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Forest thinning can be used as an adaptive measure to improve the growth and resistance of Norway spruce forests affected by climate change. The impact of different thinning intensities on sap flow, growth, and tree water deficit of 40-year-old Norway spruce was tested. High thinning intensity (-61% of basal area) resulted in increased tree-level sap flow compared to the control (+27%), but it caused a decrease in the stand-level transpiration (-34%) due to reduced leaf area index. Low-intensity thinning (-28% basal area), high-intensity thinning, and control showed similar responses of sap flow to vapour pressure deficit and global radiation, suggesting unchanged isohydric behaviour. Both low- and high-intensity treatments displayed greater radial growth than the control. There were no differences in tree water deficit between the treatments. The low-intensity treatment can be considered the best water utilisation treatment with increased growth and unchanged transpiration at the tree level. The high-intensity treatment had similar radial growth as the low-intensity but lower stand-level transpiration, implying improved soil water availability. The study expands the ecophysiological understanding of thinning as a valuable silvicultural practice for adapting forest management of Norway spruce to the effects of climate change. [ABSTRACT FROM AUTHOR]

European beech is one of the most common tree species in Europe and is generally suggested to play even more of a prominent role in forestry in the future. It seems to have the potential to partially replace Norway spruce, as it is less sensitive to expected warmer and drier conditions. It is, however, not well known in which regions these new plantings would be particularly favourable and if specific provenances may be better adapted to the new conditions than others. Therefore, we estimated the potential early height growth under climate conditions in 2040–2060 for 20 beech provenances across a region covering the Czech Republic and Slovakia. This Central European region is expected to experience considerably drier and warmer conditions in the future. For this exercise, we implemented a new neural network model developed from height growth information obtained from the open-access BeechCOSTe52 database. The simulations are driven by past and future climate data obtained from the WorldClim database of historical climate data and future climate projections. Simulations revealed that provenances originating from drier regions performed on average significantly better than those from regions with good water supply. Moreover, provenances originating from drier regions had a particularly large advantage in the relatively arid regions of Central Czechia and Southern Slovakia. We can also confirm that all provenances showed a high phenotypic plasticity of height growth across the whole investigated region. [ABSTRACT FROM AUTHOR]

• Eddy-covariance was used at two forest sites disturbed by windthrow with contrasting management. • Unmanaged site showed greater gross primary production but also higher ecosystem respiration. • Both sites showed similar levels of evapotranspiration. • The managed site had lower gross but higher net water-use efficiency compared to unmanaged site. • The unmanaged site turned into net carbon sink 17 years after windthrow. Windthrow is a major forest disturbance source in Europe. The impact of management (salvage logging) and no-management (deadwood left in ecosystem) treatments on carbon and water fluxes of Norway spruce stand affected by windthrow were analysed. The net ecosystem production (NEP), gross primary production (GPP), ecosystem respiration (R eco) and evapotranspiration (ET) were measured with eddy-covariance tower during 2019–2022 period. Additional chamber gas-exchange measurements, and vegetation inventory were performed. The unmanaged site had greater vegetation diversity and plant abundance, with higher leaf area index (LAI). The managed site showed overall higher NEP, lower GPP, lower R eco , lower GPP based water-use efficiency (WUE GPP), but higher NEP based WUE NEP , compared with unmanaged site. The ET showed no clear trend between the two treatments. The higher GPP of unmanaged site can be linked to greater abundance of herbaceous species, which showed significantly higher photosynthetic capacity than the tree species. Moreover, the higher WUE GPP of unmanaged site can be affected also by the higher LAI of the unmanaged site. Nevertheless, if the R eco is accounted for in WUE NEP , the differences between sites are reversed and the unmanaged site had lower WUE NEP compared to the managed site. The option to leave the disturbed site without management leads to more productive ecosystem (GPP), with greater species diversity and abundance, but also with greater R eco and lower WUE NEP. The discrepancy between WUE GPP and WUE NEP suggests that studies analysing natural ecosystems affected by disturbances should use WUE NEP to account for R eco carbon losses and avoid mis-interpreting the ecosystem carbon-water balance with WUE GPP. [Display omitted] [ABSTRACT FROM AUTHOR]