Abstract
Determining the role of trees in the water cycle and their impact on soil moisture and atmospheric humidity is crucial. This study aimed to investigate the patterns of leaf transpiration in Quercus robur and Acer campestre in a maple-oak forest under varying water supply conditions. The research was conducted in the lower third of the lower third of the north-facing slope and the middle third of the south-facing slope in the Viiskova ravine. A silvicultural and taxation survey of model trees was conducted on both sample plots, where the plantations are moderately dense. The diurnal course of transpiration patterns of these deciduous species was studied throughout the vegetation period. This physiological process reached its highest values in both species on the north-facing slope during the summer months, especially in Quercus robur. On the south-facing slope, in May and June, the average daily transpiration values in both species were almost indistinguishable. During the remaining months of the vegetation period, the intensity of water evaporation by Quercus robur leaves was statistically higher than that of Acer campestre. It was established that on the south-facing slope, under more arid conditions, this process is less active. This pertains to the daily transpiration loss of water by leaves per unit of their mass, monthly transpiration, and the intensity of this process per tree. The difference between the results of water loss by the leaves of a single Quercus robur and Acer campestre tree is significant and is attributed to the lower transpiration rate of Acer campestre, except in May and June under xerophytic conditions, as well as the smaller leaf mass of this species. Both Quercus robur and Acer campestre are hydrostable medium-transpiring species. The maple forest on the north-facing slope evaporates 30.6% more moisture per 1 ha per vegetation period than on the south-facing slope. The results obtained indicate that Acer campestre in a maple-oak forest, under fresh and dry forest-growing conditions, does not pose a significant competition for moisture for Quercus robur when they grow together. The results obtained can be used to develop effective forest management strategies in maple-oak forest