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Modelling nitrogen and phosphorus limitation on phytoplankton growth in Narva Bay, South-Eastern Gulf of Finland

100%

Lessin G., Lips I., Raudsepp U.

Oceanologia

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2007

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tom 49

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nr 2

The relative roles of nitrogen and phosphorus in the limitation of phytoplankton growth in Narva Bay, south-eastern Gulf of Finland, were studied by combining the results of numerical modelling and nutrient enrichment experiments.Mo delled biomass-based intracellular nutrient concentrations (nutrient functions) were used to estimate the limiting nutrient in Narva Bay.Nutr ient functions – NF ∈ [0; 1] for nitrogen and PF ∈ [0; 1] for phosphorus – define the dependence of the phytoplankton growth rate on nutrients: NF = PF = 1 corresponds to nonlimitation of phytoplankton growth by nutrients, whereas NF = 0 or PF = 0 to zero growth.T he biotests indicated the response of phytoplankton growth to an increase in nutrient concentration in the surrounding water.Thr ee locations were selected for detailed analyses of temporal variations in the nutrient functions: the offshore station N12, station N8 at the mouth of the River Narva, and coastal station 38.T he biotests were performed at the same stations. NF and PF reached values of 0.9 prior to the spring bloom. With the onset of the spring bloom, NF decreased rapidly and remained below 0.1 in the open part of Narva Bay for the rest of that period.I n the coastal zone, NF was in excess of 0. 1, with a local maximum in the river mouth area. PF decreased to 0.3–0.4 in the open bay after the spring bloom.I n the coastal zone PF remained above 0.4, with a certain increase from the midsummer minimum towards the end of summer.The numerical modelling results clearly show that nitrogen limits phytoplankton growth in Narva Bay.Ph osphorus limitation may occur only for a limited period and over a limited area at the Narva River mouth and other coastal locations.I n general, the biotests backed up the modelling results, the main exception being in the open bay during summer.The model does not account for nitrogen fixation, however.S ince N-fixing cyanobacteria were prevalent in the offshore area, the addition of phosphorus led to enhanced phytoplankton growth at station N12.

2

Soil C:P ratio along elevational gradients in Picea schrenkiana forest of Tianshan Mountains

84%

Cao Y., Wang Y., Xu Z.

Polish Journal of Ecology

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2018

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tom 66

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nr 4

Forest soils potentially store a large pool of carbon and phosphorus. A deep understanding of the total carbon and phosphorus stock in forest soils is vital in the assessment of the nutrients dynamics in forest ecosystems. This study examined the effects of elevation, soil depth, and climatic variables, specifically mean annual temperature (MAT) and mean annual precipitation (MAP), on soil carbon and organic phosphorus in Schrenk's spruce (Picea schrenkiana) forest at Tianshan Mountains. Results showed that soil organic carbon (SOC) significantly increased while organic phosphorus decreased with elevation. Interestingly, carbon increased faster with increasing elevation in the alluvial horizon than in the leached horizon, demonstrating the important role of deep soils in carbon sequestration potential. SOC concentration decreased with soil depth, whereas phosphorus concentration initially decreased and then increased. SOC had no significant relationships with MAT and MAP, whereas phosphorus concentration decreased with MAT. Similar to the impacts of MAT and MAP on SOC, these two climatic variables also exerted no significant influence on C:P ratio.

3

Unraveling the ecological functioning of the monsoonal Songkhram river floodplain in Thailand by integrating data on soil, water, and vegetation

84%

Walalite T., Dekker S. C., Schot P. P., Wassen M. J.

International Journal of Ecohydrology and Hydrobiology

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2018

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tom 18

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nr 1

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Fine resolution of primary production and its limitation in phytoplankton communities of the Darss-Zingst Bodden chain, a coastal lagoon of the Southern Baltic Sea

67%

Schumann R., Schoor A., Schubert H.

