Wyniki wyszukiwania - BazTech

1

Characteristics of the spring/summer production in the Mecklenburg Bight (Baltic Sea) as revealed by long-term pCO2data

Schneider B., Buecker S., Kaitala S., Maunula P., Wasmund N.

Oceanologia

|

2015

|

No. 57 (4)

375--385

EN

Automated CO2 partial pressure, pCO2, measurements were performed on a cargo ship that commutes between the Gulf of Finland and the Mecklenburg Bight in the southwest of the Baltic Sea. The data from 2004 to 2014 along a sub-transect in the Mecklenburg Bight are used to analyze the timing and intensity of the net community production (NCP). The start of the spring bloom, identified by the first continuous drop of the pCO2 below the atmospheric level, spanned from mid-February to mid-March. Converting the pCO2 decrease during spring to changes in the total CO2 concentration and taking into account air-sea gas exchange, the spring NCP was determined. The NCP increased by about 80% during 2004–2014, the mean amounted to 40 μmol L-1. In two years a distinct second pCO2 minimum in mid-summer succeeded the minimum in spring. This was attributed to production fuelled by nitrogen fixation since the nitrate concentrations were virtually zero and since the atmospheric deposition could not satisfy the NCP nitrogen demand. Furthermore, investigations of the plankton composition revealed a cyanobacteria biomass peak in the year with the highest mid-summer NCP. Based on the calculation of the mid-summer NCP in the two particular years and on the C/N ratio of particulate organic matter, the corresponding nitrogen fixation activity was calculated. These values and the analysis of the relationship between the integrated NCP and temperature indicated that the nitrogen fixation activity in the Mecklenburg Bight was by a factor 3–4 lower than in the central Baltic Sea.

2

Impact of ship-borne nitrogen deposition on the Gulf of Finland ecosystem : an evaluation

Raudsepp U., Laanemets J., Maljutenko I., Hongisto M., Jalkanen J. P.

Oceanologia

|

2013

|

No. 55 (4)

837--857

EN

The degree of inter-annual variability in spring and summer phytoplankton blooms and nitrogen fixation in response to the deposition of oxidized nitrogen originating from ship emissions (hereafter nitrogen deposition) was evaluated in the Gulf of Finland (Baltic Sea) based on 10-year (1997-2006) simulation results using a coupled hydrodynamic (GETM) and ecological (ERGOM) model. Ship emissions were generated for 2008 using the Ship Traffic Emission Assessment Model, and ship nitrogen deposition was calculated using the Hilatar chemistry-transport model over the Baltic Sea. The annual ship nitrogen deposition in the Gulf of Finland was 1.6 kt N, about 12% of the annual atmospheric deposition, and increased in summer, up to 30% compared to the monthly atmospheric deposition. Ship nitrogen deposition caused an increase in spring and post-bloom primary production in two functional groups (diatoms and flagellates), at the same time reducing phosphate resources in the upper layer. Nitrogen fixation due to ship nitrogen deposition decreased by 1-1.6 kt N year-1 (2-6%). The effect of ship nitrogen deposition on nitrogen fixation was greater in the western and central Gulf of Finland. The additional ship nitrogen deposition to the Gulf was practically compensated for by a decrease in nitrogen fixation.

3

Nitrate reductase activity in chosen mosses: a case of study in skalny colliery waste tip

Krywult M., Salachna A., Chmura D., Żarnowiec J.

