How is the rate of photosynthesis measured

Explanation:

The incoming and outgoing CO2 from the leaf chamber is measured by infrared spectroscopy with an infrared gas analyzer. The difference gives us the amount of CO2, from which the rate of photosynthesis can be calculated.

By the production of Oxygen or the uptake of Carbon dioxide.

for  example, forests have higher evapotranspiration than other ecosystems,  such  as grasslands, because of their deeper roots and greater leaf area. thus forests have a net moistening effect on the atmosphere and become a moisture source for downwind ecosystems.