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Understanding the relationships between provisioning and regulating ecosystem services (ESS) in papyrus wetlands of the Lake Victoria basin is crucial for livelihoods. However, the relationships between the ESS remain unexplored despite the steady conversion of wetlands to agriculture. This study identified the relationships between provisioning (crop, fibre, and mat production) and regulating (total nitrogen (TN) and total phosphorus (TP) retention) ESS and analysed the effects of shared indirect drivers of change (rainfall, non-wetland-based household income, and fertility of upland farms) on the relationships. Also, the effects of wetland conversion to agriculture on the ESS were examined. The Bayesian Network model was used to assess the relationships and the Papyrus Simulator to analyse the effects of reducing wetland area on the ESS. The results showed that there were trade-offs between crop production (low, 91%) and nutrient retention (TP, 81%) and positive synergies between fibre (high, 80%) and mat (high, 59%) production and nutrient retention. Wet conditions, high non-wetland-based household income, and high fertility of upland farms increased the trade-offs but reduced the positive synergies. Converting the entire wetland to agriculture increased crop production, diminished fibre and mat production and reduced nutrient retention. Therefore, policy interventions improving non-wetland-based household income and fertility of upland farms would decrease the dependence on wetlands for crop production and artisanal papyrus products and enhance nutrient retention. Without any policy interventions, conversion of the entire wetland to agriculture would enhance crop production at the expense of other ESS. [ABSTRACT FROM AUTHOR]

The access to an adequate quantity and quality of water is vital to sustain healthy ecosystems and human socioeconomic development. However, the shift from an agrarian, solar energy based to an industrialized, fossil fuel‐based socio‐metabolic regime has put natural water resources under stress and led to dramatic transformations of riverine landscapes in the Anthropocene. Thus, we need interdisciplinary research approaches that integrate the knowledge and methods from ecology, humanities, and engineering. The Doctoral School "Human River Systems in the 21st Century" (HR21) studies riverine landscapes as coupled socio‐ecohydrological systems (SEHS) within four research clusters, that is, connectivity, metabolism, vulnerability, and governance. HR21 analyzes the transformation processes and coevolution of nature and society in rivers and their response to future environmental, social, cultural, and economic drivers of change. HR21 aims to improve the understanding of the coupling of the socioeconomic, ecological, and hydrological systems within industrialized riverine landscapes to support their urgent, more sustainable transformation. To discuss how this agenda can be implemented, five different HR21 PhD projects are presented, clearly routed in one scientific domain, applying a combination of the research clusters and addressing various topics: (i) hydropower effects in high alpine river ecosystems, (ii) wastewater impacts on carbon storage and greenhouse gas fluxes in tropical wetlands, (iii) the nutrient retention and ecosystem service potential of floodplains in large river catchments, and the influence of hydrometeorological variables on (iv) the runoff response and on (v) the transit time distribution of runoff, both impacting water resource management at the basin level. These examples highlight how disciplinary PhD research can be framed within an interdisciplinary research agenda to coupled SEHS. [ABSTRACT FROM AUTHOR]

Context: In efforts to mitigate anthropogenic impacts on floodplain biodiversity, restoration measures that enhance habitat connectivity have been applied. However, these approaches have either neglected the spatial position of water bodies or the dynamic nature of the floodplain ecosystem. Objectives: This study focuses on the novel application of the multilayer network framework to assess changes in the aquatic habitat connectivity in floodplains, showcasing its application in the context of aquatic passive dispersal (drift) of two indicator groups of benthic macroinvertebrates (Oligochaetes and Chironomids) Methods: Our case study is located in the Donau-Auen National Park in Austria and follows floodplain restoration measures (side-channel reconnection) applied in the mid-1990s. Multilayer networks were constructed to represent the conditions before, short-term, and long-term after restoration to quantify habitat connectivity across inundation frequencies. Our network analyses involved multilayer correlation, static and dynamic monolayer centralities (centrality profiles), and multilayer centrality assessments. We used a Partial Least Squares Regression analysis as a variable selection tool to identify which centrality measures better explained the variance in α diversity and Local Contributions to Beta Diversity (LCBD) of benthic macroinvertebrates. Results: In the short-term, our connectivity analysis indicated an increase in habitat connectivity. However, centrality profiles, multilayer correlation, and multilayer centrality techniques identified a long-term decrease in connectivity. Multilayer centralities had higher Variable Importance in the Projection scores (VIP) than their monolayer counterpart in explaining variations in α diversity and LCBD for strict aquatic dispersers. Meanwhile, for flying dispersers, monolayer centralities had the highest VIP scores for explaining α diversity. Conclusions: This study underscores the relevance of integrating dynamic aspects of water-mediated transport beyond traditional pairwise distances. Although in this study we apply this tool by showcasing the aquatic passive dispersal mode, the application of this method can be extended to other dispersal modes and representative abilities for diverse groups of aquatic organisms. The expanding cross-disciplinary applications and open-source tool development for multilayer networks offer practical implications for planning and evaluating management measures. [ABSTRACT FROM AUTHOR]

This study provides a new perspective on understanding the intricacies of water‐mediated connectivity in ecosystems, bridging landscape ecology and geomorphology through network science. We highlight dryland and river‐floodplain ecosystems as distinct examples of contrasting water‐controlled systems. We (1) discuss central considerations in developing structural connectivity and functional connectivity networks of water‐mediated connectivity; (2) quantify the emergent patterns in these networks; and (3) evaluate the capacity of network science tools for investigating connectivity characteristics. With a focus on strength (weights) and direction, connectivity is quantified using seven parameters at both network and node levels. We find that link density, betweenness centrality and page rank centrality are highly sensitive to directionality; global efficiency and degree centrality are particularly sensitive to weights; and relative node efficiency remains unaffected by weights and directions. Our study underscores how network science approaches can transform how we quantify and understand water‐mediated connectivity, especially in consideration of the role(s) of weights and directionality. This interdisciplinary perspective, linking ecology, hydrology and geomorphology, has implications for both theoretical insights and practical applications in environmental management and conservation efforts. [ABSTRACT FROM AUTHOR]

Aim: Rivers belong to the most threatened ecosystems on Earth. Historical anthropogenic alterations have, and future climate change will further affect rivers and the species therein. While many studies have projected climate change effects on species, little is known about the severity of these changes compared to historical alterations. Here, we used a unique 300‐year time series of hydrological and climate data to explore the vulnerability of 48 native fish species in the upper Danube River Basin to past and potential future environmental changes. Location: Upper Danube River Basins (Germany and Austria). Methods: We applied a climate niche factor analysis and calculated species‐specific vulnerability estimates based on modelled and observed hydrological and climate data from 1800 to 2100. We compared the estimated species vulnerabilities between two historical time intervals (1800–1830 and 1900–1930) and a future time interval (2070–2100, including the two representative concentration pathways 4.5 and 8.5) to an observed reference time interval (1970–2000). In addition, we identified the main environmental drivers of species vulnerability and their change over the past 200 years and for the predicted 100 years in the future. Results: Our results showed that (i) in the past, species vulnerability was mainly driven by changes in discharge, while (ii) future potential vulnerabilities would be due to temperature. Moreover, we found that (iii) future environmental conditions for riverine fish species driven by temperature would change at a similar magnitude as past hydrological changes, driven by anthropogenic river alterations. Future changes, projected for the RCP 4.5, would result in moderate species vulnerability, whereas for the RCP 8.5, the vulnerability for all species would substantially increase compared to the historical conditions. Main Conclusion: Accounting for an extended timeline uncovers the extent of historical pressures and provides unprecedented opportunities to proactively plan conservation strategies that are necessary to address future challenges. [ABSTRACT FROM AUTHOR]

