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Application of MicroResp™ for soil ecotoxicology
2013
Wakelin, Steven | Lombi, Enzo | Donner, Erica | MacDonald, Lynne | Black, Amanda | O'Callaghan, Maureen
MicroResp™ is a miniaturised method for measuring substrate induced respiration (SIR) in soil. We modified the MicroResp™ method to develop a rapid tool for quantifying the ecotoxicological impact of contaminants. The method is based on reduction in SIR across a gradient of contaminant, allowing for determination of dose–response curves EC-values. Contaminants are mixed into soil samples at a range of concentrations; each sample is then dispensed into a column of eight wells in 96 well format (deep) plates. Moisture and glucose are added to the samples at levels to provide maximum response. Released CO2 from the soils is then measured using colorimetric gel-traps, following the standard MicroResp™ methodology. Examination revealed that this method works over a range of soil types and is insensitive to minor variations in assay length (2–7 h), alteration of moisture content (±20 μL from optimum), and soil storage conditions (4 °C versus fresh).
Show more [+] Less [-]Responses of soil Collembola to long-term atmospheric CO2 enrichment in a mature temperate forest
2013
Xu, Guo-Liang | Fu, Sheng-Lei | Schleppi, Patrick | Li, Mai-He
Responses of Collembola to 7 years of CO2 enrichment (550 ppm) in a Swiss free-air CO2 enrichment (FACE) experiment in a forest with 80- to 120-year-old trees were investigated in this study. Contrary to our expectations, increased CO2 caused a significant decrease in Collembola numbers, including a significant decrease in euedaphic Collembola. Increased CO2, however, did not affect community group richness. Collembola biomass was not significantly changed by CO2 enrichment, regardless of whether it was considered in terms of the total community, life-strategy groups, or individual species (with an exception of Mesaphorura krausbaueri). The reason for this is that CO2 enrichment caused a general increase in individual body size, which compensated for reduced abundances. The results are consistent with the idea that the rhizosphere is important for soil fauna, and the combination of reduced fine root growth and increased soil moisture might trigger a reduction in Collembola abundance.
Show more [+] Less [-]Impact of elevated CO2 and elevated O3 on Beta vulgaris L.: Pigments, metabolites, antioxidants, growth and yield
2013
Kumari, Sumita | Agrawal, Madhoolika | Tiwari, Supriya
The present study was conducted to assess morphological, biochemical and yield responses of palak (Beta vulgaris L. cv Allgreen) to ambient and elevated levels of CO2 and O3, alone and in combination. As compared to the plants grown in charcoal filtered air (ACO2), growth and yield of the plants increased under elevated CO2 (ECO2) and decreased under combination of ECO2 with elevated O3 (ECO2 + EO3), ambient O3 (ACO2 + AO3) and elevated O3 (EO3). Lipid peroxidation, ascorbic acid, catalase and glutathione reductase activities enhanced under all treatments and were highest in EO3. Foliar starch and organic carbon contents increased under ECO2 and ECO2 + EO3 and reduced under EO3 and ACO2 + AO3. Foliar N content declined in all treatments compared to ACO2 resulting in alteration of C/N ratio. This study concludes that ambient level of CO2 is not enough to counteract O3 impact, but elevated CO2 has potential to counteract the negative effects of future O3 level.
Show more [+] Less [-]Estimation of main greenhouse gases emission from household energy consumption in the West Bank, Palestine
2013
Abu-Madi, Maher | Rayyan, Ma'moun Abu
The main GHGs (CO2, NOx, and SO2) have been quantified based on national energy and population statistics. The results show that the contribution of households' energy consumption in the West Bank to global CO2 emission is about 0.016%, while contribution of total energy consumption by all sectors is about 0.041%. The results show that wood is the most polluting energy source in terms of CO2 and NOx emission, while electricity is the most polluting source in terms of SO2. Other sources like diesel, kerosene, and LPG that contribute to the GHGs emission are also quantified. The total amounts of CO2, NOx, and SO2 by households in the West Bank are 4.7 million tonne per year, 3.02 thousand tonne per year, and 2.23 thousand tonne per year respectively. This study presents a set of measures that might help in reducing the level of GHGs emission and protect the environment.
Show more [+] Less [-]Effects of ozone on stomatal responses to environmental parameters (blue light, red light, CO2 and vapour pressure deficit) in three Populus deltoides × Populus nigra genotypes
2013
Dumont, Jenny | Spicher, Fabien | Montpied, Pierre | Dizengremel, Pierre | Jolivet, Yves | Le Thiec, Didier
The effect of ozone (O3) on stomatal regulation was studied in three Euramerican poplar genotypes (Populus deltoides × Populus nigra: Carpaccio, Cima and Robusta). The impact of O3 on stomatal conductance responses to variations in blue light, red light, CO2 concentration and vapour pressure deficit (VPD) was studied. Upon O3 exposure, a sluggish response of stomatal movements was observed, characterized by slower reactions to increases in blue light intensity, CO2 concentration and VPD, and lower amplitude of the response to variations in light intensity. That sluggish response should be taken into account in stomatal conductance models for phytotoxic ozone dose (PODY) calculations. The speed of the response to variations in environmental parameters appears as a determining factor of genotype-related sensitivity.
