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life strategies
Leptostraca superorder of the class Malacostraca, subphylum Crustacea (phylum
Arthropoda). Small marine crustaceans, the most primitive of the Malacostraca. A large bilobed carapace loosely envelops a large part of the body.
The legs are simple, the eyes stalked and the abdominal tail has in contrast
to other Malacostraca seven segments. They feed on small particles and are
pelagic or bottom dwellers. Example: Nebalia, a ca. 12-mm-Iong crustacean
living on muddy bottoms.
level of no-motion to calculate the absolute velocity of currents by means of the
geostrophic balance a reference level at a certain depth is needed where the isobaric plane can be assumed to be horizontal. In this plane there should be no
current: the level of no-motion. As there are no indirect ways to establish
this level for certain (if it exists at all), the choice of it is a matter of judgement.
Liebig's law of the minimum law, formulated by A. Mayer in 1900, based on observation by J. von Liebig of 1840, who stated that harvest in agriculture was
limited by that nutrient which was in the minimum, and that by addition of
that particular nutrient the harvest could be enlarged. ~Iimiting factors.
life cycle (of animals) the various phases through which an individual species
passes from birth to maturity and death.
life strategies the ecological strategies that are evolved to maximize the survival
and fitness of the organism in its environment. These strategies for any
organism lie somewhere along an r-K continuum (K refers to the carrying
capacity and r to the maximal intrinsic rate of natural increase r max in the logistic equation). The characteristics of an organism's habitat in relation to its size
and range will largely define its optimal strategy. A very important habitat
characteristic is its duration stability: the length of time a particular habitat
type remains in a particular geographical location. This may range from
hundreds of years on a coral reef to a week in a phytoplankton bloom.
Clearly the significance of this duration stability depends on the relationship between the organism's generation time (t) and the length of time the
habitat remains favorable (H). In species where the ratio t/H approaches
unity, one generation cannot affect the resources of the next; there will be no
evolutionary penalty for overshooting the carrying capacity of the habitat.
These species then are selected for an r-strategy. Conversely, for animals that
occupy long-lived habitats where the carrying capacity (K) is fairly constant,
significant overshooting will lower K, and will adversely affect subsequent
generations. Since many other species will have colonized such stable habitats, interspecific competition is likely to be intense. Such species are selected
for harvesting food efficiently in a crowded environment and their optimal
life strategy is a K -strategy.
life strategies
Leptostraca superorder of the class Malacostraca, subphylum Crustacea (phylum
Arthropoda). Small marine crustaceans, the most primitive of the Malacostraca. A large bilobed carapace loosely envelops a large part of the body.
The legs are simple, the eyes stalked and the abdominal tail has in contrast
to other Malacostraca seven segments. They feed on small particles and are
pelagic or bottom dwellers. Example: Nebalia, a ca. 12-mm-Iong crustacean
living on muddy bottoms.
level of no-motion to calculate the absolute velocity of currents by means of the
geostrophic balance a reference level at a certain depth is needed where the isobaric plane can be assumed to be horizontal. In this plane there should be no
current: the level of no-motion. As there are no indirect ways to establish
this level for certain (if it exists at all), the choice of it is a matter of judgement.
Liebig's law of the minimum law, formulated by A. Mayer in 1900, based on observation by J. von Liebig of 1840, who stated that harvest in agriculture was
limited by that nutrient which was in the minimum, and that by addition of
that particular nutrient the harvest could be enlarged. ~Iimiting factors.
life cycle (of animals) the various phases through which an individual species
passes from birth to maturity and death.
life strategies the ecological strategies that are evolved to maximize the survival
and fitness of the organism in its environment. These strategies for any
organism lie somewhere along an r-K continuum (K refers to the carrying
capacity and r to the maximal intrinsic rate of natural increase r max in the logistic equation). The characteristics of an organism's habitat in relation to its size
and range will largely define its optimal strategy. A very important habitat
characteristic is its duration stability: the length of time a particular habitat
type remains in a particular geographical location. This may range from
hundreds of years on a coral reef to a week in a phytoplankton bloom.
Clearly the significance of this duration stability depends on the relationship between the organism's generation time (t) and the length of time the
habitat remains favorable (H). In species where the ratio t/H approaches
unity, one generation cannot affect the resources of the next; there will be no
evolutionary penalty for overshooting the carrying capacity of the habitat.
These species then are selected for an r-strategy. Conversely, for animals that
occupy long-lived habitats where the carrying capacity (K) is fairly constant,
significant overshooting will lower K, and will adversely affect subsequent
generations. Since many other species will have colonized such stable habitats, interspecific competition is likely to be intense. Such species are selected
for harvesting food efficiently in a crowded environment and their optimal
life strategy is a K -strategy.