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This is probably a softball question but because of the nature of the term, it's difficult to Google. I am not a biologist, I am a web developer. :-)

What does this measurement mean (it is a measurement of biomass production): 50 g m-2 d-1

I believe it means 50 grams per square meter per day - but not sure why there are '-' signs in there.

And perhaps more complicated, it is possible to translate this measurement to volume (either cubic meters or ideally cubic feet)?

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  • $\begingroup$ Look for negative exponents to learn about the minus signs in the unit. $\endgroup$
    – Arsak
    Sep 25 '18 at 14:40
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    $\begingroup$ Could you please make clear, what you want to achieve? Turn "50 grams per square meter per day" to "XY cubic feet" or to "XY cubic feet per square meter per day"? $\endgroup$
    – Arsak
    Sep 25 '18 at 14:42
  • $\begingroup$ Thank you, @Marzipanherz. Appreciate the Wikipedia link. I was hoping to gather something like this: "50 grams per square meter per day" to "X grams per cubic foot" but based on Bryan's answer below, I see now this isn't a reasonable expectation. $\endgroup$
    – johnny_n
    Sep 25 '18 at 15:45
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50 g m-2 d-1 translates to "50 grams per square meter per day": the negative signs are negative exponents (check a math textbook). This is equivalent to writing

((50 g)/m2)/day

You cannot transform this into volume, doing so would lose the meaning: if you are talking about biomass growth of 50 grams per square meter per day, you are saying that there is 50 grams of new biological material produced within a square meter of land (say, a patch of grassland or forest). Talking about it in terms of volume doesn't make sense because the "height" coordinate doesn't produce additional biomass, since the source of energy is the sun.

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  • $\begingroup$ Thank you, Bryan -- exactly what I was looking for. This makes perfect sense now. $\endgroup$
    – johnny_n
    Sep 25 '18 at 15:42

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