Browsing by Subject "Biomonitoring"

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Biomonitoring of ammonia deposition by means of higher plants
(2013) Ilogu Chibuzo Franklin; Fangmeier, Andreas
Atmospheric nitrogen deposition emanating from oxidized or reduced nitrogen sources has been influenced immensely by human activities. This is as a result of the need to improve and meet the ever changing demands of an increasing growth in global population. The benefits accrued from such activities however, have not been without some negative effects on several ecosystems, plants, air quality and human health. This is due to the emission of reactive nitrogen species and its contribution to the level of atmospheric nitrogen pollution in the environment as well as nitrogen deposition afterwards. Atmospheric ammonia (NH3) arguably is an important source of nitrogen deposition. Its major source is from agricultural activities involving various aspects of crop production including, fertilizer and manure applications among others and also importantly from livestock management. It is pertinent therefore, to conduct continuous monitoring studies in order to ascertain the prevailing ambient NH3 concentration in an area, so as to identify periods when threshold values are exceeded and also to determine how certain plants would respond when exposed to NH3 pollution. This necessitated the need to investigate in this thesis, through active biomonitoring, the interaction of NH3 pollution on selected indicator species namely, Italian ryegrass (Lolium multiflorum L.), barnyard grass (Echinochloa crus-galli L.), stinging nettle (Urtica dioica L.) and common lambsquarters (Chenopodium album L.). The influence of nitrogen deposition, arising from NH3 pollution on the selected indicator species were examined by the responses of the free amino acids and above ground biomass accumulation of the various plants studied, as an indicator of nitrogen accumulation. In order to execute plant and atmospheric NH3 interactions, two different experiments were conducted. The first experiment was a field study carried out around a livestock farm as a source of NH3 pollution and nitrogen deposition. Plant materials were exposed alongside passive diffusion tube samplers at three selected distances from the stable along a transect of 804m. The three different sites were selected with increasing distance from the stable, in order to enable a comparison between the plants exposed in close proximity to the source NH3 emission and those further away. The ambient NH3 concentration at each site was measured with the passive diffusion tube samplers exposed at each location. This measurement was conducted with a view to determine the ambient NH3 concentration exposed to the plant materials at each site and also to observe the influence of increasing distance on NH3 pollution and its exposure on the plants, from a point source of NH3 pollution. Furthermore, two fumigation experiments were conducted under controlled greenhouse conditions. In the fumigation study, only Lolium multiflorum and Echinochloa crus-galli, plants were used for this experiment and exposed to three treatment levels of gaseous NH3 fumigations in different growth chambers. The plants were exposed to the following treatments, non-filtered air (NFA), non-filtered air with low NH3 concentration (NFA+) and non-filtered air with high NH3 concentration (NFA++) in both fumigation experiments. In the field experiment, the ambient NH3 concentration measured at each location from the stable, decreased with increasing distance from the point of NH3 emission. This decrease in concentration of NH3 clearly demonstrates the impact of livestock management as a source of NH3 pollution. The free amino acid concentrations and compositions investigated in the various plants studied in the field experiments showed a significant response to NH3 exposure. Several fold increases in the free amino acid concentrations and changes in composition were observed in plant materials exposed to increasing NH3 concentrations at closer proximity to the stable. Observations made from this study showed that an increase in NH3 concentration with closer distance to the source of NH3 pollution influenced remarkably, the percentage increases of low carbon to nitrogen compounds such as Glutamine (Gln) in Lolium multiflorum and Chenopodium album, Asparagine (Asn) in Echinochloa crus-galli and Arginine (Arg) in Urtica dioica. The increases and alterations observed in the free amino acid compositions of the plants studied, demonstrates the uptake and sensitivity of the various plants to NH3 pollution and nitrogen deposition by inducing changes in its free amino acid metabolism. The effects of nitrogen deposition on the above ground biomass of the plants in the field study, indicated a significant effect of the ambient NH3 concentrations on Lolium multiflorum, Echinochloa crus-galli and Urtica dioica. These findings demonstrate a positive influence of NH3 pollution as a nitrogen source on growth and biomass accumulation in the plants. Considering the results obtained in this study based on the responses of the plants to atmospheric NH3 pollution in the field and in the fumigation studies, it is obvious NH3 had an influence over the growth and metabolism of the plants studied. This influence indicates the plants were able to detect changes in the ambient NH3 concentrations in the environment and responded by exhibiting changes in biomass production and alterations in free amino acid compositions, thus indicating they have good potentials as biomonitors of ammonia deposition.
Biomonitoring von Fluorwasserstoff : neue Ansätze zum Einsatz Höherer Pflanzen als Akkumulationsindikatoren
(2009) Blanckart, Peter; Fangmeier, Andreas
The standardised grass culture as described in VDI guideline 3957 sheet 2 has successfully been used for years to identify pollution related effects and to assess pollution load with hydrogen fluoride. At the moment, two directives are in preparation for the evaluation of the results from the exposure of standardised grass cultures which provide scales for judging and values for orientation on the basis of detailed studies. The directives will be published as VDI 3857 sheet 1 and sheet 2 as green print in 2009. The directive VDI 2310 sheet 3 is being revised as well. Its publication (green print) is also expected for 2009. According to no. 5.3 of the directive VDI 3957 sheet 2, samples with less than 2 g of dry substance have to be rejected. However, the rejection of these samples leads to a time gap for assessing of 14 days or even of 4 weeks. In this context it should be tested how the accumulation of fluoride after exposure with air containing hydrogen fluoride would be affected at lower growth rates. It should also be tested if samples of exposed grass with a minimum weight of less than the required 2 g of dry substance can be used for determining the pollution situation. To evaluate these problems, exposures were performed with standardised grass cultures and with modified methodology in an area ? the city of Ransbach-Baumbach ? which is highly contaminated by fluorides. Parallel to bioindication, the fluoride concentration in the air was assessed with radial symmetric passive samplers as a physicochemical method. By this means a direct comparison of the concentration of air pollutants with the pollutant concentration in the grass could be performed. The tests confirmed that the study area is indeed quite contaminated with fluoride from anthropogenic sources. The area around Ransbach-Baumbach can be considered as a hot-spot for higher fluoride concentrations within Germany. The results confirm that fluoride pollution in Central Europe is still an ongoing problem, even though the pollution is mostly scattered and small scale limited. Therefore, evaluation fundamentals for bioindication methods for fluoride (passive and active) should be worked out for the future, although fluoride accumulations are no longer regularly determined in large scale bioindication monitoring networks. The application of Deschampsia flexuosa (L.) Trin. as an accumulation indicator as a possible alternative to Lolium multiflorum Lam. could not be confirmed in this study; the deviations of fluoride concentrations in Deschampsia flexuosa (L.) Trin. and in Lolium multiflorum Lam. were too large in the spatiotemporal comparison. The measurements performed with radialsymmetric passive samplers did not show a good relationship between the hydrogen fluoride concentration in the air and the fluoride concentration F- [µg g-1 ds] in the Lolium grass cultures. There were only very low correlations between the fluoride concentration and the increase of biomass as raw and dry weight of Lolium multiflorum Lam. (R2 of 0.0258 and 0.0099 at two measurement stations, respectively). Since conventionally an R2 of ≥ 0,6 is required to indicate significant relationships in ecological/ecotoxicological field studies, no link between the increase of biomass and fluoride concentration for the accumulation indicator Lolium multiflorum Lam. is concluded. Therefore, it is recommended to revise the VDI guideline 3957 sheet 2 so that standardised grass culture samples of less than 2 g dry substance are also accounted for in the determination of the accumulation of air pollutants like fluoride in plants.