Show more [+] Less [-]Prediction of N2O emission from local information with Random Forest
2013
Philibert, Aurore | Loyce, Chantal | Makowski, David
Nitrous oxide is a potent greenhouse gas, with a global warming potential 298 times greater than that of CO2. In agricultural soils, N2O emissions are influenced by a large number of environmental characteristics and crop management techniques that are not systematically reported in experiments. Random Forest (RF) is a machine learning method that can handle missing data and ranks input variables on the basis of their importance. We aimed to predict N2O emission on the basis of local information, to rank environmental and crop management variables according to their influence on N2O emission, and to compare the performances of RF with several regression models. RF outperformed the regression models for predictive purposes, and this approach led to the identification of three important input variables: N fertilization, type of crop, and experiment duration. This method could be used in the future for prediction of N2O emissions from local information.
Show more [+] Less [-]Polycyclic aromatic hydrocarbons and nitropolycyclic aromatic hydrocarbons in particulates emitted by motorcycles
2013
Pham, Chau Thuy | Kameda, Takayuki | Toriba, Akira | Hayakawa, Kazuichi
We determined eleven PAHs and four NPAHs in particulates and regulated pollutants (CO, CO2, HC, NOx, PM) exhausted from motorcycles to figure out the characteristics of motorcycle exhausts. Fluoranthene and pyrene accounted for more than 50% of the total detected PAHs. Among four detected NPAHs, 6-nitrochrysene and 7-nitrobenz[a]anthracene were the predominant NPAHs and were highly correlated relationship with their parent PAHs (R = 0.93 and 0.97, respectively). The PM and HC emissions tended to be close to the PAH emissions. NOx and NPAHs were negatively correlated. Despite their small engine size, motorcycles emitted much more PM and PAHs, showed stronger PAH-related carcinogenicity and indirect-acting mutagenicity, but weaker NPAH-related direct-acting mutagenic potency than automobiles. This is the first study to analyze both PAHs and NPAHs emitted by motorcycles, which could provide useful information to design the emission regulations and standards for motorcycles such as PM.
Show more [+] Less [-]Impact of elevated levels of CO2 on animal mediated ecosystem function: The modification of sediment nutrient fluxes by burrowing urchins
2013
Widdicombe, S. | Beesley, A. | Berge, J.A. | Dashfield, S.L. | McNeill, C.L. | Needham, H.R. | Øxnevad, S.
A mesocosm experiment was conducted to quantify the relationships between the presence and body size of two burrowing heart urchins (Brissopsis lyrifera and Echinocardium cordatum) and rates of sediment nutrient flux. Furthermore, the impact of seawater acidification on these relationships was determined during this 40-day exposure experiment. Using carbon dioxide (CO2) gas, seawater was acidified to pHNBS 7.6, 7.2 or 6.8. Control treatments were maintained in natural seawater (pH≈8.0). Under normocapnic conditions, burrowing urchins were seen to reduce the sediment uptake of nitrite or nitrate whilst enhancing the release of silicate and phosphate. In acidified (hypercapnic) treatments, the biological control of biogeochemical cycles by urchins was significantly affected, probably through the combined impacts of high CO2 on nitrifying bacteria, benthic algae and urchin behaviour. This study highlights the importance of considering biological interactions when predicting the consequences of seawater acidification on ecosystem function.
Show more [+] Less [-]Consequences of a simulated rapid ocean acidification event for benthic ecosystem processes and functions
2013
Murray, Fiona | Widdicombe, Stephen | McNeill, C Louise | Solan, Martin
Whilst the biological consequences of long-term, gradual changes in acidity associated with the oceanic uptake of atmospheric carbon dioxide (CO2) are increasingly studied, the potential effects of rapid acidification associated with a failure of sub-seabed carbon storage infrastructure have received less attention. This study investigates the effects of severe short-term (8days) exposure to acidified seawater on infaunal mediation of ecosystem processes (bioirrigation and sediment particle redistribution) and functioning (nutrient concentrations). Following acidification, individuals of Amphiura filiformis exhibited emergent behaviour typical of a stress response, which resulted in altered bioturbation, but limited changes in nutrient cycling. Under acidified conditions, A. filiformis moved to shallower depths within the sediment and the variability in occupancy depth reduced considerably. This study indicated that rapid acidification events may not be lethal to benthic invertebrates, but may result in behavioural changes that could have longer-term implications for species survival, ecosystem structure and functioning.
Show more [+] Less [-]Monitoring of impact of anthropogenic inputs on water quality of mangrove ecosystem of Uran, Navi Mumbai, west coast of India
2013
Pawar, Prabhakar R.
Surface water samples were collected from substations along Sheva creek and Dharamtar creek mangrove ecosystems of Uran (Raigad), Navi Mumbai, west coast of India. Water samples were collected fortnightly from April 2009 to March 2011 during spring low and high tides and were analyzed for pH, Temperature, Turbidity, Total solids (TS), Total dissolved solids (TDS), Total suspended solids (TSS), Dissolved oxygen (DO), Biochemical oxygen demand (BOD), Carbon dioxide (CO2), Chemical oxygen demand (COD), Salinity, Orthophosphate (O-PO4), Nitrite–nitrogen (NO2–N), Nitrate–nitrogen (NO3–N), and Silicates. Variables like pH, turbidity, TDS, salinity, DO, and BOD show seasonal variations. Higher content of O-PO4, NO3–N, and silicates is recorded due to discharge of domestic wastes and sewage, effluents from industries, oil tanking depots and also from maritime activities of Jawaharlal Nehru Port Trust (JNPT), hectic activities of Container Freight Stations (CFS), and other port wastes. This study reveals that water quality from mangrove ecosystems of Uran is deteriorating due to industrial pollution and that mangrove from Uran is facing the threat due to anthropogenic stress.
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