In recent years, wildfires have affected relatively large areas of managed forests in Central Europe. Often, forestry uses intensive post-fire management practices, which can have negative effects on various components of the ecosystem. Fire ecology has been largely neglected in Central Europe and strategies for appropriate management and successful reforestation of burned areas are urgently needed. We have studied the effects of different post-fire forest management treatments (including different levels of salvage logging and soil disturbances such as ploughing or raking) on soil parameters (phosphorus, nitrogen, calcium, potassium, magnesium, pH), microclimate (temperatures, vapour pressure deficit (VPD), heat and drought stress), deadwood, regrowth (biomass of tree regeneration, herb and bryophyte layer) and species richness (plants and saproxylic beetles) 3 years after wildfire in a Central European Scots pine forest (northeast Germany). Intensive forest management led to more unfavourable abiotic conditions, including stronger temperature extremes and elevated VPD. Consequently, vegetation on these sites experienced increased heat and drought stress and reduced nutrient availability. The biomass of the herb and bryophyte layer, as well as the species richness of plants and saproxylic beetles, was lower on completely salvage logged sites. Tree biomass recovered on all sites, including sites with intensive forest management. Tree regeneration in our study area was mainly driven by the recolonization of the pioneer species European aspen (Populus tremula), which can tolerate a wide range of site conditions. Synthesis and applications. We recommend avoiding intensive management on burned sites, such as complete salvage logging or ploughing, as this creates extreme site conditions that could inhibit the regeneration of more sensitive tree species and result in a long-term legacy of degradation. In addition, herb and bryophyte layers, as well as the species richness of vegetation and saproxylic beetles, which are important components of forest ecosystems, are negatively affected by intense forest management.

We present the data recorded by eight institutions within the PYROPHOB project, running from 2020 to 2024 at two forest research sites in the south-west of Brandenburg, Germany. The aim of the project was to monitor abiotic and biotic parameters of forest regrowth under different management regimes on former wildfire sites in northeastern Germany. The observations comprised intermittent and continuous measurements or surveys on meteorological parameters (rainfall, temperature, vapour pressure deficit), soil (soil type and texture, soil chemistry and leaching, water content, soil temperature), deadwood, stand structure, vegetation regrowth, abundance of selected fauna (moths, beetles, mammals), UAV-based remote sensing (stand structure, spatial overview), and photo monitoring (succession). Thus, the multitude of collected data allows not only for detailed analyses of these observables separately, but also considering their interaction for a more multidisciplinary view on forest recovery after a wildfire. The data are available under the following DOIs: https://doi.org/10.23728/b2share.08a6a8b56f774a08a984871e7ef1b5a8 (Part 1, Schmehl et al., 2025a), under embargo until 31 March 2026 (Part 2, Schmehl et al., 2025b), https://doi.org/10.23728/b2share.de1661761da5481f938caf460e4f0ca9 (Part 3.1, Schmehl et al., 2025c), and https://doi.org/10.23728/b2share.51bdf4b6dc854873b6ff44fdddbf4c3b (Part 3.2, Schmehl et al., 2025d).

Fire is increasingly posing a risk to forests and plantations, even in the temperate latitudes of central Europe. Little is known about fire ecology in this region, and therefore, appropriate approaches for the management and reforestation of burned sites are mostly lacking. In a Scots pine plantation region in Brandenburg (northeast Germany), the early tree regeneration of two nearby areas that burned 1 year apart was investigated. We observed that 3 years after the fire events, the forest in one study area showed a relatively high regeneration with a mean density of 7765 saplings/ha, clearly dominated by European aspen (93%); whereas the other study area showed a lower mean density of 5061 saplings/ha, dominated by Scots pine (71%) and aspen (15%). Three years after the fires, the difference in aspen density was 11‐fold between the two areas. We studied the effects of several variables about soil and environmental properties on the aspen establishment in these two study areas in the second and third years after the fire events. We found that the post‐fire aspen regeneration was influenced by several factors, including soil texture, soil disturbance from forest management, volume of deadwood, and browsing. We also discussed that weather conditions during seed production and germination might have played a role in the difference in aspen establishment between the two study areas. We concluded that the post‐fire forest regeneration potential in the study region is highly variable and could come under critical pressure as climate change progresses.

