scholarly journals Water tracing with environmental DNA in a high-Alpine catchment

2019 ◽  
Author(s):  
Elvira Mächler ◽  
Anham Salyani ◽  
Jean-Claude Walser ◽  
Annegret Larsen ◽  
Bettina Schaefli ◽  
...  
Keyword(s):  
Environmental Dna ◽  
Water Source ◽  
Main Channel ◽  
Hyporheic Exchange ◽  
Multiple Time ◽  
Catchment Scale ◽  
Stream Network ◽  
Overbank Flow ◽  
And Storage ◽  
Biological Richness

Abstract. Alpine streams are particularly valuable for downstream water resources and for ecosystem conservation. However, the details of where and when water is stored and released in the heterogeneous mountain environment are rarely known. The use of physico-chemical flow path tracers is particularly challenging due to the temporary accumulation and storage of water in the form of snow and ice. Alternatively, biological tracers might complement information on flow and storage of water, especially as the different microhabitats in Alpine aquatic systems are inhabited by characteristic organismal communities. In this study, we explored the potential of particles of environmental DNA found in the water (eDNA) to characterize hydrological flow paths and connectivity in an Alpine catchment in Switzerland. Between March and September 2017, we sampled water at multiple time points at 11 sites distributed over the 13.4 km2 Vallon de Nant catchment for genetic species information based on naturally occurring eDNA. The sites correspond to three different water source types and habitats (main channel, tributaries, and springs). Comparison of typical hydrological tracers and eDNA with temporal evolution of streamflow revealed that in the main channel and in the tributaries, the change in streamflow, dq/dt, is strongly correlated with biological richness. In springs, electrical conductivity was found to have a positive but not as strong correlation with biological richness. At the catchment scale, our results show that biological richness as indicated by the diversity detected by eDNA samples. When streamflow is increasing, transport of additional, and probably terrestrial, DNA into water storage or flow compartments is occurring. Such processes include overbank flow, stream network expansion and retraction, and hyporheic exchange. In general, our results highlight the importance of considering the at-site sampling habitat in combination with upstream connected habitats to understand how streams integrate eDNA over a catchment and to interpret spatially distributed eDNA samples, both for hydrological and biodiversity assessments. We identify next steps to be addressed to use eDNA as an independent tracer of Alpine water sources and we provide recommendations for future observation of eDNA in Alpine stream ecosystems.

scholarly journals The variation in genetic material of a high Alpine catchment reveals (sub)surface exchange

2020 ◽  
Author(s):  
Elvira Maechler ◽  
Natalie Ceperley ◽  
Anham Salyani ◽  
Jean-Claude Walser ◽  
Annegret Larsen ◽  
...  
Keyword(s):  
Genetic Material ◽  
Environmental Dna ◽  
Main Channel ◽  
Hyporheic Exchange ◽  
Stream Network ◽  
Flow Paths ◽  
Surface Exchange ◽  
Hydrologic Processes ◽  
Hydrologic Tracers ◽  
Overbank Flow

<p>In the past years, it has been proposed that stream networks can accumulate genetic material over a given area. Accordingly, a sample of environmental DNA (eDNA) from streamflow at the outlet of a catchment can be used as an indicator of the upstream biodiversity. eDNA’s use in ecological studies is becoming more and more common and it seems reasonable to assume that eDNA might also offer a powerful tool as a hydrologic tracer. However, the original ecological proposition largely simplifies the complexity of any seasonal, diurnal, or spatial variation according to hydrologic flow paths and processes. From a hydrological perspective, this shortcoming is particularly problematic in Alpine headwater catchments, where the combination of snowmelt-dominated summer flow and particularly high climatic and geomorphologic heterogeneity results in hydrologic flow paths that are especially dynamic in space and time. </p><p>We were interested to see if on one hand, eDNA could teach us something new about hydrologic (subsurface) flow paths, and on the other hand, if biodiversity assessment should consider hydrologic variation in detail. To do so, we sampled natural occurring eDNA at 11 points distributed over the 13.4 km<sup>2</sup>, intensively monitored Vallon de Nant (1189-3051 m. a.s.l., Switzerland) between March and September 2017. We chose points corresponding to three different potential microhabitats and flow regimes (main channel, tributary, and spring) likely both inhabited by characteristic organismal communities and of interest for identifying hydrologic flow paths. We found that at moments when streamflow was increasing rapidly, biological richness in upstream points in the main channel and in tributaries was highest contrary to springs, where richness was higher when electrical conductivity was highest.  Thus, the main conclusion from our work is that elevated richness corresponds to moments in time when multiple mechanisms transport additional, probably terrestrial, DNA into water storage or flow compartments. These mechanisms could include overbank flow, stream network expansion, and hyporheic exchange. Our data demonstrates that biodiversity assessments using eDNA do need to consider hydrologic processes and shows that there is a potential future for eDNA among hydrologic tracers.  We will give recommendations in this talk about how to sample eDNA to answer hydrologic questions.</p><p> </p>

scholarly journals Environmental DNA simultaneously informs hydrological and biodiversity characterization of an Alpine catchment

