Human Influence on the Phosphorus Cycle

1. Human Influence on the Phosphorus Cycle

2. Characteristics of Phosphorus • an essential nutrient for plants and animals in the form of ions PO43- and HPO42- • part of DNA and RNA-molecules • part of molecules that store energy (ATP and ADP) • part of fats of cell membranes • a building block of certain parts of the human and animal body, such as the bones and teeth

3. Characteristics of Phosphorus • can be found on earth, water, soil and sediments; cannot be found in the gaseous state • usually liquid at normal temperatures and pressures • mainly cycling through water, soil and sediments • can be found as very small dust particles in the atmosphere • most commonly found in rock formations and ocean sediments as phosphate salts • often the limiting factor for plant growth both in land and marine ecosystems

4. Phosphorus Cycle • a biogeochemical cycle that describes the movement of phosphorus through the lithosphere, hydrosphere, and biosphere; the atmosphere does not play significant role • the slowest one of the matter cycles

7. Interferences on the Phosphorus Cycle

8. Agriculture • farmers often apply phosphate fertilizers on farmland since phosphorous is often a limiting factor in plant growth • interference in the phosphorus cycle occurs by overuse or careless use of phosphorus fertilizers • excessive amounts of nutrients, particularly phosphorous, in the soil will pollute aquatic ecosystems • this interference will result to eutrophication or algal blooms

9. Cutting down of rainforests • phosphate supplies deplete due to extensive wood chopping in forest areas • most of the phosphate can be found in the ground under the trees • when the trees are removed, the rain washes phosphates away, causing the ground to become unproductive

10. Products with phosphorus • use of laundry detergents, which contain phosphorous, contributed to significant concentrations of phosphorus in rivers, lakes, and streams • another cause of eutrophication

11. Effects of Human Influence on the Phosphorus Cycle Algal Bloom • Algal Blooms occur in both fresh and saltwater environments when certain species of algae out-compete other organisms and reproduce rapidly, often forming visible discolored patches on the surface of the water that can produce toxins detrimental to other organisms • The blooms can block sunlight and deplete oxygen in the water which causes distress to other organisms

12. Effects of Human Influence on the Phosphorus Cycle Hypoxia • Hypoxia, or oxygen depletion, is a phenomenon that occurs in aquatic environments as dissolved oxygen  becomes reduced in concentration to a point where it becomes detrimental to aquatic organisms living in the system. • This is a result of eutrophication.

13. References • http://www.lenntech.com/matter-cycles-pollution.htm • http://www.enviroliteracy.org/article.php/480.html • http://water.epa.gov/type/rsl/monitoring/vms56.cfm • http://www.lenntech.com/phosphorus-cycle.htm • http://en.wikipedia.org/wiki/Phosphorus_cycle • http://toxipedia.org/display/toxipedia/Algal+Bloom