Ecosystem is a complex system to form buy organism that live in a determined envirament. Animals and plants  make the ecosystem's biotic members, while dawnground, air, water, light, temperature, climate, clauds make abiotic members.

The members biotic and abiotic start a togheter of relations and they take its at a situation of temporary "balance".

The biotic members divide them in:

•-          producings: they are "autotrofi" organism that produce the organic substance to live and to grow using inorganic molecules like wtaer, carnonic anydride (CO2) and nitrates.

•-          Consumers: they are "eterotrofi" organisms, because they can't product their naurishment, they eat producings (herbivorans like cow and sheep and carnivorans like lions and umans).

•-          Decompositors: they are mushrooms and bacteriums that they feed decomposing the cloths of dead organisms.

Every ecosystem has determined quantity of organic mutter that she includes all her vegetal and animal organisms; this mutter's  weigh is the biomassa, it is calcolated at dry status for united of surface occupated from ecosystem.

TRANSFER OF ENERGY IN ECOSYSTEM

The relations between different members of an ecosystem are narrow, The main relations are thoose make from energy flows and nutritions flows. Ecosystem is an opered system respect energy, that is energy enters and  goes out continuonsly from system. Energy enters in the ecosystem from sum , pass biotic comunity and her alimentary chain and goes like heat, organic matter and product organisms.

Productings organisms can to pick up and to use sun's energy to transform some inorganic members in organic members  throught photosynrthesis process.

These members are use from same productings, feeding  vegetables , take up organic substances and metabolizzano them, that is transform in other organic substances right to use for all vital function and like struttural matter har their increase.

Likewise, behave theirself carnivorans animals, feed them with others animals. The transfer of energy throug alimentary chain is companion of loss like dissipated heat in the envirament for the second begimming of thermodynamics.

TROFICA CHAIN

There are two kindes of alimentary chains: the chain of grazing and the chain of delri.The alimentay chains are connect between them. In the natural ecosystem organisms abtain from sum with same number of passings belong to same trofico level. So green planst occupy the first  trofico level, organisms that feed them with plants occupy second level, carnivorans are at third  level and predatory carnivorans occupy faurth level.

The rising and the energy's quantity estabilish the kind and the numner of organisms and their developement process.

THE NUTRITIOUS

Matter has a circular run passing from biotic division to vivent organisms after to came  back at the biotic division.

These runs are biogeochimici cycles.

Carbon, hydrogen, nitrogen, phosphorous and calcium  are fondamental for vivent organisms in big quantity and for this their name is macronutrienti.

Organisms to grow and to devellop need all these substance in different quantity. The principal substances change from specie to specie. The number development ant the induvidual growth dipend from limitante factor.

Iron, magnesium, manganese and zinc there are in minus quantity abìnd their name is MICRONUTRIENTI.

PRIMARY PRODUCTIVITY

Primary productivity of an ecosystem is like velocity that the sun energy transform it's from photosintesys in organic substance.

It defines:

•-          Primary productivity net (PPN) the velocity of stare of organic matter product, at net of thet use of plant to live.

•-          Net productivity of comunity (PNC) is the velocity of stare of organic mutter doesen't use from erbivourous and carnivourous animals.

•-          Secondary productivity (PS) is the velocity  of star of organic mutter for the energy.

ALTERATION OF ALIMENTARTY CHAIN            

Tecnologic innovadions apllied for parasitic's fight involved pesticides emplayment in big quantity and for long time. These substances are tossic and they biang imbolance of biosfery because they  have formful effects for some organisms and thuman.

DDT is a substance that made dannyges in all ecosystem. It is in alla fishes of alla ward. Dameges of DDT are really alarning.

AN EXAMPLE OF ALTERED ECOSYSTEM

In Borneo the use of DDT alterated the ecosystem that it hit human. The big use of DDT to exterminate the mosquitos that transfer the malaria killed all insects. These insects are the foundamental aliment of bizards, their population us smoll, thefelines number is smoller then last year. The felines controlled the mause's popolation: the felines reduction brought an aument of mousas' numbers. The infectious illness hit the Borneo and they caused must victims then malaria.

THE ECOSYSTEM IS IMPORTANT FOR THE HUMAN

Terrestrial and acquatic ecosystem are "natural factorys" that product foundamental thing to consent the life con the Earth and to cover the world's needs: hood, fibres, water. Some ecosystem are foundamental for tourism and ricreation. Only farming produce 1.3 milions for food und fibres everyear.

THE BIOMA

A wood, a lake, a river, a park, a beach, the sea are all ecosystem. All aur world is an ecosystem, it can be different and some ecosystem join others and togheter form others types of ecosystems. Particulary near ecosystems that  share  biogeocjimici  cycles and  present abiotic components similae are "biomi". So terrester ecosystem can group togheter some biomi.

ECOSYSTEMS OF EARTH

The ecosystems can divide in:

•-          deserts

•-          savannas

•-          steppes

•-          temperate woods

•-          tropical woods

•-          boreal woods

•-          tundra

•-          mediterraneam stain

•-          sweet and solty water's ecosystems

•-          sea ecisystem

•-          metropolitan ecossystem

•-          rural ecosystem

•-          agricol ecosystem

A WORLD IN EVOLUTION: THE ECOLOGICAL SUCCESSION

The ecosystem's history from birth to maturity is ecological successione. It is a sequence of modifications of biotic and abiotic components thet make them is "serie" and the different stages of transition are "studi seriali". This is there was the formation of "pionieri", this is to be able to grow alone with difficult conditions too.

AN ARTIFICIAL ECOSYSTEM: AGRO-ECOSYSTEM

Am exemple of agr-system is an cultivated camp. It is a natural system theat human modificated with factory activities.

It is different them natural ecosystem for faur things:

•-          Semplification: factor favour a type of plants and nill all others.

•-          Energy's continbution

•-          Biomassa, this give the ecosystem open

•-          Pollution substances immissions as fertilizer and others chimical substances dangerans for enviroment.

The hause is an artificial ecosystem because it dipends from other factors and substances that there are in autside.

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