Dynamic modeling of organic carbon fates in lake ecosystems

• Autores: McCullough, Ian M.; Dugan, Hilary A.; Farrell, Kaitlin J.; Morales Williams, Ana M.; Ouyang, Zutao; Roberts, Derek; Scordo, Facundo; Bartlett, Sarah L.; Burke, Samantha M.; Doubek, Jonathan P.; Krivak Tetley, Flora E.; Skaff, Nicholas K.; Summers, Jamie C.; Weathers, Kathleen C.; Hanson, Paul C.
• Año de publicación: 2018
• Idioma: inglés
• Tipo de recurso: artículo
• Materia: Carbon Cycle; Dissolved Organic Carbon; GLEON; LTER; Mass Balance; Particulate Organic Carbon
• Institución: Consejo Nacional de Investigaciones Científicas y Técnicas

Lakes are active processors of organic carbon (OC) and play important roles in landscape and global carbon cycling. Allochthonous OC loads from the landscape, along with autochthonous OC loads from primary production, are mineralized in lakes, buried in lake sediments, and exported via surface or groundwater outflows. Although these processes provide a basis for a conceptual understanding of lake OC budgets, few studies have integrated these fluxes under a dynamic modeling framework to examine their interactions and relative magnitudes. We developed a simple, dynamic mass balance model for OC, and applied the model to a set of five lakes. We examined the relative magnitudes of OC fluxes and found that long-term (>10 year) lake OC dynamics were predominantly driven by allochthonous loads in four of the five lakes, underscoring the importance of terrestrially-derived OC in northern lake ecosystems. Our model highlighted seasonal patterns in lake OC budgets, with increasing water temperatures and lake productivity throughout the growing season corresponding to a transition from burial- to respiration-dominated OC fates. Ratios of respiration to burial, however, were also mediated by the source (autochthonous vs. allochthonous) of total OC loads. Autochthonous OC is more readily respired and may therefore proportionally reduce burial under a warming climate, but allochthonous OC may increase burial due to changes in precipitation. The ratios of autochthonous to allochthonous inputs and respiration to burial demonstrate the importance of dynamic models for examining both the seasonal and inter-annual roles of lakes in landscape and global carbon cycling, particularly in a global change context. Finally, we highlighted critical data needs, which include surface water DOC observations in paired tributary and lake systems, measurements of OC burial rates, groundwater input volume and DOC, and budgets of particulate OC.
Fil: McCullough, Ian M.. University of California; Estados Unidos
Fil: Dugan, Hilary A.. University of Wisconsin-Madison; Estados Unidos
Fil: Farrell, Kaitlin J.. Dartmouth College; Estados Unidos. University of Georgia; Estados Unidos
Fil: Morales Williams, Ana M.. University of Vermont; Estados Unidos
Fil: Ouyang, Zutao. Michigan State University; Estados Unidos
Fil: Roberts, Derek. University of California at Davis; Estados Unidos. Tahoe Environmental Research Center; Estados Unidos
Fil: Scordo, Facundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto Argentino de Oceanografía. Universidad Nacional del Sur. Instituto Argentino de Oceanografía; Argentina
Fil: Bartlett, Sarah L.. University of Wisconsin-Milwaukee; Estados Unidos
Fil: Burke, Samantha M.. University of Waterloo; Canadá
Fil: Doubek, Jonathan P.. Virginia Tech University; Estados Unidos
Fil: Krivak Tetley, Flora E.. Dartmouth College; Estados Unidos
Fil: Skaff, Nicholas K.. Michigan State University; Estados Unidos
Fil: Summers, Jamie C.. Queen’s University; Canadá
Fil: Weathers, Kathleen C.. Cary Institute of Ecosystem Studies; Estados Unidos
Fil: Hanson, Paul C.. University of Wisconsin-Madison; Estados Unidos