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Franklin PA, Bašić T, Davison PI, Dunkley K, Ellis J, Gangal M, González-Ferreras AM, Gutmann Roberts C, Hunt G, Joyce D, Klöcker CA, Mawer R, Rittweg T, Stoilova V, Gutowsky LFG. Aquatic connectivity: challenges and solutions in a changing climate. JOURNAL OF FISH BIOLOGY 2024. [PMID: 38584261 DOI: 10.1111/jfb.15727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Revised: 02/22/2024] [Accepted: 02/27/2024] [Indexed: 04/09/2024]
Abstract
The challenge of managing aquatic connectivity in a changing climate is exacerbated in the presence of additional anthropogenic stressors, social factors, and economic drivers. Here we discuss these issues in the context of structural and functional connectivity for aquatic biodiversity, specifically fish, in both the freshwater and marine realms. We posit that adaptive management strategies that consider shifting baselines and the socio-ecological implications of climate change will be required to achieve management objectives. The role of renewable energy expansion, particularly hydropower, is critically examined for its impact on connectivity. We advocate for strategic spatial planning that incorporates nature-positive solutions, ensuring climate mitigation efforts are harmonized with biodiversity conservation. We underscore the urgency of integrating robust scientific modelling with stakeholder values to define clear, adaptive management objectives. Finally, we call for innovative monitoring and predictive decision-making tools to navigate the uncertainties inherent in a changing climate, with the goal of ensuring the resilience and sustainability of aquatic ecosystems.
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Affiliation(s)
- Paul A Franklin
- National Institute of Water & Atmospheric Research, Hamilton, New Zealand
| | - Tea Bašić
- Centre for Environment, Fisheries and Aquaculture Science, Lowestoft, UK
| | - Phil I Davison
- Centre for Environment, Fisheries and Aquaculture Science, Lowestoft, UK
| | - Katie Dunkley
- Christ's College, University of Cambridge, Cambridge, UK
- Department of Zoology, University of Cambridge, Cambridge, UK
| | - Jonathan Ellis
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
| | - Mayuresh Gangal
- Manipal Academy of Higher Education, Manipal, India
- Nature Conservation Foundation, Mysore, India
| | - Alexia M González-Ferreras
- IHCantabria - Instituto de Hidráulica Ambiental de la Universidad de Cantabria. C/Isabel Torres 15, Santander, Spain
- School of Life Sciences, University of Essex, Colchester, UK
| | | | - Georgina Hunt
- School of Biological Sciences, University of Aberdeen, Aberdeen, UK
| | - Domino Joyce
- Biological Sciences, School of Natural Sciences, University of Hull, Hull, UK
| | - C Antonia Klöcker
- Institute of Marine Research, Tromsø, Norway
- Department of Biosciences, University of Oslo, Oslo, Norway
| | - Rachel Mawer
- Department of Animal Sciences and Aquatic Ecology, Ghent University, Ghent, Belgium
| | - Timo Rittweg
- Leibniz Institute of Freshwater Ecology and Inland Fisheries Berlin, Berlin, Germany
- Division of Integrative Fisheries Management, Faculty of Life Sciences, Humboldt-Universität zu Berlin, Unter den Linden, Berlin, Germany
| | - Velizara Stoilova
- Department of Environmental and Life Sciences, Karlstad University, Karlstad, Sweden
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2
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Groundwater Amphipods of the Hyporheic Interstitial: A Case Study from Luxembourg and The Greater Region. DIVERSITY 2023. [DOI: 10.3390/d15030411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/17/2023]
Abstract
Hyporheic interstitials are ecologically dynamic and often neglected aquatic environments. In this study, groundwater amphipods (Niphargidae, Pseudoniphargidae and Crangonyctidae) were sampled in hyporheic interstitials throughout Luxembourg and The Greater Region and specimens were analyzed by DNA barcoding. Sites characterized by gravel or coarse sand and high flow velocities of incoming water were the most species- and specimen-rich. A total of 11 species were detected, of which the Niphargus aquilex lineage EF of the N. aquilex cryptic species complex and juveniles of N. schellenbergi dominated the data set, but an unknown lineage of the N. aquilex-complex was also found. Some regions appeared to be devoid of groundwater amphipods. We hypothesize that underlying sandstone formations resulting in low sediment porosity may prevent physical colonization, but also that historical water pollution may have a long-lasting effect, either through the persistence of contaminants in the sediment or low recolonization rates of affected populations. In summary, our approach expanded regional species inventories, confirmed known occurrences, and validated previously questionable or historical morphology-based detections. In addition, the collection of absence data provided valuable insights into local extinctions. Finally, DNA-based distribution data are needed to gather information on the ecological affinities of groundwater amphipods to understudied hyporheic interstitial environments.
