Introduction
Rainfall interception loss by canopies of forest-forming species is a part of the losses of the forest water balance and, along with evaporation losses from leaf surface area, determine the amount of moisture flowing under deciduous canopies as well as the nature of soil moisturization and estimated characteristics of flood runoff in small watersheds of forest areas. There are neither common methods for estimating the maximum rainfall capacity interception by deciduous species, nor methods for estimating the spatial structure of these losses. The published results of empirical studies express the value of the maximum retention capacity depending on the leaf mass, which makes it difficult to use these results in calculations of water balance elements of forest areas. In fact, rainfall is intercepted and evaporated by the leaf surfaces, and retention capacity can be estimated correctly only if the relationships with leaf surface area of tree stands are taken into account.
The research purpose is to make a spatial estimation of the maximum rainfall retention capacity on tree canopies.
In this study, the authors have carried out empirical estimations of the maximum moisture retention capacity of tree species per unit leaf surface area, and have presented the result of cartographic interpretation of the results obtained in calculating the maximum moisture retention capacity within a forest watershed.