these adaptations, higher population survival rate, and these populations will have a
better place in the structure and functioning of that biocoenosis.
Ecological adaptations, as features of stability, appear in functioning of population and individuals, both qualitatively and quantitatively, but only at the level of
each population of the respective species. They are better evidenced through
assessment of populational indexes of the species from each type of ecosystems.
This fact is important, because they are not considered as individuals, seen separately, but are analysed as multitudes, more or less homogenous of individuals
taken as samples from the same population.
Adaptations to the biotic and abiotic start at biochemical, physiological or
behavioral levels and appear at the population level in a statistical way. They
became distinctive at one time (Attention! not at the level of the entire species,
but within each population which is an element of a biocoenosis from a certain type
of ecosystem).
Adaptations have a certain amplitude and always they are adequate. If an
inadequate modification appears, it is eliminated by natural selection and results
in the death of that new individuals. It is a hard selection, based on the rejection out
of population of the individuals who do not have the respective adaptation. Through
these adequate adaptations may be ensured the survival of respective population.
It is possible that during adaptation process the number of individuals of the
respective population will diminish. If the adaptations are done quickly, the number
of individuals will increase, the ecological niche of that population will become
steady and as a result, the respective population will play a more important role in
that biocoenosis.
The following adaptations are emphasized:
– Climatic adaptations – to main climate types (equatorial, tropical, subtropical,
temperate, boreal, arctic), to all periodic oscillations – diurnal, seasonal, annual
and multiannual;
– Edaphic adaptations – referring to soil or water salinity, to the presence of some
chemical compounds, limiting to primary producers, to the presence of some
toxic substances, pesticides, pollutants etc.;
– Coenotic adaptations – to the associations of organisms with which they interact
within that biocoenosis (for instance adaptations to the relations with the organisms belonging to the same trophic level, relations prey/predator, symbiotic
relations, relations with decomposers, equilibria between all the intrabiocoenotic
components, to the response versus the population of some invasive species etc).
Briefly, multiple adaptations of the populations belonging to each species have
to result in the formation of some broad ecological niches, fluctuating, perfectly
adequate for survival within the respective biocoenosis, but also, to the oscillations
of biotope features. And this, according to the Commoner’s law “all are connected
to all” (Comoner 1972).
In their turn, ecosystems occupy parts from the areal of respective type of
ecosystems. In this large area, the climate is not homogenous; relief may be various;
there are also important hydrologic differences etc. This means that, within the
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better place in the structure and functioning of that biocoenosis.
Ecological adaptations, as features of stability, appear in functioning of population and individuals, both qualitatively and quantitatively, but only at the level of
each population of the respective species. They are better evidenced through
assessment of populational indexes of the species from each type of ecosystems.
This fact is important, because they are not considered as individuals, seen separately, but are analysed as multitudes, more or less homogenous of individuals
taken as samples from the same population.
Adaptations to the biotic and abiotic start at biochemical, physiological or
behavioral levels and appear at the population level in a statistical way. They
became distinctive at one time (Attention! not at the level of the entire species,
but within each population which is an element of a biocoenosis from a certain type
of ecosystem).
Adaptations have a certain amplitude and always they are adequate. If an
inadequate modification appears, it is eliminated by natural selection and results
in the death of that new individuals. It is a hard selection, based on the rejection out
of population of the individuals who do not have the respective adaptation. Through
these adequate adaptations may be ensured the survival of respective population.
It is possible that during adaptation process the number of individuals of the
respective population will diminish. If the adaptations are done quickly, the number
of individuals will increase, the ecological niche of that population will become
steady and as a result, the respective population will play a more important role in
that biocoenosis.
The following adaptations are emphasized:
– Climatic adaptations – to main climate types (equatorial, tropical, subtropical,
temperate, boreal, arctic), to all periodic oscillations – diurnal, seasonal, annual
and multiannual;
– Edaphic adaptations – referring to soil or water salinity, to the presence of some
chemical compounds, limiting to primary producers, to the presence of some
toxic substances, pesticides, pollutants etc.;
– Coenotic adaptations – to the associations of organisms with which they interact
within that biocoenosis (for instance adaptations to the relations with the organisms belonging to the same trophic level, relations prey/predator, symbiotic
relations, relations with decomposers, equilibria between all the intrabiocoenotic
components, to the response versus the population of some invasive species etc).
Briefly, multiple adaptations of the populations belonging to each species have
to result in the formation of some broad ecological niches, fluctuating, perfectly
adequate for survival within the respective biocoenosis, but also, to the oscillations
of biotope features. And this, according to the Commoner’s law “all are connected
to all” (Comoner 1972).
In their turn, ecosystems occupy parts from the areal of respective type of
ecosystems. In this large area, the climate is not homogenous; relief may be various;
there are also important hydrologic differences etc. This means that, within the
514
N. Donița ˘ and S. Godeanu