How does leaf cover change the way rain reaches the forest floor?

In a temperate forest, leaf cover significantly alters how precipitation reaches the forest floor through a process known as interception. Rather than falling directly to the ground, a portion of rainfall is captured by the forest canopy.12

The water that reaches the forest floor is categorized into two primary types:
* Throughfall: Precipitation that passes through the canopy or drips from leaves to the ground.1
* Stemflow: Water that is intercepted by the canopy and subsequently travels down the trunks and stems of the trees to reach the soil.1

The amount of water that ultimately infiltrates the soil is the total precipitation minus the losses from canopy interception, forest floor interception, and runoff. The intercepted water is often evaporated back into the atmosphere, a process that is particularly efficient in forests due to the aerodynamic roughness of the canopy, which facilitates the transfer of water vapor. Consequently, forests act as filters and sponges, regulating the flow and storage of water within the hydrologic cycle and helping to mitigate rapid runoff compared to sparsely vegetated land.21