life tables
178
life tables the numbers or densities (numbers per unit of area) of different
developmental stages are tabulated in life tables, representing the population state in subsequent generations. Numerical techniques have been developed to derive from such life tables insight into key factors, stability, regulation, and the causes of density fluctuations. ~population dynamics.
lightthe sun is the only noteworthy source of light for the earth but the amount
of solar radiation varies from latitude to latitude. The amount of solar radiation
is usually measured with a solarimeter, having a wavelength range from 300
to 3000 nm. Marine phytoplankton uses only radiation in the range from 400
to 700 nm. The action spectra, Le., relative absorption of various wavelengths
by intact algae differ and strongly depend on the presence of various chlorophylls and accessory pigments. The depth to which the radiation used for photosynthesis penetrates (~photic zonation) is limited and varies with the wavelength (~optics). Light in the ultraviolet region (200 to 400 nm) penetrates
only in the upper few meters. The depth to which only 1 % of the surface illumination penetrates is called the euphotic zone. Also the attenuation of the
various wavelengths in the photosynthetically active region varies. The red
wavelengths penetrate least and the blue/green deepest. This situation is
reversed when there are dense phytoplankton populations with a high chlorophyll concentration absorbing in the blue region. Phytoplankton photosynthesis is a function of light intensity, it increases with light intensity to a
maximal value when algae become light (1) saturated (P max or assimilation
number). At higher irradiation levels the P versus I curve may show a decrease again due to the so-called light inhibition or photoinhibition effect.
light compass reaction movement of organisms at a constant angle to parallel
rays of a light source. In nature this light source is usually the sun and it is
called sun compass reaction or orientation.
light inhibition ~photoinhibition.
Lightning Expedition (1868) a "crancky little vessel- perhaps the very oldest paddle steamer in Her Majesty's Navy" according to C. Wyville Thomson; he,
together with W.B. Carpenter, and H. Carpenter were the scientific crew on
this expedition between Scotland and the Faroe Islands. A sea pen Bathyptilum was dredged at 650 fathoms depth. Negative bottom temperatures were
observed just north of 60° N, positive bottom temperatures south of 50° N
indicating a submarine ridge. The Wyville Thomson Ridge which separates
the North Atlantic from the below zero Arctic bottom water was discovered.
~Knight Errant Expedition.
limiting factors resource element of food or nutrients which is at a concentration
too low to allow maximum growth or reproduction of a dependent organ-
178
life tables the numbers or densities (numbers per unit of area) of different
developmental stages are tabulated in life tables, representing the population state in subsequent generations. Numerical techniques have been developed to derive from such life tables insight into key factors, stability, regulation, and the causes of density fluctuations. ~population dynamics.
lightthe sun is the only noteworthy source of light for the earth but the amount
of solar radiation varies from latitude to latitude. The amount of solar radiation
is usually measured with a solarimeter, having a wavelength range from 300
to 3000 nm. Marine phytoplankton uses only radiation in the range from 400
to 700 nm. The action spectra, Le., relative absorption of various wavelengths
by intact algae differ and strongly depend on the presence of various chlorophylls and accessory pigments. The depth to which the radiation used for photosynthesis penetrates (~photic zonation) is limited and varies with the wavelength (~optics). Light in the ultraviolet region (200 to 400 nm) penetrates
only in the upper few meters. The depth to which only 1 % of the surface illumination penetrates is called the euphotic zone. Also the attenuation of the
various wavelengths in the photosynthetically active region varies. The red
wavelengths penetrate least and the blue/green deepest. This situation is
reversed when there are dense phytoplankton populations with a high chlorophyll concentration absorbing in the blue region. Phytoplankton photosynthesis is a function of light intensity, it increases with light intensity to a
maximal value when algae become light (1) saturated (P max or assimilation
number). At higher irradiation levels the P versus I curve may show a decrease again due to the so-called light inhibition or photoinhibition effect.
light compass reaction movement of organisms at a constant angle to parallel
rays of a light source. In nature this light source is usually the sun and it is
called sun compass reaction or orientation.
light inhibition ~photoinhibition.
Lightning Expedition (1868) a "crancky little vessel- perhaps the very oldest paddle steamer in Her Majesty's Navy" according to C. Wyville Thomson; he,
together with W.B. Carpenter, and H. Carpenter were the scientific crew on
this expedition between Scotland and the Faroe Islands. A sea pen Bathyptilum was dredged at 650 fathoms depth. Negative bottom temperatures were
observed just north of 60° N, positive bottom temperatures south of 50° N
indicating a submarine ridge. The Wyville Thomson Ridge which separates
the North Atlantic from the below zero Arctic bottom water was discovered.
~Knight Errant Expedition.
limiting factors resource element of food or nutrients which is at a concentration
too low to allow maximum growth or reproduction of a dependent organ-