scholarly journals Temperature Dependence of Freshwater Phytoplankton Growth Rates and Zooplankton Grazing Rates

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1591
Author(s):  
Jennifer Pulsifer ◽  
Edward Laws
Keyword(s):  
Temperature Dependence ◽  
Chlorophyll A ◽  
Growth Rates ◽  
Eutrophic Lake ◽  
Phytoplankton Growth ◽  
Type I ◽  
Zooplankton Grazing ◽  
Temperature Range ◽  
Freshwater Phytoplankton ◽  
Louisiana State University

Phytoplankton growth rates and zooplankton grazing rates were estimated on 16 occasions over a period of 17 months in University Lake, a highly eutrophic lake on the campus of Louisiana State University. Phytoplankton growth rates and chlorophyll a concentrations averaged 1.0 ± 0.2 d−1 and 240 ± 120 mg m−3, respectively. Chlorophyll a concentrations were at or above the inflection point of the Holling type I curve that described the relationship between zooplankton grazing rates and chlorophyll a concentrations. In most cases, it was necessary to dilute lake water by more than a factor of 4 before zooplankton grazing rates became sensitive to chlorophyll a concentrations. Chlorophyll a concentrations were positively correlated with temperature and were roughly fourfold higher at 30 °C than at 15 °C. An analysis of the temperature dependence of the growth rates and grazing rates in this study and 87 other paired estimates of limnetic phytoplankton growth rates and zooplankton grazing rates revealed virtually identical temperature dependences of growth rates and grazing rates that were very similar to the temperature dependence predicted by the metabolic theory of ecology. Phytoplankton growth rates exceeded zooplankton grazing rates by 0.13 ± 0.05 d−1 at all temperatures over a temperature range of 8.5–31.5 °C. The Q10 for both phytoplankton growth rates and zooplankton grazing rates was 1.5 over that temperature range.

Temperature Dependent Morphology Transition of GaN Films

1999 ◽  
Vol 572 ◽  
Author(s):  
A. R. A. Zauner ◽  
F. K. De Theue ◽  
P. R. Hageman ◽  
W. J. P. Van ◽  
J. J. Schermer ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Temperature Dependence ◽  
Growth Rates ◽  
Temperature Dependent ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Morphology Transition ◽  
Temperature Range ◽  
Sapphire Substrates ◽  
Low Pressure Mocvd

ABSTRACTThe temperature dependence of the surface morphology of GaN epilayers was studied with AFM. The layers were grown by low pressure MOCVD on (0001) sapphire substrates in the temperature range of 980°C-1085°C. In this range the (0001) and {1101} faces completely determine the morphology of 1.5 μm thick Ga-faced GaN films. For specimens grown at 20 mbar and temperatures below 1035°C the {1101} faces dominate the surface, which results in matt-white layers. At higher growth temperatures the morphology is completely determined by (0001) faces, which lead to smooth and transparent samples. For growth at 50 mbar, this transition takes place between 1000°C and 1015°C. It is shown that the morphology of the films can be described using a parameter αGaN, which is proportional to the relative growth rates of the (0001) and the {1101} faces.

Carbon biomass, carbon-to-chlorophyll a ratios and growth rates of phytoplankton in Jiaozhou Bay, China

2021 ◽  
Author(s):  
Shujin Guo ◽  
Xiaoxia Sun
Keyword(s):  
Chlorophyll A ◽  
Growth Rates ◽  
Water Samples ◽  
Jiaozhou Bay ◽  
Phytoplankton Growth ◽  
Biomass Carbon ◽  
Carbon Biomass ◽  
Four Seasons ◽  
Carbon Based ◽  
Phytoplankton Cells

