Biogeochemical Asynchrony: Ecosystem Drivers of Seasonal Concentration Regimes across the Great Lakes Basin

2020 ◽  
Author(s):  
Kimberly Van Meter ◽  
Nandita Basu ◽  
Danyka Byrnes
Keyword(s):  
Land Use ◽  
Phase Behavior ◽  
Nutrient Dynamics ◽  
Soluble Reactive Phosphorus ◽  
Low Flow ◽  
Nutrient Concentrations ◽  
Stream Metabolism ◽  
Great Lakes Basin ◽  
Discharge Data ◽  
Reactive Phosphorus

<p>Changes in seasonal climate regimes, and related changes in seasonal nutrient dynamics, are occurring across a range of climates and land use types. Although it is known that seasonal patterns in nutrient availability are key drivers of both stream metabolism and eutrophication, there has been little success in developing a comprehensive understanding of seasonal variations in nutrient export across watersheds or of the relationship between nutrient seasonality and watershed characteristics. In the present study, we have used concentration and discharge data from more than 200 stations across US and Canadian watersheds to identify (1) archetypal seasonal concentration regimes for nitrate, soluble reactive phosphorus, and total phosphorus, and (2) dominant watershed controls on these regimes across a gradient of climate, land use, and topography. Our analysis shows that less impacted watersheds, with more forested and wetland area, most commonly exhibit concentration regimes that are in phase with discharge, with concentration lows occurring during summer low-flow periods. Agricultural watersheds also commonly exhibit in-phase behavior, though the seasonality is usually muted compared to that seen in less impacted areas. With increasing urban area, however, nutrient concentrations frequently become essentially aseasonal or even exhibit clearly out-of-phase behavior. In addition, our data indicate that seasonal SRP concentration patterns may be strongly influenced by proximal controls such as the presence of dams and reservoirs. In all, these results suggest that human activity is significantly altering nutrient concentration regimes, with large potential consequences for both in-stream metabolism and eutrophication risk in downstream water bodies.</p>

Major controls of base flow soluble reactive phosphorus losses in humid temperate headwater streams

2020 ◽  
Author(s):  
Michael Rode ◽  
Remi Dupas
Keyword(s):  
Land Use ◽  
Headwater Streams ◽  
Soluble Reactive Phosphorus ◽  
Low Flow ◽  
Temperate Climate ◽  
Redox Processes ◽  
Temperature Dependent ◽  
P Release ◽  
Reactive Phosphorus

<p>Long-term Soluble Reactive Phosphorus (SRP) monitoring in headwater streams in central Europe revealed a seasonal pattern of SRP concentrations during low flow periods, with highest concentrations in summer and lowest in winter. These seasonal concentration amplitudes often exceed the eutrophication threshold during the summer eutrophication-sensitive period. It is assumed that temperature dependent biogeochemical processes control the underlying P release mechanism, where redox processes may be responsible for this increase. Several studies have highlighted the crucial role of reactive zones such as riparian wetlands in controlling solute export regimes. Moreover especially in forest headwater streams, in-stream assimilatory uptake shows a distinct seasonal behaviour because of varying shading conditions. This can also lead to seasonal SRP amplitudes. Furthermore sorption and desorption processes are temperature dependent which may alter in-stream SRP release during the year.</p><p>Often SRP concentrations are higher in agricultural streams than in more pristine headwaters. It is not clear how land use (e.g. P status of soils) may impact the baseline SRP concentrations and which factors control the seasonal change in SRP stream concentration (riparian groundwater heads and redox processes, temperature, in-stream release and uptake processes). Therefore the objective of this study is to disentangle land use impacts from hydrological and biogeochemical controls of low flow SRP losses.  A comparative study on seasonal SRP concentration patterns will be presented comprising around 53 long term monitored headwater catchments in humid temperate climate of northern Europe and the United States. Based on hydrological and SRP headwater signals and catchment properties, P release processes are discussed. The results of the study will allow to target SRP mitigation strategies based on knowledge of the dominating control of SRP loss from headwater streams. </p>

scholarly journals Conceptual Mini-Catchment Typologies for Testing Dominant Controls of Nutrient Dynamics in Three Nordic Countries

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1776 ◽  
Author(s):  
Fatemeh Hashemi ◽  
Ina Pohle ◽  
Johannes W.M. Pullens ◽  
Henrik Tornbjerg ◽  
Katarina Kyllmar ◽  
...  
Keyword(s):  
Land Use ◽  
Nutrient Dynamics ◽  
Pollution Monitoring ◽  
Organic N ◽  
Particulate Phosphorus ◽  
Nutrient Concentrations ◽  
Data Series ◽  
Nutrient Export ◽  
Small Streams ◽  
Export Behaviour

