Importance of flood zones for nitrogen and phosphorus dynamics in the Danube Delta

Cristofor, Sergiu; Vădineanu, Angheluţă; Ignat, Gheorghe

doi:10.1007/978-94-011-1602-2_17

Cited by 13 publications

(11 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2). Higher system net SRP uptake rates in fall than in spring were also found by previous investigators (Cristofor et al 1993;Friedrich et al 2003), and were explained by two to three times larger SRP concentrations compared to May (Table 3; Fig. 2).…”

Section: Discussionsupporting

confidence: 84%

“…to the Puiu-Rosulet-Rosu complex was substantial relative to the external DIN input (5.4 mmol m -2 d -1 in both seasons), and made up *34% of TN input in May and *42% in September compared to the Uzlina-Isac complex (Table 2). Hence, external inorganic nutrient input declined with decreasing hydrological connectivity with the main river, as previously described (Cristofor et al 1993;Heiler et al 1995).…”

Section: Discussionsupporting

confidence: 69%

“…Channel water as well as backwash from extensive reed beds provided nutrients and remineralized organic biomass to these lakes. Macrophytes and reed stands are known as sources of remineralized nutrients (Carpenter and Lodge 1986), and this release can be substantial in the littoral zone, particularly during high water levels (Cristofor et al 1993). Therefore, input of nutrients from reedbeds was particularly active during May, when the Delta was flooded (Table 1).…”

Section: Discussionmentioning

confidence: 99%

See 2 more Smart Citations

Organic matter governs N and P balance in Danube Delta lakes

et al. 2010

View full text Add to dashboard Cite

The transformation of dissolved inorganic nitrogen (DIN) and soluble reactive phosphorous (SRP), and the release of dissolved organic and particulate N and P, were analyzed in two lake complexes (Uzlina-Isac and Puiu-Rosu-Rosulet) of the Danube Delta wetland during flood conditions in May and at low water level in September 2006. The Uzlina-Isac complex was hydrologically tightlyconnected with the Danube River and was flushed with river-borne nutrients and organic matter. These lakes acted as effective transformers for nutrients and produced large amounts of fresh biomass, that promoted the excretion of dissolved organic N and P during active growth. Biomass breakdown created particulate matter (\0.45 lm), which was widely liberated during low flow in the fall. The PuiuRosu-Rosulet complex was characterized by a more distant position to the Danube and proximity to the Black Sea, and received dominantly transformed organic compounds from the flow-through water and vast vegetation cover. Due to reduced nutrient input, the internal production of organic biomass also was reduced in these more remote lakes. Total N and P export from the lake nearest to the shelf was governed by dominantly dissolved organic and particulate compounds (mean 58 and 82%, respectively). Overall, this survey found that these highly productive wetlands efficiently transform nutrients into a large pool of dissolved organic and particulate N and P. Hence, wetland lakes may behave widely as net sources of organic N and P to downstream waters and coastal marine systems.

show abstract

Section: Discussionsupporting

confidence: 84%

Section: Discussionsupporting

confidence: 69%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Organic matter governs N and P balance in Danube Delta lakes

et al. 2010

View full text Add to dashboard Cite

show abstract

“…These values are comparable with those found in other European river systems such as the Danube River which has a mean TP of 0.24 mg/L (Dokulil and Janauer, 1990;Cristofor et al, 1993). But they are higher than those of Australian river systems where the mean TP values are below 0.1 mg/L (Nolan et al, 1995;Hart et al, 1999) or than Estonian ones (Loigu and Leisk, 1996).…”

Section: Phosphorus Composition In the Garonne Downstream Of The Treasupporting

confidence: 85%

Hydromorphological control of phosphorus in a large free‐flowing gravel bed river: the Garonne River (France)

Garay

Sauvage

Vervier

2001

Regul. Rivers: Res. Mgmt.

