Evaluation of nutrient stoichiometric relationships amongst ecosystem compartments of a subtropical treatment wetland. Do we have “Redfield Wetlands”?

AbstractBackgroundEvaluation of carbon (C), nitrogen (N) and phosphorus (P) ratios in aquatic and terrestrial ecosystems can advance our understanding of biological processes, nutrient cycling and the fate of organic matter (OM) in these ecosystems. Eutrophication of aquatic ecosystems can change the accumulation and decomposition of OM which can alter biogeochemical cycling and alter the base of the aquatic food web. This study investigated nutrient stoichiometry within and among wetland ecosystem compartments (i.e. water column, flocculent, soil and above ground vegetation biomass) of two sub-tropical treatment wetlands with distinct vegetation communities. Two flow-ways (FWs) within the network of Everglades Stormwater Treatment Areas in south Florida (USA) were selected for this study. We evaluated nutrient stoichiometry of these to understand biogeochemical cycling and controls of nutrient removal in a treatment wetland within an ecological stoichiometry context.ResultsThis study demonstrates that C, N, and P stoichiometry can be highly variable among ecosystem compartments and between FWs. Power law slopes of C, N and P within surface water floc, soil and vegetation were significantly different between and along FWs.ConclusionsAssessment of wetland nutrient stoichiometry between and within ecosystem compartments suggests unconstrained stoichiometry related to P that conforms with the notion of P limitation in the ecosystem. Differences in N:P ratios between floc and soil suggest different pathways of organic nutrient accumulation and retention between FWs. Surface nutrient stoichiometry was highly variable and decoupled (or closed to decoupled, by our criteria), in particular with respect to P. We hypothesize that decoupling may be the imprint of variability in inflow nutrient stoichiometry. However, despite active biogeochemical cycles that could act to restore nutrient stoichiometry along the FW, there was little evidence that such balancing occurred, as the degree of stochiometric decoupling in the water column did change with distance downstream. This information is only the beginning of a larger journey to understand stoichiometric processes within wetland ecosystems and how it related to ecosystem function.

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Evaluation of phosphorus retention in a South Florida treatment wetland

Water Science & Technology ◽

10.2166/wst.2001.0816 ◽

2001 ◽

Vol 44 (11-12) ◽

pp. 109-115 ◽

Cited By ~ 15

Author(s):

M.K. Nungesser ◽

M.J. Chimney

Keyword(s):

Removal Efficiency ◽

Nutrient Removal ◽

Aquatic Vegetation ◽

South Florida ◽

Superior Performance ◽

Stormwater Treatment ◽

Treatment Wetland ◽

Operational Conditions ◽

Macrophyte Community ◽

Floating Macrophyte

The Everglades Construction Project of the South Florida Water Management District (District) will employ large constructed wetlands known as Stormwater Treatment Areas (STAs) to reduce phosphorus concentrations in runoff entering the Everglades. The District built and operated a prototype STA, the 1,545 ha Everglades Nutrient Removal Project (ENRP), to determine the efficacy of subtropical wetlands for improving regional water quality with a focus on reducing total phosphorus (TP). In five years of operation, the ENRP has consistently exceeded its performance goals of TP outflow concentrations <50 μg P/L and a 75% TP load reduction. Since August 1994, the ENRP has retained 70.3 metric tons of TP that otherwise would have entered the Everglades. When corrected for surface area and inflow TP load, TP removal efficiency was highest in the inflow buffer cell and decreased generally in a downstream fashion through the wetland. High TP removal efficiency in treatment cell 4 was attributed to superior performance of its submerged aquatic vegetation community relative to the emergent and floating macrophyte community in the other cells. Controlled experiments in the District's STA Optimization Research Program will help clarify what effect vegetation and operational conditions may have on nutrient removal in the STAs.

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Seal Tightly and Store in a Cool Dry Place: Exploring Soil Phosphorus Storage in a Subtropical Treatment Wetland.