Optimal nutrient pollution monitoring and management in catchments requires an in-depth understanding of spatial and temporal factors controlling nutrient dynamics. Such an understanding can potentially be obtained by analysing stream concentration–discharge (C-Q) relationships for hysteresis behaviours and export regimes. Here, a classification scheme including nine different C-Q types was applied to a total of 87 Nordic streams draining mini-catchments (0.1–65 km2). The classification applied is based on a combination of stream export behaviour (dilution, constant, enrichment) and hysteresis rotational pattern (clock-wise, no rotation, anti-clockwise). The scheme has been applied to an 8-year data series (2010–2017) from small streams in Denmark, Sweden, and Finland on daily discharge and discrete nutrient concentrations, including nitrate (NO3−), total organic N (TON), dissolved reactive phosphorus (DRP), and particulate phosphorus (PP). The dominant nutrient export regimes were enrichment for NO3− and constant for TON, DRP, and PP. Nutrient hysteresis patterns were primarily clockwise or no hysteresis. Similarities in types of C-Q relationships were investigated using Principal Component Analysis (PCA) considering effects of catchment size, land use, climate, and dominant soil type. The PCA analysis revealed that land use and air temperature were the dominant factors controlling nutrient C-Q types. Therefore, the nutrient export behaviour in streams draining Nordic mini-catchments seems to be dominantly controlled by their land use characteristics and, to a lesser extent, their climate.

Effect of geomorphological setting and rainfall on nutrient exchange in mangroves during tidal inundation

2010 ◽  
Vol 61 (10) ◽  
pp. 1197 ◽  
Author(s):  
María Fernanda Adame ◽  
Bernardino Virdis ◽  
Catherine E. Lovelock
Keyword(s):  
Soluble Reactive Phosphorus ◽  
Nutrient Retention ◽  
Nutrient Concentrations ◽  
Tidal Inundation ◽  
Nutrient Exchange ◽  
Tidal Cycles ◽  
Negative Impacts ◽  
Reactive Phosphorus ◽  
Riverine Mangroves

One of the key ecosystem services provided by mangroves is their role in mediating nutrient exchange, thereby protecting coastal ecosystems from negative impacts of nutrient enrichment. In this study, we tested whether geomorphological setting and level of rainfall affect the intensity and direction of nutrient exchange. Our hypotheses were that tidal mangroves retain more nutrients than riverine mangroves and that nutrient retention is stronger during periods of high rainfall. Concentrations of soluble reactive phosphorus (SRP), nitrogen oxides (NOx–-N) and ammonium (NH4+) were measured from water entering and leaving the mangroves during tidal cycles. Our results show that nutrient concentrations were higher in the flood tide compared with the ebb tide by up to 28% for NOx–-N, 51% for SRP and 83% for NH4+, suggesting retention by the mangroves. Geomorphological setting determined nutrient exchange to some extent, with some riverine sites receiving more nutrients than tidal sites and thus, being more important in nutrient retention. Rainfall was important in determining nutrient exchange as it enhanced SRP and NH4+ retention. These results show that mangroves can improve water quality of creeks and rivers, and underscore the need for conservation of mangroves over a range of geomorphological settings.

Sediment Control of Soluble Reactive Phosphorus in Hoxie Gorge Creek, New York

1988 ◽  
Vol 45 (11) ◽  
pp. 2026-2034 ◽  
Author(s):  
R. L. Klotz
Keyword(s):  
New York ◽  
Stream Water ◽  
Soluble Reactive Phosphorus ◽  
Low Flow ◽  
Phosphorus Concentration ◽  
Sediment Control ◽  
Al Content ◽  
Exchangeable Al ◽  
Reactive Phosphorus ◽  
Highly Correlated

Stream sediments were found to regulate the soluble reactive phosphorus (SRP) of stream water by geochemical processes. This conclusion was based on sediment analysis, laboratory sorption experiments, and measurement of the equilibrium phosphorus concentration (EPC). EPC is the concentration of P in the water at which there is neither sorption nor desorption of P by the sediments. At low flow conditions, streamwater SRP was highly correlated with EPC at six sites along Hoxie Gorge Creek (r = 0.979). EPC was inversely related to the ionic strength of the equilibrating solution, with Ca2+ producing larger changes than Na+. Minimum EPC values occurred near the neutral pH of the stream water and increased sharply in acidic and basic solutions. Also, EPC was negatively correlated with the exchangeable Al content of the sediments at the six sites. These data are consistent with a mechanism previously verified for soils in which solution cations displace exchangeable Al(III) from sediments; hydrolyzed Al(III) reacts with phosphate and removes it from solution. EPC and streamwater SRP were lower at sites with sediments that had higher concentrations of P-binding sites, despite also having higher sediment P.