PYROPHOB (fire-resistant) is the name of an interdisciplinary research project that is running for five years from 2020 to 2025. In this project, eight institutions are investigating the ecological effects of wildfires and subsequent forest management strategies in pine forests (plantations) in Brandenburg (NE Germany), with the aim of formulating practical recommendations for managing fire-prone forests and the effective restoration of post-fire forest areas. We provide a brief overview of what is known about the effects of wildfire on abiotic and biotic parameters in temperate pine forests, as well as the effects of silvicultural treatments. To date, we know little about how different components of biodiversity are linked in post-fire forest ecosystems and how management affects their functioning. By describing the project, we illustrate the requirements for the implementation of such an applied research project. We emphasize the importance of the study design for dealing with interdisciplinary questions and for the quantitative synthesis of research results. The project comprises a set of standardised field plots in two wildfire areas covering different post-fire management options.Fifteen study sites were established, including two reference sites in unburned pine stands, each with ten study plots as replicates. In situ nitrogen mineralisation, litter decomposition tests and soil biological activity are used for soil biological characterisation. Microclimate data is measured continuously. Standing and lying dead wood and tree regeneration are recorded as key indicators of the success of forestry treatments. Further methods com-prise terrestrial laser scanning, remote sensing techniques as well as surveys of vegetation and above and below ground biomass. Identification of fruiting body-forming fungi, phytoparasites and ectomycorrhizal fungi is supported by marker gene sequencing. Faunistic indicators comprise predatory soil arthropods (pairs of emergence tents and soil traps), saproxylic beetles (flight traps and funnel traps), moths (automated window traps), mammals (camera traps), and breeding birds (visual and acoustic observation). We discuss the strengths and limitations of the project design. We are able to systematically capture short-term temporal shifts in parameters and trends in post-fire ecosystem development. Research in a real landscape with ongoing environmental changes and interventions pres-ents challenges for experimental design, data analysis and interpretation. The drivers of ecosystem development are rarely completely independent or perfectly balanced, and lack of replication is ine-vitable. The two fires did not occur in the same year and season, resulting in different initial conditions for the colonisation of the burned areas. Finally, a large part of one study area was again affected by a fire in 2022, which destroyed direct comparability with the other sites. Despite these obstacles the project has started to generate valuable results to address management and conservation challenges

Severe disturbances of landscapes entail an ecosystem development with the formation of structures and functions which may reach either a new equilibrium state or a state similar to the original ecosystem. Natural disturbances can result from major events such as volcanoes, glaciers, or denudations from landslides. Major disturbance may also evolve from anthropogenic influences such as from mining operations. They all can be considered starting points for the development of ecosystems from 'point zero', which was one central research interest of Dieter Mueller-Dombois. In this paper results from research in the Lusatian post-mining landscapes (Eastern Germany) are presented. Different methodological approaches are discussed. The well-defined 'point zero' of the ecosystem development allows for research on chronosequence designs as well as real time series studies. Chronosequences have been investigated to gain insight into the medium to long-term direction of the development. Real time series are recorded to obtain a more detailed understanding. The paper is structured into three main parts: First, effects of ecosystem disturbances by mining in Lusatia and the initial conditions for restoration are presented. In the following part practical rehabilitation measures and land use options are discussed. Finally, the third part summarizes results of long-term monitoring in an artificial watershed. In conclusion, post-mining landscapes allow for relevant case studies of ecosystem development after severe disturbances. Particularly, the starting point of the initial phase is very well defined which distinguishes these anthropogenically disturbed landscapes from landscapes after natural disturbances.