10.21203/rs.3.rs-824704/v1 ◽

2021 ◽

Author(s):

Paul Julian II ◽

Todd Z. Osborne ◽

Vimala D. Nair

Keyword(s):

Storage Capacity ◽

Soil Depth ◽

Soil Phosphorus ◽

Stormwater Treatment ◽

Treatment Wetland ◽

Wetland Ecosystems ◽

Soil P ◽

Iron Aluminum ◽

Variable Condition ◽

Phosphorus Storage

Abstract Oligotrophic wetlands of the Everglades are often the final recipients of nutrients from adjacent ecosystems and tend to accumulate phosphorus (P) in their soils. Understanding P source and sink dynamics in wetlands are critical for managing wetland ecosystems and protecting downstream resources. In this study, soil P storage capacity (SPSC) was evaluated within two treatment flow-ways of the Everglades Stormwater Treatment Areas (STAs). This study hypothesized that SPSC will vary between flow-ways, soil depth, and spatially along the inflow-to-outflow gradient. The P storage capacity in the STAs depend on the proportion of iron, aluminum, calcium, and magnesium (Fe, Al, Ca, and Mg, respectively) to P with floc and recently accreted soils (RAS) being associated more with Ca and Mg and pre-STA soils being associated more with Fe and Al. Phosphorus loss, as indicated from SPSC values would vary between systems and soil depths suggesting a variable condition of P sink and source within and along flow-ways. This result, while limited, demonstrates the applicability of SPSC to wetlands systems and provides information that will aid operational or management decisions associated with improving P retention of the Everglades STAs.

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Accretion of Nutrients and Sediment by a Constructed Stormwater Treatment Wetland in the Lake Tahoe Basin

JAWRA Journal of the American Water Resources Association ◽

10.1111/1752-1688.12595 ◽

2017 ◽

Vol 53 (6) ◽

pp. 1495-1512 ◽

Cited By ~ 2

Author(s):

Robert G. Qualls ◽

Alan C. Heyvaert

Keyword(s):

Lake Tahoe ◽

Stormwater Treatment ◽

Lake Tahoe Basin ◽

Treatment Wetland ◽

Tahoe Basin

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On the potential vegetation feedbacks that enhance phosphorus availability – insights from a process-based model linking geological and ecological timescales

Biogeosciences ◽

10.5194/bg-11-3661-2014 ◽

2014 ◽

Vol 11 (13) ◽

pp. 3661-3683 ◽

Cited By ~ 19

Author(s):

C. Buendía ◽

S. Arens ◽

T. Hickler ◽

S. I. Higgins ◽

P. Porada ◽

...

Keyword(s):

Biomass Production ◽

Primary Productivity ◽

Chemical Weathering ◽

Production Efficiency ◽

Root Exudation ◽

Terrestrial Ecosystems ◽

Global Scale ◽

P Uptake ◽

P Availability ◽

P Limitation

Abstract. In old and heavily weathered soils, the availability of P might be so small that the primary production of plants is limited. However, plants have evolved several mechanisms to actively take up P from the soil or mine it to overcome this limitation. These mechanisms involve the active uptake of P mediated by mycorrhiza, biotic de-occlusion through root clusters, and the biotic enhancement of weathering through root exudation. The objective of this paper is to investigate how and where these processes contribute to alleviate P limitation on primary productivity. To do so, we propose a process-based model accounting for the major processes of the carbon, water, and P cycles including chemical weathering at the global scale. Implementing P limitation on biomass synthesis allows the assessment of the efficiencies of biomass production across different ecosystems. We use simulation experiments to assess the relative importance of the different uptake mechanisms to alleviate P limitation on biomass production. We find that active P uptake is an essential mechanism for sustaining P availability on long timescales, whereas biotic de-occlusion might serve as a buffer on timescales shorter than 10 000 yr. Although active P uptake is essential for reducing P losses by leaching, humid lowland soils reach P limitation after around 100 000 yr of soil evolution. Given the generalized modelling framework, our model results compare reasonably with observed or independently estimated patterns and ranges of P concentrations in soils and vegetation. Furthermore, our simulations suggest that P limitation might be an important driver of biomass production efficiency (the fraction of the gross primary productivity used for biomass growth), and that vegetation on old soils has a smaller biomass production rate when P becomes limiting. With this study, we provide a theoretical basis for investigating the responses of terrestrial ecosystems to P availability linking geological and ecological timescales under different environmental settings.