Chemistry-Didactics-Ecology-Metrology

|

2013

|

R. 18, NR 1-2

61--68

EN

Two species of mosses in relation to nitrogen metabolism were examined. This subject is little known in this group of plant. Investigations of nitrate reductase activity in green tissues of Brachythecium rutabulum (Hedw.) Schimp. and Atrichum undulatum (Hedw.) P.Beauv. were performed. The study was conducted in two localities: heavy contaminated waste tip Skalny located in Upper Silesia, and Blonia City Park in Bielsko-Biala which place was chosen as a control area. For both species high activity of the enzyme was detected. The nitrate reductase activity varied between 99 to 9093 nmol per g dry mass per hour for B. rutabulum and 265 to 5135 nmol per g d.m. per hour of nitrite synthesized for A. undulatum respectively on Skalny waste tip. In the control area the results varied between 747 to 1077 for B. rutabulum and 171 to 518 nmol per g d.m. per hour of nitrite synthesized for A. undulatum, respectively. The differences were statistically significant only between the two species but not between habitats probably due to high dispersion and small amount of replications. The levels of nitrate and nitrite in stream water in both areas were also measured. In the Skalny waste tip there were high and reached 1.66 mg dm-3 of nitrite and 65 mg dm-3 of nitrate, respectively. In the control area these amounts were lower and reach zero level for nitrite and 4.5 mg dm-3 of nitrate, respectively.

PL

Dwa gatunki mchów badano pod kątem asymilacji azotu. To zagadnienie jest mało poznane u tej grupy roślin. Przeprowadzono badania aktywności reduktazy azotanowej w zielonych tkankach Brachythecium rutabulum (Hedw.) Schimp. i Atrichum undulatum (Hedw.) P.Beauv. Badania zostały wykonane w dwóch miejscach: na hałdzie powęglowej Skalny na Górnym Śląsku i w parku w dzielnicy Błonia w Bielsku-Białej, które zostało wybrane jako miejsce kontrolne. Dla obu gatunków stwierdzono wysoką aktywność enzymu. Aktywność reduktazy azotanowej wahała się od 99 do 9093 nmol na g suchej masy na godzinę dla B. rutabulum i 265 do 5135 nmol na g suchej masy na godzinę azotynu syntetyzowanego u A. undulatum na hałdzie Skalny. W miejscu kontrolnym wyniki wahały się od 747 do 1077 dla B. rutabulum i 171 do 518 nmol na g sm/h u A. undulatum. Różnice były statystycznie znaczące tylko pomiędzy gatunkami, ale nie pomiędzy typem siedliska prawdopodobnie ze względu na wysoką dyspersję i małą liczbę powtórzeń. Zmierzono także poziom azotanów i azotynów w strumieniu wody w obu miejscach. Na hałdzie Skalny zawartość była wysoka i osiągnęła odpowiednio: 1,66 mg dm-3 azotynu oraz 65 mg dm-3 azotanu. W miejscu kontrolnym wartości te były niższe i osiągnęły odpowiednio poziom zerowy dla azotynów i 4,5 mg dm-3 dla azotanu.

4

Processes regulating pCO2 in the surface waters of the central eastern Gotland Sea: a model study

Kuznetsov I., Neumann T., Schneider B., Yakushev E.

Oceanologia

|

2011

|

No. 53 (3)

745-770

EN

This work presents a one-dimensional simulation of the seasonal changes in CO2 partial pressure (pCO2). The results of the model were constrained using data from observations, which improved the model's ability to estimate nitrogen fixation in the central Baltic Sea and allowed the impact of nitrogen fixation on the ecological state of the Baltic Sea to be studied. The model used here is the public domain water-column model GOTM (General Ocean Turbulence Model), which in this study was coupled with a modifed Baltic Sea ecosystem model, ERGOM (The Baltic Sea Research Institute's ecosystem model). To estimate nitrogen fixation rates in the Gotland Sea, the ERGOM model was modified by including an additional cyanobacteria group able to fix nitrogen from March to June. Furthermore, the model was extended by a simple CO2 cycle. Variable C:P and N:P ratios, controlled by phosphate concentrations in ambient water, were used to represent cyanobacteria, detritus and sediment detritus. This approach improved the model's ability to reproduce sea-surface phosphate and pCO2 dynamics. The resulting nitrogen fixation rates in 2005 for the two simulations, with and without the additional cyanobacteria group, were 259 and 278 mmol N m-2 year-1respectively.

5

Comparison of the toxicity of Co(II)-Gly and Co(II)-EDTA to Lucerne (Medicago sativa L.)

Molas J.

