Assessment of irrecoverable retention of liquid atmospheric precipitation by meadow grass stands of the Middle Urals

The process of retaining precipitation by grass vegetation is important in the processes of moisture circulation in forest landscapes. At the same time, there is an erroneous opinion that grasses are not able to retain a significant amount of rain moisture, which further forms the river flow. For this reason, the question remains poorly understood. In turn, grass stands are able to retain rainfall on their leaves in whole or in part. It depends on the duration and intensity of the rain. The leaves of grass stands have a specific morphology and are arranged more vertically than the leaves of woody plants; therefore, moisture on the leaves of grasses is held in film and drip forms (in woody plants-only in drip). When droplets roll down the stem, water is trapped in bowl-shaped recesses or funnels of grass leaves. The article discusses the relationship of precipitation and vegetation. The authors conducted field experiments on the retention of rainfall by grasses that grow in the landscapes of the Middle Urals. The experiments consisted of artificial sprinkling of grass samples and their subsequent weighing (weight experiments). In the course of the experiments, the connections were developed for the retention capacity of rain deposited on the leaves of species of grass vegetation with the leaf surface area of grass stands and their green mass. The magnitude of the loss of rainfall on grass stands is comparable with the magnitude of the rainfall of individual rains. According to the results of the experiment, it was found that under the forest canopy, the interception of precipitation is 0.1–0.2 mm, in the clearings – 1–2 mm, in the clearings – 2–4 mm. The results can be used to assess the actual rainfall to the surface of the soil and to calculate the change in the discharge of water from rain floods on rivers as a result of forest successions.