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3
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Arias-Real R, Menéndez M, Muñoz I, Pascoal C. Drying shapes the ecological niche of aquatic fungi with implications on ecosystem functioning. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 859:160374. [PMID: 36427710 DOI: 10.1016/j.scitotenv.2022.160374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 11/14/2022] [Accepted: 11/16/2022] [Indexed: 06/16/2023]
Abstract
Fungi are among the most abundant and diverse organisms on Earth and play pivotal roles in global carbon processing, nutrient cycling and food webs. Despite their abundant and functional importance, little is known about the patterns and mechanisms governing their community composition in intermittent rivers and ephemeral streams, which are the most common fluvial ecosystems globally. Thus far, it is known that aquatic fungi have evolved various life-history strategies and functional adaptations to cope with drying. Nevertheless, some of these adaptations have a metabolic cost and trade-offs between growth, reproduction and dispersion that may affect ecosystem functioning. Thus, understanding their ecological strategies along a gradient of drying is crucial to assess how species will respond to global change and to identify meaningful taxa to maintain ecosystem functions. By combining in situ hydrological information with a niche-based approach, we analysed the role of drying in explaining the spatial segregation of fungal species, and we determined their specialization and affinity over a gradient of drying. In addition, we estimated whether species niches are good predictors of two key ecosystem processes: organic matter decomposition and fungal biomass accrual. Overall, we found that annual drying duration and frequency were the most influential variables upon species niche differentiation across the 15 studied streams. Our cluster analysis identified four drying niche-based groups with contrasting distributions and responses over the drying gradient: drying-sensitive, partly tolerant to drying, generalist, and drying-resistant specialist. In addition, we found that species belonging to the drying specialist group showed a weak contribution to both ecosystem processes, suggesting trade-offs between drying resistance strategies and the energy invested in growth. Taken together, our results suggest that increased water scarcity may jeopardise the capacity of aquatic fungi to guarantee ecosystem functioning and to maintain biogeochemical cycles despite their ability to cope with drying.
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Affiliation(s)
- Rebeca Arias-Real
- Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, Campus of Gualtar, 4710-057 Braga, Portugal; Institute of Science and Innovation for Bio-Sustainability (IB-S), University of Minho, Campus of Gualtar, 4710-057 Braga, Portugal; Department of Evolutionary Biology, Ecology and Environmental Sciences, Faculty of Biology, Universitat de Barcelona, Av. Diagonal, 643, 08028 Barcelona, Spain.
