reproduction
266
The advantage of remote sensing is the possibility to obtain detailed information over wide areas or extended periods. The problem, however, is that the relevant physical or biological parameters are not measured directly. Therefore
generally a combination of physical models, empirical algorithms and mathematical and statistical techniques is needed to translate an observed signal into
a quantitative estimate of the relevant parameter, and so-called ground truth
or sea truth (collection of field data) is necessary for validation.
reproduction the process by which living organisms multiply. In asexual reproduction the organisms multiply by simple division (algae, Fungi, Protozoa, Cnidaria, etc.).
Continuous division can lead to formation of a large number of small identical "spores" (spore formation) developing into identical individuals. In sexual
reproduction haploid gametes are formed in sexual organs, in higher plants
and animals usually a large number of small "male" gametes or spermatozoa
and a smaller number of large "female" gametes or eggs (ova). When eggs and
sperm are mature they are released in the spawning process and fertilization takes
place when a haploid egg melts together with a haploid spermatozoid into a
diploid zygote or fertilized egg. In higher plants and animals reproduction is
usually a seasonal process with an annual cycle in growth of sexual individuals (e.g., Cnidaria) or reproductive organs (gonads), a limited spawning period
and regression of the gonads after spawning. In lower latitudes and in smaller
organisms (Copepoda, Nematoda) reproduction can take place more often, leading
to shorter reproductive cycles. The timing of reproduction, the number of eggs
produced, and all other behavioral aspects of reproduction together form the
reproductive strategy of a species, aimed at achieving, under the prevailing
environmental conditions, a maximal reproductive success (i.e., producing the
maximal number of successful offspring in a life-time). Reproductive strategies, closely related with life strategies of species, are basically solutions to optimalization problems of energy expenditure: how to deal with the available
energy in a life-time to reach maximal reproductive success.
Reptilia, marine (lizards, snakes, crocodiles, turtles, tortoises) a class of the subphylum Vertebrata, differing from amphibians in the production of amniotic
eggs, which can be laid on land because they are protected against drying and
injury by a series of membranes, fluids, and a shell. This enabled reptiles to
become fully land animals, some of them returned to the sea. All reptiles are
cold-blooded animals (~poikilotherm) and as such best adapted to live in the
(sub)tropics. A single lizard species, the marine iguana of the Galapagos
Islands, marine in its dependence on marine algae for food, was first reported
on by Darwin in 1839. Some crocodiles and alligators frequent estuarine parts
of rivers, particularly mangrove swamps, and are sporadically seen at sea (some
reached the Cocos-Keeling atoll alive, 600 miles of ocean travel, but did not
establish themselves there). Within the family of sea snakes (Hydrophiidae)
some genera come ashore to lay eggs, others are viviparous and completely
266
The advantage of remote sensing is the possibility to obtain detailed information over wide areas or extended periods. The problem, however, is that the relevant physical or biological parameters are not measured directly. Therefore
generally a combination of physical models, empirical algorithms and mathematical and statistical techniques is needed to translate an observed signal into
a quantitative estimate of the relevant parameter, and so-called ground truth
or sea truth (collection of field data) is necessary for validation.
reproduction the process by which living organisms multiply. In asexual reproduction the organisms multiply by simple division (algae, Fungi, Protozoa, Cnidaria, etc.).
Continuous division can lead to formation of a large number of small identical "spores" (spore formation) developing into identical individuals. In sexual
reproduction haploid gametes are formed in sexual organs, in higher plants
and animals usually a large number of small "male" gametes or spermatozoa
and a smaller number of large "female" gametes or eggs (ova). When eggs and
sperm are mature they are released in the spawning process and fertilization takes
place when a haploid egg melts together with a haploid spermatozoid into a
diploid zygote or fertilized egg. In higher plants and animals reproduction is
usually a seasonal process with an annual cycle in growth of sexual individuals (e.g., Cnidaria) or reproductive organs (gonads), a limited spawning period
and regression of the gonads after spawning. In lower latitudes and in smaller
organisms (Copepoda, Nematoda) reproduction can take place more often, leading
to shorter reproductive cycles. The timing of reproduction, the number of eggs
produced, and all other behavioral aspects of reproduction together form the
reproductive strategy of a species, aimed at achieving, under the prevailing
environmental conditions, a maximal reproductive success (i.e., producing the
maximal number of successful offspring in a life-time). Reproductive strategies, closely related with life strategies of species, are basically solutions to optimalization problems of energy expenditure: how to deal with the available
energy in a life-time to reach maximal reproductive success.
Reptilia, marine (lizards, snakes, crocodiles, turtles, tortoises) a class of the subphylum Vertebrata, differing from amphibians in the production of amniotic
eggs, which can be laid on land because they are protected against drying and
injury by a series of membranes, fluids, and a shell. This enabled reptiles to
become fully land animals, some of them returned to the sea. All reptiles are
cold-blooded animals (~poikilotherm) and as such best adapted to live in the
(sub)tropics. A single lizard species, the marine iguana of the Galapagos
Islands, marine in its dependence on marine algae for food, was first reported
on by Darwin in 1839. Some crocodiles and alligators frequent estuarine parts
of rivers, particularly mangrove swamps, and are sporadically seen at sea (some
reached the Cocos-Keeling atoll alive, 600 miles of ocean travel, but did not
establish themselves there). Within the family of sea snakes (Hydrophiidae)
some genera come ashore to lay eggs, others are viviparous and completely