Master Thesis

Species-specific tree recovery from the 2018 drought considering abiotic factors

Valeska Schönlau (09/2021-03/2022)

Support: Carl Beierkuhnlein, Mirela Beloiu Schwenke

The 2018 drought was exceptional in terms of its severity and duration in Central Europe and forests in northern Bavaria showed distinct drought stress-induced damage. With climate change, drought events like this are very likely to increase in the future, leading to stress responses, reduced productivity, and increased tree mortality in temperate forests. The objective of this work is to investigate whether the recovery of common, native deciduous tree species from the 2018 drought is dependent on various abiotic factors. Based on soil and annually collected tree vitality data, the influence of temperature, precipitation, soil available water capacity, pH, soil depth, C/N ratio, rootability, and the amount of each litter and understory cover on species-specific recovery was investigated. The species studied are saplings of European beech (Fagus sylvatica L.), mountain ash (Sorbus aucuparia L.), common hornbeam (Carpinus betulus L.), silver birch (Betula pendula Roth.), sycamore maple (Acer pseudoplatanus L.), common hazel (Corylus avellana L.), and Quercus spp. (pedunculate oak (Quercus robur L.) and sessile oak (Quercus petraea (Matt.) Liebl.). Overall, all tree species show high recovery from the 2018 drought, despite ongoing drought conditions in 2019, with litter, understory vegetation, and winter precipitation having a high influence. This work contributes to the understanding of drought recovery ability under different site conditions of important tree species. These species-specific recovery patterns of broadleaved saplings are important for adaptive forest management to be able to mitigate the effects of climate change.