scholarly journals The effect of seasonality on the structure of rotifers in a black-water shallow lake in Central Amazonia

2014 ◽  
Vol 86 (3) ◽  
pp. 1359-1372 ◽  
Author(s):  
CLARICE C. NOVA ◽  
VANESSA G. LOPES ◽  
LEONARDO COIMBRA E SOUZA ◽  
BETINA KOZLOWSKY-SUZUKI ◽  
TALITA A.A. PEREIRA ◽  
...  
Keyword(s):  
Species Composition ◽  
Driving Force ◽  
Community Dynamics ◽  
Flood Pulse ◽  
Small Lakes ◽  
Black Water ◽  
Negro River ◽  
Rotifer Community ◽  
Central Amazonia ◽  
Physical And Chemical

Rotifers have often been used as indicators of sudden changes in physical and chemical features of the aquatic environment. Such features vary greatly during flood pulse events in small lakes connected to major floodplains. However, few are the studies that investigate the consequences of the flood pulse in rotifer species composition, abundance, richness and diversity, especially in Amazonian lakes. We analyzed samples from a small blackwater lake of an “igarapé” connected permanently to the Negro river, in Central Amazonia. Samples were taken twice a year for two years, comprising flooding and receding periods of the flood pulse. Rotifer abundance increased significantly after draught events, and electrical conductivity and turbidity were intrinsically related to such variation. Species composition also changed from flooding to receding periods. Some taxa, such as Brachionus zahniseri reductus and Lecane remanei were restricted to receding periods, while Brachionus zahniseri, Brachionus gillardi and Lecane proiecta were only present during flooding. A shift in the composition of rotifer families was observed from one period to another, showing the effect of renewing waters of the flood pulse. These results suggest that the flood pulse acts as a driving force and stressing condition, considerably altering rotifer community dynamics, either changing species composition or decreasing abundance.

scholarly journals Nutrients and water-forest interactions in an Amazon floodplain lake: an ecological approach

2013 ◽  
Vol 25 (2) ◽  
pp. 169-182 ◽  
Author(s):  
Fabio Aprile ◽  
Assad José Darwich
Keyword(s):  
Hydrological Cycle ◽  
Nutrient Content ◽  
Flood Pulse ◽  
Negro River ◽  
Amazon Floodplain ◽  
Flux Model ◽  
Physical And Chemical ◽  
Paspalum Repens ◽  
The City

AIM: Catalão Lake was surveyed between 2002 and 2011 with the aim of studying seasonality of the flow of nutrients between water, sediment and aquatic macrophytes. The role of the flood pulse and the ecological mechanisms influencing the forest-water interactions in the Amazon floodplain were discussed; METHODS: Catalão Lake is located in the Amazon floodplain (03º 08'-03º 14' S and 59º 53'-59º 58' W), near the confluence of the Solimões and Negro rivers, approximately 3000 m from the port of CEASA, near the city of Manaus. It is considered to be a mixed water lake because it receives white waters rich in sediments from the Solimões River and black waters with humic substances from the Negro River. Physical and chemical parameters including C, N and P levels were studied in the diverse compartments, and a flux model was developed; RESULTS: There is a strong nutritional (C, N and P) and ionic (Na+, K+, Ca2+, Mg2+, Cl-, HCO3-, CO3(2-) and SO4(2-)) flow from the rivers to the lake. The highest C:N:P ratio was found in Paspalum repens which, during periods of drought, played an important role in releaseing nutrients into the water. The connectivity of the lake with the rivers ensured a high variation of transparency and nutrient content, fundamental for biological processes. A model of the nutrient flow, interaction and connectivity between ecosystems, and the influence of the hydrological cycle has been developed.

Floristic variation across 600 km of inundation forests (Igapó) along the Negro River, Central Amazonia

Hydrobiologia ◽  
2012 ◽  
Vol 729 (1) ◽  
pp. 229-246 ◽  
Author(s):  
Juan Carlos Montero ◽  
Maria Teresa Fernandez Piedade ◽  
Florian Wittmann
Keyword(s):  
Negro River ◽  
Inundation Forests ◽  
Central Amazonia ◽  
Floristic Variation

