Through the artificial manipulation of hydrological residence time, hydropower operations on alpine lakes should not only alter their hydro-biogeochemical characteristics but also modulate the degree of sensitivity of the lake to atmospheric forcing. These hypotheses were addressed by means of in situ observations that were combined with a three-dimensional lake model of a high-altitude pump-storage

The oligotrophication of freshwater is the reduction of the nutrient concentration in the water column, which causes the depletion of organic matter and diminishes the biological production of the ecosystem. To elucidate the zooplankton response to nutrient depletion (oligotrophication), an experiment was performed in mesocosms simulating real scenarios. Phytoplankton and zooplankton inocula were collected

Continuous temperature monitoring for two adjacent tropical crater lakes in Mexico at 4200 m amsl shows that the lakes have rhythmic episodes of heating and cooling with a duration of ~ 30 days during the warmest months. The episodes were caused by rise and decline of solar irradiance reaching the lake surface. One lake, El Sol, showed over each heating and cooling episode a stable mixed layer (~ 20 days)

Deconstructing beta diversity patterns into site or species contributions is a modern approach to understand the factors affecting variation in biodiversity. In this context, estimating the Local Contribution to Beta Diversity (LCBD) and the individual Species Contribution to Beta diversity (SCBD) have been shown to be a good approach to improve knowledge of the drivers of beta diversity. We examined

In Lake Grande de Peñalara, an originally fishless small high mountain lake in the Central Iberian Peninsula, brook trout (Salvelinus fontinalis) was introduced in the 1970s, and then eradicated 30 years later using gillnets. In this study, we investigated the time-course and changes in macroinvertebrates and zooplankton communities, before and after the eradication, by studying their richness and

Shallow lake sediments may be anoxic despite overlying aerated water. In the current study, we aimed to ascertain the contribution of shallow areas to internal phosphorus (P) loading due to sediment anoxia in stratifying lakes. Moreover, we analyzed relationships of the key water quality variables with internal P loading due to sediment anoxia originating solely from stratifying areas (IPobs) and that

Estimating air–water gas transfer velocities (k) is integral to understand biogeochemical and ecological processes in aquatic systems. In lakes, k is commonly predicted using wind-based empirical models, however, their predictive performance under conditions that differ from their original calibration remains largely unassessed. Here, we collected 2222 published k estimates derived from various methods

The emission of CO2 and CH4 by diffusion, bubbling and downstream was measured in ten reservoirs representative of the diversity of French hydropower reservoirs in 2016. In all reservoirs, higher fluxes were measured in summer than in spring and winter. Low fluxes were measured in alpine reservoirs as compared to run-of-the-river and storage reservoirs. The low temperatures as well as the low organic

We investigated which environmental variables of floodplain lakes act as potential drivers of fish assemblages and how they explain the variation in taxonomic and functional diversity of the community. We evaluated the taxonomic richness, functional dispersion (the distribution of species abundances with different traits) and redundancy (how similar the species are) of fish communities from six floodplain

Large quantities of material are moved annually from the ocean to freshwater systems by migrating Pacific salmon. Previous studies have focused on nitrogen and phosphorus provided by spawning salmon but largely ignored micronutrients essential to aquatic productivity. We collected salmon tissue, water, and biofilm from seven southeast Alaskan streams both before and during the salmon run to test for

The construction of drainage canals in the upper stretch of the Salado River has caused the input of salty waters into the basin, with unexplored consequences on zooplankton dynamics and reproduction. To determine the consequences of those anthropic interventions, zooplankton samples were taken under four hydrologic conditions (high water, mean flows, low flows, very low flows) in the canals and the

Terrestrial organic matter (OM) is an essential energy source that fuels many food webs. The factors contributing to OM decomposition and the rate at which OM decomposes can influence carbon fluxes through ecosystems. Previous research demonstrates that the factors driving OM decomposition can vary with environmental condition, prompting more research that characterizes the relative importance of each

Scaling relationships, including power laws, provide quantitative predictions used in basic and applied sciences. We investigated scaling relationships between catchment area and lake surface area, the ratio of which has important implications for terrestrial-aquatic linkages. Synthesizing evidence from 9 datasets from three continents, we show that there is an approximately linear relationship between

This paper studies the influence of the impounding process during flood recession in the TGR on the distribution and rerelease of sediment phosphorus forms in the Xiangxi Bay in 2016. Influenced by the main stream of the Three Gorges Reservoir (TGR) flowing backward during impoundment, the water environmental conditions, sediment grain size and sediment-forming environment of the tributary bays change

