A central European perspective

Studies from North-America indicate that large wood is one of the key factors of pristine stream ecosystems in temperate forested ecoregions, which influences channel morphology across a wide range of spatial and temporal scales, and which has been successfully used in stream restoration. In contrast to North America, the relevance of large wood has long been overlooked in Central Europe. Transferability of the results of North American studies is limited, because land-use pressure is especially high in Central Europe and the natural setting as well as the restoration objectives differ from North America. The main objective of the thesis is to help develop a Central European perspective on the significance of large wood in streams and rivers and its use in stream restoration. Four studies are compiled in this thesis: 1. Potential natural state of Central European streams in respect to the amount and distribution of large wood: As a first step to describe the potential natural state of streams in respect to large wood, the results of nine investigations were summarized, in which the amount of large wood present in Central European reference sections was quantified (n = 34). Although these reference sections are among the most natural stream sections and in a “near-natural” condition according to Central European standards, the volume of large wood is low compared to other temperate forested ecoregions (factor 3). The data reveal that the current large wood standing stock is considerably less than the potential amount of large wood. However, the range of volumes found in the study streams can be regarded as the minimum volume of large wood that should be present in a “near-natural” Central European stream. 2. Influence of large wood (single large fallen trees) on channel morphology: The morphological effect of single large fallen trees, which are increasingly used in stream restoration projects, was investigated in six short channel sections in Central Europe. The results show that the single large fallen trees significantly increased structural diversity at almost all spatial scales, particularly in terms of pool volume and cross-section complexity. Furthermore, large wood increased variability of some cross-section parameters, which is of special importance, because habitat diversity is assumed to increase with cross-section variability. Moreover, some rare habitat types are clearly associated with the large fallen trees. These results indicate that single large fallen trees significantly enhance channel morphology within one to several years along a stretch of several tens of meters. 3. Quantification of the potential use and the simulation of the effects of large wood in restoration projects: The potential use and effects of large wood in Central European streams was quantified to assess, if large wood recruitment (passive restoration) and placement (active restoration) are suitable methods to restore a considerable part of the streams and rivers. Large wood recruitment is suited for only a small percentage of the streams and rivers, but total length of these channel reaches is high compared to the length of the reaches restored so far. The potential use of active restoration is much higher. About one fifth of the streams and rivers investigated can be restored by the placement of large wood, if the land uses pasture and grassland do not restrict the use of large wood. 4. Review of restoration projects in which large wood has been used so far: A mail survey on restoration projects in which large wood has been already used revealed the following aspects: Most stream managers used fixed wood structures to initiate natural channel dynamics. Failure rate of these structures is low, and preliminary monitoring results indicate that the hydromorphological status improved rapidly in most projects. However, there is potential for improvement from an ecological and economical point of view. The size and the potential effect of some wood structures on stream hydraulics and morphology is low and can be increased without inferring with local restrictions. Furthermore, in most of the cases, complex natural shaped wood structures could have been used instead of bare cylindrical logs to benefit from positive side effects. The data on the restoration projects investigated indicate that costs can be markedly reduced and positive side effects are to be expected, if wood structures without additional anchoring are used. Therefore, it is highly recommended to use such soft engineering methods in future projects whenever possible

Climate model variability leads to uncertain predictions of the future abundance of stream macroinvertebrates

Climate change has the potential to alter the flow regimes of rivers and consequently affect the taxonomic and functional diversity of freshwater organisms. We modeled future flow regimes for the 2050 and 2090 time horizons and tested how flow regimes impact the abundance of 150 macroinvertebrate species and their functional trait compositions in one lowland river catchment (Treene) and one mountainous river catchment (Kinzig) in Europe. We used all 16 global circulation models (GCMs) and regional climate models (RCMs) of the CORDEX dataset under the RCP 8.5 scenario to calculate future river flows. The high variability in relative change of flow among the 16 climate models cascaded into the ecological models and resulted in substantially different predicted abundance values for single species. This variability also cascades into any subsequent analysis of taxonomic or functional freshwater biodiversity. Our results showed that flow alteration effects are different depending on the catchment and the underlying species pool. Documenting such uncertainties provides a basis for the further assessment of potential climate-change impacts on freshwater taxa distributions

