Abiotic and biotic

Only controls using inhibitors of microbial growth are possible for microcosm experiments, and these may be impractical for outdoor systems, which therefore combine and may fail to discriminate abiotic and biotic reactions. 

Chapters 1 through 4 provide a broad perspective on abiotic and biotic reactions, including the significance of a range of environmental determinants. 

The time of year in which a pesticide is applied significantly affects its dissipation rate due to temperature, moisture, and solar-irradiance effects on abiotic and biotic dissipation processes. For example, dissipation rates for agrochemical applications made in the springtime are normally greater than those observed for fall (autumn) applications. Thus, the timing of agrochemical applications made in field soil dissipation studies should closely match those occurring under acmal-use conditions. 

The ammonium dynamics showed that the initial concentrations of N were reduced after the first 3 days, and after that, a release of the mineral occurred from day 3 up to day 14. Later still, the concentration of ammonium decreased by up to < 14 mg N kg 1 dry soil for all the treatments in both the Otumba and Texcoco soils, and the ammonium concentration decreased by up to < 2 mg N kg 1 dry soil for all treatments, except for the soil treated with sterilized sludge, < 31 mg N kg 1 dry soil. The contour of the ammonium dynamics was similar in both the Otumba and Texcoco soils. Many abiotic and biotic processes might affect the concentration of NH4+ in soil, such as NH4+ fixation in the soil matrix, volatilisation of NH3, and immobilization or oxidation of NH4+. Some soil processes were occurring at too low a level to be detectable, such as NH4+ fixation and the volatilisation of NH3. The nitrate dynamics were similar in both soils. The concentration of N03 was 120 mg N kg 1 dry soil in the control treatment in both soils. The ammonium concentration was similar in both soils, > 200 mg N kg 1 dry soil, treatments with sludge reached > 255 mg N kg 1 dry soil and > 300 mg N kg 1 dry soil in the Texcoco and Otumba soils respectively, and soils treated with sterilized sludge increased the concentration... 

Hakkarainen, M. Aliphatic Polyesters Abiotic and Biotic Degradation and Degradation Products. Vol. 157, pp. 1-26. 

Ferrara, R., B.E. Maserti, and R. Breder. 1991. Mercury in abiotic and biotic compartments of an area affected by a geochemical anomaly (Mt. Amiata, Italy). Water Air Soil Pollut. 56 219-233. 

On the other hand, biotic factors include natural interactions (e.g., predation and parasitism) and anthropogenic stress (e.g., the effect of human activity on other organisms). Because of the abiotic and biotic factors, the environment to which an organism is subjected can affect the life functions, growth, and reproductive success of the organism and can determine the local and geographic distribution patterns of the organism. 

The sampling points must be on groundwater flow lines from the source of contamination or above the observation point. The down-gradient observations must accurately reflect the abiotic and biotic processes occurring between the two points. 

For air, the major degradation process involves reactions with free radicals such as hydroxyl groups (Atkinson 1985). For other media, it is clear that chloroform can be mineralized through both abiotic and biotic processes. Information in the available literature (Bouer and McCarty 1983 Rhee and Speece 1992) documents the disappearance of chloroform in water and soil media under both aerobic and anaerobic conditions as well as identification of the end products. 

Other methods used to increase secondary product accumulation are elicitation, permeabilisation, product removal, immobilisation and differentiation. Elicitation is the triggering of plant defence mechanisms by the addition of abiotic and biotic elicitors. Elicitor refers to chemicals which can trigger physiologi-... 

Diazinon is subject to a variety of abiotic and biotic degradation processes in all environmental compartments. 

Scheunert I, Mansour M, Doerfler U, et al. 1993. Fate of pendimethalin, carbofuran and diazinon under abiotic and biotic conditions. Science of the Total Environment 132 361-369. 

The differentiation in abiotic and biotic particles before the actual Raman measurement allows a higher sample throughput. Here, especially morphological features can be evaluated by bright light or glancing light illumina-... 

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