The researchers studied how three types of trees respond to dehydration by measuring their photosynthetic and water-related characteristics. They found that as the trees experienced more dehydration, their transpiration rate decreased. The net photosynthetic rate reached zero at different levels of dehydration throughout the year. The relationship between transpiration rate and dehydration followed a specific curve for each tree type. The rate of transpiration variation was highest in the early growth period and lowest in the late growth period.