Organic matter governs N and P balance in Danube Delta lakes |
| |
| Authors: | E Durisch-Kaiser A Doberer J Reutimann A Pavel S Balan S Radan B Wehrli |
| |
| Institution: | (1) Institute of Biogeochemistry and Pollutant Dynamics, ETH, 8092 Zurich, Switzerland;(2) Eawag, Swiss Federal Institute of Aquatic Science and Technology, 6047 Kastanienbaum, Switzerland;(3) National Institute for Marine Geology and Geoecology–GeoEcoMar, 024053 Bucharest, Romania |
| |
| Abstract: | 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
tightly-connected 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 μm), which was widely liberated
during low flow in the fall. The Puiu–Rosu–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. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
