Biogeochemical Cycles Phosphorus Biogeochemical Cycles The great cycles

Biogeochemical Cycles Phosphorus

Biogeochemical Cycles • The great cycles of minerals as they are • used by organisms, • are converted back to abioitic forms • then are reused by organisms

Terms for Biogeochemical Cycles • Pools = storage place for a mineral (reservoir) • Fluxes = when a mineral moves from one pool to the next pool. • Processes= the chemistry/biology that move the mineral

All organisms require phosphorus in the form of phosphates • Organisms compete for each molecule • Required for • Cell membranes • DNA • Energy carrying molecules (ATP) • Bones and teeth

Phosphorus Cycle (P) The major phosphorus pool is rock. • There is a lot of it, but it can’t be used by plants until it is dissolved out of the rock (weathered) by water and it becomes phosphate = PO 43 - • Phosphate

Phosphorus can stay as rock for a long, long time. • Rocks can be weathered into soil • Phosphate dissolves from the soil and enters plants • It works its way up and around the food chain • Plants are good at picking up and conserving phosphate though their roots

Phosphate Cycle Continued • However it does dissolve well in water and can be added to streams by leaching and run off. • It becomes part of the water food cycles. • Phosphate can settle out of solution and sink to the bottom • Over millions of yeas these sediments form sedimentary rocks

Extra phosphate in water causes eutrophication • Phosphate causes algae blooms • Too many algae block the sun, causing dead algae • Dead algae decompose, using up all the oxygen. • Anoxic conditions kill any marine organisms. Fish leave.

Palau’s phosphate deposits on Angaur had many consequences • Phosphate rocks were a very valuable resource that encouraged German and Japanese settlement and mining. • Mining caused environmental damage to Angaur surface and groundwater • Many social consequences.

As the German Phosphate Company made preparations to begin mining operations, the island population of 150 … were moved to a small reservation in the southeast corner of the island. At first company officials intended to rely on Chinese labor for the Angaur mines, and they brought in eighty workers from Hong Kong. The Chinese proved as troublesome to the German overseers on Angaur as they were on Nauru. Dissatisfied with their working conditions and benefits, and insulted by the floggings they received, they killed a German employee and called a general strike during the first year of operations.

To provide “more complaisant material for the company than the Chinese”, the German government began recruiting Carolinians. With the assistance of chiefs from Yap and its outer islands, a hundred men were sent to Angaur on a one-year labor contract; a second recruiting voyage produced another two hundred laborers, eighty of them from Palau and the rest from Yap. [4] — Strangers in their Own Land: A Century of Colonial Rule in the Caroline and Marshall Islands, Francis X. Hezel, S. J. , Pacific Island Monograph Series No. 13, University of Hawaii Press, 1995.