Kvävetillförseln

Kvävetillförseln refers to the process by which nitrogen is introduced into an ecosystem. Nitrogen is a crucial nutrient for all life, forming essential components of proteins and nucleic acids. In natural environments, kvävetillförseln primarily occurs through several key pathways. Atmospheric deposition, where nitrogen compounds from the air settle onto land or water, is a significant source. This can include nitrates and ammonium from both natural processes like lightning and human activities such as the combustion of fossil fuels and agricultural emissions.

Another major pathway is biological nitrogen fixation, carried out by certain microorganisms. These bacteria convert atmospheric nitrogen gas (N2), which is largely unusable by most organisms, into ammonia (NH3) or other nitrogen compounds that can be assimilated by plants. This process is vital for replenishing the available nitrogen pool in ecosystems.

Denitrification, a microbial process that returns nitrogen to the atmosphere as N2 gas, can be seen as a form of kvävetillförseln in reverse, depleting the available nitrogen. However, kvävetillförseln specifically focuses on the addition of nitrogen. Human activities have profoundly altered natural rates of kvävetillförseln, particularly through the widespread use of synthetic nitrogen fertilizers in agriculture. This industrial fixation of nitrogen, mimicking natural processes but on a much larger scale, has led to increased nitrogen availability in many terrestrial and aquatic systems, with both beneficial and detrimental environmental consequences.