Exergy analysis of nutrient recovery processes

2003 ◽  
Vol 48 (1) ◽  
pp. 27-36 ◽  
Author(s):  
D. Hellström
Keyword(s):  
Wastewater Treatment ◽  
Exergy Analysis ◽  
Chemical Elements ◽  
Source Separation ◽  
Chemical Processes ◽  
Nutrient Recovery ◽  
Black Water ◽  
Recovery Processes ◽  
Exergy Consumption ◽  
Physical And Chemical

In an exergy analysis, the actual consumption of resources in physical and chemical processes is calculated. Energy and chemical elements are not consumed in the processes - they are only transformed into other forms with lower quality. The principals of exergy analysis are illustrated by comparing different wastewater treatment systems for nutrient recovery. One system represents an end-of-pipe structure, whereas other systems include source separation of grey water, black water, and urine. The exergy flows analysed in this paper are those related to management and treatment of organic matter and nutrients. The study shows that the total exergy consumption is lowest for the system with source separation of urine and faeces and greatest for the conventional wastewater treatment system complemented by processes for nutrient recovery.

Mesocosm study of microalgae in different weather conditions

2020 ◽  
Author(s):  
Munay Abdulqadir Alteerah ◽  
Mohammad Noor Amal Azmai ◽  
Hishamuddin Omar ◽  
Ahmad Ismail
Keyword(s):  
Species Composition ◽  
Weather Conditions ◽  
Quality Parameters ◽  
Culture Conditions ◽  
Weather Patterns ◽  
Microalgae Biomass ◽  
Chemical Conditions ◽  
Wet And Dry Cycles ◽  
And Control ◽  
Physical And Chemical

Microalgae have valuable contributions in carbon dioxide sequestration. There are no much investigations about motivation of mix microalgae productivity in outdoor cultures. This study aims to evaluate microalgae biomass production in outdoor mesocosms under different weather conditions. The experiment was done in Tilapia pond in the hatchery of fisheries of Universiti Putra Malaysia. Weather parameters were recorded daily. Microalgae seeds were obtained from Tilapia pond effluent and added to eight floating aerated mesocosms. Mesocosms were divided into four treatments. Two g triple supper phosphate: 20g Urea were used as fertilizers. Physical and chemical conditions, microalgae primary productivity and biomass, and species composition were measured every two days. Three cycles were categorized as mix, wet and dry cycles based on weather recording scores. Water quality parameters in Treatments and controls cultures showed significant variations. Primary production variables were higher in the fertilized non-sheltered mesocosms (treatment 1). Productivity variables were lower in the dry cycle and higher in the mix cycle. The highest value of fixed CO2 was (3.2) mg/L/d in treatment 1 in the mix cycle, while the lowest value was (0.11) mg/L/d in treatment 3 and control 1 in dry cycle. Changes in weather patterns are seen in the light and temperature values. Microalgae biomass was lower in dry weather conditions because of effect of high air temperature. Weather conditions and different treatments significantly influenced microalgae species composition, due to the sensitivity in some of them to different light intensities. Chlorophytes were the most abundant due to their ability to adapt with different culture conditions.

scholarly journals Ecological Gradients Influencing Waterbird Communities in Black Water Lakes in the Anavilhanas Archipelago, Central Amazonia

2012 ◽  
Vol 2012 ◽  
pp. 1-21 ◽  
Author(s):  
Renato Cintra
Keyword(s):  
Bird Species ◽  
Bird Community ◽  
High Water ◽  
Water Transparency ◽  
Aquatic Bird ◽  
Large Spatial Scale ◽  
Black Water ◽  
Bird Richness ◽  
Central Amazonia ◽  
Lake Systems

For the first time, and in a large spatial scale, the influence of ecological properties on the aquatic bird community of black water lakes in Brazilian Amazonia is evaluated. Bird surveys were conducted in 45 lakes. A total of 3626 individuals in 48 bird species were recorded; of these, 31 are aquatic, and 18 of these are primarily piscivorous. Bird richness and abundance were not significantly related to lake shape and productivity but were influenced by hydrological period (low versus high), water depth, transparency, lake isolation, and habitat richness. Matrices of bird species by lake were subjected to multivariate analyses (NMDS) to evaluate how these parameters influence bird community. The variation in bird species composition was positively correlated to lake depth and isolation and negatively correlated to water transparency and habitat richness. The results indicate that period, lake physical characteristics (depth, water transparency), isolation, and habitat richness are determinants of aquatic bird community composition in the black water lake systems of Amazonia.