Concentrations of dissolved organic carbon (DOC) have increased recently in many lakes at high latitudes in North America and Europe, but it is unclear what effect this will have on the identity of the limiting nutrient for phytoplankton [nitrogen (N) vs. phosphorus (P)]. Identifying the effect of changing DOC on phytoplankton nutrient limitation is complicated by spatial covariation between atmospheric

Our understanding of how ecosystems function has changed from an equilibria-based view to one that recognizes the dynamic, fluctuating, nonlinear nature of aquatic systems. This current understanding requires that we manage systems for resilience. In this review, we examine how resilience has been defined, measured and applied in aquatic systems, and more broadly, in the socioecological systems in

Beta diversity can be analysed using various approaches, but those integrating site and species contributions to beta diversity are rare in floodplain lake systems. We analysed the beta diversity of rotifers and cladocerans across 50 floodplain lakes in Brazil, focusing on both pelagic and littoral zones. We partitioned beta diversity into local contributions (LCBD), species contributions (SCBD), and

Small headwater streams interlink catchment soils with the river network. As water makes its way from the hillslopes to the stream, it may transport dissolved organic carbon (DOC) and potentially soil microbes into stream water. In this study, we aimed at quantifying the dynamic transfer of DOC and microbial life, namely bacteria from catchment soils into streams. We hypothesized that increased soil

Changes in land cover are one of the most extensive and influential human impacts on fluvial ecosystems. In this study, we assessed how changes in food resource quantity and type linked to forest cover affect mountain stream multitrophic macroinvertebrate community size structure. We tested whether the total organism biomass (size spectrum intercept) and the energy transfer efficiency among trophic

Extreme drying can dramatically shift abiotic characteristics of streams and species respond differently as conditions change. We modified a conceptual model describing responses of aquatic invertebrate assemblages to stream drying to facilitate predictions of fish assemblage shifts in which thresholds of physiochemical gradients lead to punctuated losses of fish diversity as stream connectivity diminishes

Elevational gradients are ideal ecological venues for testing how communities respond to environmental changes associated with global warming. Recent warming rates have been shown to increase with elevation, hypothetically translating into heat waves that more adversely affect cold-adapted alpine communities than lower montane communities exposed to cold waves. We tested this hypothesis by conducting

We investigated whether environmental filtering or dispersal-related factors mostly drive helophyte and hydrophyte species richness and community composition in 93 lakes situated in Baikal Siberia. Using partial linear regression and partial redundancy analysis, we studied (1) what are the relative roles of environmental variables, dispersal variables, spatial processes and region identity (i.e., river

In calcareous watersheds, groundwater alkalinity results largely from dissolution of carbonate minerals in soils. The alkalinity increases initially approximately in proportion to nitrate (NO3−) concentration and eventually approaches an apparent maximum of approximately 8 mmol L−1 at high NO3− concentrations. This close positive relationship between alkalinity and NO3− concentration appears to be

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Channelization can have far-reaching and long-term impacts on stream ecology. In this study, we demonstrate that channelization is associated with lower stream quality as measured by macroinvertebrate bioindicators when compared to unchannelized streams. Citizen scientists collected the data for this study between 1995 and 2014, performing 3021 sampling events during the months of May and June across

Trait-based approaches have been used to explore ecosystem level consequences of local changes in biodiversity along environmental gradients. Using a novel response–effect trait framework, we seek to identify and explain the mechanisms governing the cascading effects of environment on plant traits and ecosystem multi-functioning in the large Poyang Lake wetland, China. We sampled the above-ground biomass

The original publication of this paper contains a mistake in Figure 3.

Streams in hot, arid environments often exist as a series of isolated pools along main channels. During these periods, shallow alluvial through flow may strongly influence key ecological processes within pools. We measured diel changes in δ13C values of dissolved inorganic carbon (DIC) and dissolved oxygen (DO) in two pools of ephemeral, dryland streams. We quantified alluvial water connectivity through

Winter limnology has been developed mainly in northern-temperate or subarctic lakes, while mid-latitude Mediterranean high mountain lakes have been less studied during the ice-covered season. We present a five-year study in one of these lower latitude high mountain lakes, conducted with multiprobes located at two different depths recording high-frequency data. We have studied highly contrasted winters

