scholarly journals Impacts of reduced inorganic N:P ratio on three distinct plankton communities in the Humboldt upwelling system

2019 ◽  
Author(s):  
Kristian Spilling ◽  
Maria-Teresa Camarena-Gómez ◽  
Tobias Lipsewers ◽  
Alícia Martinez-Varela ◽  
Francisco Díaz-Rosas ◽  
...  
Keyword(s):  
Community Composition ◽  
Inorganic Nitrogen ◽  
Trophic Transfer ◽  
N:P Ratio ◽  
Plankton Community ◽  
Humboldt Current ◽  
Term Change ◽  
Plankton Community Structure ◽  
Plankton Communities

AbstractThe ratio of inorganic nitrogen to phosphorus (NP) is projected to decrease in the Eastern Boundary Upwelling Systems (EBUS) due to warming of the surface waters. In an enclosure experiment, we employed two levels of NP ratios (10 and 5) for three distinct plankton communities collected along the coast of central Chile (33°S). The primary effect of the NP treatment was related to different concentrations of NO3, which directly influenced the biomass of phytoplankton. Additionally, low inorganic NP ratio reduced the seston NP and Chla-C ratios, and there were some effects on the plankton community composition, e.g. benefittingSynechococcusspp in some communities. One of the communities was clearly top down controlled and trophic transfer to grazers was up to 5.8% during the 12 day experiment. Overall, the initial plankton community composition was more important for seston stoichiometry and trophic transfer than the inorganic NP ratio. Any long term change in the plankton community structure will likely have greater impact than direct effects of a decreasing inorganic NP ratio on the Humboldt Current ecosystem.

scholarly journals Long-Term Soil Nutrient Management Affects Taxonomic and Functional Weed Community Composition and Structure

2021 ◽  
Vol 3 ◽  
Author(s):  
Stéphane Cordeau ◽  
Sandra Wayman ◽  
Quirine M. Ketterings ◽  
Chris J. Pelzer ◽  
Amir Sadeghpour ◽  
...  
Keyword(s):  
Community Composition ◽  
Inorganic Nitrogen ◽  
Dairy Manure ◽  
N Fertilizer ◽  
High Rate ◽  
Alkaline Soil ◽  
Inorganic N ◽  
Fertility Treatments ◽  
Weed Communities

Weed communities can be influenced by nutrient availability, nutrient form (e. g., ammonium vs. nitrate), amendment timing, amendment type (e.g., organic vs. inorganic), and by immigration of seeds during amendment applications. The objective of this research was to compare the long-term effect of different fertility treatments in a corn (Zea mays L.)-alfalfa (Medicago sativa L.) rotation on taxonomic and functional structure and composition of weed communities by analyzing the soil weed seedbank. After 14 years of a long-term experiment in Aurora, NY, United States, soils were sampled in five fertility treatments for corn years in the rotation: liquid dairy manure, semi-composted separated dairy solids; or inorganic nitrogen (N) as starter fertilizer with either no sidedress N, a low rate or a high rate of inorganic N as sidedress fertilizer. Soil was collected in early spring 2015 and a greenhouse weed seed germination bioassay was used to quantify the germinable soil weed seedbank. Total weed seedbank density, species richness, and evenness did not vary by treatment. However, fertility treatments modified the ecological niche represented by 20 environmental descriptors, which filtered the weed community creating distinct functional group assemblages. A trait-based analysis revealed that nitrophilic dicotyledons preferring alkaline soil were associated with high concentrations of inorganic N fertilizer, whereas highly specialist monocotyledons preferring high amounts of light were associated with low concentrations of inorganic N fertilizer. Because fertility treatments affected weed community composition but not seed bank density and richness, results encourage the development of holistic management strategies that adopt coherent weed management and crop fertilization.

scholarly journals PLANKTON COMMUNITY STRUCTURE OF TRADITIONAL AND INTENSIVE BRACKISHWATER PONDS IN PROBOLINGGO REGENCY, EAST JAVA PROVINCE

2016 ◽  
Vol 8 (1) ◽  
pp. 269-288
Author(s):  
. Utojo ◽  
Akhmad Mustafa
Keyword(s):  
Community Structure ◽  
Suspended Solids ◽  
Total Suspended Solids ◽  
Total Suspended Solid ◽  
Suspended Solid ◽  
Plankton Community ◽  
Cell Counting ◽  
Counting Method ◽  
Plankton Community Structure ◽  
Plankton Communities

