Recent analytical advances have greatly enhanced our capacity to characterize aquatic microbial communities and dissolved organic matter (DOM) pools. This increased resolution comes with computational and conceptual challenges associated to disentangling the complex interactions that exist between these extremely complex assemblages. One way to disentangle their links is to assess the spatial covariation between microbes and molecules along a common flow path within interconnected networks. Here we present a study of microbial / DOM interactions at the whole network scale, where we have modelled the spatial patterns of individual microbial taxa (16S rRNA) and molecular formulae (FT-ICR-MS) along an aquatic continuum (from soil, headwater streams to reservoirs) in the Romaine river watershed in Canada. We aimed to describe the various spatial behaviours of both microorganisms and DOM molecular formulae along the flow path that undergoes major environmental changes, and eventually establish links between the two. Results indicate that around 90% and 80% of microbes and molecular patterns, respectively, do not have a consistent spatial pattern (i.e., largely passive). Within those that had significant spatial patterns, most molecular formulae were decreasing along the continuum, while microbial taxa were mostly balanced between those that increased and decreased. These preliminary results suggest that spatial patterns may provide a framework to unravel reactive microbial and DOM components, enabling us to effectively link microbial-molecular dynamics within aquatic networks.

Primary Presenter: Masumi Stadler, Groupe de Recherche Interuniversitaire en Limnologie, Université du Québec à Montréal, Canada (m.stadler.jp.at@gmail.com)

Authors:

Masumi Stadler, Groupe de Recherche Interuniversitaire en Limnologie, Université du Québec à Montréal, Canada  (m.stadler.jp.at@gmail.com)

Trista Vick-Majors, Michigan Technological University, U.S.A.  ()

François Guillemette, Université du Québec à Trois-Rivières, Canada  ()

Paul del Giorgio, Groupe de Recherche Interuniversitaire en Limnologie, Université du Québec à Montréal, Canada  ()