Open AccessCarbon and water cycling in lake‐rich landscapes: Landscape connections, lake hydrology, and biogeochemistry
Author(s) -
Cardille Jeffrey A.,
Carpenter Stephen R.,
Coe Michael T.,
Foley Jonathan A.,
Hanson Paul C.,
Turner Monica G.,
Vano Julie A.
Publication year - 2007
Publication title -
journal of geophysical research: biogeosciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2006jg000200
Subject(s) - wetland , watershed , hydrology (agriculture) , environmental science , carbon cycle , biogeochemistry , groundwater , surface water , ecosystem , ecology , geology , oceanography , geotechnical engineering , machine learning , environmental engineering , computer science , biology
Lakes are low‐lying connectors of uplands and wetlands, surface water and groundwater, and though they are often studied as independent ecosystems, they function within complex landscapes. One such highly connected region is the Northern Highland Lake District (NHLD), where more than 7000 lakes and their watersheds cycle water and carbon through mixed forests, wetlands, and groundwater systems. Using a new spatially explicit simulation framework representing these coupled cycles, the Lake, Uplands, Wetlands Integrator (LUWI) model, we address basic regional questions in a 72‐lake simulation: (1) How do simulated water and carbon budgets compare with observations, and what are the implications for carbon stocks and fluxes? (2) How do the strength and spatial pattern of landscape connections vary among watersheds? (3) What is the role of interwatershed connections in lake carbon processing? Results closely coincide with observations at seasonal and annual scales and indicate that the connections among components and watersheds are critical to understanding the region. Carbon and water budgets vary widely, even among nearby lakes, and are not easily predictable using heuristics of lake or watershed size. Connections within and among watersheds exert a complex, varied influence on these processes: Whereas inorganic carbon budgets are strongly related to the number and nature of upstream connections, most organic lake carbon originates within the watershed surrounding each lake. This explicit incorporation of terrestrial and aquatic processes in surface and subsurface connection networks will aid our understanding of the relative roles of on‐land, in‐lake, and between‐lake processes in this lake‐rich region.