scholarly journals Assessment of spatial variability of environmental conditions in different swine production typologies in tropical conditions

2021 ◽  
Vol 9 (3) ◽  
pp. -----
Author(s):  
Jairo Alexander Osorio Saraz ◽  
Natalia Castrillon Mejia ◽  
Veronica Gonzalez Cadavida ◽  
Yesica Paola Quintero Soto ◽  
Ana Paola Montoya Rios ◽  
...  
Keyword(s):  
Spatial Variability ◽  
Environmental Conditions ◽  
Swine Production ◽  
Tropical Conditions

Spatial variability in responses to environmental conditions in Southern Hemisphere long-finned pilot whales

2019 ◽  
Vol 629 ◽  
pp. 207-218 ◽  
Author(s):  
V Hamilton ◽  
K Evans ◽  
B Raymond ◽  
E Betty ◽  
MA Hindell
Keyword(s):  
Spatial Variability ◽  
Southern Hemisphere ◽  
Environmental Conditions ◽  
Pilot Whales

Spatial variability of environmental conditions in fjords and the importance for aquaculture

2013 ◽  
Author(s):  
Lars Asplin ◽  
Anne D. Sandvik ◽  
Ingrid A. Johnsen ◽  
Jon Albretsen ◽  
Henning Wehde ◽  
...  
Keyword(s):  
Spatial Variability ◽  
Environmental Conditions

scholarly journals Geomorphometric tool associated with soil types and properties spatial variability at watersheds under tropical conditions

2016 ◽  
Vol 73 (4) ◽  
pp. 363-370 ◽  
Author(s):  
Sérgio Henrique Godinho Silva ◽  
Michele Duarte de Menezes ◽  
Carlos Rogério de Mello ◽  
Helen Thaís Pereira de Góes ◽  
Phillip Ray Owens ◽  
...  
Keyword(s):  
Spatial Variability ◽  
Soil Types ◽  
Tropical Conditions

scholarly journals Primary production and associated environmental conditions in the East Siberian Sea in autumn

2019 ◽  
Vol 487 (6) ◽  
pp. 696-700
Author(s):  
A. B. Demidov ◽  
V. I. Gagarin
Keyword(s):  
Spatial Variability ◽  
Primary Production ◽  
Water Column ◽  
Environmental Conditions ◽  
Nitrate Concentration ◽  
Ammonium Concentration ◽  
Photosynthetically Available Radiation ◽  
Dissolved Nitrogen ◽  
East Siberian Sea ◽  
Vast Area

Spatial variability of primary production (PP) was study on vast area of East Siberian Sea in autumn 2017. Water column PP (IPP) value was equal to 28±13 mgC m-2 day-1 on average that testify ultraoligotrophic conditions. IPP was limited by low incident and underwater photosynthetically available radiation and nitrate concentration. Ammonium concentration partly compensates lack of dissolved nitrogen.

Environmental conditions and pathogen removal in macrophyte- and algal-based domestic wastewater treatment systems

2001 ◽  
Vol 44 (6) ◽  
pp. 11-18 ◽  
Author(s):  
E. Awuah ◽  
F. Anohene ◽  
K. Asante ◽  
H. Lubberding ◽  
H. Gijzen
Keyword(s):  
Wastewater Treatment ◽  
Environmental Conditions ◽  
Domestic Wastewater ◽  
Pistia Stratiotes ◽  
Water Lettuce ◽  
Pathogen Removal ◽  
Moist Sand ◽  
Tropical Conditions ◽  
Wastewater Treatment Systems ◽  
All Treatment

The environmental conditions and pathogen removal in macrophyte (Pistia stratiotes and Lemna paucicostata) and algal-based wastewater treatment systems were determined over a period of 29 days under tropical conditions. The experiment was conducted on a batch scale in 4.5 plastic containers immersed in moist sand beds. A control of raw sewage stored under dark conditions was included. Environmental conditions such as pH, temperature DO and conductivity and heterotrophic and faecal enterococci populations were monitored five times a week at 8, 12 and 20 GMT. BOD was monitored once a week for five weeks. Average temperatures within the systems ranged between 28.3°C in the control to 30.6°C in the algal-based system. Low pH levels of pH of 4.5 and DO levels of 3 mg/L were recorded in the water lettuce treatment systems. High pH levels around 10.5 and DO levels of about 20 mg/L were observed in the algal-based system. The control and duckweed system remained neutral. All treatment systems performed equally well in pathogen removal and BOD reduction. The BOD decreased from 130mg/L to 5.0, 7.5, 10 and 15 mg/L in the duckweed, water lettuce, control and algal based treatment systems respectively. The faecal enterococci population decreased from 1.18×105 /ml to values below 100/ml in all treatment systems.

