Premium
Dilution of 210 Pb by organic sedimentation in lakes of different trophic states, and application to studies of sediment‐water interactions 1
Author(s) -
Binford Michael W.,
Brenner Mark
Publication year - 1986
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.1986.31.3.0584
Subject(s) - trophic level , trophic state index , water column , sediment , organic matter , dilution , environmental science , sedimentation , sedimentary organic matter , environmental chemistry , hydrology (agriculture) , sedimentary rock , productivity , primary productivity , ecology , geology , oceanography , ecosystem , chemistry , nutrient , phytoplankton , biology , geochemistry , geomorphology , physics , geotechnical engineering , thermodynamics , macroeconomics , economics
Lake sediments reflect conditions in the water column and can be used for rapid, integrative measurements of limnological variables. Examination of 210 Pb‐dated cores from 12 Florida lakes of widely differing trophic state (expressed as Carlson’s trophic state index: TSI) shows that net accumulation rate of organic matter is related to primary productivity in the water column. In 26 other lakes the activity of unsupported 210 Pb g −1 organic matter in surficial sediments is inversely related to trophic state and, therefore, to organic accumulation rate. From this observation we develop a new method that uses fallout 210 Pb as a dilution tracer to calculate net sedimentary accumulation rates of any material in surface mud. We demonstrate strong relationships between net loss rates of biologically important materials (C, N, P, and pigments) and their respective water concentrations (expressed as TSI). Multiple regression models incorporating net sediment accumulation rates of all four variables explain up to 70% of the lake‐to‐lake variation of TSI. The 210 Pb‐dilution method has applications for studies of material cycling, paleolimnology, and sediment accumulation processes.