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In the field of instrument making, the use of indigenous wood species is becoming more and more important due to the increasing environmental awareness of instrument makers and their customers. As the properties of some of these wood species cannot meet the high demands of this field of application, processes are being sought that can achieve improvements. In recent years, many studies have shown that different modification methods, such as furfurylation, thermal treatment, densification or impregnation methods, can partly improve wood properties such as elasticity, strength values, damping behaviour, but also moisture behaviour and wood moisture content significantly. The extent to which different modification processes and their positive changes in properties can be combined with each other and thus achieve further improvements will become increasingly important in the future, not only in instrument making but also in other areas of application. Therefore, this study investigated the influence of thermal treatment followed by linseed oil impregnation of wood on its sound propagation velocity and the associated acoustic properties of characteristic impedance and acoustic radiation.
In recent years, a large number of different studies have shown that a variety of positive property changes can be achieved by thermally treating spruce resonance wood. Various methods have been established, which differ mainly in the choice of treatment atmosphere, but also in the associated treatment duration and temperature. Part of the present investigation was to compare a thermal-vacuum process with a process which takes place in an oxygen-reduced atmosphere, with regard to various property changes. The results show that both processes achieved similar results in terms of dynamic acoustic property changes. Larger differences were found with regard to moisture behavior and color change.
Different parts of the guitar body are made of certain wood species, selected by their specific properties. The sound board, which is mainly made of spruce or cedar, transfers the vibration of the strings to the resonance body by means of the bridge. The sides and the back of the guitar rather reflect the sound of the acoustic vibrations and are predominantly made of tropical hardwoods like palisander, mahogany or ebony species. These species have limited availability and are listed on the CITES Annex I and II. To substitute tropical wood species, thermally modified European wood species with improved acoustic properties and dimensional stability may be used. Although the acoustic reflection of the sides and the back parts of a guitar body is an important property, there is not much knowledge about this reflection behaviour of wood. A few studies like the work of Hong (1989), Kang (2010) or Smardzewski et al. (2013) investigated the sound absorption properties of unmodified wood. Subsequently this study considers the sound absorption coefficients of unmodified and thermally modified European wood species in comparison to an unmodified tropical wood species.
To this day, many guitar makers around the world use primarily tropical woods such as rosewood (Dalbergia spp.) for their production. Due to the current CITES regulation of January 2017 regarding the trade of tropical woods, it becomes inevitable to generate alternative materials with similar material properties to be generated and established. Part of this study is an acoustic comparison of two guitars. One made of untreated tropical wood [Dalbergia nigra Benth.)] and one made of European thermally modified wood (TMT) species. [Pyrus (L.) and Alnus (Mill.)]. The method used allows a significant statement about the acoustic radiation performance of stringed and plucked instruments. The experimental setup consists of an impulse hammer for excitation of a force in the center of the bridge and a microphone for recording the signal radiated by the guitar body at a distance of one meter from the sound hole. A front-end was used to record the data, and further processing was done using analysis software to determine frequency response functions (FRFs) of the two instruments. The FRFs determined can be subdivided into several ranges which contain the different acoustic information about bass range, loudness, clarity, brightness and sharpness of the instruments. Examination of the frequency ranges reveals an acoustic similarity between the two guitars. Slight differences can be seen in the bass and loudness areas, where the guitar from TMT has a higher average level. Clearer differences are offered by the areas of clarity, where the guitar made of tropical wood shows a higher average level. In summary, the method gives an efficient acoustic impression as a function of the natural frequencies of the two guitars. The measured data show similarities and thus comparable acoustic properties of the instruments. However, additional effects such as psychoacoustic sensations or musical taste for the complete acoustic impression of an instrument are also of importance. Therefore, further empirical and fundamental research is needed to obtain a more detailed acoustic impression of the instruments.
This work presents an adaptive architecture that performs online learning and faces catastrophic forgetting issues by means of an episodic memory system and of prediction-error driven memory consolidation. In line with evidence from brain sciences, memories are retained depending on their congruence with the prior knowledge stored in the system. In this work, congruence is estimated in terms of prediction error resulting from a deep neural model. The proposed AI system is transferred onto an innovative application in the horticulture industry: the learning and transfer of greenhouse models. This work presents models trained on data recorded from research facilities and transferred to a production greenhouse.
