ZOL 355 Lecture 10 Outline of Last Lecture I GPP gross primary production II NPP net primary production III R respiration Outline of Current Lecture II Photosynthesis requirements a Light wavelengths and frequency in the visible spectrum b What plants absorb and emit III Respiration requirements IV Nitrogen cycle V Environmental issues a Haber bosch process b Fate of fertilizer and human requirements Current Lecture I Photosynthesis requirements a Sun emits all wavelengths in the EMS b Plants use the visible light from violet 400 red 700 c In aqueous environments red and yellow are absorbed whereas violets are scattered Only the green blue wavelengths around 450 500 are left after 50m d Plants absorb and emit light i Chlorophyll absorb violet and red and emit green ii Carotenoids absorb violet and blue green and emit orange and red e This allows plants to live in different areas and not compete for light II Respiration Requirements a In some conditions such as a flooded plain the amount of O2 is limited causing plants to turn to evolution to obtain more O2 Some trees have roots that come out of the ground to have more surface area to get more O2 III Background IV V a The atmosphere is mostly Nitrogen with 3 9x10 20 g but none of that can be used by plants Plants can only use ammonium NH4 nitrate NO3 and urea NH2 2CO i Most of those are found in man made fertilizers b Bacteria algae and plants can uptake ammonium nitrate and urea across the cell wall of their roots Nitrogen synthesis a Ammonium is moved into the cell where its broken down and turned into amino acids which is then used for biomass Plants can only use N2 is they have a symbiotic relationship with bacteria that are capable of nitrogen fixation a Only bacteria can conduct N2 fixation i N2 NH4 protein biomass