| | - Margarita Menéndez
- Department of Evolutionary Biology, Ecology and Environmental Sciences, Faculty of Biology, Universitat de Barcelona, Av. Diagonal, 643, 08028 Barcelona, Spain
| | - Isabel Muñoz
- Department of Evolutionary Biology, Ecology and Environmental Sciences, Faculty of Biology, Universitat de Barcelona, Av. Diagonal, 643, 08028 Barcelona, Spain
| | - Cláudia Pascoal
- Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, Campus of Gualtar, 4710-057 Braga, Portugal; Institute of Science and Innovation for Bio-Sustainability (IB-S), University of Minho, Campus of Gualtar, 4710-057 Braga, Portugal
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4
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Wang Z, Vivoni ER. Detecting Streamflow in Dryland Rivers Using CubeSats. GEOPHYSICAL RESEARCH LETTERS 2022; 49:e2022GL098729. [PMID: 36247514 PMCID: PMC9540060 DOI: 10.1029/2022gl098729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 06/13/2022] [Accepted: 07/07/2022] [Indexed: 06/16/2023]
Abstract
Determining the flow regime of non-perennial rivers is critical in hydrology. In this study, we developed a new approach using CubeSat imagery to detect streamflow presence using differences in surface reflectance for areas within and outside of a river reach. We calibrated the approach with streamflow records in the Hassayampa River of Arizona over 3 years (2019-2021), finding good agreement in the annual fractions of flowing days at stream gages (R 2 = 0.82, p < 0.0001). Subsequently, annual fractions of flowing days were derived at 90 m intervals along the Hassayampa River, finding that 12% of reaches were classified as intermittent, with the remaining as ephemeral. Using a Hovmöller diagram, streamflow presence was visualized in unprecedented spatiotemporal detail, allowing estimates of daily fraction of flowing channel and annual fractions of flowing days. This new tool opens avenues for detecting streamflow and studying hydrological and biogeochemical processes dependent on water presence in drylands.
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Affiliation(s)
- Zhaocheng Wang
- School of Sustainable Engineering and the Built EnvironmentArizona State UniversityTempeAZUSA
| | - Enrique R. Vivoni
- School of Sustainable Engineering and the Built EnvironmentArizona State UniversityTempeAZUSA
- School of Earth and Space ExplorationArizona State UniversityTempeAZUSA
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5
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Durighetto N, Mariotto V, Zanetti F, McGuire KJ, Mendicino G, Senatore A, Botter G. Probabilistic Description of Streamflow and Active Length Regimes in Rivers. WATER RESOURCES RESEARCH 2022; 58:e2021WR031344. [PMID: 35865717 PMCID: PMC9286364 DOI: 10.1029/2021wr031344] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 01/21/2022] [Accepted: 03/30/2022] [Indexed: 05/27/2023]
Abstract
In spite of the prevalence of temporary rivers over a wide range of climatic conditions, they represent a relatively understudied fraction of the global river network. Here, we exploit a well-established hydrological model and a derived distribution approach to develop a coupled probabilistic description for the dynamics of the catchment discharge and the corresponding active network length. Analytical expressions for the flow duration curve (FDC) and the stream length duration curve (SLDC) were derived and used to provide a consistent classification of streamflow and active length regimes in temporary rivers. Two distinct streamflow regimes (persistent and erratic) and three different types of active length regimes (ephemeral, perennial, and ephemeral de facto) were identified depending on the value of two dimensionless parameters. These key parameters, which are related to the underlying streamflow fluctuations and the sensitivity of active length to changes in the catchment discharge (here quantified by the scaling exponent b), originate seven different behavioral classes characterized by contrasting shapes of the underlying SLDCs and FDCs. The analytical model was tested using data gathered in three study catchments located in Italy and USA, with satisfactory model performances in most cases. Our analytical and empirical results show the existence of a structural relationship between streamflow and active length regimes, which is chiefly modulated by the scaling exponent b. The proposed framework represents a promising tool for the coupled analysis of discharge and river network length dynamics in temporary streams.
