point Laboratory, Cambridge.
"Since bacterial communities in big arctic rivers shift
predictably with circumpolar seasonal changes in
environmental conditions, they may serve as sensitive
indicators of climate change in the Arctic." "The six river
systems studied are comparable in size to the Mississippi
river in the United States," said coauthor Rainer Amon of
Texas A&M University at Galveston. "One of the things
we learned is the bacterial communities in all six of them
seem to be very similar. There are many questions still to
be answered, such as how these bacterial communities
might respond to a continued increase in temperature."
This synchrony indicates that hemisphere-scale variation in
seasonal climate sets the pace of variation in microbial
diversity. Moreover, these seasonal communities
Genetically engineered strains of the cyanobacterium
Synechococcus elongatus in a Petri dish. (Credit: Image courtesy
of University of California - Los Angeles).
Source: www.sciencedaily.com
ONLINE REPORTS ON MICROORGANISMS
New research on bacterial communities throughout six
large Arctic river ecosystems reveals predictable temporal
patterns, suggesting that scientists could use these communities
as markers for monitoring climate change in the polar regions.
The study, published in the Proceedings of the National Academy
of Sciences, shows that bacterial communities in the six rivers
shifted synchronously over time, correlating with seasonal shifts
in hydrology and biogeochemistry. The research team documents
these patterns through a three-year, circumpolar study of
reassembled each year in all six rivers, suggesting a longterm,
predictable succession in the composition of big river
bacterial communities.
Divergence from this synchronous pattern may
provide an early signal of climate change in some regions
of the Arctic, and may result in changes to river microbial
communities and the biogeochemical transformations that
they carry out. Data for this study was collected through
the PARTNERS program, collaboration among scientists
from the U.S., Canada and Russia examining the largest
rivers of the pan-arctic watershed. By including five of the
world's 25 largest rivers in the study, the results provide a
unique perspective on global-scale patterns in bacterial
diversity.
Source: www.sciencedaily.com
ENVIS
CENTRE Newsletter Vol.7,Issue 4 October 2009
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