In Eastern Europe, several UNESCO Biosphere Reserves (BRs) have been important promoters of transnational and transboundary nature conservation and sustainable development. Nevertheless, political and institutional barriers and scarcity of resources have hindered successful cross-border cooperation. The prospects for BRs in Eastern Europe are mixed, especially in relation to the challenges of ecosystem degradation and climate change, as well as socioeconomic and (geo)political crises. Based on our own experience of one and a half decades of growing cooperation between partners in Ukraine and Germany, we conclude that transnational cooperation between BRs and science is particularly rewarding and mutually beneficial.
The muskrat is a neozoon species that has occupied many countries of continental North Europe after its introduction from north America as fur animals. Due to its burrowing activity it damages river and canal banks and structures of flood control. For this reason, the eradication of this alien species is recommended. Muskrats are also of parasitological interest since they can act as suitable intermediate hosts for Echinococcus multilocularis. On the other hand, little is known on the other helminths that infect muskrats. A total of 130 muskrats of different age groups trapped in different habitats in the Barnim district of the Brandenburg state by a professional hunter were examined for parasites and seven trematodes (Echinostoma sp., Notocotylus noyeri, Plagiorchis elegans, Plagiorchis arvicolae, Psilosostoma simillimum, P. spiculigerum, Opisthorchis felineus and four larval cestode species (Hydatigera taeniaeformis, Taenia martis, Taenia polyacantha, Taenia crassiceps) were detected. Larval stages of E. multilocularis were not found. O. felineus was found for the first time in muskrats in Germany. All the named parasites were present in Europe prior to the introduction of muskrats. With a prevalence of 48.9%, Strobilocercus fasciolaris, the larval stage of the cat tapeworm, H. taeniaeformis, was the most frequent parasite found in adult muskrats.
The development of sustainable agri-food systems requires not only new academic knowledge, but also concrete social and organizational change in practice. This article reflects on the action research process that supported and explored the learning process in an emerging agri-food value chain in the Berlin-Brandenburg region in eastern Germany. The action research study involved value chain actors, academic researchers, and process facilitators in a learning network. By framing the network’s learning and problem solving processes in concepts of organizational learning, lessons were drawn for researchers and value chain developers. The results underline the importance of process facilitation in a learning value chain to create a social space, in which the actors in the value chain can interact and find a common basis for collaboration. In the learning process, facilitators used an iterative design to consistently align learning activities with the needs of practitioners to ensure practical relevance. To establish new practices and partnerships, value chain actors challenged existing routines and developed new ideas and visions, while at the same time improving established practices within their organizations and along the entire value chain.
To develop measures to reduce the vulnerability of forests to drought, it is necessary to estimate specific water balances in sites and to estimate their development with climate change scenarios. We quantified the water balance of seven forest monitoring sites in northeast Germany for the historical time period 1961–2019, and for climate change projections for the time period 2010–2100. We used the LWF-BROOK90 hydrological model forced with historical data, and bias-adjusted data from two models of the fifth phase of the Coupled Model Intercomparison Project (CMIP5) downscaled with regional climate models under the representative concentration pathways (RCPs) 2.6 and 8.5. Site-specific monitoring data were used to give a realistic model input and to calibrate and validate the model. The results revealed significant trends (evapotranspiration, dry days (actual/potential transpiration < 0.7)) toward drier conditions within the historical time period and demonstrate the extreme conditions of 2018 and 2019. Under RCP8.5, both models simulate an increase in evapotranspiration and dry days. The response of precipitation to climate change is ambiguous, with increasing precipitation with one model. Under RCP2.6, both models do not reveal an increase in drought in 2071–2100 compared to 1990–2019. The current temperature increase fits RCP8.5 simulations, suggesting that this scenario is more realistic than RCP2.6
The floodplain areas along the Naryn River in Kyrgyzstan are essential as they hold the riparian (local) ecosystems because they provide firewood, pastureland, and areas for recreation and protection against erosion. Due to limited access to adequate, reliable, and sustainable energy services, the rural population usually derived their energy needs from multiple natural energy resources (i.e., firewood, charcoal, agricultural residues, animal dung, and wood branches). This is considered a common and predominant practice in rural Kyrgyzstan. This situation leads to a negative impact on local ecosystem services. In addition to that, the reliance on solid fuels contributes to indoor and outdoor air pollution, which is partially threatening the local ecosystem services. By contrast, the employment of renewable-based energy supply systems would substantially reduce the burden on the environment, which is mainly untapped. To integrate renewable energies, it is important to understand the energy behavior of floodplain communities. In that response, the presented article is the first attempt to capture the energy identity of the floodplain community of Kyrgyzstan based on a quantitative energy-based (on-site) household survey. Furthermore, the present research article synthesizes the driving factors that have a (direct or indirect) impact on the energy and local ecosystem services. In addition, the present article proposes a brief pathway for the sustainable energy transition. The article records the recommendation to integrate renewable energies to preserve the local ecosystems of Kyrgyzstan.
