41
caloric equivalent
(
14C-method, productivity measurement one of the most widely used methods for
measuring aquatic plant production in bottles with radioactive carbon
added as !4C in bicarbonate. First developed by E. Steemann Nielsen in 1952.
After exposure of bottles to natural light (in situ incubation), or after incubation in experimental incubators for short periods, plankton is filtered from the
water, after which the quantity of !4C present in the produced organic substances in the algae is determined, usually in a liquid scintillation counter.
Using the known ratio of labeled over total CO 2 present in the bottles at the
start of the experiment, the total amount of organic matter produced is calculated from the number of counts. Corrections have to be made for the CO 2
uptake by processes not related to primary production, which are measured
simultaneously in dark incubation bottles. ~radioisotopes.
Calanoidea ~Copepoda.
Calcarea class of the phylum Porifera or sponges. Calcareous sponges, generally
small in size, living worldwide in the oceans, mostly in coastal areas. The
skeleton consists of calcium carbonate spicula; spongine fibers are absent.
calcareous ooze ~ooze.
calcite ~carbonate, mineral.
calcium carbonate ~carbonate, mineral.
calibration in general, adjusting the output of measuring instruments or methods in standardized conditions to the output of a standard method. ~models
and ~intercalibration.
caloric equivalent for studies of energy flow, the energy content of (groups of)
organisms is expressed in caloric (or calorific) equivalents. The energy
content is estimated either by measuring heat at total oxidation (by bomb
calorimetry) or by using the known equivalents of the components of the
organism in question. Such components are lipids with a caloric value of
± 9.5 kcal go!, carbohydrates (± 4.2 kcal go!) and proteins (± 5.7 kcal g-! at
total combustion, but only ± 4 kcal g-! at metabolic oxidation within animals). Nowadays, energy content is generally and more correctly expressed
in joules (1 cal equals 4.1868 J). Caloric equivalents are high in organisms
caloric equivalent
(
14C-method, productivity measurement one of the most widely used methods for
measuring aquatic plant production in bottles with radioactive carbon
added as !4C in bicarbonate. First developed by E. Steemann Nielsen in 1952.
After exposure of bottles to natural light (in situ incubation), or after incubation in experimental incubators for short periods, plankton is filtered from the
water, after which the quantity of !4C present in the produced organic substances in the algae is determined, usually in a liquid scintillation counter.
Using the known ratio of labeled over total CO 2 present in the bottles at the
start of the experiment, the total amount of organic matter produced is calculated from the number of counts. Corrections have to be made for the CO 2
uptake by processes not related to primary production, which are measured
simultaneously in dark incubation bottles. ~radioisotopes.
Calanoidea ~Copepoda.
Calcarea class of the phylum Porifera or sponges. Calcareous sponges, generally
small in size, living worldwide in the oceans, mostly in coastal areas. The
skeleton consists of calcium carbonate spicula; spongine fibers are absent.
calcareous ooze ~ooze.
calcite ~carbonate, mineral.
calcium carbonate ~carbonate, mineral.
calibration in general, adjusting the output of measuring instruments or methods in standardized conditions to the output of a standard method. ~models
and ~intercalibration.
caloric equivalent for studies of energy flow, the energy content of (groups of)
organisms is expressed in caloric (or calorific) equivalents. The energy
content is estimated either by measuring heat at total oxidation (by bomb
calorimetry) or by using the known equivalents of the components of the
organism in question. Such components are lipids with a caloric value of
± 9.5 kcal go!, carbohydrates (± 4.2 kcal go!) and proteins (± 5.7 kcal g-! at
total combustion, but only ± 4 kcal g-! at metabolic oxidation within animals). Nowadays, energy content is generally and more correctly expressed
in joules (1 cal equals 4.1868 J). Caloric equivalents are high in organisms