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Affiliation(s)
- Nicola Durighetto
- Department of Civil, Environmental and Architectural EngineeringUniversity of PaduaPadovaItaly
| | - Veronica Mariotto
- Department of Civil, Environmental and Architectural EngineeringUniversity of PaduaPadovaItaly
| | - Francesca Zanetti
- Department of Civil, Environmental and Architectural EngineeringUniversity of PaduaPadovaItaly
| | - Kevin J. McGuire
- Department of Forest Resources & Environmental ConservationVirginia TechBlacksburgVAUSA
| | | | - Alfonso Senatore
- Department of Environmental EngineeringUniversity of CalabriaRendeItaly
| | - Gianluca Botter
- Department of Civil, Environmental and Architectural EngineeringUniversity of PaduaPadovaItaly
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6
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Messager ML, Lehner B, Cockburn C, Lamouroux N, Pella H, Snelder T, Tockner K, Trautmann T, Watt C, Datry T. Global prevalence of non-perennial rivers and streams. Nature 2021; 594:391-397. [PMID: 34135525 DOI: 10.1038/s41586-021-03565-5] [Citation(s) in RCA: 64] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Accepted: 04/19/2021] [Indexed: 02/05/2023]
Abstract
Flowing waters have a unique role in supporting global biodiversity, biogeochemical cycles and human societies1-5. Although the importance of permanent watercourses is well recognized, the prevalence, value and fate of non-perennial rivers and streams that periodically cease to flow tend to be overlooked, if not ignored6-8. This oversight contributes to the degradation of the main source of water and livelihood for millions of people5. Here we predict that water ceases to flow for at least one day per year along 51-60 per cent of the world's rivers by length, demonstrating that non-perennial rivers and streams are the rule rather than the exception on Earth. Leveraging global information on the hydrology, climate, geology and surrounding land cover of the Earth's river network, we show that non-perennial rivers occur within all climates and biomes, and on every continent. Our findings challenge the assumptions underpinning foundational river concepts across scientific disciplines9. To understand and adequately manage the world's flowing waters, their biodiversity and functional integrity, a paradigm shift is needed towards a new conceptual model of rivers that includes flow intermittence. By mapping the distribution of non-perennial rivers and streams, we provide a stepping-stone towards addressing this grand challenge in freshwater science.
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Affiliation(s)
- Mathis Loïc Messager
- Department of Geography, McGill University, Montreal, Quebec, Canada. .,RiverLY Research Unit, National Research Institute for Agriculture, Food and Environment (INRAE), Villeurbanne, France.
| | - Bernhard Lehner
- Department of Geography, McGill University, Montreal, Quebec, Canada.
| | - Charlotte Cockburn
- Department of Geography, McGill University, Montreal, Quebec, Canada.,Department of Earth Science, Dartmouth College, Hanover, NH, USA
| | - Nicolas Lamouroux
- RiverLY Research Unit, National Research Institute for Agriculture, Food and Environment (INRAE), Villeurbanne, France
| | - Hervé Pella
- RiverLY Research Unit, National Research Institute for Agriculture, Food and Environment (INRAE), Villeurbanne, France
| | | | - Klement Tockner
- Senckenberg Society for Nature Research, Frankfurt am Main, Germany.,Faculty of Biological Sciences, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Tim Trautmann
- Institute of Physical Geography, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Caitlin Watt
- Department of Geography, McGill University, Montreal, Quebec, Canada.,Lethbridge Research and Development Centre, Agriculture and Agri-Food Canada, Lethbridge, Alberta, Canada
| | - Thibault Datry
- RiverLY Research Unit, National Research Institute for Agriculture, Food and Environment (INRAE), Villeurbanne, France.
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7
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Water Storage in Dry Riverbeds of Arid and Semi-Arid Regions: Overview, Challenges, and Prospects of Sand Dam Technology. SUSTAINABILITY 2021. [DOI: 10.3390/su13115905] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Augmenting water availability using water-harvesting structures is of importance in arid and semi-arid regions (ASARs). This paper provides an overview and examines challenges and prospects of the sand dam application in dry riverbeds of ASARs. The technology filters and protects water from contamination and evaporation with low to no maintenance cost. Sand dams improve the socio-economy of the community and help to cope with drought and climate change. However, success depends on the site selection, design, and construction. The ideal site for a sand dam is at a transition between mountains and plains, with no bend, intermediate slope, and impermeable riverbed in a catchment with a slope greater than 2°. The spillway dimensioning considers the flow velocity, sediment properties, and storage target, and the construction is in multi-stages. Recently, the failure of several sand dams because of incorrect siting, evaporation loss, and one-stage construction were reported. Revision of practitioners’ manuals by considering catchment scale hydrological and hydrogeological characteristics, spillway height, and sediment transport are recommended. Research shows that protected wells have better water quality than open wells and scoop holes. Therefore, the community should avoid open defecation, pit latrines, tethering of animals, and applying pesticides near the sand dam.
