Studies of Wet Deposition and Dustfall at Pune, India

Rain water and dustfall deposition samples were collected at Pune, an urban site (1992–98) and at Sinhagad, a rural site (1992–94). The samples were collected with wet-only and bulk collectors at Pune and with bulk collector at Sinhagad. The samples were analyzed for major ions, pH and conductivity. The study showed that the rain water at both places is alkaline (pH > 5.6). The average pH at Pune was 6.1. Neutralising components, indicated by Ca and non sea salt (nss) Mg have higher concentrations than the acidifying components SO₄ and NO₃. The wet deposition fluxes of all the ionic components were higher than the dustfall fluxes. Relative contribution from dustfall was largest for K, Ca, Mg and NO₃. Dustfall was greater at Pune, compared to Sinhagad for all components and up to double for Ca.     

The Level II aggregated forest soil condition database links soil physicochemical and hydraulic properties with long-term observations of forest condition in Europe

Key message

Aggregated, consolidated, and derived soil physicochemical data of 286 ICP Forests Level II plots were completed with soil hydraulic properties for integrated use with forest monitoring data. Database access should be requested at http://icp-forests.net . Metadata associated available at https://metadata-afs.nancy.inra.fr/geonetwork/apps/georchestra/?uuid=153e599e-6624-4e2b-b862-8124386ea9cd&hl=eng

Context

The ICP Forests database is one of the most comprehensive forest ecosystem datasets in Europe and contains the accumulated results of more than two decades of harmonised forest monitoring all over Europe.

Aims

The aim of this paper is to share knowledge on the ICP Forests Level II soil data for broader use among forest scientists.

Methods

After standard analysis, quality checks, aggregation, and calculation of derived variables (e.g. nutrient stocks, base saturation, C:N ratio, and water retention parameters), data have been gathered into a static database (AFSCDB.LII.2.2), which will be updated to new versions as soon as new measurements become available.

Results

The database provides a basis for the combined evaluation of up to 130 unique soil variables of 286 plots with dynamic data on tree growth, ground vegetation, foliar chemistry, crown condition, tree phenology, leaf area index, ozone injury, litterfall, soil solution chemistry, deposition, ambient air quality, and meteorological data assessed on the same plots.

Conclusion

The unprecedented comprehensiveness and level of detail in this newly aggregated database may overcome existing restrictions so far impeding the realisation of large-scale forest ecosystem studies in Europe.

     

Microbial and microfaunal community structure in cropping systems with genetically modified plants

Soils from field sites at Foulum (DK), Narbons (FR) and Varois (FR) planted with genetically modified maize expressing either the insecticidal Bacillus thuringiensis protein (Bt) or herbicide tolerance (HT), as described elsewhere in this volume, were analysed for nematodes, protozoa and microbial community structure. These analyses were mirrored in single-species testing and in mesocosm experiments, and were coordinated with field samples taken for microarthropods, enchytraeids and earthworms so allowing for cross-comparison and a better understanding of the results observed in the field. Over the first 2 years of the field experiments (in 2002 and 2003), the effect of Bt-maize was within the normal variation expected in these agricultural systems. Sampling in 2004 and 2005 was expanded to include the effects of tillage (i.e. reduced tillage versus conventional tillage) and also the use of HT-maize. Tillage had major effects regardless of soil type (Varois or Foulum), with reduced-tillage plots having a greater abundance of microfauna and a different microbial community structure (measured both by phospholipid fatty-acid analysis (PLFA) and by community-level physiological profiling (CLPP)) from conventionally tilled plots. Grass, as a contrasting cropping system to maize, also had an effect regardless of soil type and resulted in greater microfaunal abundance and an altered microbial community structure. Differences in crop management, which for the Bt-maize was removal of the insecticide used to control European corn borer and for HT-maize was a change in herbicide formulation, were only tested at single sites. There were differences in microbial community structure (CLPP but not PLFA) and sporadic increases in protozoan abundance under the Bt-crop management. The HT-maize cropping system, which covered a shorter period and only one site, showed little change from the conventional system other than an altered microbial community structure (as measured by PLFA only) at the final harvest. The Bt-trait had a minimal impact, with fewer amoebae at Foulum in May 2003, fewer nematodes at Foulum in May 2004 but more protozoa at Varois in October 2002 and an altered microbial community structure (PLFA) at Foulum in August 2005. These were not persistent effects and could not be distinguished from varietal effects. Based on the field evaluations of microfauna and microorganisms, we conclude that there were no soil ecological consequences for these communities associated with the use of Bt- or HT-maize in place of conventional varieties. Other land management options, such as tillage, crop type and pest management regime, had significantly larger effects on the biology of the soil than the type of maize grown.     

