Question

hiii plz explain me nitrogen and carbon cycle ....?thank u and follow me

Answer 1

Cycling of Carbon

One of the ways that nature recycles matter is through the carbon cycle. The carbon cycle is carbon cycling through the global environment. Carbon is a chemical element and a key component of many systems in the biosphere, from acting as part of the earth's thermostat to being one of the key elements in photosynthesis, which is when plants make sugars for energy.

In order for the ecosystem to function properly, all parts need an adequate supply of carbon. This is usually not a problem since nature is efficient at carbon cycling. Since the process is a cycle, we need to pick some place to begin.

One of the biggest reservoirs of carbon is the atmosphere, which is about 0.038% carbon dioxide. There are two ways for carbon to be removed from the atmosphere. The first is through photosynthesis, where plants take in CO2, water and sunlight to create sugars for energy, and oxygen gas emerges as a by-product. Once inside plants, carbon moves through food chains, where organisms become nutrients including herbivores, carnivores and ultimately, decomposers. Through living organisms, carbon is either re-released back into the atmosphere through respiration (where organisms use oxygen to generate energy from nutrients and produce carbon dioxide as waste), released by combustion (the process of burning something) or broken down into the soil as part of the organism's body. Once buried in the soil, carbon can be converted into fossil fuels over long periods of time and then also reenter the atmosphere by combustion.

If carbon does not enter land plants by photosynthesis, it can be taken into the ocean

If carbon from the atmosphere does not enter a terrestrial (or land) plant by photosynthesis, it can dissolve in the ocean. Here it can be taken up by marine plants through photosynthesis - just like in land plants - or it can be incorporated into sediments. Marine organisms can also take up dissolved carbon molecules and use that along with calcium in the seawater to make calcium carbonate, which is a major component of the shells and skeletons of marine organisms.

When these organisms die, their shells and bones settle to the bottom of the ocean, where they can be covered up and remain for long periods of time. Under great pressure from the water and sediment, these shells break down and form limestone rock.

Limestone is the largest storage reservoir of carbon on the earth. Once formed into limestone, carbon usually stays locked in the rock. However, it can also dissolve very slowly to be released as carbon dioxide back into the atmosphere, or, if the limestone is exposed to weathering and dissolved by acid rain, be released as carbon dioxide. This completes the cycle, returning all carbon back to the atmosphere where it began. So, following this line of thinking, the carbon molecules that are in our body have been cycling on the earth since it was formed and will continue to do so as we exhale each breath, returning CO2 back to the atmosphere.

NITROGEN CYCLE

The nitrogen cycle is the biogeochemical cycle by which nitrogen is converted into multiple chemical forms as it circulates among the atmosphere, terrestrial, and marine ecosystems. The conversion of nitrogen can be carried out through both biological and physical processes. Important processes in the nitrogen cycle include fixation, ammonification, nitrification, and denitrification. The majority of Earth's atmosphere (78%) is nitrogen,making it the largest source of nitrogen. However, atmospheric nitrogen has limited availability for biological use, leading to a scarcity of usable nitrogen in many types of ecosystems. The nitrogen cycle is of particular interest to ecologists because nitrogen availability can affect the rate of key ecosystem processes, including primary production and decomposition. Human activities such as fossil fuel combustion, use of artificial nitrogen fertilizers, and release of nitrogen in wastewater have dramatically altered the global nitrogen cycle.