III Congreso Ibero-Latinoamericano MAD de la Madera en la Construcción (CIMAD 24) : Libro de Actas de Resúmenes Extendidos

Erosion is often mentioned as a serious problem namely in vegetation free areas such as post mining soils. Much less attention has been paid to the role of erosion and deposition on habitat formation. Study describes the effect of erosion and deposition on soil chemical and physical properties in sites with various topography using an array of artificial postmining catchments located near Sokolov (Czech Republic). All the study sites are formed by the deposition of postmining overburden consisting of clays impregnated with carbonates. Falcon was established in 2019 and allows a detailed assessment of the first stages of ecosystem development. It consists of four parallel catchments (0.25 ha each); two are rehabilitated, and two are not. The reclaimed areas are leveled and planted with alders, whereas the unreclaimed sites created longitudinal terrain waves to mimic the situation after heaping. Detailed surface change studies by means of erosion pins and 3D terrain models created with the help of drones revealed that the surface elevation rises in the flat catchments and decreased in the wave-like catchments. In contrast, sediment loss through surface runoff shows no difference between the flat and wave-like areas. Considerable heterogeneity in the erosion process is observed in wave-like areas; the upper part of the terrain waves is heavily eroded, while eroded material accumulates in the depression. The depressions contain more silt and clay material and have higher water retention rates and lower infiltration rates, whereas the opposite is true for elevated wave tops. Study show that erosion and deposition play key role in microhabitat formation, which can be crucial in future ecosystem development.

Background The decision of the German federal government to cease lignite mining until 2038 or—if possible—already earlier until 2030, will cause manifold transition processes in the remaining lignite mining districts of Germany. The two largest districts are located in geographically opposite regions: The Rhineland in the western part and Lusatia in the east of Germany. As particularly these two mining districts will experience severe changes in their socioeconomic as well environmental conditions, the federal government has adopted comprehensive economic support measures. However, the environmental changes will also cause altered ecosystem functions and services to be provided by the future post-mining landscapes. Results In this paper, the two main lignite-producing regions of Germany are compared with regard to their natural and cultural settings. The economic situation and its history are reflected and differences are outlined. Part of the disparities in the cultural development can be explained by very different natural conditions, especially edaphic factors and climatic situation. Because of dissimilar geological settings, different mining technologies were developed and are in use in the two regions with distinct effects on the resulting post-mining landscapes. Conclusion The long-standing and manifold lignite mining activities have radically restructured the landscapes in Lusatia and the Rhineland. With the ongoing decline of the mining industry and its complete cessation, presumably within the next decade, both regions will alter their faces significantly. These changes offer both challenges but also opportunities with respect to the post-mining landscapes and their ecosystem services they are going to provide. The prerequisites for a positive socioeconomic development and for sustainable land-use concepts that also consider ecological aspects are different for both regions. However, or especially because of these differences, the knowledge exchange and experience transfer between both mining regions are pivotal for the success of this extensive transformation process.

15 years of initial ecosystem development have been observed in the artificial Chicken Creek Catchment in Eastern Germany (State of Brandenburg). The 6 ha site was constructed in 2004/05 as a watershed within a post-mining landscape and was left for an unmanaged primary succession. The number of plant species increased quickly during the first years parallel to an increasing groundwater table within the catchment. In 2014 a total of about 180 vascular plants were identified in this young ecosystem. During its development vegetation differentiated according to morphological and soil related conditions. The semiaquatic part around a small pond developed differently compared to the upper, terrestrial part. In this terrestrial part Robinia pseudoacacia L. early occurred as a pioneer tree species. Large surface areas, however, remained open land areas without tree or shrub vegetation. Robinia as a N-fixing tree species accumulates nitrogen in its litter layer at the soil surface which influences the further vegetation development in these parts of the catchment. Furthermore, Robinia together with other tree species contributed obviously to a significant groundwater lowering in the constructed catchment area. This decrease of the groundwater tables in the study area was intensified by two extremely dry summer seasons (2018 and 2019). As a result, the overall composition of the vegetation in the terrestrial part of the catchment changed slightly indicating dryer conditions particularly for herbaceous plants. Initial abiotic site conditions (geomorphology and soil conditions) in combination with external abiotic drivers (amount of precipitation) shaped the development of plant communities. Vice versa, the occurrence of plant species with specific functionality (N-fixation and high water consumption) contributes to a further spatial differentiation of the vegetation composition. The constructed Chicken Creek catchment as an artificial landscape unit allows for detailed insights into these ecological differentiation processes of the initial developmental ecosystem phase.

