Stofkredsløb

Stofkredsløb refers to the biogeochemical cycles by which matter is circulated through Earth's ecosystems. These cycles involve the movement of elements and compounds between the biotic (living organisms) and abiotic (non-living components like atmosphere, lithosphere, and hydrosphere) parts of the environment. Essential elements like carbon, nitrogen, phosphorus, and water are continuously recycled, although often in different chemical forms.

The carbon cycle, for instance, involves the exchange of carbon between the atmosphere, oceans, land, and living organisms. Plants take up carbon dioxide from the atmosphere during photosynthesis, and this carbon moves through food webs as organisms consume each other. Respiration, decomposition, and combustion release carbon back into the atmosphere.

The nitrogen cycle is crucial for life as nitrogen is a key component of amino acids and nucleic acids. Bacteria play a vital role in converting atmospheric nitrogen into forms usable by plants, and then converting it back to atmospheric nitrogen through denitrification.

Water, or the hydrological cycle, involves evaporation, transpiration, condensation, precipitation, and runoff, ensuring a continuous supply of fresh water for ecosystems.

These cycles are interconnected and are fundamental to maintaining the balance and productivity of Earth's biosphere. Human activities, such as pollution and deforestation, can disrupt these natural processes, leading to environmental consequences like climate change and eutrophication. Understanding stofkredsløb is therefore essential for environmental management and conservation efforts.