This experiment aimed to determine the plankton community structure in intensive and traditional ponds of  Probolinggo Regency, East Java Province. Plankton collected with plankton net size of 60 μm and preserved with lugol 1%. Water qualities such as temperature, transparancy, salinity, dis-solved oxygen, pH, total organic matter, NO2-N, NO3-N, NH3-N, PO4-P, and total suspended solids were measured and analysed in this study. Planktons were identified using microscopy. Cells were counted using cell counting method. The results showed that in intensive pond we found 16 species of phytoplankton and 7 species of zooplankton with abundance 570-1.808 ind./L, while in traditional ponds, we found 10 species of phytoplankton and 3 species of  zooplankton with abundance  134-776 ind./L. The dominant species of phytoplankton in the intensive and traditional ponds were Navicula sp andNitzschia sp, each of Bacillariophyceae class with abundance of 423 ind./L and 198 ind./L, res-pectively. Zooplankton species in intensive pond was copepod sp, while in traditional  one was Oitho-na sp, each of Crustaceae class with abundance of  66 ind./L and 37 ind./L, respectively. Diversity and abundance of plankton in intensive pond was higher than in the traditional ponds. The water quality in intensive pond was optimal so that the response to the absorption of  N and P inorganic by phyto-plankton was quicker and more effective than in traditional pond producing an increase in plankton communities. The increase value of NO3-N and total suspended solids in intensive pond caused the in-crease abundance of Navicula sp.  The high value of NH3-N caused the abundance of Navicula sp to decline. The high values of dissolved oxygen, pH, total suspended solid, and NH3-N in traditional pond can decrease the Nitzschia sp abundance.  Keywords: plankton communities, intensive and traditional ponds, Probolinggo, East Java

scholarly journals PLANKTON COMMUNITY STRUCTURE OF TRADITIONAL AND INTENSIVE BRACKISHWATER PONDS IN PROBOLINGGO REGENCY, EAST JAVA PROVINCE

2016 ◽  
Vol 8 (1) ◽  
Author(s):  
. Utojo ◽  
Akhmad Mustafa
Keyword(s):  
Community Structure ◽  
Suspended Solids ◽  
Total Suspended Solids ◽  
Total Suspended Solid ◽  
Suspended Solid ◽  
Plankton Community ◽  
Cell Counting ◽  
Counting Method ◽  
Plankton Community Structure ◽  
Plankton Communities

<p><em>This experiment aimed to determine the plankton community structure in intensive and traditional ponds of  Probolinggo Regency, East Java Province. Plankton collected with plankton net size of 60 μm and preserved with lugol 1%. Water qualities such as temperature, transparancy, salinity, dis</em><em>-</em><em>solved oxygen, pH, total organic matter, NO<sub>2</sub>-N, NO<sub>3</sub>-N, NH<sub>3</sub>-N, PO<sub>4</sub>-P, and total suspended solids were measured and analysed in this study. Planktons were identified using microscopy. Cells were counted using cell counting method. The results showed that in intensive pond we found 16 species of phytoplankton and 7 species of zooplankton with abundance 570-1.808 ind./L, while in traditional ponds, we found 10 species of phytoplankton and 3 species of  zooplankton with abundance  134-776 ind./L. The dominant species of phytoplankton in the intensive and traditional ponds were Navicula sp andNitzschia sp, each of Bacillariophyceae class with abundance of 423 ind./L and 198 ind./L, res</em><em>-</em><em>pectively. Zooplankton species in intensive pond was copepod sp, while in traditional  one was Oitho</em><em>-</em><em>na sp, each of Crustaceae class with abundance of  66 ind./L and 37 ind./L, respectively. Diversity and abundance of plankton in intensive pond was higher than in the traditional ponds. The water quality in intensive pond was optimal so that the response to the absorption of  N and P inorganic by phyto</em><em>-</em><em>plankton was quicker and more effective than in traditional pond producing an increase in plankton communities. The increase value of NO<sub>3</sub>-N and total suspended solids in intensive pond caused the in</em><em>-</em><em>crease abundance of Navicula sp.  The high value of NH<sub>3</sub>-N caused the abundance of Navicula sp to decline. The high values of dissolved oxygen, pH, total suspended solid, and NH<sub>3</sub>-N in traditional pond can decrease the Nitzschia sp abundance.  </em></p><p><strong><em>Keywords:</em></strong><em> plankton communities, intensive and traditional ponds, Probolinggo, East Java </em></p>

Effects of different plankton communities and spring bloom phases on seston C:N:P:Si:chl a ratios in the Baltic Sea

2020 ◽  
Vol 644 ◽  
pp. 15-31
Author(s):  
T Lipsewers ◽  
R Klais ◽  
MT Camarena-Gómez ◽  
K Spilling
Keyword(s):  
Baltic Sea ◽  
Community Composition ◽  
Growth Phase ◽  
Spring Bloom ◽  
Inorganic Nitrogen ◽  
Generalized Additive Models ◽  
Additive Models ◽  
The Baltic Sea ◽  
The Baltic ◽  
Plankton Communities

