Tree trait-mediated differences in soil moisture regimes: A comparative study of Beech, Spruce, and Larch in a drought-prone area of Central Europe

Abstract

Abstract Species-specific tree traits substantially impact precipitation partitioning, soil infiltration, retention, and overall water management. With the changing climate, the evidence of drought-induced tree mortality is increasing, indicating the need for a shift to more resilient species. Therefore, the knowledge of tree species' effect on soil-water management is needed. We used a total of 54 stations for monitoring the soil moisture regimes of silt loam soil in Central Bohemia under three common and different tree species (spruce, larch, and beech). For the dry and warm part of the year 2022, the soil moisture in winter and early spring was significantly lowered by high canopy interception and gradually depleted by early spring transpiration of evergreen spruce, where mean values were more than 15% lower than for beech. Since March, the soil moisture under spruce was already below the limit of easily available water. In contrast, the deciduous beech and larch did not show a significant decrease until the foliage emergence in early May. The beech stands showed the highest soil moisture levels, which we attributed to a more effective water recharge mechanism induced by its structural traits. This adaptive strategy is vital as soil-water storage is critical for coping with climate change. In general, the results show a distinct advantage in the water recharge ability of deciduous trees and that the selection of tree species can distinctly affect soil moisture conditions, especially during drought periods in areas characterized by tight hydrological balance.