scholarly journals Riparian and in-stream controls on nutrient concentrations and fluxes in a headwater forested stream

2015 ◽  
Vol 12 (6) ◽  
pp. 1941-1954 ◽  
Author(s):  
S. Bernal ◽  
A. Lupon ◽  
M. Ribot ◽  
F. Sabater ◽  
E. Martí
Keyword(s):  
Nutrient Dynamics ◽  
Riparian Forest ◽  
Stream Water ◽  
Soluble Reactive Phosphorus ◽  
Terrestrial Ecosystems ◽  
Nutrient Concentrations ◽  
Vegetative Period ◽  
Terrestrial Inputs ◽  
Net Uptake ◽  
Sources Of Variation

Abstract. Headwater streams are recipients of water sources draining through terrestrial ecosystems. At the same time, stream biota can transform and retain nutrients dissolved in stream water. Yet studies considering simultaneously these two sources of variation in stream nutrient chemistry are rare. To fill this gap of knowledge, we analyzed stream water and riparian groundwater concentrations and fluxes as well as in-stream net uptake rates for nitrate (NO3−), ammonium (NH4+), and soluble reactive phosphorus (SRP) along a 3.7 km reach on an annual basis. Chloride concentrations (used as conservative tracer) indicated a strong hydrological connection at the riparian–stream interface. However, stream and riparian groundwater nutrient concentrations showed a moderate to null correlation, suggesting high in-stream biogeochemical processing. In-stream net nutrient uptake (Fsw) was highly variable across contiguous segments and over time, but its temporal variation was not related to the vegetative period of the riparian forest. For NH4+, the occurrence of Fsw > 0 μg N m−1 s−1 (gross uptake > release) was high along the reach, while for NO3−, the occurrence of Fsw < 0 μg N m−1 s−1 (gross uptake < release) increased along the reach. Within segments and dates, Fsw, whether negative or positive, accounted for a median of 6, 18, and 20% of the inputs of NO3−, NH4+, and SRP, respectively. Whole-reach mass balance calculations indicated that in-stream net uptake reduced stream NH4+ flux up to 90%, while the stream acted mostly as a source of NO3− and SRP. During the dormant period, concentrations decreased along the reach for NO3−, but increased for NH4+ and SRP. During the vegetative period, NH4+ decreased, SRP increased, and NO3− showed a U-shaped pattern along the reach. These longitudinal trends resulted from the combination of hydrological mixing with terrestrial inputs and in-stream nutrient processing. Therefore, the assessment of these two sources of variation in stream water chemistry is crucial to understand the contribution of in-stream processes to stream nutrient dynamics at relevant ecological scales.

scholarly journals Dissolved Organic Matter Quality and Biofilm Composition Affect Microbial Organic Matter Uptake in Stream Flumes

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3246
Author(s):  
Gabriele Weigelhofer ◽  
Tania Sosa Jirón ◽  
Tz-Ching Yeh ◽  
Gertraud Steniczka ◽  
Matthias Pucher
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Algal Growth ◽  
Soluble Reactive Phosphorus ◽  
Single Pulse ◽  
Interactive Effects ◽  
Nutrient Concentrations ◽  
Cow Dung ◽  
Organic Matter Quality ◽  
Reactive Phosphorus

Agriculture delivers significant amounts of dissolved organic matter (DOM) to streams, thereby changing the composition and biodegradability of the aquatic DOM. This study focuses on the interactive effects of DOM quality and biofilm composition on the degradation of DOM in a laboratory flume experiment. Half of the flumes were exposed to light to stimulate algal growth, the other half was shaded. Leachates of deciduous leaves, maize leaves, and cow dung were added to the flumes in a single pulse and changes of DOC (dissolved organic carbon) and nutrient concentrations, DOM composition (absorbance and fluorescence data), chlorophyll-a concentrations, bacterial abundances, and enzymatic activities were recorded over a week. DOM was taken up with rates of 50, 109, and 136 µg DOC L−1 h−1 for dung, leaf, and maize leachates, respectively, in the light flumes and 37, 80, and 170 µg DOC L−1 h−1 in the dark flumes. DOC uptake correlated strongly with initial SRP (soluble reactive phosphorus) and DOC concentrations, but barely with DOM components and indices. Algae mostly stimulated the microbial DOC uptake, but the effects differed among differently aged biofilms. We developed a conceptual model of intrinsic (DOM quality) and external (environmental) controlling factors on DOM degradation, with the microbial community acting as biotic filter.

scholarly journals Variation of stream metabolism along a tropical environmental gradient

