A study in Northeast China looked at how four shrub plants photosynthesize and transpire. They used a special device to measure these processes. The results showed that different shrubs have different patterns of photosynthesis and transpiration throughout the day. Stomatal conductance and CO2 levels inside the leaves affect how much photosynthesis and transpiration happen. The amount of light, CO2 in the air, and humidity also play a role in these processes. Overall, the amount of light has a positive effect on photosynthesis, while high CO2 levels inside the leaves and in the air have a negative impact.