scholarly journals Hydrology and riparian forests drive carbon and nitrogen supply and DOC:NO<sub>3<sup>−</sup></sub> stoichiometry along a headwater Mediterranean stream

2021 ◽  
Author(s):  
José L. J. Ledesma ◽  
Anna Lupon ◽  
Eugènia Martí ◽  
Susana Bernal
Keyword(s):  
Riparian Forest ◽  
Base Flow ◽  
Riparian Forests ◽  
Storm Events ◽  
Flow Conditions ◽  
Heterotrophic Activity ◽  
Molar Ratios ◽  
Mediterranean Stream ◽  
Storm Flow ◽  
Forest Coverage

Abstract. In forest headwater streams, metabolic processes are predominately heterotrophic and depend on both the availability of carbon (C) and nitrogen (N) and a favourable C:N stoichiometry. In this context, hydrological conditions and the presence of riparian forests adjacent to streams can play an important, yet understudied role determining dissolved organic carbon (DOC) and nitrate (NO3−) concentrations and DOC:NO3− molar ratios. Here, we aimed to investigate how the interplay between hydrological conditions and riparian forest coverage drives DOC and NO3− supply and DOC:NO3− stoichiometry in an oligotrophic headwater Mediterranean stream. We analysed DOC and NO3− concentrations, and DOC:NO3− molar ratios during both base flow and storm flow conditions at three stream locations along a longitudinal gradient of increased riparian forest coverage. Further, we performed an event analysis to examine the hydroclimatic conditions that favour the transfer of DOC and NO3− from riparian soils to the stream during large storms. Stream DOC and NO3− concentrations were generally low (overall average ± SD was 1.0 ± 0.6 mg C L−1 and 0.20 ± 0.09 mg N L−1), although significantly higher during storm flow compared to base flow conditions in all three stream sites. Optimal DOC:NO3− stoichiometry for stream heterotrophic microorganisms (corresponding to DOC:NO3− molar ratios between 4.8 and 11.7) was prevalent at the midstream and downstream sites under both flow conditions, whereas C-limited conditions were prevalent at the upstream site, which had no surrounding riparian forest. The hydroclimatic analysis of large storm events highlighted different patterns of DOC and NO3− mobilization depending on antecedent soil moisture conditions: drier antecedent conditions promoted rapid elevations of riparian groundwater tables, hydrologically activating a wider and shallower soil layer, and leading to relatively higher increases in stream DOC and NO3− concentrations compared to events preceded by wet conditions. These results suggest that (i) increased supply of limited resources during storms can promote in-stream heterotrophic activity during high flows, especially during large storm events preceded by dry conditions, and (ii) C-limited conditions upstream were gradually overcome downstream, likely due to higher C inputs from riparian forests present at lower elevations. The contrasting spatiotemporal patterns in DOC and NO3− availability and DOC:NO3− stoichiometry observed at the study stream suggests that groundwater inputs from riparian forests are essential for maintaining in-stream heterotrophic activity in oligotrophic, forest headwater catchments.

scholarly journals A multi-functional and multi-compartment constructed wetland to support urban waterway restoration

2018 ◽  
Vol 13 (4) ◽  
pp. 764-770 ◽  
Author(s):  
T. M. Adyel ◽  
M. R. Hipsey ◽  
C. Oldham
Keyword(s):  
Constructed Wetland ◽  
Flow System ◽  
Surface Flow ◽  
Base Flow ◽  
Low Flow ◽  
Nutrient Loads ◽  
Storm Events ◽  
Flow Conditions ◽  
Storm Flow ◽  
Diverse Area

Abstract This study assessed the significance of a multi-functional and multi-compartment constructed wetland (CW) implemented to restore a degraded urban waterway in Western Australia. The wetland was initially constructed as a surface flow system, then modified through the incorporation of the additional laterite-based subsurface flow system, with the potential for operation of a recirculation scheme and groundwater top-up during low water flows in summer. The CW performance was assessed by comparing nitrogen (N) and phosphorus (P) attenuation during base flow, high flow and episodic storm flow conditions. The performance varied from approximately 41% total nitrogen (TN) and 66% total phosphorus (TP) loads reduction during storm events, increasing up to 62% TN and 99% TP during low flow and summer recirculation periods. In overall, the CW attenuated about 45% TN and 65% TP loads from being delivered to the downstream sensitive river between 2009 and 2015. The CW design proved to be not only highly effective at reducing nutrient loads, but also improved the ecological services of the urban waterway by providing a diverse area for habitat and recreational activities.