Sustainability Transfer as a Concept for Universities in Regional Transformation—A Case Study
(2021)
The research object of this study is the in-depth discourse on the sustainability transfer activities of higher education institutions (HEIs) and their contribution to a regional sustainable transformation. For this purpose, a heuristically-derived concept of sustainability transfer is empirically tested with a mixed-methods approach based on the example of Eberswalde University for Sustainable Development (HNEE). The empirical findings demonstrate that the realization of sustainability transfer depends mainly on the personal initiative of teachers and researchers. Major barriers are a lack of time and financial resources. The observed concept of sustainability transfer is applicable to all study and research areas of HNEE. Involvement in sustainability transfer can include the whole of society, from politics, enterprises, and civil society to education and research institutions. Overall, the empirical testing of the concept offered by this study illustrates its practical suitability to capturing specifically those sustainability transfer activities that are not tapped by third mission approaches. This opens up a novel dimension for transfer potential at universities and their role in regional sustainability transformation. It also highlights that the interdependencies between HEIs and practitioners need to be more contextualized with quality criteria such as the value of the transfer performance or level of ambition.
Background: Over the last 25 years, the prominent forest certification system established by the Forest Stewardship Council (FSC) has used by many companies worldwide for claiming responsible forest management. The objectives of the Russian National FSC standard to decrease the size of clearcuts and the retention of forest elements such as residual seed trees need on-site validation to proof the effectiveness of FSC. To assess the ecological impacts of harvesting practices and benefits of FSC certification, we geospatially compared logging activities with and without FSC certification. Within a sample area covering approximately 3,000 km 2 in the east of the Russian Arkhangelsk Region, we used available data on tree cover loss and satellite images to assess secondary impacts of clearcuttings
on adjacent remnant forests and to quantify the logging intensity. Additionally, the size and structure as well as the density of skidding trails of ten specific clearcuttings located within the sample area were surveyed using satellite images and in the field observation to delineate the boundaries of clearcuts and forested remnants within the clearcuts.
Results: We found a significant increase of small-scale tree cover loss in the proximity of the clearcuts. Patchy dieback is possibly linked to the scale and intensity of logging in the surroundings. On the investigated clearcuts, FSC failed to reduce the size, to increase the retention of forest remnants including seed trees on logged areas, and to maintain larger tracts of undisturbed ground and soil compared to clearcuts that were logged before they received FSC-certification.
Conclusions: Trees and forest remnants remaining inside an increasingly stressed forest ecosystem matrix may not resist further harvesting-related and climate change-induced stresses and disturbances. Large-scale clearcuttings seem to have negative impacts even in adjacent forests and undermine the ecological effectiveness of FSC certification in the study area. The Russian FSC standard is not clearly setting effective guidelines that induce a change in clearcutting practices in order to reduce ecological risks.
