Why Are Nutrients Recycled in Ecosystems?
Ecosystems can serve as sources and sinks for nutrients, with many possible pathways for nutrients to enter and exit. Ecosystems can also serve to transform nutrients from one form to another; the nature of these changes varies by ecosystem. Recycling of nutrients in ecosystems maintains their availability for life processes.
Other People Are Reading
-
Carbon
-
Carbon, in the atmosphere as carbon dioxide, is converted into organic matter in plants. When the plants are eaten by animals, the carbon is transferred to the animals. When plants and animals die, the carbon from their tissues is returned to the atmosphere through decomposition.
Nitrogen
-
Like carbon, nitrogen moves from the atmosphere into plants and animals. It falls on the earth dissolved in rain water and is then available in the soil. Humus in soil is also broken down by microbes to release inorganic nitrogen, which is incorporated into plant tissues. Nitrogen can return to the atmosphere as ammonia gas or through denitrification, which is a process performed by microbes under conditions lacking oxygen.
-
Phosphorus
-
Phosphorus is obtained through the weathering of rocks and minerals and is used by plants and animals for cell maintenance and growth. As plants and animals die and decompose, the phosphorus from their tissues can be taken up by other plants or moved by water to another system.
Living Organisms
-
Many nutrients in ecosystems enter living tissue from the atmosphere, soil or water. Once in living tissue, they are bound there, and may be utilized by animals that eat and digest the tissue, until the plant or animal dies and decomposes. These nutrients are then available for other living organisms to utilize, allowing the many nutrient cycles to continue.
Environmental Cycles
-
Nutrients continually cycle between the soil, water and atmosphere. These cycles are often mediated by living organisms, and the forms and types of transformation are governed by the nutrient requirements of the plants and animals.
-