Analysis of parameter variations in L–Q equations for river runoff processes from the viewpoint of spatial and temporal conditions

2006 ◽  
Vol 53 (10) ◽  
pp. 141-152 ◽  
Author(s):  
S. Fujii ◽  
B.R. Shivakoti ◽  
K. Shichi ◽  
P. Songprasert ◽  
H. Ihara ◽  
...  
Keyword(s):  
Continuous Monitoring ◽  
Base Flow ◽  
Storm Event ◽  
Storm Events ◽  
Flow Conditions ◽  
Regional Effect ◽  
Run Off ◽  
Parameter Variations ◽  
Variation Characteristics ◽  
Temporal Flow

This study aims to find out variation characteristics of the parameters of ‘a’ and ‘b’ in L=a ·Qb, an empirical equation for run-off loading (L) and flow rate (Q), by evaluating the effects of flow conditions and regional properties of the watersheds on the values. We selected the Kamo River basin (155 km2) as a study field, and conducted various kinds of investigations, such as 80 day high frequency observations, continuous monitoring for more than 2 years, storm event surveys, and simultaneous surveys of 39 stations. Then, we obtained 7–170 data in each of 39 sampling stations. The main results obtained are as follows: 1) L–Q equation with a range of ‘a’ can express L–Q relation in most of the WQIs (water quality indices); 2) ‘a’ receives temporal (flow condition) effects more in SS, VSS and Al, while it receives regional effect more in inorganic carbon, TN, Ca and Fe; 3) both of flow change in storm events, and base flow levels affect the L–Q relation, and their effects can classify the WQIs into several groups; 4) the effects of regional properties were obviously observed in ‘a’, and quantitatively evaluated, especially for density of population.

Effects of Urbanization on Stream Ecosystems

2005 ◽  
Keyword(s):  
Water Quality ◽  
Suspended Sediment ◽  
Brown Trout ◽  
Dose Response ◽  
Quality Criteria ◽  
Base Flow ◽  
Response Model ◽  
Storm Events ◽  
Flow Conditions ◽  
Blood Samples

<em>Abstract.</em>—Urban streams typically have increased flows, high suspended sediment concentrations, and reduced water quality during rainstorms as a result of changes within the watershed related to human activity. In the 6-month periods from May through October of 2001 and 2002, water quality was monitored continuously at five sites along Rapid Creek within Rapid City, South Dakota. Water quality samples were collected for eight base flows (nonevents) and eight storm events. Blood samples were collected from wild adult brown trout <em>Salmo trutta </em>during base flow conditions and six of eight storm events to determine if storm events could elicit physiological stress responses. Blood samples were also collected 24, 48, and 96 h after each storm event had started. Water monitoring results showed significant increases in runoff volume and peak flows during storm events. Water quality parameters exceeding South Dakota’s water quality criteria for a coldwater fishery were total suspended solids and temperature. Plasma concentrations of cortisol and lactate, during and after storm events, were not significantly different than those measured during base flow conditions. Plasma glucose values were lower during storm events than during nonevent periods. These observations were compared to those predicted by a suspended sediment dose–response model developed for adult salmonids. The dose–response model overpredicted the severity of the effects of increased total suspended sediment on the brown trout during stormwater runoff events.

scholarly journals Hydrological, Environmental and Taxonomical Heterogeneity during the Transition from Drying to Flowing Conditions in a Mediterranean Intermittent River