2020 ◽  
Author(s):  
Elvira Mächler ◽  
Anham Salyani ◽  
Jean-Claude Walser ◽  
Annegret Larsen ◽  
Bettina Schaefli ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Water Storage ◽  
Environmental Dna ◽  
Main Channel ◽  
Low Flow ◽  
Multiple Time ◽  
Water Types ◽  
Naturally Occurring ◽  
Overbank Flow ◽  
Alpine System

Abstract. Alpine streams are particularly valuable for downstream water resources and of high ecological relevance, however a detailed understanding of water storage and release in such heterogeneous environments is still often lacking. Observations of naturally occurring tracers, such as stable isotopes of water or electrical conductivity, are frequently used to track and explain hydrological patterns and processes. Importantly, some of these hydrological processes also create microhabitat variations in Alpine aquatic systems, each inhabited by characteristic organismal communities. The inclusion of such ecological diversity in a hydrologic assessment of an Alpine system may improve our understanding of hydrologic flows while also delivering biological information. Recently, the application of environmental DNA (eDNA) to assess biological diversity in water and connected habitats has gained popularity in the field of aquatic ecology. A few of these studies have started to link aquatic diversity with hydrologic processes, but hitherto never in an Alpine system. Here, we collected water from an Alpine catchment in Switzerland and compared the genetic information of eukaryotic organisms conveyed by eDNA with the hydrologic information conveyed by naturally-occurring, hydrologic tracers. Between March and September 2017, we sampled water at multiple time points at 10 sites distributed over the 13.4 km2 Vallon de Nant catchment (Switzerland). The sites corresponded to three different water types and habitats, namely low flow or ephemeral tributaries, groundwater fed springs, and the main channel receiving water from both previous mentioned water types. Accompanying observations of typical physico-chemical hydrologic characteristics with eDNA revealed that in the main channel and in the tributaries the biological richness increases according to change in streamflow, dq/dt. Whereas, in contrast, the richness in springs increased in correlation with electrical conductivity. At the catchment scale, our results suggest that transport of additional, and probably terrestrial, DNA into water storage or flow compartments occurs with increasing streamflow. Such processes include overbank flow, stream network expansion, and hyporheic exchange. In general, our results highlight the importance of considering the at-site sampling habitat in combination with upstream connected habitats to understand how streams integrate eDNA over a catchment and to interpret spatially distributed eDNA samples, both for hydrologic and biodiversity assessments. At the intersection of two disciplines, our study provides complementary knowledge gains and identifies the next steps to be addressed for using eDNA to achieve complementary insights into Alpine water sources. Finally, we provide recommendations for future observation of eDNA in Alpine stream ecosystems.

scholarly journals Environmental DNA simultaneously informs hydrological and biodiversity characterization of an Alpine catchment

2021 ◽  
Vol 25 (2) ◽  
pp. 735-753
Author(s):  
Elvira Mächler ◽  
Anham Salyani ◽  
Jean-Claude Walser ◽  
Annegret Larsen ◽  
Bettina Schaefli ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Water Storage ◽  
Environmental Dna ◽  
Main Channel ◽  
Low Flow ◽  
Water Types ◽  
Hydrologic Processes ◽  
Naturally Occurring ◽  
Overbank Flow ◽  
Alpine System

