objective (Subject)	Diversification of forests with indigenous and non-indigenous trees and against the background of cultural history taking the Spessart (Bavaria) as a case study (DIVERS)
content	Since the paradigm shift towards near-natural silviculture in the 1990s, a major goal of current forestry is the conversion or restoration of anthropogenic pure coniferous stands towards more diverse and structurally rich mixed forests. The diversification of forests may be a promising strategy to increase their potential adaptation and resilience to the increasing uncertainties of global (climate) change, to support the conservation and promotion of biodiversity and to ensure the provision of diverse ecosystem services. The diversification of tree species is seen as a viable strategy for the future, particularly, if it can be achieved cost-effectively by natural regeneration. Thus, the conversion of pure coniferous stands into mixed forests can be effectively supported by spontaneously regenerating tree species in addition to the artificial introduction of target tree species. The northern High Spessart with its currently still extensive coniferous stands represents a region in which this can be exemplarily investigated. Extensive vegetation surveys from the 1990s provide a valuable basis for identifying vegetation changes and assessing them against the background of natural ecological processes and management measures. In addition, the abiotic and biotic site factors are to be investigated in their influence on the natural regeneration of the Spessart’s target tree species. In addition to the naturally dominant beech, other natural tree species and in particular the culturally and historically important sessile oak and the non-native Douglas fir are to be examined. The following research gaps are addressed by the study: 1) changes in the vegetation and structure of coniferous stands over the past 25 years under the influence of management measures and climate change, 2) potential of silvicultural integration of culturally and historically important tree species such as oak in the conversion of pure coniferous stands, indicated by natural regeneration, 3) invasion potential of Douglas fir in Central European low mountain ranges.
appropriation period	01.03.2021 - 31.12.2023
funded by	The Bavarian State Institute of Forestry (LWF) by means of Bayerischen Staatsministerium für Ernährung, Landwirtschaft und Forsten (StMELF)
partners	Free University of Bozen-Bolzano
persons in charge	Alexander Seliger
publications	Zerbe S, Lange F, Seliger A, Leitinger G, Ammer C (2023) Wie invasiv ist die Douglasie? Ein Fallbeispiel aus dem Spessart. AFZ-DerWald 16/2023: 30-34 Seliger A, Ammer C, Kreft H, Zerbe S (2023) Diversification of coniferous monocultures in the last 30 years and implications for forest restoration: a case study from temperate lower montane forests in Central Europe. European Journal of Forest Research. DOI:10.1007/s10342-023-01595-4 Seliger A, Ammer C, Kreft H, Zerbe S (2023) Changes of vegetation in coniferous monocultures in the context of conversion to mixed forests in 30 years – Implications for biodiversity restoration. Journal of Environmental Management. DOI:10.1016/j.jenvman.2023.118199 Lange F, Ammer C, Leitinger G, Seliger A, Zerbe S (2022) Is Douglas Fir (Pseudotsuga menziesii [Mirbel] Franco) Invasive in Central Europe? A Case Study from South-West Germany. Frontiers in Forests and Global Change 5: 844580. DOI:10.3389/ffgc.2022.844580