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Water quality, isoscapes and stoichioscapes of seagrasses indicate general P limitation and unique N cycling in shallow water benthos of Bermuda

Biogeosciences ◽

10.5194/bg-12-6235-2015 ◽

2015 ◽

Vol 12 (20) ◽

pp. 6235-6249 ◽

Cited By ~ 19

Author(s):

J. W. Fourqurean ◽

S. A. Manuel ◽

K. A. Coates ◽

W. J. Kenworthy ◽

J. N. Boyer

Keyword(s):

Water Column ◽

Spatial Patterns ◽

Animal Movement ◽

P Availability ◽

Seagrass Species ◽

Δ13c And Δ15n ◽

Elemental Ratios ◽

Syringodium Filiforme ◽

P Limitation ◽

Near Shore

Abstract. Striking spatial patterns in stable isotope ratios (isoscapes) and elemental ratios (stoichioscapes) of seagrass leaves and the water column nutrients indicate general P-limitation of both water column and benthic primary productivity on the Bermuda Platform, and they highlight the role of the Bermuda Islands as a source of N and P. We found consistent differences among the four seagrass species (Syringodium filiforme, Thalassia testudinum, Halodule sp. and Halophila decipiens) in the N, P, δ13C and δ15N of leaf tissues. The δ15N of seagrass leaves was especially variable, with values from −10.1 to 8.8 ‰, greatly expanding the reported range of values for all seagrass species globally. Spatial patterns from both the water column and the seagrass leaves indicated that P availability was higher near shore, and δ15N values suggest this was likely a result of human waste disposal. Spatially contiguous areas of extremely depleted seagrass 15N suggest unique N sources and cycling compared to other seagrass-dominated environments. Seagrass N : P values were not as far from the stoichiometric balance between N and P availability as in the water column, and there were no strong relationships between the water column N : P and the seagrass N : P. Such isoscapes and stoichioscapes provide valuable ecogeochemical tools to infer ecosystem processes as well as provide information that can inform food web and animal movement studies.

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Carbon flux response and recovery to drought years in a hemi-boreal peat bog between different vegetation types

10.5194/egusphere-egu2020-13891 ◽

2020 ◽

Author(s):

Chris R Taylor ◽

Ben Keane ◽

Iain Hartley ◽

Gareth Phoenix

Keyword(s):

Carbon Dioxide ◽

Nutrient Availability ◽

Anthropogenic Activities ◽

Terrestrial Ecosystems ◽

Phosphorus Limitation ◽

Atmospheric Concentration ◽

Ecosystem Responses ◽

N Limitation ◽

Plant Soil ◽

P Limitation

Terrestrial ecosystems absorb 30% of anthropogenic carbon dioxide (CO2) emissions, slowing its rising atmospheric concentration and substantially inhibiting climate change. This uptake is believed to be due to elevated CO2 (eCO2) stimulating plant photosynthesis and growth, thus increasing carbon (C) storage in plants and soil organic matter. However, nitrogen (N) limitation can reduce ecosystem C uptake capacity under eCO2 by as much as 50%. Phosphorus (P) limitation in ecosystems is almost as common as N-limitation and is increasing due to ongoing deposition of N from anthropogenic activities. Despite this, we do not know how P-limited ecosystems will respond to eCO2, constituting a major gap in our understanding of how large areas of the biosphere will impact atmospheric CO2 over the coming decades.In the first study conducted into the effect of eCO2 on P-limited ecosystems with manipulated nutrient availability, the Phosphorus Limitation And ecosystem responses to Carbon dioxide Enrichment project (PLACE), investigates the effects of eCO2 on C cycling in grasslands, which are a critical global C store. Turf mesocosms from P-limited acidic and limestone grasslands, where N and P inputs have been manipulated for 20 years (control, low N (3.5 g m-2 y-1), high N (14 g m-2 y-1), and P (3.5 g m-2 y-1)), have been exposed to either ambient or eCO2 (600 ppm) in a miniFACE (mini Free Air Carbon Enrichment) system. Long-term P addition has alleviated P limitation while N additions have exacerbated it. The two contrasting grasslands contain different amounts of organic versus mineral P in their soils and, thus, plants may have to use contrasting strategies to acquire the additional P they need to increase growth rates under elevated CO2.We present data from the first two growing seasons, including above and below ground productivity, and C, N and P cycling through plant, soil and microbial pools. Aboveground harvest data from the second year have shown eCO2 has only increased biomass production in the limestone grassland (by 17%; p< 0.0001), and not in the acid grassland. There was also a significant effect of nutrient treatment (p< 0.001) with biomass increasing under P and HN, indicating some co-NP limitation. Stable isotope tracing, using the fumigation CO2 signal has shown the fate of newly assimilated C and its contribution to gaseous C flux to the atmosphere in the form of methane (CH4) and respired CO2. &#160;In summary, our first two years of eCO2 treatment suggests that productivity of limestone and acidic grassland respond differently and that these responses depend on nutrient availability, indicating the complexity of predicting P-limited ecosystem responses as atmospheric CO2 continues to rise.