Our study deals with human-wildlife conflicts in the Namibian component of the Kavango-Zambezi Transfrontier Conservation Area (KAZA TFCA). The study reconstructs the historical occurrence of selected mammal species and adopts a socio-ecological approach to assess the impact of human dimensions in the KAZA TFCA. Our results reveal pronounced human–wildlife conflicts with considerable impacts on the livelihoods of communities. Human–wildlife conflict has the potential to become a significant contributor to the failure of the TFCA concept. Conflicts are influenced by a growing human population and large mammal species re-colonising formerly abandoned areas. Mapping the occurrence of selected mammal species over time reveals an interesting picture: although conservation initiatives have led to an increase in the population size of selected species, their occurrence is more restricted than in times of heavily decimated wildlife populations. The increasing restriction of wildlife to protected areas reduces the resilience of the ecosystem. To sustainably manage and conserve wildlife populations, a bigger picture including areas outside of the current borders of KAZA TFCA should be considered. This could support re-connecting ecologically important areas for congested populations to move to and reduces the concentration of wildlife and pressure on the land and people of the region.
Urban green space (UGS) is crucial to the healthy development of urban residents. However, UGS that is accessible can benefit residents to an even greater degree. Based on the two-step floating catchment area model (2SFCA) and the location quotient (LQ), we analyzed the changes from 1999 to 2019 in UGS walking accessibility and equity in built-up areas of Urumqi at different administrative levels, and how UGS policy affects the improvement of accessibility. The results showed that UGS accessibility and equity are not evenly distributed at different administrative levels and UGS categories. Although the overall UGS accessibility and equity has improved with policy implementation, these changes are caused by metro-level UGS construction in urban fringe areas. The improvement in UGS accessibility at the neighborhood level in densely populated areas is neglected, which leads to a mismatch between UGS construction and population distribution. In addition, the accessibility of UGS is also limited by geographical location, population density, road distribution, and water shortage in arid metropolitan Urumqi. Our research results provide a theoretical basis for Urumqi and other cities in the optimization of UGS structure and the realization of social equity.
The study investigates the extent to which sustainability is anchored in university curricula of a federal state (Brandenburg, Germany). (1) It provides a baseline for identifying opportunities for sustainability-related curriculum reform by analyzing study programs, levels and type of degree, level of anchoring, and context within the documents. (2) The case studies included an analysis and quantitative evaluation of 748 curricular documents. (3) A third of the study programs refer to sustainability; to an equal extent in both bachelor’s and master’s programs, and to an above-average extent in the fields of science and engineering. There is a strong commitment to sustainability in 12% of the curricula; however, it is strongly anchored in only 3% of study and examination regulations, and in only 9% of module descriptions. (4) For the first time, we have comprehensive results on sustainability in university curricula of an entire federal state and can discuss potentials for its further integration. The innovative method was developed out of the National Monitoring on Education for Sustainable Development (ESD) and adapted to the federal state level; the analysis of curricula through a wider set of variables is transferrable to other states. (5) The study provides indications for the regional development of universities which is crucial for future regional sustainability transformation.
Higher education institutions (HEIs) are increasingly confronted with societal needs beyond research and teaching. These include sustainable development and technology transfer as well as the practical application of knowledge and ideas. Several HEIs already put sustainable development and transfer into practice. These practitioner–university partnerships comprise a broad range of actors, disciplines, topics, and formats. However, transfer activities that contribute to sustainable development in society still make up only a very small part of HEIs’ activities. In response to calls from society as a whole, HEIs could combine transfer and sustainable development more systematically. In this article, we suggest a concept of transfer for sustainable development. The focus is on sustainability transfer in teaching. We used mixed methods for this conceptual work: exploratory workshops, expert interviews, and a case study of transfer in teaching. One of the results presented in this article is a working definition of sustainability transfer at HEIs. In addition, six characteristics for describing sustainability transfer in its various forms are formulated. This conceptualization makes it possible to analyze the diversity of HEIs’ sustainability transfer activities, it helps to identify and encourage potential transfer actors at HEIs as well as practitioners, and, thus, tap the full potential of sustainability transfer.
