Biological cycle
A biological cycle is understood to be the cyclical path of (inorganic) substances through food chains and back to the initial state via excretions or the breakdown of dead organisms by destructors . In contrast to such cycles - such as that of the water cycle - it is required that the substance pass through living organisms as an essential part of metabolism .
If biological cycles are interrupted or diverted, there is necessarily an accumulation of intermediate products before the break point, followed by a depletion . Large biological cycles, also known as ecological cycles , suffer from various human-induced changes, as demonstrated , for example, by the eutrophication of bodies of water through untreated waste water from water toilets . Excrement from land animals in the natural cycle is usually broken down by microorganisms in the soil in a natural way and does not end up in the water cycle.
Conversely, the carbon released by civilization in the form of carbon dioxide , which was naturally withdrawn from the carbon cycle through underground deposits over millions of years, causes serious changes in the entire bio- and earth atmosphere , namely in the form of global warming .
Many indigenous peoples believe that you have to give back what you have taken from nature - i. This means that the natural cycles are kept “alive”.