Adapting water management along forest roads to climate change: A survey study among German experts

• Relevant measures for adapting drainage of forest roads to consequences of climate change were compiled for implementation in practical forestry operations. • Evaluation of the feasibility and necessity of the measures mentioned by experts. • In combination with a previous literature review ( https://doi.org/10.1007/s10342-02501777-2 ), areas for further research were identified. These include, e.g., investigating the usefulness of individual measures, but also in combination towards climate change adapted forest road water management. Progressing climate change makes it imperative to adapt existing forest road systems. Decentralizing drainage with the aim to reduce accumulation of surface run-off is expected to enhance the availability of water in forest ecosystems and to mitigate risks of road damage and flooding. To identify and evaluate potential and relevant measures for managing road run-off, we conducted a survey among eleven German forest road experts. The questionnaire covered 42 questions over five categories: (1) Road decommissioning, (2) Segments prone to damage by water due to gradient, (3) Ditch relief, (4) Crossing structures, and (5) Timber extraction. Participants were recruited from the “committee for forest access” and have extensive experience (mean of 19 years) with practical measures for drainage and water management. Their accumulated area of operation (2.2 Mio. ha) is representative of 19.1% of the forested land in Germany. Our survey showed that most experts incorporate measures for adapting forest road infrastructure to climate change. Of the eleven experts consulted in this study, nine actively pursue reduced ditch relief culvert spacing. Further measures mentioned include using off-take-ditches, adapting stream crossings to increased peak flows, intensifying maintenance, and disconnecting ditches and streams. Roads with an outsloped cross-sectional profile and the decommissioning of road segments in general, are not preferred strategies. Besides discussing survey results, potential follow-up research possibilities are presented. The development of specialized GIS tools could facilitate the practical implementation of the proposed measures. While this study’s results reflect the input of only a select few experts, the results help to outline existing measures for managing forest road systems under climate change conditions and support decision makers in other regions.