The phytoplankton functional group (FG) classification system sensu Reynolds enables evaluating the ecological status of rivers using the Q(r) compositional index. Here, we apply the Q(r) index to analyze the ecological conditions of the Southern Bug River, at the entire river length, in the early 20th century, testing it first on historic river phytoplankton data. Moreover, we combined the FG approach with the saprobic index and taxonomic richness to assess the ecological status of the river more reliably. The Bray–Curtis Similarity index highlighted the spatial clustering of river sites that corresponded well to the bioregions of the Eastern Lowlands and the Pontian Province. The Q(r) index revealed a higher variation in ecological status among sites than the saprobic index. Therefore, we argue that the FG approach provides a sensitive ecological status indication approach for river phytoplankton, including historical human impacts. The method may improve understanding of reference conditions and assessing the ecological status of Ukrainian rivers, as requested by the European Water Framework Directive. [ABSTRACT FROM AUTHOR]

Information is scarce on how environmental and dispersal processes interact with biological features of the organisms, such as their habitat affinity, to influence patterns in biodiversity. We examined the role of habitat specialist vs. generalist species, and the spatial configuration, connectivity, and different environmental characteristics of river-floodplain habitats to get a more mechanistic understanding of alpha and beta diversity of fish metacommunities. We used environmental DNA metabarcoding to characterize species (taxa) richness and composition in two separate floodplains of the river Danube (Austria and Hungary) during two different hydrological conditions. Results showed that differences in the number of generalist and specialist species and their responses to connectivity and environmental gradients influenced patterns in alpha and beta diversity. Of the components of beta diversity, richness difference (nestedness) showed consistently higher values than replacement (turnover), mainly due to the decrease of specialist species along the connectivity gradient (i.e., from the mainstem to the most isolated oxbows). Variance in both alpha and beta diversity could be well predicted by a set of local and regional variables, despite high environmental variability, which characterizes river-floodplain ecosystems. Of these, the joint or shared variance fractions proved to be the most important, which indicates that the effects of local and regional processes cannot be unambiguously separated in these river-floodplain systems. Local scale environmental variables were more important determinants of both alpha and beta diversity in the low water period than in the high water period. These results indicate the differential role of local and regional processes in community organization during different hydrological conditions. Maintenance of both local and regional scale processes are thus important in the preservation of alpha and beta diversity of floodplain fish metacommunities, which should be considered by environmental management. [ABSTRACT FROM AUTHOR]

In riverine floodplains, the hydrological connectivity of the aquatic habitats with the main channel is paramount for aquatic metacommunities, as it influences organism dispersal and the local environmental conditions. We assessed phytoplankton, rotifer and microcrustacean metacommunity structures and species richness along an empirical gradient of hydrological connectivity of the aquatic habitats with the main channel and compared them between high and low water levels of the main river. In addition to exploring the relative influence of hydrological connectivity, local environmental and spatial factors on metacommunity composition and the relationship between species richness and environmental and hydrological connectivity variables during both hydrological conditions. During high water levels, when high nutrient and suspended solid concentrations occurred in sites with higher hydrological connectivity and sites with opposite features and high macrophyte cover occurred in sites with lower connectivity, metacommunities showed Quasi-Nested structures (species-poor sites were subsets of species-richer sites). During low water levels, the environmental variation of the water bodies was not associated to the connectivity gradient and metacommunities showed Clementsian or Quasi-Clementsian structures: discrete groups of species replaced each other along the floodplain. Spatial factors generally were the most important for community composition; during high water levels the flood contributed to the spatial effect by transporting organisms among neighbor water sections, and during low waters it indicated dispersal limitation and/or unmeasured variables that are spatially structured. Species richness was not associated to the gradient of hydrological connectivity, no matter the hydrological condition, and showed stronger association with local factors during low than during high water levels, indicating a better match between organisms and the environment in the absence of recent floods. Our results show that the discharge regime of the river influences plankton metacommunities and their relationship with local environmental factors. This highlights the relevance of natural river water level fluctuations for aquatic communities in the present context of increasing river flow regulation worldwide. [ABSTRACT FROM AUTHOR]

Anxiety has been linked to altered belief formation and uncertainty estimation, impacting learning. Identifying the neural processes underlying these changes is important for understanding brain pathology. Here, we show that oscillatory activity in the medial prefrontal, anterior cingulate and orbitofrontal cortex (mPFC, ACC, OFC) explains anxiety-related learning alterations. In a magnetoencephalography experiment, two groups of human participants pre-screened with high and low trait anxiety (HTA, LTA: 39) performed a probabilistic reward-based learning task. HTA undermined learning through an overestimation of volatility, leading to faster belief updating, more stochastic decisions and pronounced lose-shift tendencies. On a neural level, we observed increased gamma activity in the ACC, dmPFC, and OFC during encoding of precision-weighted prediction errors in HTA, accompanied by suppressed ACC alpha/beta activity. Our findings support the association between altered learning and belief updating in anxiety and changes in gamma and alpha/beta activity in the ACC, dmPFC, and OFC.Magnetoencephalography data from participants with high and low trait anxiety reveals a potential role for oscillations in the anterior cingulate and medial prefrontal cortex in anxiety-associated learning. [ABSTRACT FROM AUTHOR]

Intense efforts have focused on ecosystem conservation and restoration (ECR) over the past decades, promoting considerable advances in science and practice in this field. However, the applications of the ecosystem services (ESs) concept are rarely considered in the literature when assessing the success and targets of ECR.The ECR literature was systematically reviewed to analyse the relevance of the ES concept in ECR research published from 2007 to 2019 and to assess how the ES concept is integrated into freshwater ECR.In general, the number of publications focusing on ECR and ESs shows a temporal increase (from 12 to 101 publications, 685 in total). The proportion of publications considering ESs as freshwater ECR targets increased from 33 to 70% until 2019, while the proportion of publications that prioritized ecosystem processes and functions as the target declined from 33 to 16%. Despite the clear upward trend, most studies have focused only on the conceptual framework. In addition, the idea of using market‐based approaches for ESs has spread quickly, but it has still not been broadly accepted.The number of academic researchers who have contributed to this research field varies substantially across different countries. A country's economic conditions and the extent of freshwater withdrawal can affect efforts devoted to studies on freshwater ECR and ESs. Some ecosystems, such as rivers and wetlands, have attracted much more attention than others. Although most studies have discussed ESs in general, the provisioning and regulation of ESs are mainly considered in studies that differentiate specific ES categories.Current limitations in applying the ES concept in ECR across different studies suggest that further collaboration is needed among ecologists, practitioners, stakeholders and policy‐makers to develop a broad mix of approaches for the best and widest use of the ES concept in protecting and enhancing freshwater ecosystems. [ABSTRACT FROM AUTHOR]

Copyright of Österreichische Wasser- und Abfallwirtschaft is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We present the development of novel ion‐selective electrodes for tropane, atropine, and scopolamine, as a general model for tropane alkaloids and drugs such as e. g. cocaine. These potentiometric sensors rely either on a metallocarborane or tetraphenylborate complex as recognition element and led to systems with a near‐Nernstian behaviour in the range of 10−5–10−2 mol/L and detection limits around 2 ⋅ 10−5 mol/L. Selectivity studies with commonly used drug additives (caffeine, phenacetin) and closely related tropane derivatives show very low influence of the additives and a structure dependent interference for the derivatives. Beside this, a hydrogel‐based concept with a similar performance was developed, which could be used for on‐site measurement of solid samples. The developed sensors therefore demonstrated their suitability and might be used to enable the development of portable sensor arrays for the quantification of a wide range of tropane alkaloids. [ABSTRACT FROM AUTHOR]