The frequency and intensity of drought are expected to increase worldwide in the future. However, it is still unclear how ecosystems respond to drought. Ecosystem water use efficiency (WUE) is an essential ecological index used to measure the global carbon–water cycles, and is defined as the carbon absorbed per unit of water lost by the ecosystem. In this study, we applied gross primary productivity (GPP), evapotranspiration (ET), land surface temperature (LST), and normalized difference vegetation index (NDVI) data to calculate the WUE and drought index (temperature vegetation dryness index (TVDI)), all of which were retrieved from moderate resolution imaging spectroradiometer (MODIS) data. We compared the mean WUE across different vegetation types, drought classifications, and countries. The temporal and spatial changes in WUE and drought were analyzed. The correlation between drought and WUE was calculated and compared across different vegetation types, and the differences in WUE between drought and post-drought periods were compared. The results showed that (1) ecosystems with a low (high) productivity had a high (low) WUE, and the mean ecosystem WUE of Central Asia showed vast differences across various drought levels, countries, and vegetation types. (2) The WUE in Central Asia exhibited an increasing trend from 2000 to 2014, and Central Asia experienced both drought (from 2000 to 2010) and post-drought (from 2011 to 2014) periods. (3) The WUE showed a negative correlation with drought during the drought period, and an obvious drought legacy effect was found, in which severe drought affected the ecosystem WUE over the following two years, while a positive correlation between WUE and drought was found in the post-drought period. (4) A significant increase in ecosystem WUE was found after drought, which revealed that arid ecosystems exhibit high resilience to drought stress. Our results can provide a specific reference for understanding how ecosystems will respond to climate change.
The management and preservation of structures in our built environment are central and challenging tasks for practicing engineers. Within the CEN member states (European Committee for Standardization), the so-called Eurocodes form the basis of the design and verification of the load-bearing capacity of structures. Current Eurocodes do not contain special recommendations for existing structures, meaning that the principles for new structures are applied. This can lead to an incorrect estimation of the load-bearing capacity within the semi-probabilistic safety concept. A central task within the investigation and evaluation of existing structures is the strength grading of the material in situ using non-/semi-destructive technical devices. Studies show the potential of the ultrasonic time-of-flight measurement in combination with visual evaluation for an improved grading. The information on the material from an improved grading technique can be used to update the material parameters as a target variable using a measured reference variable. In this contribution, test data from a partner project (spruce, pine, and oak) are analyzed, applying the stochastic grading model of Pöhlmann and Rackwitz. It can be shown that different grading techniques influence the updated distribution function of the material strength within the grade. The results depend on the timber species. Perspectives to develop updated models dependent on the knowledge available are shown and discussed.
The springback effect in molded wood laminations within the elastic range has, to date, not yet been mathematically described. Once cured, residual internal stresses within the laminations cause the final form to deviate from that of the die. Test pieces of beech laminations of 1 mm, 2 mm and 4 mm thicknesses and stack sizes of between 2 and 16 laminations were used. The elasticity value of each stack was obtained using non-glued laminations in a three-point bending test within the elastic region. The laminations were glued with polyurethane resin and mounted in a radius form die. The stress induced by the die onto the stack is within the elastic region of the material without any prior chemical or physical plasticisation of the wood. After curing was complete and the laminations removed from the die, the actual radius was calculated using a circular equation within the CAD program, using three measurement points taken from the stack. The radius of the die within the limits of this study has a negligible effect when predicting the springback of the stack. The exponential correlation between springback and the number of laminations, was used to calculate the springback effect on molded laminated stacks.
The reestablishment of agroforestry systems in Central Asia, combining crop production with protective tree shelterbelts, provides significant potential to improve farming systems. This includes increasing crop yields, additional income from timber, as well as reducing soil degradation and wind erosion. Thus, adopting shelterbelts as a form of pro-environmental behavior provides a number of socio-economic benefits, although some trade-offs need to be considered as well. This paper investigates factors that shape the perception of—and attitude towards—the establishment of tree shelterbelts by farmers in two case study regions in Kyrgyzstan. Applying a conceptual framework distinguishing between extrinsic and intrinsic factors, research methods included semi-structured interviews with farmers and local policy makers. The results show spatial differences in the perception of shelterbelts, both on the regional and on the village scale. In general, shelterbelts were negatively perceived by more than half of the farmers. The main concern raised by farmers was the shading of crops by shelterbelts, resulting in a decrease of yield. In addition, small field sizes and potential conflicts with neighbors were key concerns. Furthermore, rules set by local self-government bodies were inconsistent with the legislative framework, posing significant restrictions to the adoption of sustainable land use practices.