Grants and Contributions:

Grant or Award spanning more than one fiscal year. (2017-2018 to 2022-2023)

Freshwater ecosystems are biogeochemical hotspots embedded in the
terrestrial landscape that undergoes rapid human-driven changes such as
agriculture and urbanization. Central to this role are the metabolic activities
of heterotrophic bacteria, which are responsible for most of the degradation
and mineralization of the organic matter (OM) transiting in inland waters in
addition to providing nutrients and energy to the aquatic food web. Despite the
recognition of this role at the ecosystem level, little is known about how and
to which extent anthropogenic disturbances may alter the metabolism and
functioning of aquatic microbial communities through changes in the amount,
chemical character, and age of the OM delivered to surrounding waters.
Conducting research at the interface of microbial ecology and aquatic
biogeochemistry, I propose to further our understanding of the links existing
between microbial metabolism and the molecular properties of OM across
perturbation gradients to better understand and predict the overall ecosystemic
response of inland waterbodies to human activities. The main objectives of my
research program are to: (i) identify the organic molecules released into the
aquatic interface along gradients in land-cover from forested landscapes to
agriculture and urban areas, (ii) assess the microbial strategies involved in
the uptake of the mobilized organic pool by human activities, and (iii)
determine the metabolic response of aquatic bacterial communities along
perturbation gradients. Relying on state-of-the-art technics in analytical
chemistry and unique experimental approaches, my research program will combine
temporal and spatial field-based surveys in the Mauricie region of Québec
taking advantage of the large gradient in anthropogenic influence present in this region, as well
as laboratory assays shedding light into the bacterial strategies of resource
utilization in representative impacted systems. This program represents a
crucial step towards an integrative understanding of how human disturbance may disrupt not only the flow of elements at the land-water interface, but also
the functioning of aquatic food webs and ecosystems. This understanding will in
turn allow scientists and policy makers to forecast the response of aquatic
ecosystems and food webs to human pressure and to direct the most pressing
restoration efforts in impacted watersheds.