With climate change, streams and rivers are at increased risk of droughts and flow intermittency. The full implications of these conditions for fluvial carbon (C) processing and stream-atmosphere CO2 emissions are not well understood. We performed a controlled drought experiment in outdoor hyporheic flumes. We simulated small rain events that increase sediment moisture content, but do not cause streamflow in order to investigate how these events affect streambed dissolved organic C dynamics, biofilm respiration and enzyme activity, and bacterial community composition. Flumes were subject to a non-flow phase of one month with small rain events with varying frequency (weekly, 3 × weekly, and no rain). Sediment was sampled at the surface and from the hyporheic zone at the end of the non-flow phase. We quantified microbial respiration of the dry sediments and sediment DOC leaching after simulated flow resumption. We found that, at the surface, more frequent rain events significantly increased microbial respiration from 12.6 ± 0.25 µg CO2 g−1 DW h−1 to 26.5 ± 11.3 µg CO2 g−1 DW h−1 between the control and 3 × weekly rain events. The average amount of DOC leached from surface sediments during flow resumption was reduced by 0.813 ± 0.62 mg L−1 with more frequent rain events. More frequent rain events also resulted in the leaching of fresher DOM with increased tryptophan fluorescence and a higher BIX. This, along with higher glucosidase activity in the biofilms, indicates higher OC processing during the drought period with more frequent rain events. Small rain events also enhanced Shannon diversity of microbial communities, with a stronger presence of 'terrestrial-like' bacterial clades. We propose that rain events during drought, even those of small size, are highly relevant for fluvial organic C processing during the dry phase. Future research should explicitly consider small rain events when investigating C fluxes in intermittent streams to fully understand the C processing in these systems with climate change. We conclude that small rain events impact DOM dynamics during reflow and likely impact the cascading C processing in the downstream river network. [ABSTRACT FROM AUTHOR]

Aquatic-terrestrial interfaces may act as biogeochemical hotspots for greenhouse gas emissions, especially when exposed to frequent transitions between wet and dry phases. The study aimed to analyze the dynamics of nitrogen (N) processing along an inundation gradient from floodplain soils to river sediments and identify environmental factors affecting net nitrous oxide (N2O) production from different microbial sources. Intact soil and sediment coreswere subject to two consecutive drying-rewetting cycles in laboratory experiments. The 15N isotope pairing technique was used to quantify N2O emissions sourced fromdenitrification and nitrification. We observed enhanced N2O emissions from both nitrification and denitrification following drying events. Sites exposed to frequent drying-rewetting cycles appear less affected by drying than hydrologically more stable habitats. Fluxes from nitrification were related to the organic matter content, while fluxes from denitrification were controlled by dissolved organic matter quality changes during the drying-rewetting cycles. This study shows the potential link between carbon metabolism and N2O production, combining the effect of drying-rewetting cycles. [ABSTRACT FROM AUTHOR]

Over the last 40 years, a growing number of restoration projects have been implemented to improve the ecological conditions of highly degraded rivers and their floodplains. Despite considerable investment in these projects, information is still limited about the effectiveness and the success of such river restoration measures, mainly due to a lack of standardised and interdisciplinary assessment approaches. During the project 'Wilde Mulde—Restoration of a dynamic riverine landscape in Central Germany', we implemented hydromorphological restoration measures (installation of large wood, removal of rip‐rap, reconnection of a former river side‐arm) along a lowland river in Central Germany. We carried out intensive scientific monitoring of biodiversity, hydromorphology, ecosystem functions and services, as well as socio‐economic aspects. A Before/After‐Control/Impact (BACI) design was used to identify the spatial and temporal effects of the restoration measures and to distinguish them from changes caused by background variation. For this, we used a comprehensive set of indicators, including abiotic (flow velocity, diversity of riverbed topography, and flow resistance), biological (ecosystem respiration, macroinvertebrates, fish, carabids, vegetation, and birds) and socio‐economic (acceptance and public awareness) indicators as well as the ecosystem service indicator aesthetic quality of the landscape. To meet the inherent challenges of such a large‐scale field experiment, like unpredictable environmental conditions, we used an experimental approach that allowed us to demonstrate a measurable success of the implemented restoration measures. The majority of the abiotic and some of the biological and socio‐economic indicators at the restored sites approached values of a natural reference site while already deviating from values of a nonnatural reference site two years after restoration. In addition to the applied interdisciplinary approach, multiple scales of field investigations and data analyses are essential as key components for evaluating successful river and floodplain restoration projects. [ABSTRACT FROM AUTHOR]

Demand for dynamic random access memory (DRAM) bandwidth has outpaced DRAM transistor performance. Given the options of major process investment to scale beyond sixth-generation graphics double-data-rate (GDDR6) or replace GDDR6 with costly high bandwidth memory (HBM), this article presents a solution that simultaneously increases pin and energy efficiency through the integration of four-level pulse amplitude modulation (PAM-4) into the single-ended memory interface. Building upon the existing GDDR6 architecture, evolutionary modifications to input, output, clocking, and data path, along with the component package design, enable a per-pin data rate of more than 22 Gb/s. [ABSTRACT FROM AUTHOR]

In dynamic systems, many species use dormancy as a strategy to survive harsh periods and disperse through time, a fundamental aspect scarcely explored in metacommunities studies. We compared spatial patterns of resting egg bank and active zooplankton diversity across scales (rotifers and cladocerans), explored relationships between diversity and environmental and spatial factors and compared their species composition in riverine floodplains of the Danube River. The egg bank was similarly or even more heterogeneous than the active communities, and signals of community homogenization detected for active communities were not observed for the egg bank. The strong relationships detected between rotifers egg bank diversity and local hydrological parameters suggest that floods would not weaken diversity–environment relationships, as observed for the active communities. These results imply that spatial patterns of resting and active stages are affected by different processes and that the egg bank would not contribute to the homogenizing tendencies observed for the active communities. Our study contributes to a more thorough understanding of zooplankton metacommunities in riverine floodplains and shows the need to further investigate the spatial and temporal patterns of the egg banks within the framework of metacommunities. [ABSTRACT FROM AUTHOR]

Freshwater ecosystems are among the most threatened in the world, while providing numerous essential ecosystem services (ES) to humans. Despite their importance, research on freshwater ecosystem services is limited. Here, we examine how freshwater studies could help to advance ES research and vice versa. We summarize major knowledge gaps and suggest solutions focusing on science and policy in Europe. We found several features that are unique to freshwater ecosystems, but often disregarded in ES assessments. Insufficient transfer of knowledge towards stakeholders is also problematic. Knowledge transfer and implementation seems to be less effective towards South-east Europe. Focusing on the strengths of freshwater research regarding connectivity, across borders, involving multiple actors can help to improve ES research towards a more dynamic, landscape-level approach, which we believe can boost the implementation of the ES concept in freshwater policies. Bridging these gaps can contribute to achieve the ambitious targets of the EU's Green Deal. [ABSTRACT FROM AUTHOR]

