The nutrient cycle is a system where energy and matter are transferred between living organisms and non-living parts of the environment. This occurs as animals and plants consume nutrients found in the soil, and these nutrients are then released back into the environment via death and decomposition. In forest environments, there is an exchange of nutrient elements such as hydrogen, nitrogen and oxygen among the soil, plants and animals living within the environment.
What are the Essential Nutrients?
Non-mineral elements make up 95% of the mass of all living organisms
- The non-mineral elements are Carbon (C), Hydrogen (H), Oxygen (O)
- These nutrients are often obtained from carbon dioxide (CO2) in the air and water (H2O)
Macronutrients are chemical elements that plants need in large quantities to perform basic functions, and their availability can limit the growth of organisms.
- They include the elements (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg)
Micronutrients are taken up in much smaller amounts than macronutrients, but are still vital for growth and metabolism.
- The micronutrients include boron (B), copper (Cu), iron (Fe), manganese (Mn) and zinc (Zn).
Nutrient Cycling in Forest Ecosystems
In forest environments, the nutrient cycle involves animals, plants, fungi and bacteria living above- and below-ground (the soil is alive!), as well as mineral components of soil, dead leaves and wood, and water from rain and snowfall. Trees and other plants take up mineral and non-mineral nutrients from the soil through their roots. These nutrients are stored in the leaves, flowers and other parts of plants. The nutrients are either transferred to animals when animals eat the plants or they are transferred back into the soil. For instance, when plants and animals die, arthropods, earthworms, fungi and bacteria in the soil break them down. Arthropods are insects such as mites. Arthropods and earthworms grind up the decaying material and they mix this material with the soil. Fungi can break apart some of the more complex compounds and break them down into smaller components. All of these organisms ultimately consume and respire much of the material back into carbon dioxide gas, which is why it disappears over time.
Andrews, S. (2011, September 19). Nutrient Cycling. Retrieved April 03, 2017, from http://soilquality.org/functions/nutrient_cycling.html
Bernhard, A. (2010). The Nitrogen Cycle: Processes, Players, and Human Impact. Retrieved April 03, 2017, from http://www.nature.com/scitable/knowledge/library/the-nitrogen-cycle-processes-players-and-human-15644632
Conradin, K. (2009). The Nutrient Cycle. Retrieved April 03, 2017, from http://www.sswm.info/category/concept/nutrient-cycle
Hristovski, S. (2014) Limitless decomposition in leaf litter of American beech: Patterns, nutrients’ and heavy metal's dynamics. Pedobiologia. http://dx.doi.org/10.1016/j.pedobi.2014.01.005
Carbon and Nutrient Cycling: Courtesy of the U.S. Geological Survey
Micro and Macro Nutrients Involved in Nutrient Cycling: Copyright Perri Keehn
Forest Leaves: Copyright Perri Keehn