<p>Carbon biomass, carbon-to-chlorophyll a ratio (C:Chl a) values and growth rates of phytoplankton cells were studied during four seasonal cruises in 2017 and 2018 in Jiaozhou Bay, China. Water samples were collected from twelve stations, and phytoplankton carbon biomass (phyto-C) was estimated from microscope-measured cell volumes. Phyto-C ranged from 5.05 to 78.52 μg C/L (mean 28.80 μg C/L) in the bay, and it constituted a mean of 38.16% of the total particulate organic carbon in the bay. High phyto-C values always appeared in the northern or northeastern bay. Diatom carbon was predominant during all four cruises. Dinoflagellate carbon contributed much less (<30%) to the total phyto-C, and high values always appeared in the outer bay. The C:Chl a of phytoplankton cells varied from 11.50 to 61.45 (mean 31.66), and high values appeared in the outer bay during all four seasons. The phyto-C was also used to calculate the intrinsic growth rates of phytoplankton cells in the bay, and phytoplankton growth rates ranged from 0.56 to 1.96 day<sup>-1</sup>; the rate was highest in summer (mean 1.79 day<sup>-1</sup>), followed by that in fall (mean 1.24 day<sup>-1</sup>) and spring (mean 1.17 day<sup>-1</sup>), and the rate was lowest in winter (mean 0.77 day<sup>-1</sup>). Temperature and silicate concentration were found to be the determining factors of phytoplankton growth rates in the bay. To our knowledge, this study is the first report on phytoplankton carbon biomass and C:Chl a based on water samples in Jiaozhou Bay, and it will provide useful information for studies on carbon-based food web calculations and carbon-based ecosystem models in the bay.</p>

Identification of a single-copy gene encoding a Type I chlorophyll a/b-binding polypeptide of photosystem I in Arabidopsis thaliana

1992 ◽  
Vol 84 (4) ◽  
pp. 561-567 ◽  
Author(s):  
Poul E. Jensen ◽  
Michael Kristensen ◽  
Tine Hoff ◽  
Jan Lehmbeck ◽  
Bjarne M. Stummann ◽  
...  
Keyword(s):  
Arabidopsis Thaliana ◽  
Chlorophyll A ◽  
Photosystem I ◽  
Single Copy ◽  
Type I ◽  
Single Copy Gene ◽  
Gene Encoding ◽  
Copy Gene

Specific features of the temperature dependence of tryptophan fluorescence lifetime in the temperature range of −170–20 °C

2020 ◽  
Vol 393 ◽  
pp. 112435
Author(s):  
Peter P. Knox ◽  
Vladimir V. Gorokhov ◽  
Boris N. Korvatovsky ◽  
Nadezhda P. Grishanova ◽  
Sergey N. Goryachev ◽  
...  
Keyword(s):  
Temperature Dependence ◽  
Fluorescence Lifetime ◽  
Tryptophan Fluorescence ◽  
Temperature Range

Selection for biomass production based on respiration parameters in eucalypts: effects of origin and growth climates on growth rates

1996 ◽  
Vol 26 (9) ◽  
pp. 1556-1568 ◽  
Author(s):  
Thimmappa S. Anekonda ◽  
Richard S. Criddle ◽  
Lee D. Hansen ◽  
Mike Bacca
Keyword(s):  
Temperature Dependence ◽  
Growth Rates ◽  
Heat Rate ◽  
Eucalyptus Species ◽  
Relative Growth ◽  
Relative Growth Rates ◽  
Metabolic Heat ◽  
Respiratory Parameters ◽  
Metabolic Heat Rate ◽  
Different Climates

Seventeen Eucalyptus species and 30 rapid-growing Eucalyptuscamaldulensis trees (referred to as plus trees), growing in a plantation were studied to examine relationships among measured plant growth and respiratory parameters, geographical origins, and growth climate. The respiratory parameters measured at two different temperatures by isothermal calorimetry were metabolic heat rate, rate of CO2 production, and the ratio of heat rate to CO2 rate. Metabolic heat rate was also measured as a continuous function of temperature by differential scanning calorimetry in the range of 10 to 40 °C. Tree growth was measured as rates of height and stem volume growth. The values of respiratory and growth variables of Eucalyptus species are significantly correlated with latitude and altitude of origin of their seed sources. The maximum metabolic heat rate, the temperature of the maximum heat rate, the temperature coefficients of metabolic rate, and the temperatures at which the slopes of Arrhenius plots change are all genetically determined parameters that vary both within and among species. Measurement of growth rate–respiration rate–temperature relationships guide understanding of why relative growth rates of Eucalyptus species and individual genotypes differ with climate, making it possible to identify genotypes best suited for rapid growth in different climates. The temperature dependence of respiration rates is an important factor determining relative growth rates of eucalypts in different climates. To achieve optimum biomass production the temperature dependence of individual plants must be matched to growth climate.

