We tested the relation between the below- and aboveground tree phenology, determining if beech and oak have a greater fine-root lifespan and a smaller turnover rate than birch and if thinner fine-roots or fine-roots born in spring have a shorter lifespan and greater turnover rate than thicker fine-roots or fine-roots born in another season. The fine-root phenology, bud burst, and leaf senescence in Belgian stands were monitored using minirhizotrons, visual observations, and chlorophyll measurements, respectively. The fine-root phenology and the lifespan and turnover rate were estimated using generalized additive models and Kaplan–Meier analyses, respectively. Unlike the aboveground phenology, the belowground phenology did not show a clear and repeating yearly pattern. The cumulative root surface remained stable for birch but peaked for beech and oak around summer to autumn in 2019 and spring in 2020. The new root count was larger in 2019 than in 2020. The mean lifespan of fine-roots with a diameter below 0.5 mm (308 to 399 days) was shorter than those with a diameter between 0.5 to 1 mm (438 to 502 days), 1 to 2 mm (409 to 446 days), or above 2 mm (418 to 471 days). Fine-roots born in different seasons showed a species-specific lifespan and turnover rate.

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<p>The Svratka river basin represents an important water resource in the South Moravian Region of the Czech Republic. Due to its relatively low aridity index (the ratio of precipitation to potential evapotranspiration), it belongs to river basins sensitive to climate change. This is also supported by significant negative runoff trends over the past 40 years. The aim of this study is to evaluate the impacts of a hypothetical land use change on the hydrological processes of the Svratka river basin. We used a physically based and spatially distributed hydrological model Mike SHE. The Mike SHE model was calibrated and validated using measured river discharge data in the three hydrological profiles in the Svratka basin for the period 1981–2020. Several land use scenarios were tested against the reference scenario (i.e. current land use) to analyze the impacts of land use change. The land use scenarios encompassed the following hypothetical extreme changes where the entire basin in the model was changed to (i) grassland, (ii) mixed deciduous-coniferous forest, (iii) deciduous forest, or (iv) cropland. These extreme land use scenarios were tested for the baseline period 1981–2020 and also for several CMIP6 downscaled climate models and different socioeconomic pathways (emissions scenarios) up to the end of the 21<sup>st</sup> century. The results showed that the evapotranspiration was the highest for mixed deciduous-coniferous forest while the lowest was the grassland scenario and cropland . The lowest total runoff from the river basin was simulated for both forest scenarios (mixed forest and deciduous forest). The results also demonstrated that the dominant loss component for all scenarios of the water balance in the Svratka river basin is evapotranspiration. The sensitivity of the hydrological balance in the Czech landscape was also demonstrated, where a slight increase in the evapotranspiration value in the basin has a significant effect on the total runoff from the Svratka basin. The climate change scenarios additionally suggest further exacerbating the water balance and runoff decline in the region. The results of this study are a first step towards evaluating and designing nature-based adaptation measures to climate change in the Svratka river basin.</p> <p> </p> <p><strong>Acknowledgment:</strong> <br />The research infrastructure and CzechGlobe team was financially supported by the SustES - Adaptation strategies for sustainable ecosystem services and food security under adverse environmental conditions (CZ.02.1.01/0.0/0.0/16_019/0000797). The study was also supported by the Internal Grant Agency of the AgriSciences faculty at Mendel University in Brno (AF-IGA2023-IP-031).</p>

To investigate the different responses of crops to drought stress under field conditions of Central European Climate for selected crop rotations, a field experiment was conducted at a test site in the Czech Republic from 2014 to 2021. Depending on the crop, rainout shelters were placed in late spring and early summer to study the effects of drought in the final stages of crop development. Due to these rainout shelters and the associated lower water availability for the crops during the summer, a reduction in leaf area index, biomass and yield was observed. For example, a yield decrease of more than 30% was observed for spring barley, winter rape and winter wheat compared to conditions without rainout shelters. The reduction was 25% and 18% for winter rye and silage maize, respectively, under rainout shelters. Soil moisture played a significant role in yield, where a predictive model based on monthly soil moisture explained up to 79% (winter rape) of the yield variance.