Exploring hydrological and ecological processes plays a key role in understanding ecosystem developments. In this respect, the constructed catchment, Chicken Creek, has been established for fundamental and interdisciplinary scientific research. Since 2005, an ongoing monitoring program has been launched to measure hydrological, biological, meteorological, and pedological parameters during the ecological development of the site. This comprehensive and multidisciplinary monitoring program has produced a diverse large data set. Handling such complex data for research purposes can be a cumbersome task. Consequently, we developed an online data portal (https://www.b-tu.de/chicken-creek/apps/datenportal/) to efficiently handle the data from Chicken Creek catchment. The portal was constructed using Shiny package of the R programming language. This platform provides a web-based data repository allowing for data discovery, download, visualization, and analysis. The data include time series of different parameters from installed sensors, data from laboratory analyses, vegetation data, data from sampling campaigns, and aerial photos. This platform demonstrates the relevancy and potentiality of the R-Shiny for constructing an online data portal to be used for multidisciplinary scientific purposes. The Chicken Creek data portal thus provides a comprehensive and reliable database to give scientists a fast and easy access to all collected data.

After completion of the construction in 2005 (Gerwin et al. 2009), a major challenge was to develop and install a cross-disciplinary long-term monitoring program for the 6 ha area to record major environmental parameters adapted to the development of the site (Schaaf et al. 2013). During its first 15 years, Chicken Creek showed a very dynamic development (Elmer et al 2013). Whereas the abiotic geosystem of the first 2-3 years was characterized by heavy erosion and sediment transport, primary succession by invading vegetation and the unexpected formation of soil crusts within few years resulted in more biotic-abiotic feedbacks that controlled catchment hydrology. Our observations over a period of 15 years indicate that even minor variations in initial substrate characteristics (e.g. texture) can have lasting impacts on geomorphical, hydrological and biological development like erosion intensity, groundwater levels or establishment of vegetation patterns. The time-series of monitoring data combined with a structure model of the catchment (Gerke et al. 2013) allowed the closure of the water balance by relatively simple calculations of water storage volumes and the estimation of evapotranspiration (Schaaf et al. 2017). From these data three stages of ecosystem development were derived which are characterized by increasing influence of biota and increasing system complexity.

The Huehnerwasser catchment was constructed 2004-2005 in a post-mining landscape in Eastern Germany and was left for an unmanaged primary ecosystem succession. At the same time a comprehensive monitoring program was launched for observing the expected dynamic development of this 6 ha site. During the following years this artificially created system was subject to a series of fast changes with regard to morphology, hydrology or vegetation cover. In summary, these processes resulted in significant alterations of the original, initial system within a short period of time. This development can be divided up into single phases with dominating processes or groups of processes. A first phase was mainly characterized by interactions between abiotic system components such as water and substrate. However, already in this very early developmental phase biotic components in the form of microorganisms were a crucial system forming factor by means of biological soil crusts. This period was quickly replaced by a second phase with dominating hydrological processes. During this phase the local groundwater body of the system developed to its full extent. With the beginning of the present phase biota gained control of the system behavior. Particularly plants and related processes such as water uptake and evapotranspiration are now responsible for new modifications of the system. The Huehnerwasser site offers an example of young and highly dynamic ecological systems. This transitional development of a very young ecosystem contrasts with the behavior of mature ecosystems with slow and less pronounced changes unless the system is disturbed. In this paper we present insights into a unique landscape observatory which illustrates the dynamic nature of natural systems in fast motion.