Spatial soil respiration measurements under varying environmental conditions in a dry grassland

2020 ◽  
Author(s):  
János Balogh ◽  
Szilvia Fóti ◽  
Bernadett Gecse ◽  
Marianna Papp ◽  
Gabriella Süle ◽  
...  
Keyword(s):  
Soil Respiration ◽  
Spatial Variability ◽  
Environmental Conditions ◽  
Summer Drought ◽  
Dry Grassland ◽  
Greenhouse Gas Flux ◽  
Major Disadvantage ◽  
Flux Measurements ◽  
Eddy Covariance Measurements ◽  
Footprint Area

<p>Spatial variability of ecosystem processes constitutes significant uncertainty source in greenhouse gas flux measurements and estimations. The major disadvantage of the chamber-based flux measurements is the poor spatial representativeness, but eddy-covariance measurements also have an uncertainty due to the unequal and not constant footprint area. One way to overcome these difficulties is the spatial sampling improving the field-scale data coverage.</p><p>The aim of this study was to describe the spatial variability of grassland soil CO<sub>2</sub> efflux under varying environmental conditions. For this reason, we conducted spatial measurements on a range of variables including soil respiration, above-ground biomass, greenness index of the vegetation, soil water content and soil temperature during a seven-year study in a dry grassland site in Hungary. Altitude and soil organic carbon (SOC) content of the measuring positions were also used as background factors. Measurements were repeated 19 times at 78 positions during the study, in the main phenological stages of the grassland vegetation: spring growth, summer drought, autumn regrowth. The sampling scheme was based on 80×60 m grid of 10 m resolution. SOC content was highly variable among the positions due to the exposure differences and their environmental constrains. We analyzed the effect of the drivers on soil respiration grouping the measuring positions by the SOC content of the soil.</p>

Combining (U-Th-Sm)/He dating and geochemical budget to understand laterite formation

2020 ◽  
Author(s):  
Claire Ansart ◽  
Damien Calmels ◽  
Cécile Gautheron ◽  
Gaël Monvoisin ◽  
Pierre Agrinier ◽  
...  
Keyword(s):  
Environmental Conditions ◽  
Chemical Weathering ◽  
Equatorial Position ◽  
Secondary Minerals ◽  
Weathering Processes ◽  
Fe Oxides ◽  
Tropical Conditions ◽  
Geochemical Variations ◽  
Climate Evolution

<p>Laterite formations are deep regoliths, up to one hundred of meters thick, that represent about 80% of the global soil volume. Formed under tropical conditions, laterites result from successive chemical weathering reactions over long periods up to tens of millions of years. Laterites can thus be seen as both an actor of the long-term carbon cycle, through CO<sub>2</sub> consumption by silicate weathering and witness of the long-term climate evolution. Indeed, secondary minerals found nowadays in lateritic profiles may have recorded past environmental conditions that prevailed at the time of their formation. Despite the large distribution of lateritic formations around the world, their timing and processes of formations as well as their preservation over long period of time remain unclear.</p><p>Here, we investigate an entire weathering profile developed on the Guiana Shield, in Brownsberg mountains, Suriname. The sampling region has remained in equatorial position for the last 100 Myr and has seen lateritic development since early Tertiary [1]. Such latitudinal stability offers the possibility to look at links between long-term climate evolution or climatic events and long-term chemical weathering processes.</p><p>The lateritic profile shows a strong loss in both alkali and alkaline-earth elements as well as a desilication, and an enrichment in Fe, particularly in the duricrust. The study of trace elements and rare earth elements highlights various geochemical processes behind the development of a lateritic – bauxitic profile.</p><p> (U-Th-Sm)/He ages of iron oxides from the duricrust show the presence of multiple generations of Fe oxides, demonstrating that the Brownsberg profile underwent multiple dissolution and recrystallization phases since its formation, at least 19.9 ± 1.8 Ma ago. These successive weathering processes may have led to the particular enrichment in the profile such as the one observed for Fe and V in the duricrust. Measurement of d18O – dD on secondary minerals, i.e. kaolinite and Fe-oxides s.l., will help to connect mineralogical and geochemical variations with the environmental conditions that prevailed at the time of their formation [2].</p><p>[1] Theveniaut and Freyssinet, 2002. Pal. Pal. Pal., 178, 91-117</p><p>[2] Girard et al., 2000. GCA, 64 n°3, 409 – 426</p>

scholarly journals Spatial variability in the icthyoplankton structure of a subtropicalhypersaline lagoon

2016 ◽  
Vol 64 (2) ◽  
pp. 149-156 ◽  
Author(s):  
Judson da Cruz Lopes da Rosa ◽  
Mariana Dantas Alberto ◽  
Wanda Maria Monteiro Ribas ◽  
Maria Helena Campos Baeta Neves ◽  
Lohengrin Dias de A. Fernandes
Keyword(s):  
Spatial Variability ◽  
Fish Species ◽  
Environmental Conditions ◽  
Environmental Changes ◽  
High Salinity ◽  
Fish Larvae ◽  
Reproductive Season ◽  
Uneven Distribution ◽  
Eggs And Larvae ◽  
Spatial And Temporal Analyses

Abstract The Lagoa de Araruama is a hypersaline ecosystem inhabited by distinct fish species, either permanently or during their reproductive season. Over recent years, some significant environmental changes have been observed in this ecosystem related to the sewage runoff, as salinity decrease (from 64 to 41 psu during the last 40 years) and nutrients increase. As both changes are thought to affect the ichthyoplankton assemblage, the present study aimed to evaluate all the potential relationships between salinity disruption and fish larvae distribution. Ichtyoplankton samples were collected monthly from January 2010 to March 2011 at eight sites in Araruama Lagoon by means of a WP2 plankton net equipped with a flowmeter. During this period, low egg densities were coincident with high salinity regions, suggesting that adults are avoiding to release their eggs under less favorable environmental conditions to the larvae. The uneven distribution of eggs and larvae inside the lagoon, as revealed by both spatial and temporal analyses lead us to suggest that changes in salinity have influenced the reproductive rhythms of those fish species that depend upon the Lagoa de Araruama.

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