The effect of riparian forest on landscape connectivity for the EPT community across European regions

Ephemeroptera, Plecoptera and Trichop- tera are three orders of freshwater macroinvertebrates with a short terrestrial adult life-stage that they use to disperse by flying upstream. This aerial dispersal can be assisted by native riparian forest, but regional variation has not yet been empirically tested. In this study we compared the EPT community of 153 sampling sites located in freshwater streams in four European regions (Central Plains, Central Highlands, Alps, Iberia). In each site, we assessed the EPT com- munity dispersal ability using the Species Flying Pro- pensity index. We also calculated the native decidu- ous forest cover in the riparian buffer and several environmental stressors such as saprobic pollution or catchment anthropization. Finally, we tested which of these parameters have a significant effect on the EPT community. In the Central Highlands and in Iberia, the share of weak dispersers increased with native deciduous forest cover, indicating a positive effect on dispersal of EPTs. In the Central Plains and the Alps, no such effect was found. We conclude that the effect of native deciduous forest depends on regional land- scape characteristics and the regional species pool, but considering the dispersal of the regional EPT communities is needed to create effective river man- agement policies.info:eu-repo/semantics/publishedVersio

Ökologische Funktionen von Gewässerrandstreifen: Ökologische Funktionen von Gewässerrandstreifen für die Wasserrahmenrichtlinie

Die Studie zeigt die große Bedeutung der natürlichen bachbegleitenden Vegetation für unsere Bäche und Flüsse. Bäume sorgen für Beschattung, Stoffrückhalt, Uferstrukturierung und sind ein sehr artenreicher Lebensraum. In der Veröffentlichung werden zahlreiche nationale und internationale Facharbeiten ausgewertet und die ökologischen Funktionen genau beschrieben.Die daraus gewonnenen Erkenntnisse liefern für alle Akteure an unseren Fließgewässern wichtige Fachgrundlagen. Daneben wird allen Interessierten der große Wert von natürlichen Gewässerrandstreifen näher gebracht. Redaktionsschluss: 23.03.202

Если человечество не изменит концепцию своего развития, оно погибнет

Сложная современная политическая, социально-экономическая, межнациональная, религиозная и пр. ситуация в мире требует от интеллектуальной элиты и особенно от политиков, ученых обществоведов, экономистов сформировать и предложить новую концепцию развития мира.Складна сучасна політична, соціально-економічна, міжнаціональна, релігійна та ін. ситуація в суспільстві вимагає від інтелектуальної еліти і особливо від політиків, вчених суспільствознавців, економістів сформувати та запропонувати нову концепцію розвитку суспільства.Complicated modern political, socio-economic, international, religious and other situations in the world call on all the brainpower and especially policy-makers, scholars, social scientists, economists to elaborate and offer a new concept of the world development

Bringing the margin to the focus: 10 challenges for riparian vegetation science and management

Riparian zones are the paragon of transitional ecosystems, providing critical habitat and ecosystem services that are especially threatened by global change. Following consultation with experts, 10 key challenges were identified to be addressed for riparian vegetation science and management improvement: (1) Create a distinct scientific community by establishing stronger bridges between disciplines; (2) Make riparian vegetation more visible and appreciated in society and policies; (3) Improve knowledge regarding biodiversity—ecosystem functioning links; (4) Manage spatial scale and context-based issues; (5) Improve knowledge on social dimensions of riparian vegetation; (6) Anticipate responses to emergent issues and future trajectories; (7) Enhance tools to quantify and prioritize ecosystem services; (8) Improve numerical modeling and simulation tools; (9) Calibrate methods and increase data availability for better indicators and monitoring practices and transferability; and (10) Undertake scientific validation of best management practices. These challenges are discussed and critiqued here, to guide future research into riparian vegetation

Storylines articulating scenarios for an assessment of the importance of woody buffers along European streams