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Integrated survey of elemental stoichiometry (C, N, P) from the Western to Eastern Mediterranean Sea

Biogeosciences Discussions ◽

10.5194/bgd-7-7315-2010 ◽

2010 ◽

Vol 7 (5) ◽

pp. 7315-7358 ◽

Cited By ~ 22

Author(s):

M. Pujo-Pay ◽

P. Conan ◽

L. Oriol ◽

V. Cornet-Barthaux ◽

C. Falco ◽

...

Keyword(s):

Mediterranean Sea ◽

Water Column ◽

Surface Waters ◽

Eastern Mediterranean ◽

Vertical Gradient ◽

Western Basin ◽

P Limitation ◽

Severe Deficiency ◽

Elemental Stoichiometry ◽

Redfield Ratios

Abstract. This paper provides an extensive vertical and longitudinal description of the biogeochemistry in the whole Mediterranean Sea during the summer 2008. During this strong stratified period, the distribution of nutrients, particulate and dissolved organic carbon (DOC), nitrogen (DON) and phosphorus (DOP) were investigated along a 3000 km transect (BOUM cruise) crossing the Western and Eastern Mediterranean basins. The partitioning of chemical C, N and P species among all these mineral and organic pools has been analysed to produce a detailed spatial and vertical extended examination of the elemental stoichiometry. Surface Mediterranean waters were depleted in nutrients and the thickness of this depleted layer increased towards the East from about 10 m in the Gulf of Lion to more than 100 m in the Levantine basin, concomitantly to the gradual deepening of the thermocline and nutriclines. We used threshold in oxygen concentration to discriminate the water column in three layers; surface (Biogenic Layer BL), intermediate (Mineralization Layer ML), and deep layer (DL) and to propose a schematic representation of biogeochemical fluxes between the different compartments and to compare the functioning of the two basins. The stoichiometry revealed a clear longitudinal and vertical gradient in the mineral fraction with a P-depletion evidenced on both dimension. As a consequence of the severe deficiency in phosphorus, the C:N:P ratios in all pools within the BL largely exceed the Redfield ratios. Despite these gradients, the deep estimated fluxes in the mineral compartment tend towards the canonical Redfield values in both basins. A change in particulate matter composition has been evidenced by a C increase relative to N and P along the whole water column in the western basin and between BL and ML in the eastern one. More surprisingly, a decrease in N relative to P with depth was encountered in the whole Mediterranean Sea. We suggest that there was a more rapid recycling of N than P in intermediate waters (below BL) and a complete use of DOP in surface waters. DOC accumulated in surface waters according to the oligotrophic status but this was not the case for nitrogen nor phosphorus. Our data clearly showed a noticeable stability of the DOC:DON ratio (12–13) in the whole Mediterranean Sea, contradicting the fact that N is recycled faster than C in the DOM but in agreement with a P limitation of bacterial activity. Finally, comparisons between these elemental distributions and ratios along the West-East Mediterranean gradient of trophic status provide new insights for identifying and understanding fundamental interactions between marine biogeochemistry and ecosystems, which will help to predict the impacts of environmental climate changes on the Mediterranean marine ecosystems. Indeed, the outflowing through the various Mediterranean straits have been shown to be changing, the functioning of the BL ecosystem could be impacted, not only by changes in nutrients surface sources but also by changes in deep nutrients one.