Plankton communities and their temporal development have shifted towards earlier onset of the spring bloom and lower diatom-dinoflagellate proportions in parts of the Baltic Sea. We studied the effects of community composition and spring bloom phases on seston nutrient stoichiometry, revealing possible consequences of these shifts. Community composition, seston C:N:P:Si:chl a ratios, and physiological and environmental variables were determined for 4 research cruises, covering all major sub-basins and bloom phases. A redundancy analysis revealed that temperature and inorganic nutrients were the main drivers of community changes, and high diatom biomass was linked to low temperatures (growth phase). The effects of changing dominance patterns on seston stoichiometry were studied by applying a community ordination (non-metric multidimensional scaling and generalized additive models). C:N:P ratios increased from the growth phase (103:14:1) to the peak phase (144:18:1) and decreased after inorganic nitrogen was depleted (127:17:1). Taxonomic differences explained ~50% of changes in C:Si, N:Si, and chl a:C ratios and <30% for C:P and N:P, whereas C:N was virtually unaffected by the community composition. The fixed chl a:C range (~0.005-0.04) was largely determined by diatoms, independent of the dominant species. Thus, C:Si and N:Si could be used to estimate the share of diatoms to the seston and chl a:C to describe bloom phases and C budgets during spring. Interestingly, mixed communities featured higher C:N:P ratios than diatom-dominated ones. However, as community composition explained <30% of changes in C:N:P, we conclude that these ratios rather represent the total plankton physiology in natural plankton assemblages.

Long‐term inorganic nitrogen application changes the ammonia‐oxidizing archaeal community composition in paddy soils

2021 ◽  
Author(s):  
Sandipan Samaddar ◽  
Jaak Truu ◽  
Poulami Chatterjee ◽  
Kristjan Oopkaup ◽  
Marika Truu ◽  
...  
Keyword(s):  
Community Composition ◽  
Inorganic Nitrogen ◽  
Archaeal Community ◽  
Paddy Soils ◽  
Nitrogen Application

Consistent, long-term change in rotifer community composition across four Polish lakes

Hydrobiologia ◽  
2008 ◽  
Vol 624 (1) ◽  
pp. 107-114 ◽  
Author(s):  
Ashley J. Steinberg ◽  
Jolanta Ejsmont-Karabin ◽  
Jim R. Muirhead ◽  
Chad T. Harvey ◽  
Hugh J. MacIsaac
Keyword(s):  
Community Composition ◽  
Rotifer Community ◽  
Term Change

scholarly journals A <sup>13</sup>C labelling study on carbon fluxes in Arctic plankton communities under elevated CO<sub>2</sub> levels

2013 ◽  
Vol 10 (3) ◽  
pp. 1425-1440 ◽  
Author(s):  
A. de Kluijver ◽  
K. Soetaert ◽  
J. Czerny ◽  
K. G. Schulz ◽  
T. Boxhammer ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Primary Production ◽  
Dissolved Inorganic Carbon ◽  
Carbon Fluxes ◽  
Sediment Traps ◽  
Plankton Community ◽  
Nutrient Addition ◽  
Production Rates ◽  
Plankton Community Structure ◽  
Plankton Communities

Abstract. The effect of CO2 on carbon fluxes (production, consumption, and export) in Arctic plankton communities was investigated during the 2010 EPOCA (European project on Ocean Acidification) mesocosm study off Ny Ålesund, Svalbard. 13C labelled bicarbonate was added to nine mesocosms with a range in pCO2 (185 to 1420 μatm) to follow the transfer of carbon from dissolved inorganic carbon (DIC) into phytoplankton, bacterial and zooplankton consumers, and export. A nutrient–phytoplankton–zooplankton–detritus model amended with 13C dynamics was constructed and fitted to the data to quantify uptake rates and carbon fluxes in the plankton community. The plankton community structure was characteristic for a post-bloom situation and retention food web and showed high bacterial production (∼31% of primary production), high abundance of mixotrophic phytoplankton, low mesozooplankton grazing (∼6% of primary production) and low export (∼7% of primary production). Zooplankton grazing and export of detritus were sensitive to CO2: grazing decreased and export increased with increasing pCO2. Nutrient addition halfway through the experiment increased the export, but not the production rates. Although mixotrophs showed initially higher production rates with increasing CO2, the overall production of POC (particulate organic carbon) after nutrient addition decreased with increasing CO2. Interestingly, and contrary to the low nutrient situation, much more material settled down in the sediment traps at low CO2. The observed CO2 related effects potentially alter future organic carbon flows and export, with possible consequences for the efficiency of the biological pump.

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