Woodlands and lines of trees along streams can have multiple effects on stream water quality stream biota and ecosystem functions of the riparian zone and wider floodplain. One of the tasks of the research project OSCAR is to assess and explore plausible future development of these woody buffer strips in the near future with 2050 as time horizon. For this purpose, the current study used existing scenarios of climate (RCPs) and societal change (SSPs) and selected three, SSP1, 2 and 3 (respectively ‘sustainability’, ‘middle of the road’ and ‘regional rivalry’). We downscaled the SSPs in an articulate and consistent way to reflect three different, contrasting overall pathways of change in society and three corresponding plausible ways river management would develop accordingly (dubbed Riparian Management Packages). In this way, we produced an elaborate tabulation of possible changes in a.o. land use, agriculture, economic strength, institutional focus which can be applied in modelling exercises in OSCAR.Kantsoner langs elver med trær eller skog kan ha ulike effekter på vannkvalitet, livet i vannet og økosystemets funksjoner langs elvens bredder. En av de oppgaver av forskningsprosjektet OSCAR er å definere plausible scenarier for framtiden av slike kantsoner til og med 2050. Vi har utredet i detalj hva eksisterende scenarier av klima (RCPs) og samfunnets utviklinger (SSPs) kunne bety. Vi har utvalgt SSPs 1,2 og 3, nedskalert disse og koplet dem opp til ‘vann-forvaltingspakker’. Slik har vi produsert en utarbeidet tabell med plausible utviklinger i blant annet jord- og skogbruket, økonomi, institusjonell vinkling so er klar til bruk i videre modelleringsarbeid i OSCAR

The effect of riparian woodland cover on ecosystem service delivery by river floodplains: a scenario assessment

publishedVersio

Data from: Spatial scaling of environmental variables improves species-habitat models of fishes in a small, sand-bed lowland river

Habitat suitability and the distinct mobility of species depict fundamental keys for explaining and understanding the distribution of river fishes. In recent years, comprehensive data on river hydromorphology has been mapped at spatial scales down to 100 m, potentially serving high resolution species-habitat models, e.g., for fish. However, the relative importance of specific hydromorphological and in-stream habitat variables and their spatial scales of influence is poorly understood. Applying boosted regression trees, we developed species-habitat models for 13 fish species in a sand-bed lowland river based on river morphological and in-stream habitat data. First, we calculated mean values for the predictor variables in five distance classes (from the sampling site up to 4000 m up- and downstream) to identify the spatial scale that best predicts the presence of fish species. Second, we compared the suitability of measured variables and assessment scores related to natural reference conditions. Third, we identified variables which best explained the presence of fish species. The mean model quality (AUC = 0.78, area under the receiver operating characteristic curve) significantly increased when information on the habitat conditions up- and downstream of a sampling site (maximum AUC at 2500 m distance class, +0.049) and topological variables (e.g., stream order) were included (AUC = +0.014). Both measured and assessed variables were similarly well suited to predict species’ presence. Stream order variables and measured cross section features (e.g., width, depth, velocity) were best-suited predictors. In addition, measured channel-bed characteristics (e.g., substrate types) and assessed longitudinal channel features (e.g., naturalness of river planform) were also good predictors. These findings demonstrate (i) the applicability of high resolution river morphological and instream-habitat data (measured and assessed variables) to predict fish presence, (ii) the importance of considering habitat at spatial scales larger than the sampling site, and (iii) that the importance of (river morphological) habitat characteristics differs depending on the spatial scale

Set_AV_TV: Single boosted regression tree (BRT) habitat models for 13 fish species based on assessed hydromorphological variables and topological variables

Results for single boosted regression tree (BRT) models for 13 fish species, 4 modelled distance classes (0, 200, 2500, 4000 m) and assessed hydromorphological data (AV) with topological variables (stream orders, distance from mouth). Model results include a global BRT model (brt.model.global, including all variables) and a final BRT model (brt.model.final, including only statistically relevant variables) for each species. Furthermore, summarizing statistics (brt.stats.final) for each final model (e.g. cross-validated AUC) and associated plots showing the influence of selected selected variables (species_response.pdf) are provided. Models are stored as R objects in the *.rds format and can be loaded with the R command readRDS()