Legacies of human land use impacts in central European forests

Forests are generally considered relatively near-natural ecosystems, despite often experiencing fairly intensive uses, including conversion of the main tree species and intensive management. In Central Europe, it can be assumed that continuously forested areas remained for thousands of years only in locations inaccessible to humans (e.g., steep slopes). For most other forested areas, it is obvious that they were completely or partly deforested at least once in the past and used as non-forested land (e.g., arable land or grassland). The wide distribution of historical arable fields (e.g., Celtic fields or ridges-and-furrows) throughout Europe is the best confirmation of this belief. Particularly in the last two decades, the long-lasting effect of previous non-forest uses on patterns and processes of abiotic and biotic parameters of currently forested areas has been studied more intensively. In parallel, the research field of historical ecology, which is not new in itself, has received increased attention and is considered significant to the further study of ecosystems and landscapes. Due to the large number of existing publications, it is possible to summarise the results to date and to identify research gaps that still exist. This information was compiled and is contained in the five sections in this paper. Definitions and procedures are presented in section 2, which is divided into subsections on the definition of landscape legacies, human interventions and time frame establishment (subsection 2.1) and the search and selection of publications (subsection 2.2). The findings on aboveground and belowground legacies (section 3) are presented separately for vascular plants and cryptogams (subsection 3.1), animals or animal communities (subsection 3.2), topographic features (subsection 3.3), soil chemistry and soil biological activity (subsection 3.4), and biomass and tree growth (subsection 3.5). In section 4, these issues are discussed in connection with research questions that have not been answered or have only been answered incompletely. Finally, essential conclusions are concisely provided (section 5). Research domain: Ecology of Agricultural Landscapes Research question: The main objectives are (i) to provide a comprehensive overview of published studies and to compile them in publicly accessible files, (ii) to summarize the most important results, (iii) to identify research gaps, and (iv) to discuss important questions for future research on the topic.