Sediment and nutrient retention are essential ecosystem functions that floodplains provide and that improve river water quality. During floods, the floodplain vegetation retains sediment, which settles on plant surfaces and the soil underneath plants. Both sedimentation processes require that flow velocity is reduced, which may be caused by the topographic features and the vegetation structure of the floodplain. However, the relative importance of these two drivers and their key components have rarely been both quantified. In addition to topographic factors, we expect vegetation height and density, mean leaf size and pubescence, as well as species diversity of the floodplain vegetation to increase the floodplain's capacity for sedimentation. To test this, we measured sediment and nutrients (carbon, nitrogen and phosphorus) both on the vegetation itself and on sediment traps underneath the vegetation after a flood at 24 sites along the River Mulde (Germany). Additionally, we measured biotic and topographic predictor variables. Sedimentation on the vegetation surface was positively driven by plant biomass and the height variation of the vegetation, and decreased with the hydrological distance (total R2 = 0.56). Sedimentation underneath the vegetation was not driven by any vegetation characteristics but decreased with hydrological distance (total R2 = 0.42). Carbon, nitrogen and phosphorus content in the sediment on the traps increased with the total amount of sediment (total R2 = 0.64, 0.62 and 0.84, respectively), while C, N and P on the vegetation additionally increased with hydrological distance (total R2 = 0.80, 0.79 and 0.92, respectively). This offers the potential to promote sediment and especially nutrient retention via vegetation management, such as adapted mowing. The pronounced signal of the hydrological distance to the river emphasises the importance of a laterally connected floodplain with abandoned meanders and morphological depressions. Our study improves our understanding of the locations where floodplain management has its most significant impact on sediment and nutrient retention to increase water purification processes. [ABSTRACT FROM AUTHOR]

Populations of large wildlife have declined in many landscapes around the world, and have been replaced or displaced by livestock. The consequences of these changes on the transfer of organic matter (OM) and nutrients from terrestrial to aquatic ecosystems are not well understood. We used behavioural data, excretion and egestion rates and C: N: P stoichiometry of dung and urine of zebu cattle, to develop a metabolism-based estimate of loading rates of OM (dung), C, N and P into the Mara River, Kenya. We also directly measured the deposition of OM and urine by cattle into the river during watering. Per head, zebu cattle excrete and/or egest 25.6 g dry matter (DM, 99.6 g wet mass; metabolism) - 27.7 g DM (direct input) of OM, 16.0–21.8 g C, 5.9–9.6 g N, and 0.3–0.5 g P per day into the river. To replace loading rates OM of an individual hippopotamus by cattle, around 100 individuals will be needed, but much less for different elements. In parts of the investigated sub-catchments loading rates by cattle were equivalent to or higher than that of the hippopotamus. The patterns of increased suspended materials and nutrients as a result of livestock activity fit into historical findings on nutrients concentrations, dissolved organic carbon and other variables in agricultural and livestock areas in the Mara River basin. Changing these patterns of carbon and nutrient transport and cycling are having significant effects on the structure and functioning of both terrestrial and aquatic ecosystems. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Applied Ecology is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Droughts are expected to become more common with climate change resulting in more frequent occurrences of flow intermittency in temperate streams. As intermittency has deleterious effects on fluvial microbial biofilms, there is a need to better understand how droughts affect the microbial functioning and thereby nutrient and organic matter processing in temperate stream ecosystems. Here, the hyporheic zone is of particular importance as it has been shown to be a hot spot for biogeochemical activity under flow intermittence. This study evaluates how drought duration affects microbial biofilm dynamics in the hyporheic zone of intermittent temperate streams. To do so, we used outdoor hyporheic flumes that were subject to periods of drought ranging from 4 to 105 days. Sediment was sampled before and during the drought, and at several occasions after rewetting. Samples were analyzed for extracellular enzymatic activity, bacterial respiration, and bacterial abundances including live to dead cell ratios. The high moisture content remaining in the hyporheic zone of the flumes allowed for the sustained microbial functioning during drought, regardless of drought duration. This can be attributed to cooler temperatures in these climate zones and shading by riparian forests. The high moisture content inhibited the local habitat and community changes that the biofilm might have undergone during more severe desiccation. However, the change in the hyporheic flow regime (flow cessation and resumption) may stimulate microbial processing in these moderate drought conditions. We suggest that the hyporheic zone may act as a buffer against drought and the factors determining this buffer capacity, such as sediment characteristics and climatic regions, need to be analyzed in more detail in future. [ABSTRACT FROM AUTHOR]

We investigated the impact of converting a natural tropical freshwater wetland in Uganda into a rice paddy wetland on climate change mitigation, by comparing carbon dioxide (CO2) and methane (CH4) fluxes from the natural section (under different vegetation communities dominated by Cyperus papyrus, Typha latifolia and Phragmites mauritianus) and from a rice paddy section, during the dry and wet seasons. CO2 fluxes (mg C m− 2 h− 1) from the rice paddy section during the dry and wet seasons were 1045.4 ± 46.6 (mean ± SE) and 804.4 ± 50.2 respectively, significantly higher (p < 0.05) than those obtained from all the three vegetation communities of the natural section. However, CH4 fluxes (mg C m− 2 h− 1) from the rice paddy section during the dry and wet seasons were 2.1 ± 0.4 and 5.1 ± 0.5 respectively, significantly lower (p < 0.05) than those observed from all the vegetation communities of the natural section. Considering total carbon emission, it was observed that whereas conversion of natural tropical freshwater wetlands into rice paddies may limit CH4 emission, it compromises climate change mitigation efforts by increasing total carbon emission, that could make rice paddy wetlands net carbon sources. Fluxes of CO2 and CH4 from the wetland were mainly influenced by water level. Further, we estimated that rice paddy wetlands currently emit only 0.72 and 0.14 % of the total annual CO2 and CH4 respectively, emitted from Uganda’s wetland soils due to their low spatial coverage. However, we predict that future emission of both gases from Uganda’s wetlands will mainly originate from rice paddy wetlands due to their rapid expansion rate. [ABSTRACT FROM AUTHOR]

Uptake and release patterns of dissolved organic matter (DOM) compounds and co-transported nutrients are entangled, and the current literature does not provide a consistent picture of the interactions between the retention processes of DOM fractions. We performed plateau addition experiments with five different complex DOM leachates in a small experimental stream impacted by diffuse agricultural pollution. The study used a wide range of DOM qualities by including leachates of cow dung, pig dung, corn leaves, leaves from trees, and whole nettle plants. We measured changes in nutrient and dissolved organic carbon (DOC) concentrations along the stream course and determined DOM fractions by fluorescence measurements and parallel factor (PARAFAC) decomposition. To assess the influences of hydrological transport processes, we used a 1D hydrodynamic model. We developed a non-linear Bayesian approach based on the nutrient spiralling concept, which we named the "interactions in nutrient spirals using Bayesian regression" (INSBIRE) approach. This approach can disentangle complex interactions of biotic and abiotic drivers of reactive solutes' uptake in multi-component DOM sources. It can show the variability of the uptake velocities and quantify their uncertainty distributions. Furthermore, previous knowledge of nutrient spiralling can be included in the model using prior probability distributions. We used INSBIRE to assess interactions of compound-specific DOM and nutrient spiralling metrics in our experiment. Bulk DOC uptake varied among sources, showing decreasing uptake velocities in the following order: corn > pig dung > leaves > nettles > cow dung. We found no correlations between bulk DOC uptake and the amounts of protein-like compounds or co-leached soluble reactive phosphorus (SRP). The fastest uptake was observed for SRP and the tryptophan-like component, while the other DOM components' uptake velocities more or less resembled that of the bulk DOC. Almost all DOM components showed a negative relationship between uptake and concentration, known as efficiency loss. Furthermore, we observed a few negative and (weak) positive interactions between the uptake and the concentration of different components, such as a decreased uptake of protein-like compounds at high concentrations of a high-molecular-weight humic-like compound. We also found an influence of the wetted width on the uptake of SRP and a microbially derived humic substance, which indicates the importance of the sediment–water interface for P and humic C cycling in the studied stream. Overall, we show that bulk DOC is a weak predictor of DOC uptake behaviour for complex DOM leachates. Individual DOM compound uptake, including co-leached nutrients, is controlled by both internal (quality-related) and external (environmental) factors within the same aquatic ecosystem. We conclude that the cycling of different C fractions and their mutual interaction with N and P uptake in streams is a complex, non-linear problem, which can only be assessed with advanced non-linear approaches, such as the presented INSBIRE approach. [ABSTRACT FROM AUTHOR]

