ZLV Online

Abstrakt

Presented monitoring in the Hrubý Jeseník Mountains is part of a research project focused on the impact of large-scale clear-cuts carried out during the extensive bark beetle outbreak in 2015–2020 on hydrological processes in small forest catchments. During the 2022–2024 growing seasons, precipitation, soil moisture, and soil water potential were monitored in clear-cuts and Norway spruce stands. Soil moisture was the highest at the beginning of vegetation season, then declined as the evapotranspiration increased. In open areas, significantly higher soil moisture was generally measured compared to Norway spruce stands due to their relatively high interception (29–69 %) and transpiration. However, the drought stress episodes with the strongly negative soil water potential (≈ -1.5 MPa) were identified rather exceptionally and exclusively in forest stands and in upper 10 cm of mineral soil. We conclude that the loss of forest cover, which temporarily occurred because of the bark beetle outbreak, does not have a fundamental impact on the development of soil moisture – at least there is no “drying out of the landscape”. The potential issue is rather the reduction in the retention capacity of soils to absorb larger amounts of torrential rainfall due to higher water reserves in the soil in clear-cut locations and reduced interception.