The study looked at how pine trees in a specific area in China collect rainwater. They measured how much rainwater went through the trees, how much ran down the trunks, and how much was caught by the leaves. They used a computer model to predict how much water the trees would catch. They found that most of the rainwater went through the trees, with only a small amount running down the trunks. The computer model was pretty accurate in predicting how much water the trees caught. The model was affected by how much water the trees could hold, how much of the ground was covered by trees, how hard it rained, and how quickly the water evaporated.