Abstract. Alpine streams are particularly valuable for downstream water resources and of high ecological relevance; however, a detailed understanding of water storage and release in such heterogeneous environments is often still lacking. Observations of naturally occurring tracers, such as stable isotopes of water or electrical conductivity, are frequently used to track and explain hydrologic patterns and processes. Importantly, some of these hydrologic processes also create microhabitat variations in Alpine aquatic systems, each inhabited by characteristic organismal communities. The inclusion of such ecological diversity in a hydrologic assessment of an Alpine system may improve our understanding of hydrologic flows while also delivering biological information. Recently, the application of environmental DNA (eDNA) to assess biological diversity in water and connected habitats has gained popularity in the field of aquatic ecology. A few of these studies have started to link aquatic diversity with hydrologic processes but hitherto never in an Alpine system. Here, we collected water from an Alpine catchment in Switzerland and compared the genetic information of eukaryotic organisms conveyed by eDNA with the hydrologic information conveyed by naturally occurring hydrologic tracers. Between March and September 2017, we sampled water at multiple time points at 10 sites distributed over the 13.4 km2 Vallon de Nant catchment (Switzerland). The sites corresponded to three different water types and habitats, namely low-flow or ephemeral tributaries, groundwater-fed springs, and the main channel receiving water from both previous mentioned water types. Accompanying observations of typical physicochemical hydrologic characteristics with eDNA revealed that in the main channel and in the tributaries, the biological richness increases according to the change in streamflow, dq/dt, whereas, in contrast, the richness in springs increased in correlation with electrical conductivity. At the catchment scale, our results suggest that transport of additional, and probably terrestrial, DNA into water storage or flow compartments occurs with increasing streamflow. Such processes include overbank flow, stream network expansion, and hyporheic exchange. In general, our results highlight the importance of considering the at-site sampling habitat in combination with upstream connected habitats to understand how streams integrate eDNA over a catchment and to interpret spatially distributed eDNA samples, both for hydrologic and biodiversity assessments. At the intersection of two disciplines, our study provides complementary knowledge gains and identifies the next steps to be addressed for using eDNA to achieve complementary insights into Alpine water sources. Finally, we provide recommendations for future observation of eDNA in Alpine stream ecosystems.

scholarly journals Theoretical evaluation of concentration time and storage coefficient with their application to major dam basins in Korea

2018 ◽  
Vol 19 (2) ◽  
pp. 644-652
Author(s):  
Chulsang Yoo ◽  
Jiho Lee ◽  
Eunsaem Cho
Keyword(s):  
Channel Length ◽  
Main Channel ◽  
Flow Conditions ◽  
Empirical Formulas ◽  
Theoretical Evaluation ◽  
Storage Coefficient ◽  
Concentration Time ◽  
Channel Slope ◽  
And Storage ◽  
Laminar Flow Conditions

Abstract This study theoretically evaluated the basin concentration time and storage coefficient with their empirical formulas available worldwide. The evaluation results were also validated in the application to major dam basins in Korea. The findings are summarized as follows. As a result of analytical analysis, the concentration time was found to be proportional to the main channel length under laminar flow conditions and to the square of it under turbulent flow conditions, but inversely proportional to the channel slope. It was also found that the storage coefficient and the concentration time are linearly but loosely related. Most empirical formulas for the concentration time concurred with the basic equation form, but just a few for the storage coefficient. Applications to major dam basins in Korea also showed that the concentration time agrees well with the result of theoretical analysis. However, the behavior of the storage coefficient varied much, basin by basin, indicating that additional factors may be needed to explain it.

Integrating water isotopes and cosmic ray sensor data with modelling to understand near-surface storage-discharge relationships in managed landscapes

2020 ◽  
Author(s):  
Katya Dimitrova Petrova ◽  
Josie Geris ◽  
Mark Wilkinson ◽  
Allan Lilly ◽  
Lucile Verrot ◽  
...  
Keyword(s):  
Land Use ◽  
Model Calibration ◽  
Cosmic Ray ◽  
Rainfall Runoff ◽  
Runoff Generation ◽  
Catchment Scale ◽  
Stream Network ◽  
Near Surface ◽  
Transit Times ◽  
Water Isotope

