ENV234H1 Lecture Notes - Lecture 22: Experimental Lakes Area, Dimethyl Sulfate, Phosphorus Cycle
Document Summary
14 biogeochemical cycles: phosphorus, sulfur, carbon cycles. Crustal rocks, deep soils, sediments 99. 99% In the form of apatite: ca5(po4)3(f2oh2cl: phosphorus strongly locked up, weathering, leached off land, ends up in the ocean, binds to particles that sinks into the ocean (sedimentation, very slow geological uplift, and then weathered again. Of the 0. 01%: most is in the upper 60cm of soils on land: 68, 31% in oceans, biota: 1, very tiny portion in atmosphere as dust particles: 0. 000001% Not very available to organisms: limiting, no quick replenishment. Only one main form: po4 3: cannot be changed by chemoautotrophs; no redox reaction. Human activities dominate dissolved inorganic phosphorus (dip) exports. Most of the export into ocean basins is sewage, detergents (96%); also from manure (2%) and fertilizers (2%) Humans contributing a lot to natural phosphorus cycle. Major net loss of phosphorus: not many phosphorus mines, p must be uplifted and weathered long process.