The impact of different vegetation communities on soil organic carbon (SOC) in a tropical freshwater wetland in Uganda was investigated. SOC content, density and storage potential were determined under three different dominant vegetation communities: Cyperus papyrus L., Typha latifolia L. and Phragmites mauritianus Kunth. SOC content (123.7 ± 2.6 SE g C kg−1 dry soil) in C. papyrus was significantly higher (p < 0.05) than in both T. latifolia and P. mauritianus, whereas SOC density (kg C m−2) insignificantly varied (p > 0.05) among the three vegetation communities (C. papyrus = 7.2 ± 0.1, T. latifolia = 6.7 ± 0.1 and P. mauritianus = 6.2 ± 0.1). Similarly, for the entire sampled soil depth (0–50 cm), SOC storage potential was significantly higher (p < 0.05) in C. papyrus (36 118.08 ± 552.52 t C km−2), and was in the order of decreasing magnitude: C. papyrus > T. latifolia > P. mauritianus. Plant biomass density, and soil physico-chemical characteristics, bulk density, salinity, pH and temperature were significantly correlated (p < 0.05) with SOC. In conclusion, where climate change mitigation is considered as a wetland ecosystem service, restoration priorities for degraded/lost tropical freshwater wetlands need to consider C. papyrus plants. In addition, comparing SOC storage by ecosystems, Uganda's wetlands contain three times more SOC than is contained in the country's forests. [ABSTRACT FROM AUTHOR]

Background. Sediments frequently exposed to dry-wet cycles are potential biogeochemical hotspots for greenhouse gas (GHG) emissions during dry, wet and transitional phases. While the effects of drying and rewetting on carbon fluxes have been studied extensively in terrestrial and aquatic systems, less is known about the effects of dry-wet cycles on N2O emissions from aquatic systems. As a notable part of lotic systems are temporary, and small lentic systems can substantially contribute to GHG emissions, dry-wet cycles in these ecosystems can play a major role on N2O emissions. Methodology. This study compiles literature focusing on the effects of drying, rewetting, flooding, and water level fluctuations on N2O emissions and related biogeochemical processes in sediments of lentic and lotic ecosystems. Results. N2O pulses were observed following sediment drying and rewetting events. Moreover, exposed sediments during dry phases can be active spots for N2O emissions. The general mechanisms behind N2O emissions during dry-wet cycles are comparable to those of soils and are mainly related to physical mechanisms and enhanced microbial processing in lotic and lentic systems. Physical processes driving N2O emissions are mainly regulated by water fluctuations in the sediment. The period of enhanced microbial activity is driven by increased nutrient availability. Higher processing rates and N2O fluxes have been mainly observed when nitrification and denitrification are coupled, under conditions largely determined by O2 availability. Conclusions. The studies evidence the driving role of dry-wet cycles leading to temporarily high N2O emissions in sediments from a wide array of aquatic habitats. Peak fluxes appear to be of short duration, however, their relevance for global emission estimates as well as N2O emissions from dry inland waters has not been quantified. Future research should address the temporal development during drying-rewetting phases in more detail, capturing rapid flux changes at early stages, and further explore the functional impacts of the frequency and intensity of dry-wet cycles. [ABSTRACT FROM AUTHOR]

River systems are among the world's most threatened ecosystems, facing multiple and often interlinked pressures across different spatial and temporal scales (Best, 2019; Tockner, Pusch, Borchardt, & Lorang, 2010; Vörösmarty et al., 2010). Such process-based approaches are needed in modern river management and restoration to sustainably rehabilitate engineered river systems and obtain information about the potential for "river recovery" under changing environmental and climatic conditions. The Ecosystem services (ES) approach incorporates different regulating, provisioning, and cultural services provided by rivers and their floodplains within integrative river-floodplain management, considering both the current state and future potential. Monitoring the resilience of rivers as social-ecological systems: A paradigm shift for river assessment in the twenty-first century. [Extracted from the article]

Macrophytes are important organisms in running water systems, having a decisive role in ecological processes and interactions. Their temporal and spatial distribution in streams can be highly variable, and this is often determined by flow velocity. In this study, macrophyte growth, morphology and nutrient stoichiometry were studied monthly during one growing season in reaches with different flow velocity and flow velocity distribution and, as a result, different distributional plant patterns in an Austrian lowland stream, dominated by evergreen macrophyte species, Berula erecta. Flow velocity, water depth, fine sediment layer depth and metabolism were measured in the stream and the correlation with plant biomass and morphological traits was tested. We aimed to study differences between reaches with different distributional plant patterns and whether common interactions between macrophytes and flow velocity can also be observed when vegetation is evergreen. Plant biomass showed seasonal variation, with the highest values in June and the lowest in February. In the reach with low flow velocity and homogeneous macrophyte distribution, biomass peaked in summer and plant morphology changed with the seasons, whereas biomass and morphology in the reach with high flow velocity and patchy distribution were more constant throughout the year. Plant carbon, nitrogen and phosphorus content were higher in spring and autumn than in summer, whereas biogenic silica accumulated over the course of the growth season. Stream metabolism was strongly correlated with macrophyte biomass, and this correlation was stronger in the reach with homogeneous macrophyte distribution than in the reach with a patchy distribution. Moreover, average leaf area and stem length were positively correlated with fine sediment layer depth, and negatively with flow velocity. The results stress the importance of macrophyte growth and morphology in river processes like metabolism, hydromorphology and nutrient dynamics: especially plant morphology plays an important role in macrophyte–flow interactions. [ABSTRACT FROM AUTHOR]

River floodplains are hotspots of productivity and biodiversity and recognized to fulfil vital ecosystem functions and services. Restoration measures of the decoupled Danube floodplains east of Vienna aim to re‐establish multi‐functionality, that is, ensure navigation, preserve and restore unique fluvial and riparian habitats and re‐establish natural processes and service provisioning. Side‐channels are proposed for reconnection combined with the removal of embankments and groins. We evaluated how a programme of measures influences the diversity and quantity of specific ecosystem services (ES) and therefore, the overall multi‐functionality of the floodplain compared to the current situation. Therefore, regulating ecosystem services (RES), such as nutrient retention and habitat provisioning, were modelled and predicted using multivariate regression models. Also, the potential of cultural ecosystem services (CES) was assessed based on mapping of recreational activities. The impact of proposed measures on ES quantity, that is, quantitative spatial representation, and quality, that is, biodiversity and nature experience, as well as potential synergies and trade‐offs were analysed. Our results show clear synergies especially for RES (habitat for the rheotopic community and nutrient retention) and the CES of nature experience. Those services have a weak and local trade‐off with the quantitative availability of opportunities for recreation. This pattern could only be detected by considering both, quantitative as well as qualitative aspects of ES. Overall, our results show that the restoration measures have a high potential to increase the multi‐functionality of the floodplain system by supporting the provisioning of RES including habitat for endangered species and selected CES. [ABSTRACT FROM AUTHOR]

In dynamic systems, many species use dormancy as a strategy to survive harsh periods and disperse through time, a fundamental aspect scarcely explored in metacommunities studies. We compared spatial patterns of resting egg bank and active zooplankton diversity across scales (rotifers and cladocerans), explored relationships between diversity and environmental and spatial factors and compared their species composition in riverine floodplains of the Danube River. The egg bank was similarly or even more heterogeneous than the active communities, and signals of community homogenization detected for active communities were not observed for the egg bank. The strong relationships detected between rotifers egg bank diversity and local hydrological parameters suggest that floods would not weaken diversity–environment relationships, as observed for the active communities. These results imply that spatial patterns of resting and active stages are affected by different processes and that the egg bank would not contribute to the homogenizing tendencies observed for the active communities. Our study contributes to a more thorough understanding of zooplankton metacommunities in riverine floodplains and shows the need to further investigate the spatial and temporal patterns of the egg banks within the framework of metacommunities. [ABSTRACT FROM AUTHOR]

