Nutrient stoichiometry of linked catchment-lake systems along a gradient of land use

Freshwater BiologyVolume 56, Issue 5 p. 791-811 Nutrient stoichiometry of linked catchment-lake systems along a gradient of land use MICHAEL J. VANNI, MICHAEL J. VANNI Department of Zoology, Miami University, Oxford, OH, U.S.A.Search for more papers by this authorWILLIAM H. RENWICK, WILLIAM H. RENWICK Department of Geography, Miami University, Oxford, OH, U.S.A.Search for more papers by this authorANNA M. BOWLING, ANNA M. BOWLING Department of Zoology, Miami University, Oxford, OH, U.S.A.Search for more papers by this authorMARTIN J. HORGAN, MARTIN J. HORGAN Department of Zoology, Miami University, Oxford, OH, U.S.A.Search for more papers by this authorALAN D. CHRISTIAN, ALAN D. CHRISTIAN Department of Zoology, Miami University, Oxford, OH, U.S.A.Search for more papers by this author MICHAEL J. VANNI, MICHAEL J. VANNI Department of Zoology, Miami University, Oxford, OH, U.S.A.Search for more papers by this authorWILLIAM H. RENWICK, WILLIAM H. RENWICK Department of Geography, Miami University, Oxford, OH, U.S.A.Search for more papers by this authorANNA M. BOWLING, ANNA M. BOWLING Department of Zoology, Miami University, Oxford, OH, U.S.A.Search for more papers by this authorMARTIN J. HORGAN, MARTIN J. HORGAN Department of Zoology, Miami University, Oxford, OH, U.S.A.Search for more papers by this authorALAN D. CHRISTIAN, ALAN D. CHRISTIAN Department of Zoology, Miami University, Oxford, OH, U.S.A.Search for more papers by this author First published: 04 April 2011 https://doi.org/10.1111/j.1365-2427.2010.02436.xCitations: 69 Michael J. Vanni, Department of Zoology, Miami University, Oxford, OH 45056, U.S.A. E-mail: vannimj@muohio.edu Present address: Alan D. Christian, Department of Biology, University of Massachusetts-Boston, Boston, MA 02125, U.S.A. Present address: Anna M.Bowling, Department of Public and Environmental Affairs, Indiana University, Bloomington, IN47405, U.S.A. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Summary 1. Catchments export nutrients to aquatic ecosystems at rates and ratios that are strongly influenced by land use practices, and within aquatic ecosystems nutrients can be processed, retained, lost to the atmosphere, or exported downstream. The stoichiometry of carbon and nutrients can influence ecosystem services such as water quality, nutrient limitation, biodiversity, eutrophication and the sequestration of nutrients and carbon in sediments. However, we know little about how nutrient stoichiometry varies along the pathway from terrestrial landscapes through aquatic systems. 2. We studied the stoichiometry of nitrogen and phosphorus exported by three catchments of contrasting land use (forest versus agriculture) and in the water column and sediments of downstream reservoirs. We also related stoichiometry to phytoplankton nutrient limitation and the abundance of heterocystous cyanobacteria. 3. The total N : P of stream exports varied greatly among catchments and was 18, 54 and 140 (molar) in the forested, mixed-use and agricultural catchment, respectively. Total N : P in the mixed layers of the lakes was less variable but ordered similarly: 35, 52 132 in the forested, mixed-use and agricultural lake, respectively. In contrast, there was little variation among systems in the C : N and C : P ratios of catchment exports or in reservoir seston. 4. Phytoplankton in the forested lake were consistently N limited, those in the agricultural lake were consistently P limited, and those in the mixed-use lake shifted seasonally from P- to N limitation, reflecting N : P supply ratios. Total phytoplankton and cyanobacteria biomass were highest in the agricultural lake, but heterocystous (potentially N fixing) cyanobacteria were most abundant in the forested lake, corresponding to low N : P ratios. 5. Despite large differences in catchment export and water column N : P ratios, the N : P of sediment burial (integrated over several decades) was very low and remarkably similar (4.3–7.3) across reservoirs. N and P budgets constructed for the agricultural reservoir suggested that denitrification could be a major loss of N, and may help explain the relatively low N : P of buried sediment. 6. Our results show congruence between the catchment export N : P, reservoir N : P, phytoplankton N versus P limitation and the dominance of heterocystous cyanobacteria. However, the N : P stoichiometry of sediments retained in the lakes was relatively insensitive to catchment stoichiometry, suggesting that a common set of biogeochemical processes constrains sediment N : P across lakes of contrasting catchment land use. Citing Literature Volume56, Issue5May 2011Pages 791-811 RelatedInformation