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8
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Mietchen D, Penev L, Georgiev T, Ovcharova B, Kostadinova I. Open science in practice: 300 published research ideas and outcomes illustrate how RIO Journal facilitates engagement with the research process. RESEARCH IDEAS AND OUTCOMES 2021. [DOI: 10.3897/rio.7.e68595] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Since Research Ideas and Outcomes was launched in late 2015, it has stimulated experimentation around the publication of and engagement with research processes, especially those with a strong open science component. Here, we zoom in on the first 300 RIO articles that have been published and elucidate how they relate to the different stages and variants of the research cycle, how they help address societal challenges and what forms of engagement have evolved around these resources, most of which have a nature and scope that would prevent them from entering the scholarly record via more traditional journals. Building on these observations, we describe some changes we recently introduced in the policies and peer review process at RIO to further facilitate engagement with the research process, including the establishment of an article collections feature that allows us to bring together research ideas and outcomes from within one research cycle or across multiple ones, irrespective of where they have been published.
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9
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Jelil SN, Gaykar A, Girkar N, Ben C, Hayward MW, Krishnamurthy R. Mammal Persistence Along Riparian Forests in Western India Within a Hydropower Reservoir 55 Years Post Construction. Front Ecol Evol 2021. [DOI: 10.3389/fevo.2021.643285] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
While the negative impacts of dam construction on downstream river stretches and riparian forests are well studied, the status of wildlife presence and persistence in upstream reservoir deltas is virtually unknown. We investigated the drivers of terrestrial mammal occupancy and persistence along riparian forests of Koyna reservoir in western India 55 years after its construction. We adopted a catchment-wide field design grounded in the river continuum concept and sampled different stream orders within the reservoir. Camera traps, nested in an occupancy modeling framework, were deployed across 72 riparian sites and replicated for four seasons across all stream types. We recorded a total of nineteen species of terrestrial mammals during the study period. Multi-season occupancy models revealed three key patterns of mammal persistence: (a) ungulates were more frequently photo-captured in riparian forests; gaur and wild pig had the highest proportions of the total sampled area (0.84 ± 0.12 SE; 0.77 ± 0.07 SE, respectively); (b) small-sized ungulates were more vulnerable to local extinction than large-bodied ungulates; extinction probability was highest for barking deer (0.59 ± 0.07) and lowest for sambar (0.15 ± 0.07); and (c) distance from stream played major roles in determining mammal detection. Riparian forests are fundamentally important to ecosystem functioning and biodiversity conservation, and using the data from this study, managers can plan to sustain high mammal persistence along riparian forests at Koyna reservoir or similar Indian reserves. Further, our robust sampling approach, grounded in the terrestrial-riverine continuum concept, can be applied globally to understand species assemblages, aiding in multi-landscape and wildlife management planning.
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10
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Alteration of the Ecohydrological Status of the Intermittent Flow Rivers and Ephemeral Streams due to the Climate Change Impact (Case Study: Tsiknias River). HYDROLOGY 2021. [DOI: 10.3390/hydrology8010043] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Climate change projections predict the increase of no-rain periods and storm intensity resulting in high hydrologic alteration of the Mediterranean rivers. Intermittent flow Rivers and Ephemeral Streams (IRES) are particularly vulnerable to spatiotemporal variation of climate variables, land use changes and other anthropogenic factors. In this work, the impact of climate change on the aquatic state of IRES is assessed by the combination of the hydrological model Soil and Water Assessment Tool (SWAT) and the Temporary Rivers Ecological and Hydrological Status (TREHS) tool under two different Representative Concentration Pathways (RCP 4.5 and RCP 8.5) using CORDEX model simulations. A significant decrease of 20–40% of the annual flow of the examined river (Tsiknias River, Greece) is predicted during the next 100 years with an increase in the frequency of extreme flood events as captured with almost all Regional Climate Models (RCMs) simulations. The occurrence patterns of hyporheic and edaphic aquatic states show a temporal extension of these states through the whole year due to the elongation of the dry period. A shift to the Intermittent-Pools regime type shows dominance according to numerous climate change scenarios, harming, as a consequence, both the ecological system and the social-economic one.