Baltic Coastal Zone. Journal of Ecology and Protection of the Coastline

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2009

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tom 13 part II

Evaluated direct methods for estimating primary production are both a precondition and a supplement for modeling scenarios in a eutrophicated and changing coastal ecosystem. Analyses of phytoplankton succession, integral primary production and potential limitation of phytoplankton growth of the shallow brackish Darss-Zingst Bodden chain indicate the extraordinary importance of colony-forming nanophytoplankton for primary productivity. Respective studies began in the 1990s. Exemplary studies focus on the contribution of individual aggregates and phytoplankton colonies to potential primary production as well as the microscale visualization and seasonal variability of extracellular enzymatic phosphate hydrolysis. Results from these studies suggest that an inhomogeneous distribution of productivity and limitation is relevant to the pelagic zones. This paper discusses the effect of heterogeneity on ecosystem behavior in this specific trophy succession state in the context of a future strategy to supplement bulk methods for productivity and limitation analyses especially for barely distinguishable phytoplankton species in euthropicated coastal waters.

5

Nutrients availability and hydrological conditions of selected wetland ecosystems in the Biebrza river valley

67%

Stelmaszczyk M., Okruszko T., Meire P.

Annals of Warsaw University of Life Sciences - SGGW. Land Reclamation

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2015

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tom 47

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nr 1

Nutrients availability and hydrological conditions of selected wetland ecosystems in the Biebrza river valley. Paper presents results of investigation of hydrological conditions and nutrients limitation and availability for wetland vegetation in selected sites within Biebrza river valley. Analysed sites were overgrown by tall sedge Magnocaricion vegetation (Caricetum gracilis and Caricetum elatae), wet meadow Molinio-Arrhenatheretea vegetation (Molinietum caeruleae), and sedge-moss Scheuchzerio-Caricetea nigrae vegetation (Caricetum lasiocarpae). There were noted a close relationship between vegetation types, hydrological regimes and kind of nutrient limitation. Low productive Molinio-Arrhenatheretea and Scheuchzerio-Caricetea nigrae vegetations fed mainly by groundwater were limited by phosphorus, while highly productive Magnocaricion vegetation, fed by river water, was subjected to nitrogen limitation. We have found big diversifi cation of groundwater and surface water levels within habitats of different vegetation types along the Biebrza river valley. Magnocaricion vegetation present on fl ooded areas is characterized by signifi cant water level fl uctuations and long-lasting inundations. On areas covered by Molinio- -Arrhenatheretea vegetation we noted majority of water levels not exceeding the level of the ground surface. Whereas Scheuchzerio-Caricetea nigrae vegetation, fed by groundwater, is characterized by low variation of groundwater levels.

6

Photosynthetic response of five marine diatoms to acute exposure to PAR and UV radiations

67%

Montero O., Hader D.-P.

Acta Protozoologica

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2007

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tom 46

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nr 2

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Experimental studies on processes taking place in enclosures with mixed sea and Vistula River water

51%

Witek Z., Pastuszak M., Nakonieczny J., Ochocki S., Zalewski M., Maciejowska M., Gromisz S., Mackiewicz T., Wrzesinska-Kwiecien M.

Oceanological Studies

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1997

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tom 26

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nr 1

Ograniczanie wyników

Modelling nitrogen and phosphorus limitation on phytoplankton growth in Narva Bay, South-Eastern Gulf of Finland

Soil C:P ratio along elevational gradients in Picea schrenkiana forest of Tianshan Mountains

Unraveling the ecological functioning of the monsoonal Songkhram river floodplain in Thailand by integrating data on soil, water, and vegetation

Fine resolution of primary production and its limitation in phytoplankton communities of the Darss-Zingst Bodden chain, a coastal lagoon of the Southern Baltic Sea

Nutrients availability and hydrological conditions of selected wetland ecosystems in the Biebrza river valley

Photosynthetic response of five marine diatoms to acute exposure to PAR and UV radiations

Experimental studies on processes taking place in enclosures with mixed sea and Vistula River water