Lake and watershed characteristics rather than climate influence nutrient limitation in shallow lakes
Kosten, S. ; Huszar, V.M. ; Mazzeo, N. ; Scheffer, M. ; Sternberg, L.S.L. ; Jeppesen, E. - \ 2009
Ecological Applications 19 (2009)7. - ISSN 1051-0761 - p. 1791 - 1804.
waterkwaliteit - voedingsstoffen - meren - stikstof - fosfor - cyanobacteriën - eutrofiëring - herstel - klimaat - zuid-amerika - primaire productie - water quality - nutrients - lakes - nitrogen - phosphorus - cyanobacteria - eutrophication - rehabilitation - climate - south america - primary production - phytoplankton community structure - fresh-water - meteoric precipitation - nitrogen-retention - subtropical lakes - trophic state - danish lakes - n-p - denitrification
Both nitrogen (N) and phosphorus (P) can limit primary production in shallow lakes, but it is still debated how the importance of N and P varies in time and space. We sampled 83 shallow lakes along a latitudinal gradient (5°–55° S) in South America and assessed the potential nutrient limitation using different methods including nutrient ratios in sediment, water, and seston, dissolved nutrient concentrations, and occurrence of N-fixing cyanobacteria. We found that local characteristics such as soil type and associated land use in the catchment, hydrology, and also the presence of abundant submerged macrophyte growth influenced N and P limitation. We found neither a consistent variation in nutrient limitation nor indications for a steady change in denitrification along the latitudinal gradient. Contrary to findings in other regions, we did not find a relationship between the occurrence of (N-fixing and non-N-fixing) cyanobacteria and the TN:TP ratio. We found N-fixing cyanobacteria (those with heterocysts) exclusively in lakes with dissolved inorganic nitrogen (DIN) concentrations of