105
ecotoxicology
Scattering layers consisting of organisms may sometimes give echoes that can
be taken for bottom echoes (phantom bottom). In marine geology, lower frequencies « 7 kHz) with higher energetic content are applied. Then, not only
the sea bottom reflects the sound pulses, but also layers of different density
deeper in the sediment. The echogram then gives information on the sediment
structure. ~seismic instruments.
ecological efficiency the fraction of the energy consumed at a given trophic level
that is transferred to the next higher trophic level.
ecological models simplified representations of the interactions of organisms or
assemblies of organisms with the environment. Ecological models of complete natural systems, or ecosystems, are called ecosystem models. In models of
an aquatic ecosystem, the system is broken down into a series of components, such as phytoplankton, zooplankton, detritus, nutrients, etc.; and numbers
(system variables) are used to describe the state of each component (say, the
biomass) at a given time. In ecosystem models, as in other models, their use
as a tool or as a means for prediction depends on properties like accuracy,
realism, and general manageability, that can be mutually conflicting.
ecological monitoring ~monitoring.
ecology study of the interactions between organisms and their environment.
Autecology concerns a single species organized in one or more populations,
while synecology applies to studies of populations of more than one species
organized in a community.
ecosystem models ~ecological models.
ecosystem strictly speaking any part of the biosphere can be considered an
ecosystem, comprising living and nonliving constituents with a complicated
network of mutual interactions, and as a whole having inputs from and outputs to the surrounding biosphere. Those parts of the biosphere, whose
internal interactions are much stronger than the interactions with the outer
world, might be considered ecosystems, like ponds, inland seas, or sea areas
(that are isolated in terms of, e.g., temperature, salinity). In more complicated cases, like, e.g., estuaries, a coastal ecosystem, or the benthic and pelagic
ecosystem, the specific character is due to the specific physical nature of the
area, while interactions with the outside biosphere may dominate internal
dynamics. The clearest example of the latter may be an ecosystem that is a
section of a river or a sea area with strong currents.
ecotoxicology the science dealing with the identification and quantification of
the biogeochemical processes and toxic effects of chemical substances occur-
ecotoxicology
Scattering layers consisting of organisms may sometimes give echoes that can
be taken for bottom echoes (phantom bottom). In marine geology, lower frequencies « 7 kHz) with higher energetic content are applied. Then, not only
the sea bottom reflects the sound pulses, but also layers of different density
deeper in the sediment. The echogram then gives information on the sediment
structure. ~seismic instruments.
ecological efficiency the fraction of the energy consumed at a given trophic level
that is transferred to the next higher trophic level.
ecological models simplified representations of the interactions of organisms or
assemblies of organisms with the environment. Ecological models of complete natural systems, or ecosystems, are called ecosystem models. In models of
an aquatic ecosystem, the system is broken down into a series of components, such as phytoplankton, zooplankton, detritus, nutrients, etc.; and numbers
(system variables) are used to describe the state of each component (say, the
biomass) at a given time. In ecosystem models, as in other models, their use
as a tool or as a means for prediction depends on properties like accuracy,
realism, and general manageability, that can be mutually conflicting.
ecological monitoring ~monitoring.
ecology study of the interactions between organisms and their environment.
Autecology concerns a single species organized in one or more populations,
while synecology applies to studies of populations of more than one species
organized in a community.
ecosystem models ~ecological models.
ecosystem strictly speaking any part of the biosphere can be considered an
ecosystem, comprising living and nonliving constituents with a complicated
network of mutual interactions, and as a whole having inputs from and outputs to the surrounding biosphere. Those parts of the biosphere, whose
internal interactions are much stronger than the interactions with the outer
world, might be considered ecosystems, like ponds, inland seas, or sea areas
(that are isolated in terms of, e.g., temperature, salinity). In more complicated cases, like, e.g., estuaries, a coastal ecosystem, or the benthic and pelagic
ecosystem, the specific character is due to the specific physical nature of the
area, while interactions with the outside biosphere may dominate internal
dynamics. The clearest example of the latter may be an ecosystem that is a
section of a river or a sea area with strong currents.
ecotoxicology the science dealing with the identification and quantification of
the biogeochemical processes and toxic effects of chemical substances occur-