Carbon is a fundamental element of life and circulates continuously between the atmosphere, biosphere, hydrosphere, and lithosphere through a complex series of processes known as the carbon cycle. In terrestrial and aquatic ecosystems, plants play a central role by fixing atmospheric carbon dioxide during photosynthesis and converting it into organic compounds such as carbohydrates, proteins, and lipids. This fixed carbon becomes the primary source of energy for herbivores and is subsequently transferred to higher trophic levels through food chains. Respiration by plants, animals, and microorganisms releases carbon dioxide back into the atmosphere, completing a major biological loop. When plants and animals die, their remains are decomposed by bacteria and fungi, which break down organic matter and