stemflow

Stemflow refers to the portion of precipitation that, after reaching a plant canopy, flows down the stems and trunks of plants to the ground. This process is distinct from throughfall, which is precipitation that passes directly through the canopy to the ground. Stemflow is influenced by the architecture and characteristics of the plant, including leaf size and shape, branching patterns, and the presence of hairs or waxes on the stem.

The amount of stemflow can vary significantly between different plant species and even within the same species under different environmental conditions. For example, plants with large, cupped leaves or rough bark may channel more water down their stems. Stemflow plays a role in the redistribution of water and nutrients within an ecosystem. It can concentrate water and dissolved substances, such as nutrients leached from the canopy or pollutants, at the base of the plant, potentially influencing soil moisture and nutrient availability in that localized area. This localized wetting can also affect microbial activity and seed germination. Understanding stemflow is important in hydrological studies, forest ecology, and agricultural science, particularly when assessing water budgets and nutrient cycling.