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Nutrient-imbalanced Conditions Shift the Interplay Between Zooplankton and Gut Microbiota

10.21203/rs.3.rs-43571/v1 ◽

2020 ◽

Author(s):

Yingdong Li ◽

Zhimeng Xu ◽

Hongbin Liu

Keyword(s):

Gut Microbiota ◽

Anaerobic Metabolism ◽

Exchange Process ◽

Nutrient Concentrations ◽

Nutrient Stoichiometry ◽

Compensatory Feeding ◽

P Limitation ◽

Community Model ◽

Gut Microbial Community ◽

Limited Diet

Abstract Nutrient stoichiometry of phytoplankton changes frequently with aquatic ambient nutrient concentrations, which is mainly influenced by environmental factors and the dynamics of ecosystems. Consequently, the stoichiometry of phytoplankton can markedly alter the metabolism and growth of zooplankton. However, the effects of nutrient-imbalanced prey on the interplay between zooplankton and their gut microbiota remain unknown. Using metatranscriptome sequencing, neutral community model (NCM), and experimental validation, we investigated the interactions between Daphnia magna and its gut microbiota on nutrient-imbalanced algal diet. Our results showed that in nutrient depleted water, nutrient-enriched zooplankton gut stimulated the accumulation of microbial polyphosphate and the assimilation of ammonia under phosphorus and nitrogen limited diet, respectively. Comparing with nutrient replete group, both N and P limitation had markedly promoted the gene expression of gut microbial for organic matter degradation but repressed that for anaerobic metabolisms. Besides, with N and P limited diet, the gut microbial community exhibited a higher fitting to NCM, suggesting increased ambient-gut exchange process favored by compensatory feeding of D. magna. This process also elevated oxygen level in the gut and explained the repressed anaerobic metabolism of gut microbes. Further axenic grazing experiment revealed that bacteria can still benefit D. magna to achieve a better growth under nutrient-imbalanced diet by enhancing their digestion capability. Together, these results demonstrated that under nutrient-imbalanced diet, the microbes not only benefit themself by absorbing excess nutrients inside zooplankton gut but also benefit zooplankton to achieve a better adaptation.

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A Phased Assessment of Restoration Alternatives to Achieve Phosphorus Water Quality Targets for Lake Okeechobee, Florida, USA

Water ◽

10.3390/w11020327 ◽

2019 ◽

Vol 11 (2) ◽

pp. 327 ◽

Cited By ~ 11

Author(s):

Yogesh Khare ◽

Ghinwa Naja ◽

G. Stainback ◽

Christopher Martinez ◽

Rajendra Paudel ◽

...

Keyword(s):

Best Management Practices ◽

Management Practices ◽

Nutrient Management ◽

Control Strategies ◽

Cost Effective ◽

South Florida ◽

Assessment Model ◽

Lake Okeechobee ◽

Stormwater Treatment ◽

Maximum Daily Loads

Achieving total phosphorus (TP) total maximum daily loads (TMDL) for Lake Okeechobee (Florida, FL, USA), a large freshwater lake, is a key component of the greater Everglades ecosystem restoration and sustainability of south Florida. This study was aimed at identification of a cost-effective restoration alternative using four TP control strategies—Best Management Practices (BMPs), Dispersed Water Management (DWM), Wetland Restoration, and Stormwater Treatment Areas (STAs)—to achieve a flow-weighted mean TP concentration of 40 µg/L at lake inflow points, through a phased scenario analysis approach. The Watershed Assessment Model was used to simulate flow and phosphorus dynamics. The 10-year (1998–2007) ‘Base’ scenario calibration indicated ‘acceptable’ to ‘good’ performance with simulated annual average flows and TP load of 2.64 × 109 m3 and 428.6 metric tons, respectively. Scenario results showed that TP load reduction without STAs would be around 11–40% with respect to Base compared to over 75% reduction requirement to achieve TMDL, indicating STAs as a necessary component to achieve restoration. The most cost-effective alternative to achieve TP target consisted of implementation of nutrient management BMPs, continuation of existing DWM projects, and the construction of ~200 km2 of STAs for a total project cost of US $4.26 billion.

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