Biology ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 316
Author(s):  
Andy Banegas-Medina ◽  
Isis-Yelena Montes ◽  
Ourania Tzoraki ◽  
Luc Brendonck ◽  
Tom Pinceel ◽  
...  
Keyword(s):  
Ecosystem Services ◽  
Base Flow ◽  
Ephemeral Streams ◽  
Biogeochemical Processes ◽  
Flow Conditions ◽  
Intermittent Rivers ◽  
Terrestrial Biodiversity ◽  
Turn Over ◽  
Zero Flow ◽  
Intermittent River

Intermittent rivers and ephemeral streams (IRES) are increasingly studied because of their often-unique aquatic and terrestrial biodiversity, biogeochemical processes and associated ecosystem services. This study is the first to examine the hydrological, physicochemical and taxonomic variability during the dry-wet transition of an intermittent river in the Chilean Mediterranean Zone. Based on 30-years of river monitoring data and the TREHS tool, the hydrology of the river was characterised. Overall, the river shows a significant reduction in streamflow (−0.031 m3/s per year) and a substantial increase of zero flow days (+3.5 days per year). During the transition of hydrological states, variations were observed in the environmental conditions and invertebrate communities. During the drying phase, abundance, richness, and diversity were highest, while species turn-over was highest during base flow conditions. The disconnected pools and the flow resumption phases were characterised by high proportions of lentic taxa and non-insects, such as the endemic species of bivalves, gastropods, and crustaceans, highlighting the relevance of disconnected pools as refuges. Future climatic change scenarios are expected to impact further the hydrology of IRES, which could result in the loss of biodiversity. Biomonitoring and conservation programmes should acknowledge these important ecosystems.

Ptaquiloside from bracken in stream water at base flow and during storm events

2016 ◽  
Vol 106 ◽  
pp. 155-162 ◽  
Author(s):  
Frederik Clauson-Kaas ◽  
Carmel Ramwell ◽  
Hans Chr. B. Hansen ◽  
Bjarne W. Strobel
Keyword(s):  
Stream Water ◽  
Base Flow ◽  
Storm Events

scholarly journals Water-use dynamics of an alien-invaded riparian forest within the Mediterranean climate zone of the Western Cape, South Africa

2017 ◽  
Vol 21 (9) ◽  
pp. 4551-4562 ◽  
Author(s):  
Bruce C. Scott-Shaw ◽  
Colin S. Everson ◽  
Alistair D. Clulow
Keyword(s):  
South Africa ◽  
Water Use ◽  
Sap Flow ◽  
Riparian Forest ◽  
Riparian Forests ◽  
Ratio Method ◽  
Natural State ◽  
Indigenous Species ◽  
Western Cape ◽  
Selection Of

Abstract. In South Africa, the invasion of riparian forests by alien trees has the potential to affect the country's limited water resources. Tree water-use measurements have therefore become an important component of recent hydrological studies. It is difficult for South African government initiatives, such as the Working for Water (WfW) alien clearing program, to justify alien tree removal and implement rehabilitation unless hydrological benefits are known. Consequently, water use within a riparian forest along the Buffeljags River in the Western Cape of South Africa was monitored over a 3-year period. The site consisted of an indigenous stand of Western Cape afrotemperate forest adjacent to a large stand of introduced Acacia mearnsii. The heat ratio method of the heat pulse velocity sap flow technique was used to measure the sap flow of a selection of indigenous species in the indigenous stand, a selection of A. mearnsii trees in the alien stand and two clusters of indigenous species within the alien stand. The indigenous trees in the alien stand at Buffeljags River showed significant intraspecific differences in the daily sap flow rates varying from 15 to 32 L day−1 in summer (sap flow being directly proportional to tree size). In winter (June), this was reduced to only 7 L day−1 when limited energy was available to drive the transpiration process. The water use in the A. mearnsii trees showed peaks in transpiration during the months of March 2012, September 2012 and February 2013. These periods had high average temperatures, rainfall and high daily vapor pressure deficits (VPDs – average of 1.26 kPa). The average daily sap flow ranged from 25 to 35 L in summer and approximately 10 L in the winter. The combined accumulated daily sap flow per year for the three Vepris lanceolata and three A. mearnsii trees was 5700 and 9200 L, respectively, clearly demonstrating the higher water use of the introduced Acacia trees during the winter months. After spatially upscaling the findings, it was concluded that, annually, the alien stand used nearly 6 times more water per unit area than the indigenous stand (585 mm a−1 compared to 101 mm a−1). This finding indicates that there would be a gain in groundwater recharge and/or streamflow if the alien species are removed from riparian forests and rehabilitated back to their natural state.

