scholarly journals Competitive exclusion in phytoplankton communities in a eutrophic water column

2017 ◽  
Vol 22 (11) ◽  
pp. 0-0
Author(s):  
Robert Stephen Cantrell ◽  
◽  
King-Yeung Lam ◽  
Keyword(s):  
Water Column ◽  
Competitive Exclusion ◽  
Eutrophic Water ◽  
Phytoplankton Communities

scholarly journals Effects of Vertical Spatial Overlap on Phytoplankton Diversity under Experimentally Altered Lake Stratification Regimes

2021 ◽  
Vol 9 (12) ◽  
pp. 2447
Author(s):  
Philippe Le Noac’h ◽  
Vincent Ouellet Jobin ◽  
Beatrix E. Beisner
Keyword(s):  
Water Column ◽  
Competitive Exclusion ◽  
Zooplankton Community ◽  
Taxonomic Diversity ◽  
Physical Structure ◽  
Similar Species ◽  
Top Down ◽  
Phytoplankton Diversity ◽  
Spatial Overlap ◽  
Phytoplankton Communities

In phytoplankton communities, competitive exclusion might occur when functionally similar species are impeded from regulating their positions along light and nutrient gradients to reduce niche overlap. Greater spatial overlap (SO) between species due to water column mixing could thus promote competitive exclusion, reducing community taxonomic diversity. However, greater SO could also promote coexistence of functionally different taxa. Using data from a whole-lake experiment, we investigated the effects of SO and other relevant environmental factors on phytoplankton diversity across the water columns of lake basins with different thermocline manipulations. We estimated SO using an in situ fluorometer, and overall community diversity microscopically. Using structured equation models, we estimated directional relationships between phytoplankton diversity, SO, the lake physical structure and the zooplankton community. No significant effect of SO on phytoplankton taxonomic diversity was observed, but higher SO was associated with greater functional diversity. Change in lake physical structure and in the zooplankton community also affected diversity, with a negative response to increased top-down interactions. Overall, despite the fact that the alteration of water column stratification structure and top-down interactions were stronger drivers of phytoplankton diversity in our system, some effect of spatial overlap on the outcome of inferred competitive interactions were observable.

Extracellular enzymatic activities in the aquatic ecosystems of the Danube Delta. 2. Alkaline phosphatase activity

2021 ◽  
Vol 26 (1) ◽  
pp. 2269-2274
Author(s):  
IOAN PĂCEŞILĂ ◽  
EMILIA RADU
Keyword(s):  
Alkaline Phosphatase ◽  
Water Column ◽  
Aquatic Ecosystems ◽  
Temporal Dynamics ◽  
Extracellular Enzyme ◽  
Danube Delta ◽  
Phytoplankton Communities ◽  
Extracellular Enzymatic Activities ◽  
Adjacent Channels ◽  
Hydrolysis Of

Phosphorus is one of the most important inorganic nutrients in aquatic ecosystems, the development and functioning of the phytoplankton communities being often correlated with the degree of availability in assimilable forms of this element. Alkaline phosphatase (AP) is an extracellular enzyme with nonspecific activity that catalyses the hydrolysis of a large variety of organic phosphate esters and release orthophosphates. During 2011-2013, AP Activity (APA) was assessed in the water column and sediments of several aquatic ecosystems from Danube Delta: Roșu Lake, Mândra Lake and their adjacent channels – Roșu-Împuțita and Roșu-Puiu. The intensity of APA widely fluctuated, ranging between 230-2578 nmol p-nitrophenol L-1h-1 in the water column and 2104-15631 nmol p-nitrophenol g-1h-1 in sediment. Along the entire period of the study, APA was the most intense in Roșu-Împuțita channel, for both water and sediment samples. Temporal dynamics revealed its highest values in summer for the water column and in autumn for sediment. Statistical analysis showed significant seasonal diferences of the APA dynamics in spring vs. summer and autumn for the water column, and any relevant diferences for sediment.

The nitrogen reduction in eutrophic water column driven by Microcystis blooms

2020 ◽  
Vol 385 ◽  
pp. 121578 ◽  
Author(s):  
Yingshi Shen ◽  
Yingying Huang ◽  
Jun Hu ◽  
Panpan Li ◽  
Chen Zhang ◽  
...  
Keyword(s):  
Water Column ◽  
Nitrogen Reduction ◽  
Eutrophic Water ◽  
Microcystis Blooms

Winter phytoplankton communities in different depths of three mesotrophic lakes (Łęczna-Włodawa Lakeland, Eastern Poland)

Biologia ◽  
2008 ◽  
Vol 63 (3) ◽  
Author(s):  
Agnieszka Pasztaleniec ◽  
Tomasz Lenard
Keyword(s):  
Water Column ◽  
Green Algae ◽  
Winter Season ◽  
Mixing Conditions ◽  
Blue Green Algae ◽  
Species Analysis ◽  
Phytoplankton Communities ◽  
Different Depths ◽  
Limnothrix Redekei ◽  
Snow And Ice

