Zwanzig, M. | Search bioRxiv

bioRxiv2026

Reforestation under climate change - a cross-regional deadwood retention experiment to develop multifunctional forests on disturbed Norway spruce areas

The impact of extreme weather events such as droughts, heatwaves, storms and the associated intensification of bark beetle outbreaks in Norway spruce forests in recent years, has led to a large-scale forest loss in Central Europe. There are various options for post-disturbance management, from complete clearing to no intervention, but their pros and cons - in the context of multifunctional forest management - are not resolved. The "ResEt-Fi" project ("Pioneering reforestation: Regional management for establishing multifunctional forests on post-disturbed Norway spruce areas") consortium implemented a cross-regional field trial to test how specific practices of deadwood retention affect the ecological conditions and subsequent reforestation dynamics of natural regeneration and planted trees. It aims at generating climate-stable mixed forests within an ecological valuable transition, balancing ecosystem functioning and socio-economic benefits. As an outcome for stakeholders and forest practitioners, guidelines and showcase scenarios for facilitating the selection of management procedures will be created. In this article, we provide insight into (i) the applied post-disturbance deadwood management practices and the rationale for their selection, (ii) the experimental setup of our cross-regional field trial, (iii) the initial post-disturbance status and perspective with respect to regional site conditions and deadwood treatment. While the setup and site conditions will primarily serve as a reference for subsequent studies in our joint project, this is the first systematic, cross-regional study on the effects of the management options standing deadwood, high stumps and clearing on microclimate, biodiversity, and tree regeneration in the critical early stages of forest regeneration after disturbance.

ecology↗

bioRxiv2020

Self-organisation and persistence of antibiotic resistance in evolving plasmid communities

A key source of genetic variation of microbial populations are plasmids: extrachromosomal genetic elements that replicate autonomously and can be highly mobile between individual cells. Diverse plasmids were found in environmental samples and bacterial populations. Here we explore the mechanisms that help to preserve this gene pool as a fundamental basis for bacterial adaptation. An individual-based model of the plasmidome is presented and used to investigate how intra- and intercellular competition between diverse plasmid types affects the evolution of plasmid communities. It indicates the relative importance of stochastic and deterministic drivers of plasmid persistence both under neutral conditions and when the environment selects for specific plasmid-encoded traits such as antibiotic resistance for a certain period of time. We found that evolving plasmid communities exhibit a cyclical dynamics that contributes to the maintenance of plasmid diversity and the persistence of costly plasmid-mediated antibiotic resistance after stopped abiotic selection.

ecology↗