Proceedings of ECOpole

|

2008

|

Vol. 2, No. 1

71--75

EN

In sand pot experiment the toxicity of Co(II)-Gly and Co(II)-EDTA chelates to Lucerne (Medicago sativa L. cv. Vela) was investigated. The Co(II)-Gly chelate was definitely more toxic than the Co(II)-EDTA chelate. This chelate, more than the Co(II)-EDTA chelate, reduced the crop of dry matter of Lucerne, the content of nitrogen, protein and essential amino acids. It reduced the physiological efflciency of the symbiotic system of Lucerne and caused changes in its structural organisation.

PL

Badano toksyczność chelatów kobaltu Co(II)-Gly i Co(II)-EDTA dla lucerny (Medicago sativa L.) odmiany Vela, której hodowlę przeprowadzono metodą kultur wazonowych. Chelaty kobaltu zastosowane w koncentracji nadmiarowej powodowały redukcję plonu suchej masy roślin oraz obniżały zawartość azotu ogólnego, białka i niezbędnych aminokwasów. Zmniejszały także sprawność fizjologiczną układu symbiotycznego lucerny oraz destrukcyjnie oddziaływały na jego strukturę. Chelat Co(II)-Gly wykazywał istotnie większą toksyczność w stosunku do badanej odmiany lucerny niż chelat Co(II)-EDTA.

6

Effect of excess of Co(II)-Gly and Co(II)-EDTA chelates on the nitrogen fixation and structure of N2-fixing region of lucerne root nodules

Molas J.

Ecological Chemistry and Engineering. A

|

2008

|

Vol. 15, nr 11

1301-1310

EN

In sand pot culture the influence of two cobalt chelates, ie Co(II)-Gly and Co(II)-EDTA on the process of N2 fixation and on the anatomical and ultrastructural organization of N2-fixing region of root nodules of Lucerne cv. Vela was studied. The chelates were used in the concentration of 0.5 mmol Co ź kg-1 of soil of pH 6.2. Application of both chelates decfreased the amount of fixed nitrogen, the content of nitrogen compounds in plants and the plant crop. It caused a reduction of the number, area and enzymatic activity (measured by nitrogenase activity) of root nodules. After Co chelates treatment, a decrease of the area of N2-fixing region of nodules as well as degeneration of bacteroids and infected cells were observed. The degree of toxicity of the Co chelates under study depended on their chemical properties and, first of all, on the ion speciation in water solution of pH 6.2 and on the stability constant of the complex. The chelate whose stability constant was lower, ie Co(II)-Gly, which dissociates in water solution to Co2+ free ion and to complex cations was more toxic than Co(II)-EDTA, whose stabil-ity constant is higher and which dissociates to only complex anions.

PL

W doświadczeniu wazonowym, przeprowadzonym na czystym chemicznie piasku, badano wpływ nadmiaru kobaltu w formie chelatów Co(II)-Gly i Co(II)-EDTA na proces wiązania wolnego azotu, stopień nodulacji korzeni oraz strukturę regionu wiązania N2 brodawek korzeniowych lucerny odmiany Vela. Chelaty te zastosowano w stężeniu 0,5 mmol Co ź kg-1 gleby o pH 6,2. Aplikacja obu tych chelatów do gleby mniej lub bardziej zmniejszyła plon świeżej i suchej roślin, ilość związanego wolnego azotu oraz zawartość związków azotowych w roślinach badanej odmiany lucerny. Zredukowała także liczbę, powierzchnię i aktywność enzymatyczną (mierzoną aktywnością nitrogenazy) brodawek korzeniowych. Chelaty te powodowały redukcję powierzchni regionu wiązania N2 oraz jego mniejszą lub większa destrukcję, w tym też destrukcję komórek bakteroidów. Stopień toksyczności badanych chelatów kobaltu m.in. zależał od ich stałej trwałości i specjacji jonowej w roztworze. Zdecydowanie bardziej toksyczny był chelat o mniejszej stałej trwałości (K1 = 5,07), występujący w roztworze o pH 6,2 w dominującej ilości w formie kationów kompleksowych i wolnego jonu Co2+, czyli Co(II)-Gly niż Co(II)-EDTA, tj. chelat o większej stałej trwałości (K1 = 16,45), w roztworze wodnym o pH 6,2 występujący w formie anionów kompleksowych.