AbstractPhytoplankton samples were collected from three mesotrophic lakes: Piaseczno, Rogóźno and Krasne during winter seasons (from January to March). The samples were analyzed for species analysis and abundance of planktonic algae in relation to different depths of water column (0–7 m). Selected water physical-chemical parameters were also measured. Abundance of phytoplankton depended strongly on the thickness of snow and ice cover or mixing conditions. The maximal phytoplankton total number reached about 5 × 106 ind. L−1 beneath the clear ice in the Krasne Lake, minimal numbers were recorded under the thick snow and ice layers in the Piaseczno Lake (2 × 103 ind. L−1). The winter phytoplankton communities were dominated by flagellates principally cryptomonads (Cryptomonas spp. Rhodomonas minuta), euglenophytes (Trachelomonas volvocina, T. volvocinopsis), dinoflagellates (Peridinium bipes, Gymnodinium helveticum) and chrysophytes (Mallomonas elongata, M. akrokomos, Dinobryon sociale) or non-motile small species of blue-green algae (e.g. Rhabdoderma lineare, Limnothrix redekei), diatoms (Stephanodiscus spp., Asterionella formosa), and green algae (e.g. Scenedesmus spp., Monoraphidium spp.). Phytoplankton abundance and structure showed differentiation during the winter season and along the water column as well.

scholarly journals Multiple interacting environmental drivers reduce the impact of solar UVR on primary productivity in Mediterranean lakes

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Marco J. Cabrerizo ◽  
E. Walter Helbling ◽  
Virginia E. Villafañe ◽  
Juan M. Medina-Sánchez ◽  
Presentación Carrillo
Keyword(s):  
Global Change ◽  
Water Column ◽  
Primary Productivity ◽  
Environmental Drivers ◽  
Dust Deposition ◽  
In Situ Experiment ◽  
Solar Ultraviolet Radiation ◽  
Phytoplankton Communities ◽  
Mediterranean Lakes ◽  
The Impact

AbstractIncreases in rainfall, continental runoff, and atmospheric dust deposition are reducing water transparency in lakes worldwide (i.e. higher attenuation Kd). Also, ongoing alterations in multiple environmental drivers due to global change are unpredictably impacting phytoplankton responses and lakes functioning. Although both issues demand urgent research, it remains untested how the interplay between Kd and multiple interacting drivers affect primary productivity (Pc). We manipulated four environmental drivers in an in situ experiment—quality of solar ultraviolet radiation (UVR), nutrient concentration (Nut), CO2 partial pressure (CO2), and light regime (Mix)—to determine how the Pc of nine freshwater phytoplankton communities, found along a Kd gradient in Mediterranean ecosystems, changed as the number of interacting drivers increased. Our findings indicated that UVR was the dominant driver, its effect being between 3–60 times stronger, on average, than that of any other driver tested. Also, UVR had the largest difference in driver magnitude of all the treatments tested. A future UVR × CO2 × Mix × Nut scenario exerted a more inhibitory effect on Pc as the water column became darker. However, the magnitude of this synergistic effect was 40–60% lower than that exerted by double and triple interactions and by UVR acting independently. These results illustrate that although future global-change conditions could reduce Pc in Mediterranean lakes, multiple interacting drivers can temper the impact of a severely detrimental driver (i.e. UVR), particularly as the water column darkens.

scholarly journals Warming and Eutrophication Effects on Phytoplankton Community of Two Tropical Systems with Different Trophic States—An Experimental Approach

2017 ◽  
Author(s):  
Andreia Maria Da Anunciação Gomes ◽  
Marcelo Manzi Marinho ◽  
Marcella Coelho Berjante Mesquita ◽  
Ana Carolina Coelho Prestes ◽  
Miquel Lürling ◽  
...  
Keyword(s):  
Global Warming ◽  
Temperature Variation ◽  
Trophic State ◽  
Cyanobacterial Blooms ◽  
Effect Of Temperature ◽  
Temperature Changes ◽  
Relative Contribution ◽  
Eutrophic Water ◽  
Phytoplankton Communities ◽  
State Water