Phytoplankton play a key role in supporting aquatic food webs. However, the effects of ongoing large-scale changes in the concentrations and stoichiometry of important biological compounds [dissolved inorganic N (DIN), total phosphorus (TP), dissolved organic carbon (DOC) and DIN:TP] on the development and nutritional quality of phytoplankton for higher trophic levels are unclear. We conducted lake

Dissolved organic matter (DOM) in freshwaters is recognised as a significant and active component of the global carbon budget. DOM exported from terrestrial ecosystems may be compositionally and functionally altered by chemical and biological reactions as it is transported downstream. The processes affecting DOM in headwater streams remain uncertain but are potentially highly variable depending on

Biogeochemical rates within streams vary with ecosystem properties including the distribution of fishes. While many studies investigate the singular effect of fishes on ecosystem components, there is a limited understanding of how fish presence interacts with other ecosystem properties to affect ecosystem structure and function. Here, we used path analyses to elucidate direct and indirect effects of

Shallow lakes are typically found in one of two stable states, a macrophyte-dominated clear water state or a turbid state due to excessive phytoplankton and suspended sediment. Whether shallow backwater lakes in large river floodplains exhibit similar alternate stable states is less understood. This study considers mechanisms, interactions and feedbacks associated with a shift in environmental conditions

It is well recognized that river-floodplain systems contribute significantly to riverine ecosystem metabolism, and that bacteria are key players in the aquatic organic carbon cycle, but surprisingly few studies have linked bacterial community composition (BCC), function and carbon quality in these hydrologically highly dynamic habitats. We investigated aquatic BCC and extracellular enzymatic activity

Mixotrophy seems to be widespread among phytoplankton, but whether this strategy is more relevant in oligotrophic lakes remains unclear. Here, we tested the hypothesis that the relative abundance of mixotrophic flagellates in lakes increases along an elevational gradient paralleling increasingly oligotrophic conditions. For this purpose, 12 lakes located between 575 and 2796 m above sea level were

Climate-change driven increases in water temperature pose challenges for aquatic organisms. Predictions of impacts typically do not account for fine-grained spatiotemporal thermal patterns in rivers. Patches of cooler water could serve as refuges for anadromous species like salmon that migrate during summer. We used high-resolution remotely sensed water temperature data to characterize summer thermal

The temporal dynamic of riverine ecosystems and their fish communities and populations has been addressed in ecological theory and management for several decades. A growing number of case studies on the historic development especially of European and North American rivers have been published. Nonetheless, a theoretical debate about the contributions and limits of historical approaches and interdisciplinary

Using historical sources from the turn of the 19th to the 20th century, we investigated the long-term evolution of the fish community in a mountainous river network and the influence of different human uses and management measures. Within the alpine Salzach catchment, historical presence was reconstructed for 26 fish species, abundance classes for 19 species. Due to channelization, flood protection

Species distributions models (SDM) that rely on estimated relationships between present environmental conditions and species presence-absence are widely used to forecast changes of species distributions caused by global warming but far less to reconstruct historical assemblages. By compiling historical fish data from the turn to the middle of the twentieth century in a similar way for several European

The main objective of this paper is to investigate how archaeological fish remains and written historical records can contribute to the reconstruction of long-term developments of fish communities along the Austrian and Hungarian Danube. Although such approaches are sensitive to various factors, the chronological subdivision and relative quantification of proxy data demonstrate environmental and faunal

Spectroscopic techniques and extracellular enzyme activity measurements were combined with assessments of bacterial secondary production (BSP) to elucidate flood-pulse-linked differences in carbon (C) sources and related microbial processes in a river-floodplain system near Vienna (Austria). Surface connection with the main channel significantly influenced the quantity and quality of dissolved organic

The catchment land-use composition of 249 fish sampling sites in Austrian running waters revealed effects on the biological integrity. Beyond correlative analysis, we investigated (1) which land-use category had the strongest effect on fish, (2) whether metrics of functional fish guilds reacted differently, (3) whether there were cumulative effects of land-use categories, and (4) whether effects varied

Changes in habitat acoustics over the year can potentially affect fish hearing and orientation to sound, especially in temperate climates. This is the first study where year-round changes in ambient noise in aquatic habitats were assessed. Seven different European fresh-water habitats were chosen for this study. Sound pressure level (SPL) and spectral composition of the ambient noise varied in both

A short overview of currently available studies on the ecology of viruses in running waters is provided. Additionally, a survey was conducted on the dynamics of both viruses and bacteria in an isolated floodplain segment of the Danube River and in the main channel near Vienna (Austria) during the hydrologically most dynamic phase (spring - summer). The study evaluates the differences between the main