Rheological properties of acid gels prepared from heated pH-adjusted skim milk

Reconstituted skim milk was adjusted to pH values between 6.5 and 7.1 and heated (90 degrees C) for up to 30 min. The skim milk samples were then readjusted to pH 6.7. Acid gels prepared from heated milk had markedly higher G ' values, a reduced gelation time, and an increased gelation pH than those prepared from unheated milk. An increased pH at heating decreased the gelation time, increased the gelation pH, and increased the final G ' of acid set gels prepared from the heated milk samples. There were only small differences in the level of whey protein denaturation in the samples at different pH values, and these differences could not account for the differences in the G ' of the acid gels. The levels of denatured whey protein associated with the casein micelles decreased and the levels of soluble denatured whey proteins increased as the pH at heating was increased. The results indicated that the soluble denatured whey proteins had a greater effect on the final G ' of the acid gels than the denatured whey proteins associated with the casein micelles.     

Long term trends in atmospheric deposition and seepage output in northwest German forest ecosystems

Long term trends of element fluxes in atmospheric deposition and of concentrations in seepage output of seven coniferous and deciduous forest stands in northwestern Germany have been evaluated for the period 1981 – 1994. Decreasing deposition rates of SO₄ (50 – 70%) and H⁺ (60 – 80%) occured at all sites concomitant with the decline of SO₂ emission rates in the former Federal Republic of Germany. Deposition of Ca, Mg, and K decreased at the Soiling and Göttinger Wald stands. During this period no consistent trends in the flux rates of NH₄ and NO₃ were apparent. Sulfate concentrations in soil solution decreased at the Soiling and Göttinger Wald stands, whereas an increase occured at Lange Bramke south slope. As a consequence of reduced deposition and mobile anion concentrations a decrease of Ca, Mg, K, Al, and Mn in soil solution has been observed at the Soiling stands. At the other stands trends of cations in soil solution are not consistent. Nitrate concentrations in soil solution decreased at the Göttinger Wald. A rising tendency with great fluctuations of NO₃ concentrations occured at the Soiling spruce stand.     

Does transport of water to roots limit water uptake of field crops?

The question was examined under which conditions the water extraction rate of plant roots in the field can be limited by water transport to the roots. For this purpose we used a numerical solution of the single root model. Scenario calculations were carried out in order to investigate the general model behaviour. A sensitivity analysis showed that initial volumetric water content and root length density are of greater importance than root diameter in determining the maximum water transport rate to the roots. Data from a field experiment were taken, describing root length density, volumetric water content and water uptake rates under oats (Avena saliva L.) and faba beans (Vicia faba L.) as model input parameters. With this data the model calculated the water content difference between the bulk soil and the root surface which is necessary to induce a water flow to the roots matching the observed water uptake rate. Root length densities below the grain legume crop faba beans are one order of magnitude lower compared to that of the cereal crop oats. The therefore higher specific water influx rates of faba beans roots resulted in a higher decrease in water content near the root surface. However, water uptake by faba beans was controlled by the water flow towards the roots probably only in deeper soil layers with very low root length density. For the given conditions no transport limitation of water uptake was calculated, when rooting densities were higher than about 0.1 cm.cm^?3.     

