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- Al-Haidarey, Mohammed J. S. A., et al.
(författare)
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The Trophic State Index of Bahr Al-Najaf Depression reservoir, Iraq
- 2016
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Ingår i: Journal of Environmental Hydrology. - 1058-3912 .- 1996-7918. ; 24, s. 1-10
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Tidskriftsartikel (refereegranskat)abstract
- Bahr Al-Najaf Depression Reservoir (BNDR) is located 5 kilometers south-southwest of Najaf city in central Iraq. It covers an area of approximately 360 square kilometers. Carlson’s Trophic State Index (CTSI) was applied to the BNDR. To do so, Chlorophyll (A), total phosphorus (TP), Secchi disc depth Transparency (SD) and some physiochemical parameters were measured. The mean value of Chl-a was 1,06 (±1,33), the maximum and minimum values of TSI based on total Chl-a were recorded during summer and spring respectively. The classification of trophic state using TSI (TP) and TSI (SD) was closed, but by using TSI (Chl-a) it was much higher, the value of TSI (Chl-a) > TSI (TP) >TSI (SD), the CTSI value of BNDR was between 35.11-71.33 (r2 = -27, 53), the highest value of CTSI was in summer while the lowest values were during winter, the average of physiochemical parameters (±standard deviation) were: 26,5 (±1,42), 7,6 (±0,88), 0,1 (±0,16), 71 (±16,57), 10100 (±5591), 1,55 (±2,26), 53350 (±24143), 243299 (±358773), 30752 (±44649), 20 (±13), 2499 (±1819), 2659 (±2561), 0,22 (±0,02), 0,32 (±0,06) for temperature, pH, DO, Ec, HCO- 3, TN, TH, Cl- SO= 4 , TOC, Na+, K+, Fe+, and Mn+ respectively. According to CTSI, BNDR can be classified as eutrophic. CTSI results were very close to those of lakes Sawa and Al-Razzazah, while there were some slight differences when compared with Al-Habbanayh and Derbandikhan lakes, where the level of trophic index was decreasing (56, and 52 for Al-Habbanayh lake and Derbandikhan lake respectively).
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| 3. |
- Hamdan, Mohammed, 1978-, et al.
(författare)
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Carbon dioxide limitation of benthic primary production in a boreal lake
- 2022
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Ingår i: Freshwater Biology. - : John Wiley & Sons. - 0046-5070 .- 1365-2427. ; 67:10, s. 1752-1760
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Tidskriftsartikel (refereegranskat)abstract
- Gross primary production (GPP) by benthic microalgae growing on soft sediments is an important contributor to lake productivity in many lakes world-wide. As benthic microalgae have access to nutrients in the sediment they have been regarded as primarily controlled by light, while the role of CO2 as a limiting factor for benthic GPP in lake ecosystems is largely unknown.In this study, we experimentally tested for CO2 limitation of benthic GPP by collecting littoral surface sediments, with associated benthic microalgae, from a typical boreal lake. Intact sediment cores were incubated at different depths (light conditions) after addition of dissolved inorganic (bicarbonate) or organic (DOC; glucose) carbon as direct and indirect sources of CO2, respectively.Benthic microalgal GPP was stimulated by both dissolved inorganic carbon and DOC additions at high, but not at low, light levels.This study shows that benthic microalgal GPP can be CO2-limited when light is not limiting and suggests that both direct (e.g., via groundwater inflow) and indirect (via mineralisation of DOC) CO2 supply can stimulate benthic GPP.
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