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11
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Stubbington R, Acreman M, Acuña V, Boon PJ, Boulton AJ, England J, Gilvear D, Sykes T, Wood PJ. Ecosystem services of temporary streams differ between wet and dry phases in regions with contrasting climates and economies. PEOPLE AND NATURE 2020. [DOI: 10.1002/pan3.10113] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Affiliation(s)
- Rachel Stubbington
- School of Science and Technology Nottingham Trent University Nottingham UK
| | | | - Vicenç Acuña
- Catalan Institute for Water Research (ICRA) Girona Spain
- University of Girona Girona Spain
| | | | - Andrew J. Boulton
- School of Environmental and Rural Science University of New England Armidale NSW Australia
| | - Judy England
- Research, Analysis and Evaluation Environment Agency Wallingford UK
| | - David Gilvear
- School of Geography, Earth and Environmental Sciences University of Plymouth Plymouth UK
| | - Tim Sykes
- Romsey District Office Environment Agency Romsey UK
| | - Paul J. Wood
- Geography and Environment Loughborough University Loughborough UK
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12
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Arias-Real R, Muñoz I, Gutierrez-Cánovas C, Granados V, Lopez-Laseras P, Menéndez M. Subsurface zones in intermittent streams are hotspots of microbial decomposition during the non-flow period. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 703:135485. [PMID: 31761375 DOI: 10.1016/j.scitotenv.2019.135485] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Revised: 11/08/2019] [Accepted: 11/10/2019] [Indexed: 06/10/2023]
Abstract
The microbial decomposition of organic matter is a fundamental ecosystem process that transforms organic matter and fuels detritus-based food webs, influencing biogeochemical cycles such as C-cycling. The efficiency of this process can be compromised during the non-flow periods of intermittent and ephemeral streams (IRES). When water flow ceases, sediments represent the last wet habitat available to microorganisms and may play an important role in sustaining microbial decomposition. However, despite the increasing prevalence of IRES due to climate change and water abstraction, it is unclear to what degree the subsurface habitat can sustain microbial decomposition during non-flow periods. In order to gather information, we selected 20 streams across Catalonia (Spain) along a gradient of flow intermittency, where we measured microbial decomposition and fungal biomass by placing wood sticks in both the surface and subsurface zones (15 cm below the streambed) over the course of one hydrological year. Our results showed that microbial decomposition and fungal biomass were consistently greater in the subsurface zone than in the surface zone, when intermittency increased. Although flow intermittency was the main driver of both microbial decomposition and fungal biomass, phosphorus availability in the water, sediment C:N ratio and sediment grain size also played relevant roles in surface and subsurface organic matter processing. Thus, our findings demonstrate that although the OM processing in both zones decreases with increased intermittency, the subsurface zone made an important contribution during the non-flow periods in IRES. Therefore, subsurface activity during non-flow periods has the potential to affect and maintain ecosystem functioning.