Bamboo, as a pioneer vegetation, often forms forests on bare lands after catastrophic landslides. Compared to evergreen forest soil, bamboo forest soil is much more labile, with a higher percentage of microbially derived organic carbon (OC), lower molecular weight, and lower humic acid content. We hypothesised that different terrigenous organic matter (tOM) sources with varying lability and phosphorus (P) availability select for bacterioplankton with distinct metabolic pathways.We incubated natural bacterioplankton assemblages with tOM leached from bamboo forest soil (BOM) and evergreen forest soil (EOM) and compared these to a lake water control. To test if microbial metabolism would be limited by OC or P availability of each tOM treatment, we used acetate as an extra labile OC source and phosphate as an inorganic P source. Bacterial metabolism was measured by analysing respiration via O2 consumption and production via tritiated thymidine (TdR) assimilation.Bacterioplankton metabolism is limited by the availability of P in BOM substrates. When using BOM, bacteria had higher enzymatic activities for phosphatase. The nutrients required for bacterial biomass seemed to be derived from organic matter. Under BOM treatment, bacterial production (BP) (0.92 ± 0.13 μg C L−1 hr−1) and cell specific TdR assimilation rates (0.015 ± 0.002 10–18 M TdR cell−1 hr−1) were low. Adding P enhanced BP (BOM+P 1.52 ± 0.31 and BOM+C+P 2.25 ± 0.37 μg C L−1 hr−1) while acetate addition had no significant effect on BOM treatment.This indicated that the bacteria switched to using added inorganic P to respire a P‐limited BOM substrate, which increased total BP and abundance, resulting in even more active respiration and lower growth efficiency. We also found higher activities for chitin‐degrading enzyme β‐N‐acetylglucosaminidase, which is associated with N mining from aminosaccharides.Microbes using EOM, however, did not change metabolic strategies with additional acetate or/and inorganic P. This is due to higher concentrations of organic P in EOM substrates and the presence of inorganic N in the EOM leachates an alternative nutrient source. Bacteria produced β‐glucosidase and leucyl‐aminopeptidase in order to utilise the humic substances, which sustained greater bacterial abundance, higher BP (2.64 ± 0.39 μg C L−1 hr−1), and lower cell‐specific respiration. This yielded a much higher bacterial growth efficiency (15 ± 9.2%) than the lake water control.Our study demonstrated the aquatic metabolic discrepancy between tOM of different forest types. Bacterioplankton in BOM and EOM exhibit distinct metabolic responses. Bacterial metabolic strategy when using BOM implied that the supposedly stabilised biomass OM might be efficiently used by aquatic bacterioplankton. As the labile and nutrient‐deficient BOM is more susceptible to the influence of additional nutrients, fertiliser residues in bamboo forest catchments might have a stronger effect on aquatic bacterial metabolic pathways. Thus, it is important to take tOM differences into consideration when building models to estimate soil carbon turnover rates along a terrestrial–aquatic continuum. [ABSTRACT FROM AUTHOR]

Uptake and release patterns of dissolved organic matter (DOM) compounds and nutrients are entangled, and the current literature does not provide a consistent picture of the link between DOM composition, nutrient concentrations, and effects on their cycling. We performed two plateau addition experiments for each of five different, realistic, complex DOM leachates in a small stream, heavily enriched in nitrate but not phosphate or DOM due to diffuse agricultural pollution. By including cow and pig dung as well as corn, leaves and nettles leachates, the study used a wide range of different DOM qualities. We measured changes in nutrient concentrations and determined DOM fractions by fluorescence measurements and parallel factor (PARAFAC) decomposition. To assess influences from hydrological transport processes, we used a 1-D hydrodynamic model. We propose a non-linear Bayesian approach to the nutrient spiralling concept, the Interactions in Nutrient Spirals using BayesIan REgression (INSBIRE) approach. This approach can disentangle complex and interacting biotic and abiotic drivers in nutrient uptake metrics, show their variability and quantify their error distribution. Furthermore, previous knowledge on nutrient spiralling can be included in the model using prior probability distributions. We used INSBIRE to assess interactions of compound-specific DOM and nutrient spiralling metrics the data of our experiment. The uptake processes of different DOM fractions were linked to each other. We observed stimulating and dampening effects of DOM fractions on each other and the overall DOM uptake. We found saturation effects for dissolved organic carbon (concentration of C, DOC) uptake, as rising concentrations of a DOM fraction dampened its uptake. The degradation of a humic DOM component of terrestrial origin was stimulated by other DOM fractions, pointing to priming effects. We also found an influence of the wetted width on the uptake of soluble reactive phosphorus (SRP) and a microbially derived humic substance, which indicates the importance of the sediment-water interface for P and humic C cycling in the studied stream. Interestingly, we found no interactions between DOM uptake and nitrate or SRP concentrations, or any effect of the added DOM leachates on nitrate uptake, indicating that the increase in DOC concentrations and SRP concentrations were not sufficient to affect the relatively steady nitrate uptake during the experiments. Overall, we show that bulk DOC is a weak predictor of DOC uptake behaviour for complex DOM leachates and that individual DOM compound uptake, nitrate uptake and SRP uptake are controlled very differently within the same aquatic ecosystem. We also found effects of hydromorphology on the uptake of one humic fluorophore and SRP. We conclude that cycling of different C fractions, their interaction and interactions with N and P uptake in streams is a complex, non-linear problem, which can only be assessed with advanced non-linear approaches, such as we present with INSBIRE. [ABSTRACT FROM AUTHOR]

Climate change can result in multiple indirect alterations of the environment in riverine ecosystems, due to changes in precipitation and runoff. Flow velocity, concentrations of CO2 and nutrients are thereby expected to change, and consequences of the combination of those effects for macrophytes, a key organism group, are still poorly understood. This was tested in a racetrack flume experiment on macrophyte species Berula erecta, an amphibious species growing fully submerged in the experiment. In a full-factorial design, plants were exposed to two different CO2 concentrations, two nutrient concentrations (N, P and Si) and two flow velocities. Apart from individual dose–response tests, two climate change scenarios were tested: a wet scenario simulating heavy precipitation and runoff with high flow velocity, high CO2 and high nutrient concentrations and a dry scenario simulating evapotranspiration with low flow velocity, high CO2 and high nutrient concentrations. Growth rate, biomass, morphology, chlorophyll and nutrient content were measured. Berula erecta responded strongly to both scenarios. Biomass and relative growth rate increased, leaf BSi content decreased, and especially in the wet scenario macrophytes had shorter stems and formed stolons with new ramets: the plants invested in horizontal growth to avoid hydrodynamic stress. Moreover, the C/N ratio was higher, leading to lower quality of macrophyte tissue as food source, and chlorophyll concentration was lower in the high CO2 treatment. It can be concluded that combined stressors caused by climate change strongly affect macrophytes, which may indirectly have consequences for other organisms of the aquatic ecosystem that depend on macrophytes. [ABSTRACT FROM AUTHOR]

Biotic interactions shape the community structure and function of ecosystems and thus play an important role in ecosystem management and restoration. To investigate how water temperature (related to the season) and water depth (related to spatial patterns of river morphology) affect macrophyte–bacterioplankton interactions in a groundwater-fed river, we conducted the structural equation modeling on datasets grouped by hydrological conditions. In addition to direct effects on macrophyte growth and/or bacterioplankton development, water temperature and water depth could both regulate the role of different nutrients (inorganic and organic) on affecting these biological indicators. Deeper water depth intensified the positive relationship between macrophytes and bacterioplankton, while higher temperature switched the relationship from being positive to negative. Our study provides empirical evidences that abiotic variables, even with relatively low fluctuations, play a critical role in regulating the patterns and strengths of interaction between macrophytes and bacterioplankton. [ABSTRACT FROM AUTHOR]