Relationship between Morphology and Trophic Ecology in an Assemblage of Passerine Birds in Riparian Forests of the Paraná River (Argentina)

2018 ◽  
Vol 11 (1) ◽  
pp. 44-53 ◽  
Author(s):  
Virginia Quiroga ◽  
Rodrigo E. Lorenzón ◽  
Gisela Maglier ◽  
Ana L. Ronchi-Virgolini
Keyword(s):  
Trophic Ecology ◽  
Riparian Forest ◽  
A Priori ◽  
Bird Species ◽  
Morphological Characteristics ◽  
Paraná River ◽  
Riparian Forests ◽  
Phylogenetic Constraint ◽  
Parana River ◽  
Coexisting Species

We describe the ecomorphology of an assemblage of bird species found in riparian forests of the Middle Paraná River, Argentina. We sought to determine (1) the more important morphological characteristics that separate coexisting species, (2) whether such separation was related to the trophic ecology of each species and (3) whether a priori guilds showed morphological similarity. We tested the hypotheses that (a) a species’ morphology is related to the trophic ecology of that species and (b) that species of a priori guilds are morphometrically more similar to each other than to species of different a priori guilds. For this, we considered an assemblage of 29 species of birds from riparian forest that were sampled with mist nets during the 2011 and 2014 breeding seasons. We obtained morphometric measurements of captured individuals and supplemented those data with measurements from museum specimens. Trophic characterisation (diet and trophic microhabitat) was based on a literature review. Results showed a separation of bird species as a function of variables related to trophic ecology (diets and trophic microhabitats) and morphology. After controlling for phylogenetic constraint, species’ morphology partially reflected the trophic ecology of the species, supporting the central hypothesis of the ecomorphological discipline and showing that the use of trophic and morphometric data provides complementary data to improve the guild organisation of riparian bird assemblages.

scholarly journals Forecasting Low Stream Flow Rate Using Monte—Carlo Simulation of Perigiali Stream, Kavala City, NE Greece

Proceedings ◽  
2018 ◽  
Vol 2 (11) ◽  
pp. 580 ◽  
Author(s):  
Thomas Papalaskaris ◽  
Theologos Panagiotidis
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Flow Rate ◽  
Stream Flow ◽  
Simulation Method ◽  
Base Flow ◽  
Low Flow ◽  
Rate Data ◽  
Storm Flow ◽  
Management Plans

A small number of scientific research studies with reference to extremely low flow conditions, have been conducted in Greece, so far. Predicting future low stream flow rate values is an essential and of paramount importance task when compiling watershed and drought management plans, designing water reservoirs and general hydraulic works capacity, calculating hydrological and drought low flow values, separating groundwater base flow and storm flow of storm hydrographs etc. The Monte-Carlo simulation method generates multiple attempts to define the anticipated value of a random (hydrological in this specific case) variable. The present study compiles, correspondingly, artificial low stream flow time series of both the same part of the year (2016) as well as a part of the calendar year (2017), based on the stream flow data observed during the same two different interval periods of the years 2016 and 2017, using a 3-inches U.S.G.S. modified portable Parshall flume, a 3-inches conventional portable Parshall flume, a 3-inches portable Montana (short Parshall) flume and a 90° V-notched triangular shaped sharp crested portable weir plate. The recorded data were plotted against the fitted one and the results were demonstrated through interactive tables providing us the ability to effectively evaluate the simulation procedure performance. Finally, we plot the observed against the calculated low stream flow rate data, compiling a log-log scale chart which provides a better visualization of the discrepancy ratio statistical performance metric and calculate statistics featuring the comparison between the recorded and the forecasted low stream flow rate data.

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