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Affiliation(s)
- Rebeca Arias-Real
- Department of Evolutionary Biology, Ecology and Environmental Sciences, Faculty of Biology, Universitat de Barcelona, Barcelona, Spain..
| | - Isabel Muñoz
- Department of Evolutionary Biology, Ecology and Environmental Sciences, Faculty of Biology, Universitat de Barcelona, Barcelona, Spain
| | - Cayetano Gutierrez-Cánovas
- Department of Evolutionary Biology, Ecology and Environmental Sciences, Faculty of Biology, Universitat de Barcelona, Barcelona, Spain.; Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, Campus of Gualtar, 4710-057 Braga, Portugal.; Institute of Science and Innovation for Bio-Sustainability (IB-S), University of Minho, Campus of Gualtar, 4710-057 Braga, Portugal
| | - Verónica Granados
- Department of Evolutionary Biology, Ecology and Environmental Sciences, Faculty of Biology, Universitat de Barcelona, Barcelona, Spain
| | - Pilar Lopez-Laseras
- Department of Evolutionary Biology, Ecology and Environmental Sciences, Faculty of Biology, Universitat de Barcelona, Barcelona, Spain
| | - Margarita Menéndez
- Department of Evolutionary Biology, Ecology and Environmental Sciences, Faculty of Biology, Universitat de Barcelona, Barcelona, Spain
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13
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An Intermittent Karst River: The Case of the Čikola River (Dinaric Karst, Croatia). WATER 2019. [DOI: 10.3390/w11112415] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Intermittent and ephemeral streams (IRES) are responsible for transporting about half of the water on Earth’s surface. Their hydrological behavior is different in various landscapes. IRES are found more often in karst terrains than in any other regions, as a consequence of strong and direct interaction between groundwater and surface water. This paper presents a hydrogeological and hydrological analysis of the intermittent Čikola River and Spring catchment, which is located in deeply karstified and developed parts of the Dinaric karst in Croatia. Hydrological calculations determined that the catchment area covers approximately 300 km2 and very probably changes in accordance with rapid variations in groundwater level. The karst spring of the Čikola River is a cave, extracted for a public water supply with four drilled extraction wells. The results of the interrelated hydrological and hydrogeological analysis show interesting phenomena from an intermittent karst spring (cave) and its catchment, flowing downstream through a karst polje with several smaller confluences, then entering a karst canyon (where the river sinks during certain periods), and ending in an estuary before contributing to the larger Krka River. The research presented was based on water balance calculations, climatic and hydrological time series analyses, spring pumping tests, and thorough hydrogeological interpretation.
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14
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Weigand AM, Macher JN. A DNA metabarcoding protocol for hyporheic freshwater meiofauna: Evaluating highly degenerate COI primers and replication strategy. METABARCODING AND METAGENOMICS 2018. [DOI: 10.3897/mbmg.2.26869] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The hyporheic zone, i.e. the ecotone between surface water and the groundwater, is a rarely studied freshwater ecosystem. Hyporheic taxa are often meiofaunal (<1 mm) in size and difficult to identify based on morphology. Metabarcoding approaches are promising for the study of these environments and taxa, but it is yet unclear if commonly applied metabarcoding primers and replication strategies can be used. In this study, we took sediment cores from two near natural upstream (NNU) and two ecologically improved downstream (EID) sites in the Boye catchment (Emscher River, Germany), metabarcoding their meiofaunal communities. We evaluated the usability of a commonly used, highly degenerate COI primer pair (BF2/BR2) and tested how sequencing three PCR replicates per sample and removing MOTUs present in only one out of three replicates impacts the inferred community composition. A total of 22,514 MOTUs were detected, of which only 263 were identified as Metazoa. Our results highlight the gaps in reference databases for meiofaunal taxa and the potential problems of using highly degenerate primers for studying samples containing a high number of non-metazoan taxa. Alpha diversity was higher in EID sites and showed higher community similarity when compared to NNU sites. Beta diversity analyses showed that removing MOTUs detected in only one out of three replicates per site greatly increased community similarity in samples. Sequencing three sample replicates and removing rare MOTUs is seen as a good compromise between retaining too many false-positives and introducing too many false-negatives. We conclude that metabarcoding hyporheic communities using highly degenerate COI primers can provide valuable first insights into the diversity of these ecosystems and highlight some potential application scenarios.
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