Bodenvariabilität und Verhalten von Pflanzenschutzmitteln

Soil variability and pesticide behaviour The spatial variability of selected soil characteristics (organic carbon, particle size), pesticide adsorption and leaching was estimated for an agricultural location. Variograms were calculated to describe the spatial dependence of data. All parameters showed a nearly isotropic behaviour. According to variograms a kriging interpolation was done and the spatial variability of parameters was estimated. Leaching of terbuthylazine was calculated (model PRZM) with regard to soil variability and adsorption pattern (K_d-values). Leaching depth in the winter season varied between 10 and 22 cm depending strictly on soil characteristics.     

Effects of Sarcocystis miescheriana infection on carcass quality and on the water-binding capacity of the meat of halothane-tested fattening pigs

Ten halothane-positive pigs (stress sensitive, group A) and ten halothane-negative pigs (stress insensitive, Group C) with a mean body weight of 36 kg were each inoculated orally with 50,000 sporocysts of Sarcocystis miescheriana. Twelve halthane-positive pigs (Group B) and ten halothane-negative pigs (Group D) served as non-infected controls. Thirteen weeks post infection (p.i.) the lean: fat ratios of the pigs of the infected groups A and C were lower (A, 1:0.41 +/- 0.09; C, 1:0.50 +/- 0.10) than those of the pigs of the non-infected groups B and D (B, 1:0.50 +/- 0.08; D, 1:0.55 +/- 0.08). The back-fat thickness, the fat thickness 'A' and the fat thickness 'B' were thinner in infected pigs than in non-infected pigs. The difference in Lendenst?rkespeckquotient (Loin Fat Thickness Quotient) (LSQ) between infected and non-infected pigs was not statistically significant. The values of the water-holding capacity were lower in infected pigs than in non-infected pigs, the difference being statistically significant only in the halothane-negative groups (C, 0.45 +/- 0.02; D, 0.48 +/- 0.04). The water-absorbing capacity was significantly higher in the infected groups (A, 5.92 +/- 3.99%; B, 2.26 +/- 1.08%; C, 8.96 +/- 2.90%; D, 4.97 +/- 2.51%). In conclusion, it can be said that there was a slight tendency towards a better carcass quality and a better water-binding capacity in infected pigs, although this was combined with reduced growth rates.     

Hydrology influences breeding time in the white-throated dipper

While nitrogen and carbon stable isotope values can reflect ecological segregation, prey choice and spatial distribution in seabirds, the interpretation of bulk stable isotope values is frequently hampered by a lack of isotopic baseline data. In this study, we used compound-specific isotope analyses of amino acids (CSIA-AA) to overcome this constraint and to study interspecific differences, seasonal and historical changes in trophic positions of five seabird species, three penguins and two petrels, from a sub-Antarctic seabird community. CSIA-AA allowed comparing trophic positions of seabirds with temperate and polar distributions. Gentoo and Magellanic penguins had the highest trophic positions during the breeding season (3.7 and 3.9), but decreased these (2.9 and 3.3) during the feed-up for moult. Intra-specific differences were also detected in Thin-billed prions, where carbon isotope values clearly separated individuals with polar and temperate distributions, both in the breeding and interbreeding periods. Thin-billed prions that foraged in polar waters had lower trophic positions (3.2) than conspecifics foraging in temperate waters (3.8). We further investigated historical changes by comparing museum samples with samples collected recently. Our pilot study suggests that Rockhopper penguins, Magellanic penguins and Thin-billed prions with temperate non-breeding distributions had retained their trophic levels over a 90–100 year period, while Gentoo penguins and Thin-billed prions with polar non-breeding distributions had decreased trophic levels compared to historical samples. In contrast, Wilson’s storm-petrels had slightly increased trophic levels compared to samples taken in 1924–1930. We applied compound-specific stable isotope analyses across a range of contexts, from intra-specific comparisons between stages of the breeding cycle to inter-specific seabird community analysis that would not have been possible using bulk stable isotope analyses alone due to differences in isotopic baselines.