Question No. 2

What is biota?
Answered 6 July 2003.
Question author: anonymous.
Asked 6 July 2003.

Biota and biosphere are two scientific terms that, at each stage of scientific progress, should be defined so as to maximise the convenience of their usage.

Biota comprises all living organisms (bacteria, fungi, plants, animals) that inhabit a given area. For example, one can speak of the global biota, oceanic biota, terrestrial biota, biotas of forests, bogs, lakes etc. Biosphere means biota plus its environment, including stores of dead organic and inorganic substances continuously used and recycled by life.

There is a fundamental difference between the notions of disturbed biota and undisturbed (natural) biota. Unlike the disturbed biota (that of arable lands, pastures, exploited forests and other disturbed areas), natural biota does not represent a random conglomerate of living organisms. Natural biota is composed of internally correlated ecological communities of biological species, where each species features a strictly specified population density and consumes a strictly specified energy flux.

The main quantitative criterion for the undisturbed state of the biota is the age of the last disturbance. For example, temperate forests with the age of last disturbance (fire, cutting) in excess of 150-200 years can be classified as undisturbed. In this period the structure and function of forest communities as well as their regulatory environmental potential fully recover to the undisturbed state.

Biotic regulation of the environment can be only performed by the undisturbed biota.

Forest lake