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- •Normalization of the harmful substances, disposal with sewage.
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- •Global Warming
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Types of communications and mutual relations between organisms
Types of relations between organisms. Influence of one species on another can be positive, negative and neutral. Thus different combinations of types of influence are possible. There are neutralism, mutualism, commensalism, predatoriness, parasitism, a competition, amensalism.
Parasitism. In this association one organism [the parasite] benefits and the other [the host] is adversely affected [weakened, sickened, damaged etc]. This description would also fit the relationship between a carnivore and its live prey and a herbivore and the plant it feeds on, especially if they are very specialized in the food they eat. We normally define parasites as organisms which cannot survive without their host and have special modifications to their body or their life cycle for this association.
A parasitic relationship is one in which one member of the association benefits while the other is harmed. This is also known as antagonistic or antipathetic symbiosis. Parasitic symbioses take many forms, from endoparasites that live within the host's body to ectoparasites that live on its surface. In addition, parasites may be necrotrophic, which is to say they kill their host, or biotrophic, meaning they rely on their host's surviving. Biotrophic parasitism is an extremely successful mode of life. Depending on the definition used, as many as half of all animals have at least one parasitic phase in their life cycles, and it is also frequent in plants and fungi. Moreover, almost all free-living animals are host to one or more parasite taxa. An example of a biotrophic relationship would be a tick feeding on the blood of its host.
Circulation of substances and a stream of energy in the ecosystem
Circulation of substances and the stream of energy in ecosystem
In ecosystem organic substances are synthesized by autotrophic from inorganic substances. Then they are consumed by heterotrophic. Allocated during ability to live or after destruction of organisms (both autotrophic and heterotrophic) organic substances are exposed to a mineralization i.e. transformation into inorganic substances. These inorganic substances can be again used by autotrophic to synthesize organic substances. So, biological circulation of substances is carried out.
At the same time, energy cannot circulate within the limits of ecosystem. The stream of energy (transfer of energy), having in food, in the ecosystem is unidirectional carried out from autotrophic to heterotrophic.
In picture the simplified scheme of energy stream at three trophic levels of the food chain is shown. Trophic levels are shown as tanks, which size corresponds to the energy having in their biomass (B), the size of channels connecting them is equal to size of streams of energy. The stream of solar energy (L} enters in an input in the system.
At the first trophic level green plants absorb about 50 % of the solar energy (LА.) | But, during photosynthesis, its some part will be transformed to energy of chemical bonds of organic substances. It is total primary production (PG ). The most part of not assimilated energy disperses in an environment in the form of thermal energy. The part of the formed organic substances is oxidized, and liberated energy is consumed for maintenance of all metabolic processes. These are so-called expenses for breath (R). This energy, finally, also disperses in the form of heat. The remained part of new-formed organic substances makes up a gain of plants biomass (DB) and it is called as pure primary production (РN). Only 1 % of the energy absorbed by a plant is transformed into pure initial production. Thus, РN = PG - R.
Producers. Consumers. Reducers.
The bottom heterotrophic circle, or «a brown belt» is a circle of soil and the precipitation, decompositing substances, roots and etc. in which use, transformation and decomposition of complex compounds prevail.
From the biological point of view in structure of ecosystem there are following components (Odum, 1986):
1) inorganic substances;
2) organic compounds;
3) air, water and substrate medium;
4) producers;
5) macroconsumers;
6) microconsumers.
1. Producers are the autotrophic organisms, which are capable to produce organic substances from inorganic, using photosynthesis or chemosynthesis (plants and autotrophic bacteria).
2. Consumers (macroconsumers) are the heterotrophic organisms consuming organic substance of producers or others consumers (animals, heterotrophic plants, some microorganisms). There are consumers of the first order and the second order.
3. Reducers (microconsumers, destructors) are the heterotrophic organisms, eating fossils and decomposing them to mineral substances (saprotrophic bacteria and mushrooms).
As a rule, in any ecosystem it is possible to note three functional groups of organisms: producers, consumers and reducers. In ecosystems formed only by microorganisms, consumers are absent. Each group consists of set of the populations occupying ecosystem.
In ecosystem, food and power bonds proceed in a line: producers->consumers-> reducers.