Species distribution models (SDMs) are statistical tools to identify potentially suitable habitats for species. For SDMs in river ecosystems, species occurrences and predictor data are often aggregated across subcatchments that serve as modeling units. The level of aggregation (i.e., model resolution) influences the statistical relationships between species occurrences and environmental predictors—a phenomenon known as the modifiable area unit problem (MAUP), making model outputs directly contingent on the model resolution. Here, we test how model performance, predictor importance, and the spatial congruence of species predictions depend on the model resolution (i.e., average subcatchment size) of SDMs. We modeled the potential habitat suitability of 50 native fish species in the upper Danube catchment at 10 different model resolutions. Model resolutions were derived using a 90‐m digital‐elevation model by using the GRASS‐GIS module r.watershed. Here, we decreased the average subcatchment size gradually from 632 to 2 km2. We then ran ensemble SDMs based on five algorithms using topographical, climatic, hydrological, and land‐use predictors for each species and resolution. Model evaluation scores were consistently high, as sensitivity and True Skill Statistic values ranged from 86.1–93.2 and 0.61–0.73, respectively. The most contributing predictor changed from topography at coarse, to hydrology at fine resolutions. Climate predictors played an intermediate role for all resolutions, while land use was of little importance. Regarding the predicted habitat suitability, we identified a spatial filtering from coarse to intermediate resolutions. The predicted habitat suitability within a coarse resolution was not ported to all smaller, nested subcatchments, but only to a fraction that held the suitable environmental conditions. Across finer resolutions, the mapped predictions were spatially congruent without such filter effect. We show that freshwater SDM predictions can have consistently high evaluation scores while mapped predictions differ significantly and are highly contingent on the underlying subcatchment size. We encourage building freshwater SDMs across multiple catchment sizes, to assess model variability and uncertainties in model outcomes emerging from the MAUP. [ABSTRACT FROM AUTHOR]

Nitrate (NO3-) removal from aquatic ecosystems involves several microbially mediated processes including denitrification, dissimilatory nitrate reduction to ammonium (DNRA), and anaerobic ammonium oxidation (anammox) regulated by slight changes in environmental gradients. Saline lakes are prone to the accumulation of anthropogenic contaminants, making them highly vulnerable environments to NO3- pollution. We investigated nitrate removal pathways in mesocosm experiments using lacustrine, undisturbed, organic-rich sediments from Pétrola Lake (Spain), a highly saline waterbody subject to anthropogenic NO3- pollution. We used the revised 15N-isotope pairing technique (15N-IPT) to determine NO3- sink processes. Our results demonstrate the coexistence of denitrification, DNRA, and anammox processes, and their contribution was determined by environmental conditions (oxygen and light). DNRA and N2O-denitrification were the dominant nitrogen (N) removal pathways when oxygen and/or light were present (up to 82 %). In contrast, anoxia and darkness promoted NO3- reduction by DNRA (52 %) and N loss by anammox (28 %). Our results highlight the role of coupled DNRA-anammox, as yet has never been investigated in hypersaline lake ecosystems. We conclude that anoxia and darkness favored DNRA and anammox processes over denitrification and therefore reduce N2O emissions to the atmosphere. [ABSTRACT FROM AUTHOR]

Citizen science has proved acutely useful in collecting vast amounts of environmental data at large spatial and temporal scales. However, evidence on successful experimental approaches with citizen scientist involvement is still scarce. We demonstrate that collaborations with high school students in biogeochemical experiments may generate robust and reliable data for scientific analyses. Within an Austrian research-education-cooperation dealing with landuse effects on stream processes, we performed laboratory experiments on P adsorption capacities of stream sediments together with high school students. The students were involved in every step of the procedure, from the planning of the study design to the interpretation of the results. Data quality was checked via comparisons of coefficients of variation among replicates and R 2 values of adsorption curves performed by students and scientists. Data generated by students did not differ significantly from those of professionals regarding both absolute values and variability among replicates. Based on our experiences, we discuss preconditions, restrictions, and advantages of collaborating with high school students in scientific laboratory experiments. [ABSTRACT FROM AUTHOR]

Aim: Systematic conservation planning is vital for allocating protected areas given the spatial distribution of conservation features, such as species. Due to incomplete species inventories, species distribution models (SDMs) are often used for predicting species' habitat suitability and species' probability of occurrence. Currently, SDMs mostly ignore spatial dependencies in species and predictor data. Here, we provide a comparative evaluation of how accounting for spatial dependencies, that is, autocorrelation, affects the delineation of optimized protected areas. Location: Southeast Australia, Southeast U.S. Continental Shelf, Danube River Basin. Methods: We employ Bayesian spatially explicit and non‐spatial SDMs for terrestrial, marine and freshwater species, using realm‐specific planning unit shapes (grid, hexagon and subcatchment, respectively). We then apply the software gurobi to optimize conservation plans based on species targets derived from spatial and non‐spatial SDMs (10%–50% each to analyse sensitivity), and compare the delineation of the plans. Results: Across realms and irrespective of the planning unit shape, spatially explicit SDMs (a) produce on average more accurate predictions in terms of AUC, TSS, sensitivity and specificity, along with a higher species detection probability. All spatial optimizations meet the species conservation targets. Spatial conservation plans that use predictions from spatially explicit SDMs (b) are spatially substantially different compared to those that use non‐spatial SDM predictions, but (c) encompass a similar amount of planning units. The overlap in the selection of planning units is smallest for conservation plans based on the lowest targets and vice versa. Main conclusions: Species distribution models are core tools in conservation planning. Not surprisingly, accounting for the spatial characteristics in SDMs has drastic impacts on the delineation of optimized conservation plans. We therefore encourage practitioners to consider spatial dependencies in conservation features to improve the spatial representation of future protected areas. [ABSTRACT FROM AUTHOR]

Transport of riverine dissolved carbon (including DOC and DIC) is a crucial process linking terrestrial and aquatic C reservoirs, but has rarely been examined in subtropical small mountainous rivers (SMRs). This study monitored DOC and DIC concentrations on a biweekly basis during non-event flow periods and at 3 h intervals during two typhoon events in three SMRs in southwestern Taiwan between January 2014 and August 2016. Two models, HBV (the Hydrologiska Byråns Vattenbalansavdelning model) and a three-endmember mixing model, were applied to determine the quantities of DOC and DIC transport from different flow paths. The results show that the annual DOC and DIC fluxes were 2.7–4.8 and 48.4–54.3 t C km -2 yr -1 , respectively, which were approx. 2 and 20 times higher than the global mean of 1.4 and 2.6 t C km -2 yr -1 , respectively. The DIC / DOC ratio was 14.08, which is much higher than the mean of large rivers worldwide (1.86), and indicates the high rates of chemical weathering in this region. The two typhoons contributed 12 %–14 % of the annual streamflow in only 3 days (about 1.0 % of the annual time), whereas 15.0 %–23.5 % and 9.2 %–12.6 % of the annual DOC and DIC flux, respectively, suggested that typhoons play a more important role in DOC transport than DIC transport. The endmember mixing model suggested that DOC and DIC export was mainly from surface runoff and deep groundwater, respectively. The unique patterns seen in Taiwan SMRs characterized by high dissolved carbon flux, high DIC / DOC ratio, and large transport by intense storms should be taken into consideration when estimating global carbon budgets. [ABSTRACT FROM AUTHOR]

