Project summary: Dissolved organic matter (DOM) provides a significant source of energy and nutrients to ecosystems and its biogeochemical cycling is inextricably linked to dissolved inorganic nitrogen (DIN). In stream ecosystems in particular, there is considerable spatial and temporal variation in the relationships between the different fractions of DOM (dissolved organic carbon and nitrogen) and DIN.

forested stream

Credit: Marty Downs/LTER-NCO. CC BY-SA 4.0.

Here we propose to use LTER data, as well as other data sources, to examine global patterns in the cycling of DOM and DIN. We ask the over-arching question: Under what environmental conditions are the different fractions of DOM and DIN linked? We will examine the interaction between DOM and DIN among biomes ranging from tundra, boreal, desert, temperate forests, tall-grass prairies, and tropical rainforests. Compiling this unprecedented global database will also allow us to examine energy and nutrient cycling across seasons and environmental and management gradients. Our working group is comprised of leaders in the field of stream biogeochemistry, emerging early-career scientists and graduate and undergraduate students. Our synthesis will generate new results and insights, leading to high-profile publications relevant to our understanding of how streams regulate the export of energy and nutrients.