Global warming, as well as europhication are predicted to promote cyanobacterial blooms, but how tropical phytoplankton communities from different trophic state systems respond to temperature variation is less known. To further explore the effect of temperature changes and nutrient addition on phytoplankton communities and to get insight in possible resistance to these effects, we tested the hypothesis that temperature variation will have a stronger effect on cyanobacteria dominance in eutrophic water than in oligo-mesotrophic. Hereto, we conducted an experiment with phytoplankton communities from two aquatic ecosystems differing in trophic state. Water samples from a eutrophic and an oligo-mesotrophic system were collected and incubated in 25 and 30ºC. Also, treatments that received additional surplus N and P were included that served as eutrophication treatments. Temperature variation itself did not promote cyanobacteria in either water from the oligo-mesotrophic or the eutrophic system. However, nutrient enrichment of water from the eutrophic system significantly boosted cyanobacteria, and biomass increased 10 times in both 25ºC and 30ºC treatments. In contrast, eutrophication of water from the oligo-mesotrophic system did not change the relative contribution of phytoplankton groups and response ratios were much lower than those for water from the eutrophic system. Although using a very simple experimental design, the results suggest that in eutrophic systems cyanobacteria dominance can be favoured by further addition of nutrients, independently of a direct temperature effect and that more pristine environments possess some resistance against eutrophication. Since global warming is assumed to intensify eutrophication symptoms indirectly, our study underscores the importance of nutrient control.

scholarly journals Short-term dynamics of microplankton abundance and diversity in NW Mediterranean Sea during late summer conditions (DYNAPROC 2 cruise; 2004)

2011 ◽  
Vol 8 (3) ◽  
pp. 743-761 ◽  
Author(s):  
S. Lasternas ◽  
A. Tunin-Ley ◽  
F. Ibañez ◽  
V. Andersen ◽  
M.-D. Pizay ◽  
...  
Keyword(s):  
Mediterranean Sea ◽  
Water Column ◽  
Late Summer ◽  
Taxonomic Composition ◽  
Marine Phytoplankton ◽  
Pigment Analysis ◽  
Phytoplankton Communities ◽  
Nw Mediterranean ◽  
Nw Mediterranean Sea ◽  
Abundance And Diversity

Abstract. Changes in marine phytoplankton communities at short-time scales have rarely been examined. As a part of the DYNAPROC 2 cruise (14 September–17 October 2004), conducted in the NW Mediterranean Sea, we daily sampled and determined taxonomic composition and abundance of the microphytoplankton and the dominant microzooplanktonic groups from both net and bottle sampling, during 4 cycles of 5 days. Hydrological conditions were characterised by the dominance of a stratified water column and nutrient-depleted conditions. However the stratification index revealed a destabilization of the water column from the beginning of the second cycle, related to a wind stress event accompanied with coastal water intrusion. This conducted to an increase of taxonomic richness and a general decrease of evenness, depicting the dominance of species with the best fitness. We also emphasised on the great interest of taxonomic studies, as able to provide valuable information on biogeochemical-important groups of species, potential water masses indicators and trophic aspects of the community that are ignored or largely underestimated with other kind of phytoplankton studies, such as pigment analysis.

Competition for nutrients and light among phytoplankton species in a mixed water column: theoretical studies

1995 ◽  
Vol 32 (4) ◽  
pp. 143-147 ◽  
Author(s):  
J. Huisman ◽  
F. J. Weissing
Keyword(s):  
Water Column ◽  
Competitive Interactions ◽  
Theoretical Studies ◽  
Phytoplankton Species ◽  
Qualitative Understanding ◽  
Phytoplankton Communities ◽  
Modelling Studies ◽  
Mixed Water

A brief overview is given of modelling studies that aim to analyse the effects of nutrient and light limitations on the development of phytoplankton communities and lead to a qualitative understanding of the competitive interactions involved.

Effects of Calcite Treatment on Primary Producers in Acidified Adirondack Lakes. II. Short-Term Response by Phytoplankton Communities

1989 ◽  
Vol 46 (2) ◽  
pp. 352-359 ◽  
Author(s):  
Paul A. Bukaveckas
Keyword(s):  
Species Composition ◽  
Water Column ◽  
Biomass Productivity ◽  
Phytoplankton Production ◽  
Short Term ◽  
Phytoplankton Communities ◽  
Posttreatment Period ◽  
Adirondack Lakes ◽  
Treatment Changes ◽  
Term Response

The effects of calcite addition on two acidic Adirondack lakes were studied by investigators participating in the Lake Acidification Mitigation Project. Changes in phytoplankton biomass, productivity, and species composition were monitored during the ice-free period prior to and following lake treatment. Changes in water chemistry following limestone addition were largely restricted to the upper water column since calcite particles applied to the lake surface did not effectively penetrate the thermocline. Increased phytoplankton production and biomass were observed during the posttreatment period. Phytoplankton densities and rates of production were similar in both the neutralized (pH > 7.5) and acidic (pH < 5.5) portions of the water column; however, species composition was markedly different. The phytoplankton assemblage of the upper water column was largely comprised of chlorophytes and chrysophytes which had not been observed prior to treatment. In contrast, the deep-water assemblage comprised many of the same taxa that had been dominant during the pretreatment periodsss.

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