Nitrogen and phosphorus inputs control phytoplankton growth in eutrophic Lake Taihu, China

2009 ◽  
Vol 55 (1) ◽  
pp. 420-432 ◽  
Author(s):  
Hai Xu ◽  
Hans W. Paerl ◽  
Boqiang Qin ◽  
Guangwei Zhu ◽  
Guang Gaoa
Keyword(s):  
Lake Taihu ◽  
Eutrophic Lake ◽  
Phytoplankton Growth ◽  
Nitrogen And Phosphorus

Temperature Dependence of the Intervalley Deformation Potential of GaAs/AlAs Superlattices Under Hydrostatic Pressure

1997 ◽  
Vol 499 ◽  
Author(s):  
S. Guha ◽  
Q. Cai ◽  
M. Chandrasekhar ◽  
H. R. Chandrasekhar ◽  
Hyunjung Kim ◽  
...  
Keyword(s):  
Hydrostatic Pressure ◽  
Temperature Dependence ◽  
Pressure Dependence ◽  
Type I ◽  
Type Ii ◽  
Deformation Potential ◽  
Intervalley Scattering

ABSTRACTWe have studied the pressure dependence of the type-I and type-II transitions in (GaAs)m/(AlAs)m superlattices by photoluminescence (PL) spectroscopy. From the study of PL linewidths of the type-I exciton as a function of pressure and temperature, we determine the intervalley deformation potential. Beyond the type-I and type-II crossover, the PL linewidth increases both as a function of pressure and temperature. We find that the electron-phonon deformation potential for Γ-X intervalley scattering varies with temperature.

Temperature dependence of chlorine-35 N.Q.R. in 2,6-Dichlorophenol

1978 ◽  
Vol 31 (4) ◽  
pp. 791 ◽  
Author(s):  
R Chandramani ◽  
SP Basavaraju ◽  
N Devaraj
Keyword(s):  
Temperature Dependence ◽  
Room Temperature ◽  
Temperature Range ◽  
Temperature Coefficients ◽  
Brown's Method

Chlorine n.q.r, in 2,6-dichlorophenol has been investigated at temperatures from 77 K to room temperature. Two resonance lines due to chemically inequivalent sites have been observed throughout this temperature range. Torsional frequencies of the molecule have been calculated at temperatures from 77 to 300 K according to Bayer's theory and Brown's method. Also the temperature coefficients of the torsional frequencies have been calculated.

scholarly journals PSEUDO-GAP FEATURES OF INTRINSIC TUNNELING IN (HgBr2)-Bi2212 SINGLE CRYSTALS

1999 ◽  
Vol 13 (29n31) ◽  
pp. 3758-3763 ◽  
Author(s):  
AUGUST YURGENS ◽  
DAG WINKLER ◽  
TORD CLAESON ◽  
SEONG-JU HWANG ◽  
JIN-HO CHOY
Keyword(s):  
Temperature Dependence ◽  
Single Crystals ◽  
Room Temperature ◽  
Unit Cell ◽  
Superconducting Gap ◽  
Axis Direction ◽  
Temperature Range ◽  
Dynamic Conductance

The c-axis tunneling properties of both pristine Bi2212 and its HgBr 2 intercalate have been measured in the temperature range 4.2-250 K. Lithographically patterned 7-10 unit-cell heigh mesa structures on the surfaces of these single crystals were investigated. Clear SIS-like tunneling curves for current applied in the c-axis direction have been observed. The dynamic conductance d I/ d V(V) shows both sharp peaks corresponding to a superconducting gap edge and a dip feature beyond the gap, followed by a wide maximum, which persists up to a room temperature. Shape of the temperature dependence of the c-axis resistance does not change after the intercalation suggesting that a coupling between CuO 2-bilayers has little effect on the pseudogap.

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