Different values may be due to differences of climate and weather, including the age of the wood type, the measured values, photosynthesis is different from the reference value.
The difference may be due to the different conditions of space weather and the age of the species. As a result, the photosynthesis measurements differed from the reference value.
Different values may be due to the difference of area and the weather, including the age of the species Therefore, the photosynthesis measured different from the reference value.