View full text Add to dashboard Cite

The objective of this paper is to relate phosphorus (P) transport dynamics and hydromorphological characteristics of a large human-influenced river, the River Garonne within a sector receiving the waste water of a sewage treatment plant for a population of 600 000. Two studies were conducted in 1997 and 1999 during two different hydrological conditions at low-flow periods. The 1997 study was carried out on an 18-km stretch with discharges varying between 33 and 53 m 3 /s and with very small fluctuations. The 1999 study concerned a longer stretch of 47 km, divided into four smaller reaches, and with discharges fluctuating rapidly from 40 to 108 m 3 /s. Downstream of the sewage treatment plant, total phosphorus (TP) concentrations ranged from 0.19 to 0.27 mg/L and were mainly in the dissolved form: between 60 and 78% of TP was dissolved reactive phosphorus (DRP). P concentrations were significantly lower upstream of the sewage treatment plant.By a mass-balance approach, we estimated that the sewage treatment plant represents more than half the input (between 59 and 67%) of the studied sector. TP dynamic is linked to suspended solids for discharges above 60 m 3 /s. During established low-flow period in the 1997 study (B 60 m 3 /s), 22 and 27% of TP and DRP were retained by the river bed.In the 1999 study, under different low-water period hydraulic conditions, we calculate that particulate P retention occurred in two reaches among the four under study and only for discharges below 60 m 3 /s. We show that for established discharges below 60 m 3 /s, there is an active uptake of transported P by functional compartments (i.e. the hyporheic zone and the periphyton). During the low-water period with relatively high hydraulic fluctuations, and for discharges \60 m 3 /s, P retention is controlled as expected by suspended matter dynamics.We conclude that management of the hydrological regime can influence P retention during sensitive low-water periods.

show abstract

“…Only in the last decade and a half there has been intensive and extensive research monitoring programmes begun to contribute to the available data and to the development of knowledge on ecosystem and landscape perspective (Vadineanu and Cristofor, 1989;Cristofor et al 1993, Stara~ et al, 1994.…”

Section: Introductionmentioning

confidence: 98%

Changes and opportunities for integrated management of the Razim-Sinoe Lagoon System

Vădineanu

Cristofor

Ignat

et al. 1997

International Journal of Salt Lake Research

View full text Add to dashboard Cite

Abstract. The aim of this paper is to identify the general trend of changes and the basic requirements of the most important lagoon system of the Black Sea, on the basis of critical analysis of existing data. A more coherent set of data sampled after 1988 on the basis of some intensive and extensive study and research programmes, including the main trophic parameters and the most representative structural and functional features of this complex of ecotonal lakes, is comparatively analysed together with more fragmentary data previously existing. The structural and functional changes within this complex of lakes were analysed based on 31 most representative variables belonging to the main abiotic and biological compartments of the two main lakes, Razim and Sinoe: dissolved organic carbon, dissolved oxygen, trophic state index TSI, nutrient content and ratio, salinity, chlorophyll, phytoplankton, zooplankton, submerged macrophytes, zoobenthos, fish and birds. Two stages were distinguished in the main structural changes, including morphometric connections with the Danube River and the Black Sea and hydrochemistry and its effects on communities. These transitions were associated with two main driving forces, water desalinisation and rapid eutrophication, and with other two kinds of man-induced changes, local hydrotechnical buildings and long-distance variables operating over the entire Danube River watershed. The information support system for sustainable management of the Razim-Sinoe Lagoon Complex as a part of the Danube Delta Biosphere Reserve, integrating existing data from research programmes and an integrated monitoring system for new data is a final conclusion on further needs.

show abstract

Importance of flood zones for nitrogen and phosphorus dynamics in the Danube Delta

Cited by 13 publications

References 0 publications

Organic matter governs N and P balance in Danube Delta lakes

Organic matter governs N and P balance in Danube Delta lakes

Hydromorphological control of phosphorus in a large free‐flowing gravel bed river: the Garonne River (France)

Changes and opportunities for integrated management of the Razim-Sinoe Lagoon System

Contact Info

Product

Resources

About