_version_ 1867171816452128768
author Gallegos, Charles L
author_facet Gallegos, Charles L
collection Datos científicos de ciencias marinas y ambientales
contents Parameters in the photosynthesis-irradiance (P-E) relationship of phytoplankton were measured at weekly to bi-weekly intervals for 20 yr at 6 stations on the Rhode River, Maryland (USA). Variability in the light-saturated photosynthetic rate, PBmax, was partitioned into interannual, seasonal, and spatial components. The seasonal component of the variance was greatest, followed by interannual and then spatial. Physiological models of PBmax based on balanced growth or photoacclimation predicted the overall mean and most of the range, but not individual observations, and failed to capture important features of the seasonal and interannual variability. PBmax correlated most strongly with temperature and the concentration of dissolved inorganic carbon (IC), with lesser correlations with chlorophyll a, diffuse attenuation coefficient, and a principal component of the species composition. In statistical models, temperature and IC correlated best with the seasonal pattern, but temperature peaked in late July, out of phase with PBmax, which peaked in September, coincident with the maximum in monthly averaged IC concentration. In contrast with the seasonal pattern, temperature did not contribute to interannual variation, which instead was governed by IC and the additional lesser correlates. Spatial variation was relatively weak and uncorrelated with ancillary measurements. The results demonstrate that both the overall distribution of PBmax and its relationship with environmental correlates may vary from year to year. Coefficients in empirical statistical models became stable after including 7 to 10 yr of data. The main correlates of PBmax are amenable to automated monitoring, so that future estimates of primary production might be made without labor-intensive incubations.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_816494
institution PANGAEA
language en
publishDate 2012
publisher PANGAEA
record_format pangaea
spellingShingle Photosynthetic parameters, chlorophyll concentration, and diffuse attenuation coefficients in the Rhode River, Maryland (USA), 1990-2009
Gallegos, Charles L
Calculated; Carbon, inorganic, dissolved; Chlorophyll a; DATE/TIME; DEPTH, water; Diffuse attenuation coefficient, downward; Elevation of event; Intercept in carbon per chlorophyll a; Intercept in carbon per chlorophyll a, standard deviation; LATITUDE; LONGITUDE; Maximum light utilization coefficient in carbon per chlorophyll a; Maximum light utilization coefficient in carbon per chlorophyll a, standard deviation; Number; Photoinhibition in carbon per chlorophyll a; Photoinhibition in carbon per chlorophyll a, standard deviation; Production rate, maximal, light saturated, as carbon per chlorophyll a; Production rate, maximal, light saturated, as carbon per chlorophyll a, standard deviation; RhodeRiver_1; RhodeRiver_2; RhodeRiver_3; RhodeRiver_4; RhodeRiver_5; RhodeRiver_6; RhodeRiver_7; Rhode River, Maryland, USA; Sample code/label; see reference(s); Spectrophotometric assay of acetone extraction (GF/F filtered); Temperature, technical; Water sample; WS
Parameters in the photosynthesis-irradiance (P-E) relationship of phytoplankton were measured at weekly to bi-weekly intervals for 20 yr at 6 stations on the Rhode River, Maryland (USA). Variability in the light-saturated photosynthetic rate, PBmax, was partitioned into interannual, seasonal, and spatial components. The seasonal component of the variance was greatest, followed by interannual and then spatial. Physiological models of PBmax based on balanced growth or photoacclimation predicted the overall mean and most of the range, but not individual observations, and failed to capture important features of the seasonal and interannual variability. PBmax correlated most strongly with temperature and the concentration of dissolved inorganic carbon (IC), with lesser correlations with chlorophyll a, diffuse attenuation coefficient, and a principal component of the species composition. In statistical models, temperature and IC correlated best with the seasonal pattern, but temperature peaked in late July, out of phase with PBmax, which peaked in September, coincident with the maximum in monthly averaged IC concentration. In contrast with the seasonal pattern, temperature did not contribute to interannual variation, which instead was governed by IC and the additional lesser correlates. Spatial variation was relatively weak and uncorrelated with ancillary measurements. The results demonstrate that both the overall distribution of PBmax and its relationship with environmental correlates may vary from year to year. Coefficients in empirical statistical models became stable after including 7 to 10 yr of data. The main correlates of PBmax are amenable to automated monitoring, so that future estimates of primary production might be made without labor-intensive incubations.
title Photosynthetic parameters, chlorophyll concentration, and diffuse attenuation coefficients in the Rhode River, Maryland (USA), 1990-2009
topic Calculated; Carbon, inorganic, dissolved; Chlorophyll a; DATE/TIME; DEPTH, water; Diffuse attenuation coefficient, downward; Elevation of event; Intercept in carbon per chlorophyll a; Intercept in carbon per chlorophyll a, standard deviation; LATITUDE; LONGITUDE; Maximum light utilization coefficient in carbon per chlorophyll a; Maximum light utilization coefficient in carbon per chlorophyll a, standard deviation; Number; Photoinhibition in carbon per chlorophyll a; Photoinhibition in carbon per chlorophyll a, standard deviation; Production rate, maximal, light saturated, as carbon per chlorophyll a; Production rate, maximal, light saturated, as carbon per chlorophyll a, standard deviation; RhodeRiver_1; RhodeRiver_2; RhodeRiver_3; RhodeRiver_4; RhodeRiver_5; RhodeRiver_6; RhodeRiver_7; Rhode River, Maryland, USA; Sample code/label; see reference(s); Spectrophotometric assay of acetone extraction (GF/F filtered); Temperature, technical; Water sample; WS
url https://doi.org/10.1594/PANGAEA.816494