BMBF-REGULUS-Project "ResEt-Fi"

As part of the funding measure REGULUS (regional innovation groups for a climate-protective forestry and wood industry), initiated by the German Federal Ministry of Education and Research, the research project "ResEt-Fi" focuses on studying variants of silvicultural management with the intention of establishing multifunctional forests on disturbed areas of spruce. The interdisciplinary research consortium consists of several universities and research institutions in Germany, which form the following sub-projects:

• Sub-project 1: Overall Coordination (Forestry Research and Competence Centre (FFK) Gotha, ThüringenForst AöR)
• Sub-project 2: Remote Sensing (Georg August University of Göttingen)
• Sub-project 3/1: Soil Science (Friedrich Schiller University Jena)
• Sub-project 3/2: Vegetation (Friedrich Schiller University Jena)
• Sub-project 4: Microbial Diversity and Ecosystem Processes (University of Bayreuth)
• Sub-project 5: Zoology (Hessian Agency for Nature Conservation, Environment and Geology)
• Sub-project 6/1: Silviculture (TUD Dresden University of Technology)
• Sub-project 6/2: Modelling (TUD Dresden University of Technology)

With thorough monitoring and targeted field trials on research sites in Thuringia, the project consortium studies the effects of practical variants of forest management on microclimate, soil, flora, fauna and fungi. In addition, a site-specific and economic evaluation is performed, which is highly relevant for forest practitioners. The overarching goal is the development of a holistic management approach for disturbed spruce forests and the compilation of practical recommendations and action plans for reforestation under consideration of important forest functions and ecosystem services. The developed concepts combine the findings of the different sub-projects on the local scale of the research sites, and are accompanied by a transfer from the local to the regional scale (sub-project "Remote Sensing" at the University of Göttingen) as well as modelling of reforestation dynamics. The holistic view is especially based on the combination of diverse research approaches.

Research design of the project


Figure 1: Silvicultural management variants of disturbed spruce areas: (a) clearing, (b) high stumps and (c) standing deadwood patches.

To gain robust findings, investigations are carried out on plots with different variants of silvicultural management, implemented in cooperation with the responsible forestry offices, in three regions with three areas (repetitions) each. The studied regions are low mountain ranges in Thuringia: Southern Harz Mountains, Thuringian Forest and Thuringian Slate Mountains. Within the three areas in each region, the following management variants are examined (Figures 1 und 2):

• Clearing (complete removal of dead spruce trees)
• "High stumps" (dead spruce trees, cut at a height of 2 to 4 meters)
• Standing deadwood patches (partially cleared areas with a chessboard-like arrangement of standing dead spruce trees, which no longer pose a risk of spreading bark beetle infestation)

As a reference, each area also includes plots of intact spruce forest. In addition to the mentioned management variants, the effects of natural and artifical regeneration as well as deadwood variations are studied.


Figure 2: Research design with examined variants of silvicultural management.

All research areas share a common instrumentation. Climate stations (Figure 3) continually measure air temperature, humidity, precipication, global irradiance as well as wind speed and direction in all management variants. Microclimatic data loggers record the air temperature near and at the soil surface as well as soil temperature and moisture. Based on this continuous data, microclimatic differences between the variants can be assessed with regard to the potential for a successful and sustainable reforestation.


Figure 3: Climate station for continuous recording of the local climate in different management variants, exemplified in the variant "high stumps".

Sub-project "Remote Sensing" within the research project
The junior research group Landscape Resilience is involved in the ResEt-Fi project with its sub-project on remote sensing. This participation is a direct continuation and extension of a cooperation with the Forestry Research and Competence Centre (FFK) Gotha, ThüringenForst AöR, in the "Dürrständerinitiative", in which a monitoring of dead spruce stands has been established since the year 2021.

The remote sensing sub-project has the following aims:

• Characterization of feedbacks between microclimate and vegetation development depending on management variants
• Multi-scale analysis – from the plot level to the regional scale
• Assessment of biogeophysical effects of post-disturbance management and upscaling

With the continuous measurements at the ground conducted in the ResEt-Fi project as well as remote sensing methods, both satellite- and UAV-based, changes in the land cover and land use "forest", like a loss of vitality, widespread dieback, reforestation and succession, as well as consequences for the microclimate can be quantified. In particular, a combination of different sensor technologies, such as optical and thermal remote sensing, is supposed to contribute to the evaluation of the areas' development on a regional scale on the way to a land use form that offers a higher level of adaptation to climate change. Especially the upscaling of findings from the local scale of the plots to the regional scale can contribute to the development of practical recommendations for the post-disturbance management of disturbed spruce forests under different site conditions.