Landscapes and ecosystems are complex systems with many feedback mechanisms acting between the various abiotic and biotic components. The knowledge about these interacting processes is mainly derived from mature ecosystems. The initial development of ecosystem complexity may involve state transitions following catastrophic shifts, disturbances, or transgression of thresholds. We propose a conceptual framework of feedback processes in early states of ecosystem development affected by spatiotemporal environmental drivers. To test this concept, we used 10-year time series of hydrological, biological, geomorphological, and soil data from the constructed catchment Chicken Creek.” The 6ha site was left to unrestricted development since 2005 and was intensively monitored. The data showed a very rapid development of the site with an increasing complexity and heterogeneity. In the first years, stochastic signals like the initial substrate conditions and external drivers like extreme weather events were the most important factors resulting in abiotic/abiotic feedback mechanisms shaping the morphology of the site and creating site diversity. Initial abiotic feedback mechanisms between water and substrate were soon followed by abiotic/biotic feedbacks between biological soil crusts, invading vegetation, geomorphology, and hydrology resulting in state transitions of catchment functioning.

The cultivation of bioenergy plants in fertile, arable lands increasingly results in new land use conflicts with food production and cannot be considered as sustainable. Marginal lands have been frequently considered as potential alternatives for producing bioenergy from biomass. However, clear definitions and assessment methods for selecting marginal lands and for calculating potentials are still widely missing. The project “SEEMLA” aims at triggering the exploitation of currently underused marginal lands for biomass production for energy purposes. Study sites have been selected in different European countries: Germany, Greece, and Ukraine. The selected sites represent a wide variety of different types of marginal lands. Based on a soil assessment set given by the Muencheberg Soil Quality Rating (SQR) system potentially “marginal” sites have been investigated. The SQR system allows for clearly distinguishing between soils of higher and lower quality. Soils with SQR scores below 40 are regarded as “marginal”. They can be classified into different groups with regard to the importance of soil hazard indicators as evaluated by the SQR approach. The calculated SQR scores correlate significantly with biomass yields of bioenergy plants. Further, the SQR method was adapted for use in a GIS study on marginal-land potentials in Europe. Thus, 46 % of the investigated European area could be classified as “marginal” with SQR scores below 40. From that area 22.6 % can be considered as potentially suitable for producing renewable resources after eliminating protected sites or other places not suitable for any kind of land use. Taking the ecological demands of selected bioenergy plants into account it is possible to give first preliminary recommendations for regional crop cultivation. It can be concluded that Europe offers a large potential for renewable resources from marginal sites. However, the implementation into practice is often impeded by missing or varying policies and regulations. A proper implementation needs clear regulations and also incentives for farmers at the European level.

General comments: The paper presents a methodology to assess and map marginal lands for biomass production for energy purposes using Muencheberg soil quality indicators (SQR) framework and GIS procedures. The demonstration of practical applicability of bioenergy production on marginal areas is carried on six European case study sites representing different types of marginal lands, method of bioenergy production and climate regimes. Moreover, SQR method is adapted for GIS analysis by means of pre-existent European database. As such, marginal lands potentials available for biomass production and for certain bioenergy crops have been mapped and quantified across Europe. The objective of the study is of outstanding interest not only for the scientific community but also for supporting European policies to identify areas

Das Huhnerwasser-Einzugsgebiet ist ein 6 ha groses, kunstlich geschaffenes Wassereinzugsgebiet im Tagebau Welzow-Sud in Sudost-Brandenburg. Das Zweischichtsystem mit einer Ton- und einer daruber liegenden Sandschicht wurde im Jahr 2005 fertiggestellt und ohne weitere Rekultivierungsmasnahmen fur Forschungszwecke bereitgestellt. Es lasst exemplarisch die Untersuchung der initialen Landschaftsgenese zu. Insbesondere die Entwicklung von einem zunachst noch abiotisch kontrollierten hin zu einem biotisch gesteuerten System lasst sich hier beobachten. In diesem Beitrag werden beispielhaft einige in diesem Kontext aufgetretene Interaktionen zwischen abiotischen und biotischen Strukturelementen vorgestellt. Dies sind zum einen Erosions- und Sedimentationsprozesse und ihre Wechselwirkungen mit der Vegetation. Zum anderen wird der Einfluss der Vegetation auf die Grundwasserentwicklung dargestellt.