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Omozokpea Daniel

Measuring Gross Primary Productivity (GPP) using Light and Dark Bottle methods: Sample Question

Benjamin Tsavkegh  Follow

The dynamics are:

Light bottle: GPP - Ra = 0.15Dark bottle : Ra = 0.08

Then GPP = 0.15 + 0.08.

The amount of O2 used in the respiration is 0.08 mg O2 / L, not -0.08 mg O2 / L.

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Craig Lenhard  Follow

If you think about what is going on in the light bottle, this should make more sense. Oxygen is being produced by photosynthesis, but respiration is using up the oxygen being produced. Therefore, the total amount is NPP. So if you want to find out how much oxygen was originally created through photosynthesis (GPP), you need to put those losses due to cellular respiration back into the light bottle (in other words, add the R amount to the light bottle amount).

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James Alexander  Follow
Your wish to help the poster is admirable, but as you are a new user, may I suggest you check the dates of questions. This one was posted in 2016, so I imagine the poster has moved on to other things. You may wonder why it has resurfaced after three years. This happens when a question hasn’t had an answer with enough votes to be “put to bed”, and the reposting is to give people an opportunity to review and vote for the answers. (Unlikely for this sort of homework question.)More
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Gerald Arnoult  Follow
moved on to other things! But it's okay, lol.More
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