2018 ◽  
Author(s):  
Wesley A. Saltarelli ◽  
Walter K. Dodds ◽  
Flavia Tromboni ◽  
Maria do Carmo Calijuri ◽  
Vinicius Neres-Lima ◽  
...  
Keyword(s):  
Land Use ◽  
Total Phosphorus ◽  
Ecosystem Respiration ◽  
Gross Primary Production ◽  
Canopy Cover ◽  
Tropical Streams ◽  
Nutrient Concentrations ◽  
Stream Metabolism ◽  
Mixed Effect ◽  
Single Station

Stream metabolism is affected by both natural and human-induced processes. While metabolism has multiple implications for ecological processes, relatively little is known about how metabolic rates are influenced by land use in tropical streams. In this study, we assessed the metabolic characteristics and related environmental factors of six streams located in a transition area from Cerrado to Atlantic Forest (São Carlos/Brazil). Three streams were relatively preserved, while three were flowing through more agriculturally and/or urban impacted watersheds. Surface water samples were analyzed for biological and physico-chemical parameters as well as discharge and percentage of canopy cover. Metabolism was determined through the single-station method to estimate gross primary production (GPP), ecosystem respiration (ER) and net ecosystem production (NEP) with BAyesian Single-station Estimation (BASE). Nutrient concentrations tended to be higher in impacted versus preserved streams (e.g., average total phosphorus between 0.028-0.042 mg L-1 and 0.009-0.038 mg L-1, respectively). Average canopy cover varied between 58 and 77%, with no significant spatial or seasonal variation. All streams were net heterotrophic (ER exceeded GPP) in all sampling periods. GPP rates were always lower than 0.7 gO2 m-2 d-1 in all streams and ER varied from 0.6 to 42.1 gO2 m-2 d-1.  Linear Mixed-Effect models showed that depth, discharge, velocity and total phosphorus are the most important predictors for GPP. For ER, depth, velocity and canopy cover are significant potential predictors. Canopy cover was the main light limiting factor and influenced stream metabolism. Our findings reinforced the concepts that shifts in the shading effect provided by vegetation (e.g., through deforestation) or changes in discharge (e.g., through land use conversion or water abstractions) can impact freshwater metabolism. Our study suggests that human activities in low latitude areas can alter tropical streams’ water quality, ecosystem function, and the degree of riparian influence. Our data showed that tropical streams can be especially responsive to increases of organic matter inputs leading to high respiration rates and net heterotrophy, and this should be considered to support management and restoration efforts.

scholarly journals Land Use and Season Influence Event‐Scale Nitrate and Soluble Reactive Phosphorus Exports and Export Stoichiometry from Headwater Catchments

2020 ◽  
Vol 56 (10) ◽  
Author(s):  
Dustin W. Kincaid ◽  
Erin C. Seybold ◽  
E. Carol Adair ◽  
William B. Bowden ◽  
Julia N. Perdrial ◽  
...  
Keyword(s):  
Land Use ◽  
Soluble Reactive Phosphorus ◽  
Event Scale ◽  
Headwater Catchments ◽  
Reactive Phosphorus

scholarly journals Nutrient concentrations and fluxes for podzolic and gley soils at Plynlimon, mid-Wales: implications for modelling inorganic nitrogen and phosphorus in upland UK environments

2002 ◽  
Vol 6 (3) ◽  
pp. 403-420
Author(s):  
C. Neal
Keyword(s):  
Inorganic Nitrogen ◽  
Soluble Reactive Phosphorus ◽  
Sitka Spruce ◽  
Nutrient Concentrations ◽  
Nitrogen And Phosphorus ◽  
Podzolic Soils ◽  
Forestry Management ◽  
Order Of Magnitude ◽  
Reactive Phosphorus ◽  
Stream Nitrate

Abstract. The effect of felling on stream nitrate, ammonium and soluble reactive phosphate (SRP) concentrations is examined for acidic and acid sensitive Sitka Spruce afforested catchments with podzolic and gley soils in mid-Wales. For the streams draining the felled podzolic areas, the concentrations of nitrate can be up to an order of magnitude higher than pre-fell values and post-fell concentrations can even be lower than the pre-fell values. Felling for the podzolic soils barely leads to any changes in ammonium or SRP concentration. For the gley soils, felling results in an order of magnitude increase in nitrate, ammonium and SRP for a small drainage ditch, but the pulse is much reduced before it reaches the main Nant Tanllwyth channel. Rather, within-catchment and within-stream processes not only imbibe nitrate, ammonium and SRP fluxes generated, but in the case of nitrate, concentrations with- and post-felling are lower than pre-felling concentrations. The flux changes involved are described in terms of (a) input-output relationships and (b) "felling disruption" and "felling recovery responses". The findings are linked to issues of hydrobiological controls and forestry management. Keywords: Plynlimon, Hafren, Hore, streams, nitrate, ammonium, SRP, phosphorus, soluble reactive phosphorus, phosphate, orthophosphate, Sitka spruce, forestry, felling, podzol, gley

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