Effects of Targeted Grazing and Prescribed Burning on Community and Seed Dynamics of a Downy Brome (Bromus tectorum)–Dominated Landscape

2012 ◽  
Vol 5 (2) ◽  
pp. 259-269 ◽  
Author(s):  
Joel M. Diamond ◽  
Christopher A. Call ◽  
Nora Devoe
Keyword(s):  
Species Composition ◽  
Seed Bank ◽  
Community Dynamics ◽  
Prescribed Burning ◽  
Bromus Tectorum ◽  
Downy Brome ◽  
Stable States ◽  
Targeted Grazing ◽  
Northern Nevada ◽  
Seed Dynamics

AbstractDowny brome (Bromus tectorum L.)—dominated communities can remain as stable states for long periods, even with frequent disturbance by grazing and fire. The objective of this study was to determine the effectiveness of using targeted cattle grazing and late-season prescribed burning, alone and in combination, to reduce B. tectorum seed bank input and seed bank density and thus alter aboveground community dynamics (species composition) on a B. tectorum–dominated landscape in northern Nevada. Cattle removed 80 to 90% of standing biomass in grazed plots in May of 2005 and 2006 when B. tectorum was in the boot (phenological) stage. Grazed and ungrazed plots were burned in October 2005 and 2006. The combined grazing–burning treatment was more effective than either treatment alone in reducing B. tectorum seed input and seed bank density, and in shifting species composition from a community dominated by B. tectorum to one composed of a suite of species, with B. tectorum as a component rather than a dominant. This study provides a meso-scale precursor for landscape-scale adaptive management using grazing and burning methodologies.

Phytoplankton species turnover controlled by physical forcing at different time scales

2008 ◽  
Vol 65 (1) ◽  
pp. 47-60 ◽  
Author(s):  
Alexandrine Pannard ◽  
Myriam Bormans ◽  
Yvan Lagadeuc
Keyword(s):  
Species Composition ◽  
Time Scale ◽  
Phytoplankton Community ◽  
Diversity Index ◽  
Species Turnover ◽  
Rate Of Change ◽  
Original Structure ◽  
Short Term ◽  
Physical Forcing ◽  
Physical And Chemical

Changes in the physical and chemical environment induced by forcing events such as wind and rain can control the short-term dynamics of the phytoplankton community of inland waters. In two temperate reservoirs, species composition, diversity index, and species dynamics were characterized over periods of 3 weeks during different seasons, in parallel with changes in the physical and chemical structure of the water column. Dominant species and diversity index were shown to be controlled by environmental factors fluctuating on a seasonal and weekly time scale, whereas some rarer species responded to wind events and were indicators of a very short-term environmental change. As a consequence of the response of indicator species, the rate of change in species composition increased following meteorological events. Shifts in species composition were observed during each sampling period, except during the strongest stratification period. The shifts were associated with a modification of resource availability or intensity of stratification. We found that the resistance of the phytoplankton community to short-term physical forcing by wind increased with intensity of stratification. After the forcing event, the community did not return to its original structure because of modifications of the physical and chemical conditions induced by meteorological forcing on a weekly time scale.

scholarly journals Pinnularia caprichosa sp. nov.: a diatom from a black water Brazilian Amazon system

Phytotaxa ◽  
2015 ◽  
Vol 239 (3) ◽  
pp. 280 ◽  
Author(s):  
Andreia Cavalcante Pereira ◽  
Lezilda Carvalho Torgan ◽  
Ana Luiza Burliga ◽  
John Patrick Kociolek ◽  
Carlos E. Wetzel ◽  
...  
Keyword(s):  
New Species ◽  
River Basin ◽  
Amazon Basin ◽  
Brazilian Amazon ◽  
New Taxon ◽  
Middle Portion ◽  
Black Water ◽  
Negro River ◽  
Electron Microscopical ◽  
Scanning Electron

While possessing a remarkable diversity in the acidic and oligotrophic waters of the Amazon basin, the genus Pinnularia appears underdescribed in the region. In this study, we present light and scanning electron microscopical observations on Pinnularia caprichosa sp. nov. from Tupé Lake, a dendritic lake located on the floodplain of the Negro River basin. This new taxon has a large axial area and transapical striae that are slightly radiate to parallel and longer in the middle portion of the valve. The species was compared with Pinnularia elliptica, P. instabilis, P. lacunarum, P. montana, P. permontana and P. subflexuosa, all of which closely resemble P. caprichosa but differ from the new species in specific details of size, striae density and valve shape.

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