Two traits that represent a sustainable society is an emphasis on egalitarianism - where there would be a tendency to strive towards a society of equals. Another would be an emphasis on using renewable energy.
On the other hand, an unsustainable society would have an emphasis on using fossil fuels due to being cheaper and having an ever-increasing productions of goods, not considering how taxing this might be on the planet.
I believe the answer is the Regeneration stage.
A this stage of the Calvin Cycle, only one of the G3P molecules leaves the cycle and is sent to the cytoplasm to contribute to the formation of other compounds needed by the plant. Because the G3P exported from the chloroplast has three carbon atoms, it takes three "turns" of the Calvin cycle to fix enough net carbon to export one G3P. Each turn makes two G3Ps, therefore three turns make six G3Ps.
An example of decomposers in the desert could be worms, beetles, or bacteria. Decomposers can't always stay alive because of the drought. Good luck!!