ENV234H1 Lecture Notes - Lecture 21: Estuary, Electric Power Industry, Sulfur Dioxide
Document Summary
Lecture 21 (lecture 18 slides cont"d) global n cycle. Most of the nitrogen is in atmosphere in form of n2 (not available to organisms) Most of the rest of the nitrogen is locked up in deep soils (mantle and crust) so also not available. Have pools and fluxes (rates of transfers between pools) Fixation: taking in atmospheric nitrogen and bringing it in land, same in ocean (fixation brings nitrogen into water) Denitrification: some organisms take nitrogen from land and return it to atmosphere, very important, or else biosphere would come to standstill (nitrogen used up) Human impact: agriculture and burning of fossil fuels = input of nitrogen. Marine cycling / ocean-ocean atmospheric exchange: within oceans have cycling between different pools of different types of nitrogen. Env234h1 december 2nd, 2015: a lot of this (recall pools of nitrogen slide) Ammonium: form that has the most energy potential, ready to be taken up fairly cheaply by organisms.