<p>Subsurface water storage strongly influences runoff generation processes, regulates agricultural production and defines catchment buffering capacities to hydrometeorological extremes. Knowledge about the amount and spatio-temporal distribution of catchment storage can also be important for constraining and evaluating hydrological models. While it is still challenging to measure this directly, characterisation of catchment-scale storage is more likely to be achieved via a combination of estimation methods at appropriate scales. While stable water isotopes can provide insights into (timescales of) dominant stores and flow paths, novel cosmic ray sensors (CRS) offer insights into large scale water storage dynamics.</p><p>Here, we combined stable water isotope analyses with CRS data and rainfall runoff modelling to better understand subsurface storage dynamics and how these relate to catchment runoff generation. We focussed specifically on humid managed environments, such as in NE Scotland, where short-term changes in both storage and management activities occur predominantly at or near the surface. To understand spatial patterns in flow pathways and the evolution of water ages (as mean transit times), we conducted long-term (~5y) stable water isotope monitoring of a nested stream network in a 10km<sup>2</sup> mixed-agricultural catchment. Monitoring also involved artificial drains of agricultural fields and country roads. This was complemented with a short-term study (~14 months) of mobile soil water in key soil-land use units. Additionally, we characterised field scale near-surface storage dynamics in these same key soil-land use units using CRS technology. Finally, we explored the storage-discharge relationships based on these CRS storage estimates and the information content of these novel data for rainfall-runoff model calibration to better characterise catchment-scale storage dynamics.</p><p>The outcomes of both transit time and rainfall-runoff modelling highlighted the importance of near-surface storage dynamics for catchment functioning and streamflow generation. Predominantly young waters (<1 y) across the stream network were associated mainly with shallow soils and the extensive artificial field drainage, which short-circuits water delivery to the streams, especially during wet periods. Water ages in soil mobile water were also short (1 – 6 months) and subtle differences between the key soil-land use units were associated with land management practices, which either enhanced (artificial drainage, ploughing) or delayed (compaction) transit times in the soil. As CRS near-surface storage estimates related well to catchment scale storage dynamics (R<sup>2</sup>=0.91) and stream discharge (R<sup>2</sup>=0.71), we evaluated the effect of using CRS data in model calibration. Including it in the model calibration was especially useful during intermediate and wet periods. Overall, our results showed that a combined model calibration using discharge and CRS estimates provided a better representation of catchment internal dynamics, additionally reducing uncertainty during low flows.</p><p>In the context of a humid managed catchment, our results showed that the integration of water isotope analyses and CRS-derived storage estimates can provide unique insights into catchment scale sub-surface storage dynamics, runoff generation and the evolution of water ages in soils and streams. They also demonstrated the potential of these data for informing rainfall-runoff modelling frameworks, but further work is needed across a range of different environments to explore wider applications.</p>

Origin and Storage of Large Woody Debris in a Third-order Mountain Stream Network, Gangwon-do, Korea

2020 ◽  
Vol 34 (3) ◽  
pp. 249-258
Author(s):  
Suk Woo Kim ◽  
◽  
Kun Woo Chun ◽  
Jung Il Seo ◽  
Young Hyup Lim ◽  
...  
Keyword(s):  
Woody Debris ◽  
Large Woody Debris ◽  
Mountain Stream ◽  
Stream Network ◽  
Third Order ◽  
And Storage

scholarly journals Hydrologiczne uwarunkowania morfogenezy wybranych erozyjnych form rzeźby równi zalewowej na przykładzie doliny Bugu

2018 ◽  
Vol 27 (1) ◽  
pp. 57-70
Author(s):  
Piotr Ostrowski ◽  
Marta Utratna
Keyword(s):  
Flow Direction ◽  
Main Channel ◽  
River Valley ◽  
Oxbow Lakes ◽  
Hydrological Conditions ◽  
Ice Storms ◽  
Overbank Flow ◽  
The Relationship

The aim of the study was to analyze the relationship between hydrological conditions and morphogenesis of erosional landforms on the floodplain of the Bug river valley. It was found that forms such as side arms and oxbow lakes as a result of cyclical floods are subject to secondary erosion. The main reason for this phenomenon is the fact that they combine strings of overbank flow direction. In the case of ice storms, these forms take on the role of the main channel limiting the effects of floods.

Emerging controls of in-stream uptake at the catchment scale

2021 ◽  
Author(s):  
Joni Dehaspe ◽  
Andreas Musolff
Keyword(s):  
Aquatic Ecosystems ◽  
Food Production ◽  
Ecological Status ◽  
Low Frequency ◽  
River Networks ◽  
Catchment Scale ◽  
Stream Network ◽  
Uptake Efficiency ◽  
Wide Range ◽  
Landscape Types

<p>Nitrate (NO<sub>3</sub><sup>-</sup>) and phosphate (PO<sub>4</sub><sup>3-</sup>) inputs to rivers are high in Germany and Europe following energy and food production demands, which can cause harm to aquatic ecosystems and jeopardize drinking water supplies. It is known that permanent and non-permanent nutrient uptake can retain significant amounts of NO<sub>3</sub><sup>-</sup> and PO<sub>4</sub><sup>3-</sup> in river networks, however, there is little knowledge about the mechanistic processes involved and their controlling factors on catchment scales. In this work we apply a data driven analysis using the shape of stable, multi-annual, low frequency concentration-discharge (C-Q) relationships in about 500 German monitoring stations. More specifically, the bending of NO<sub>3</sub><sup>-</sup> C-Q relationship was shown to encode uptake efficiency. We systematically address the effects of light and shading, stream ecological status, land-use, hydrological conditions, stream network configurations and chlorophyll a patterns as potential in-stream processing predictors. This assessment allows us to conclude on dominant controls of NO<sub>3</sub><sup>-</sup> uptake efficiency across a wide range of landscape types.</p>

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