Our study aimed to analyze the effects of chronic nutrient loading on the capacity of headwater streams to retain phosphorus and ammonium pulses of different duration. For this purpose, we selected nine headwater streams located across a gradient of increasing agricultural land use and eutrophication. In each stream, we performed sequential plateau additions with increasing nutrient concentrations in summer 2015 and instantaneous slug additions in summer 2016 under similar hydrological conditions. We modelled kinetic uptake curves from the slug additions via the Tracer Additions for Spiraling Curve Characterization method and calculated ambient uptake parameters. Ambient uptake rates generally increased (1.4-20.8 µg m−2 s−1 for NH4-N and 0.3-10.3 µg m−2 s−1 for SRP, respectively), while ambient uptake velocities decreased from oligotrophic to polytrophic streams (1.8-14.0 mm min−1 for NH4-N and 1.6-9.9 mm min−1 for SRP, respectively). However, correlations between ambient uptake parameters and background concentrations were weak. Concentration-dependent uptake rates followed either a linear or a Michaelis-Menten saturation model, regardless of the degree of nutrient loading. Uptake rate curves showed counter-clockwise hysteresis in oligotrophic streams and clockwise hysteresis in streams of higher trophic states, indicating a reduced significance of hyporheic uptake with increasing nutrient loading. Comparisons of slug and plateau additions revealed that oligotrophic streams were most efficient in uptake during short nutrient pulses, while eutrophic streams profited from longer pulse duration. The results indicate that nutrient uptake is increasingly transport-controlled in polluted streams where increased biofilm thickness and clogging of sediments restrict nutrient transport to reactive sites. [ABSTRACT FROM AUTHOR]

We present a long-standing case of an 88-year-old woman with multiple comorbidities receiving intra-articular Botox® (onabotulinumtoxinA) injections for bilateral chronic knee osteoarthritis. She reported improved pain control and function supported by validated outcome measures. [ABSTRACT FROM AUTHOR]

Abstract: Species diversity is affected by processes operating at multiple spatial scales, although the most relevant scales that contribute to compositional variation and the temporal shifts of the involved mechanisms remain poorly explored. We studied spatial patterns of phytoplankton, rotifers and microcrustacean diversity across scales in a river floodplain system of the Danube in Austria under contrasting hydrological conditions (post‐flood versus low water level). The species turnover between water sections (β2) and between wetlands (β3) was the major components of regional diversity for all studied groups, with species turnover between habitats (β1) as a minor contributor. β1 diversity and β2 diversity were lower than expected by chance in most cases, suggesting that communities are more homogeneous than expected at these scales. β3 diversity was higher than expected by chance in many cases, indicating more distinct communities at the wetland level. Patterns were highly similar under different hydrological conditions, indicating no major immediate effect of flood events. Local environmental and spatial factors were similarly important in structuring phytoplankton, rotifer and microcrustacean communities in both hydrological conditions. Relevant environmental factors were spatially structured in post‐flood conditions especially between sections, suggesting flood‐driven homogenisation within the wetlands. Under low water level, spatial structuring of environment decreased and pure environmental factors gained relevance for phytoplankton and rotifers. Our results suggest that although β2 diversity between water sections is a major component of regional diversity, long‐term spatial processes responding to connectivity across the wetland structure phytoplankton, rotifer and microcrustacean communities. Aquatic sections within the limited spatial extent of the remaining floodplain areas appear more homogeneous than expected probably due to flood recurrence over the years. These results highlight that adequate planning of restoration and conservation strategies of floodplain wetlands should consider environmental heterogeneity together with long‐term spatial processes. [ABSTRACT FROM AUTHOR]

Transport of riverine dissolved carbon (including DOC and DIC) is a crucial process which links terrestrial and aquatic C storages, but is rarely examined in small subtropical mountainous rivers. This study monitored DOC and DIC concentrations on a biweekly basis during regular flow period and at 3-hour intervals during two typhoons in 3 small mountainous rivers in southwestern Taiwan between Jan 2014 and Aug 2016. A hydrological model, HBV, and three end-member mixing model were applied to determine the quantities of DOC and DIC transport from different flowpaths. The results showed that the annual DOC and DIC fluxes were 2.7-4.8 and 48.4-54.3 ton-C km-2 yr-1, which were 2- and 20 times higher than the global mean of 1.4 and 2.6 ton-C km-2 yr-1. The DIC / DOC ratio was 14.08, much higher than the mean (1.86) of large rivers worldwide, indicating the high rates of chemical weathering and/or low rates of decomposition in this region. Two typhoons contributed 12-14 % of the annual streamflow in only 3 days (~ 1.0 % of the annual time), whereas 15.0-23.5 % and 9.2-12.6 % of the annual DOC and DIC flux, respectively, suggested that typhoons play a more important role on DOC transport than DIC transport. End-member mixing model suggested that DOC export was mainly from surface runoff, while DIC transport was mainly through deep groundwater. The unique patterns seen in Taiwan SMRs characterized by high dissolved carbon flux, high DIC / DOC ratio, and large transport by intense storms should be taken into consideration when estimating global carbon budgets. [ABSTRACT FROM AUTHOR]

Publisher's Note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. The online version of the original article can be found at https://doi.org/10.1007/s10531-022-02459-w B Correction to: b https://doi.org/10.1007/s10531-022-02459-w In the original article, the names of the authors were published as Meulenbroek Paul1,2 - Hein Thomas1,2 - Friedrich Thomas1 - Valentini Alice3 - Er"os Tibor4 - Schabuss Michael5 - Zornig Horst5 - Lenhardt Mirjana6,7 - Pekarik Ladislav8 - Jean Pauline3 - Dejean Tony3 - Pont Didier It must be published as: Paul Meulenbroek1,2,*, Thomas Hein 1,2, Thomas Friedrich 1, Alice Valentini 3, Tibor Er"os4, Michael Schabuss5, Horst Zornig5, Mirjana Lenhardt6,7, Ladislav Pekarik8, Pauline Jean3, Toni Dejean3, Didier Pont9 The original article has been corrected. [Extracted from the article]

The graphic DRAM interface standard GDDR5X is developed as an evolutionary extension to the widely available GDDR5. The implementation presented here achieves a data rate of 12 Gb/s/pin on a single-ended signaling interface with 32 IOs for a total memory bandwidth of 48 GB/s. The GDDR5X DRAM relies on the quad data rate operation enabled by a phase-locked loop (PLL), a receiver with a pre-amplifier in a dual-regulation loop and a one-tap digital feedback equalizer (DFE). To support lower performance modes, an additional GDDR5-like operation is provided, which bypasses the PLL. The interface is realized on a conventional high-volume DRAM process to provide a cost-efficient, discrete package 8-Gb DRAM for high-performance graphic cards and compute applications. [ABSTRACT FROM PUBLISHER]

Patches are of central interest to many areas of environmental science because they provide a lower limit of structural detail in synoptic studies, and an upper limit of contextual structure for point measurement-based studies. Identification and delineation of macrophyte patches however, is often arbitrary and case-specific. In this paper we propose a widely-applicable set of guidelines for delineating a “patch” and “patch matrix” – the latter implying a collection of interacting patches – which could standardise future research. To support this proposal, we examine examples from eco-hydrological studies, focusing on interactions between plants, water flow, sediment, and invertebrates. We discuss three aspects that are key to the delineation of a patch: (1) constitution (variable(s) whose values define the patch), (2) spatial properties (patch boundaries), and (3) distinction (of isolated single patches from multiple separate-but-interacting patches). The discussion of these aspects results in guidelines for identifying and delineating a patch which is applicable to any aquatic habitat, and covers a broad range of disciplines such as plant and animal ecology, biogeochemistry, hydraulics, and sedimentology. [ABSTRACT FROM AUTHOR]

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