Silviculture as a tool to support stability and diversity of forests under climate change: study from Krkonoše Mountains

In Europe, warming, droughts and the rise of extreme climate events have an increasing significant negative effect on forest stands. Therefore, it is necessary to create appropriate adaptation strategies of silviculture to mitigate the impacts of global climate change on forest ecosystems in Central Europe. The objectives of this paper were to evaluate stand production, structure and diversity on eight experimental research plots in the Krkonoše Mountains. Subsequently, three variants of management were compared in mixed stands at the age of 17 – 20 years originating from natural regeneration: A) control variant (stands before thinning), B) applied newly designed thinning in the context of climate change adaptation and C) simulative thinning from below. Number of trees decreased from 3,256 trees ha⁻¹ by 32% after adaptation thinning and by 36% after thinning from below. The basal area decreased in variant B by 22% and in variant C by 12%. Structural diversity and tree species richness increased after application of adaptation thinning, while decrease of diameter differentiation and total diversity was observed after thinning from below. Moreover, horizontal structure changed from aggregated spatial pattern to random distribution after the interventions, especially under adaptation thinning. The newly designed structuralizing adaptation thinning method seems to be a more suitable option in given habitat and stand conditions compared to the commonly performed thinning from below. In future, this issue will certainly require further close cooperation of forestry experts in order to arrive at optimal variants of solutions differentiated according to specific conditions.