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Recording the causes, effects, and effect mechanisms of vegetation health is crucial to understand process-pattern interactions in ecosystem processes. NOX and SOX in the form of air pollution are both triggers and sources of vegetation health that can have an effect on the local or the global level and whose impacts need to be monitored. In this study, the growth patterns in Scots pines (Pinus sylvestris L.) were studied in the context of changing atmospheric depositions in the lowlands of north-eastern Germany. Under the influence of atmospheric sulfur (S) and nitrogen (N) depositions, pine stands showed temporal variations in their normal growth behavior. In such cases, the patterns of normal growth can be suppressed or accelerated. Pine stands which were influenced by high S deposition up until 1990 changed from suppressed growth to accelerated growth by decreasing S, but increasing N depositions between 1990 and 2003. The cause of these changes in pine growth patterns was imbalances in S and N nutrition, in particular, enrichments of sulfate, non-protein nitrogen or arginine, and finally, also imbalances and deficiencies in phosphorus, glucose, and adenosine triphosphate in the needles. Our long-term monitoring study shows that biochemical markers (traits) are crucial bioindicators for the qualitative and quantitative assessment of tree vitality and growth patterns in Scots pines. Furthermore, we were able to show that NOX and SOX depositions need to be monitored locally to be able to assess the local effects of biomolecular markers on the growth patterns in Scots pine stands.

Ectomycorrhiza (EM) formation improves tree growth and nutrient acquisition, particularly that of nitrogen (N). Few studies have coupled the effects of naturally occurring EM morphotypes to the nutrition of host trees. To investigate this, pine seedlings were grown on raw humus substrates collected at two forest sites, R2 and R3. Ectomycorrhiza morphotypes were identified, and their respective N uptake rates from organic (2-13C, 15N-glycine) and inorganic (15NH4Cl, Na15NO3, 15NH4NO3, NH415NO3) sources as well as their phosphate uptake rates were determined. Subsequently, the growth and nutritional status of the seedlings were analyzed. Two dominant EM morphotypes displayed significantly different mycorrhization rates in the two substrates. Rhizopogon luteolus Fr. (RL) was dominant in R2 and Suillus bovinus (Pers.) Kuntze (SB) was dominant in R3. 15N uptake of RL EM was at all times higher than that of SB EM. Phosphate uptake rates by the EM morphotypes did not differ significantly. The number of RL EM correlated negatively and the number of SB EM correlated positively with pine growth rate. Increased arginine concentrations and critical P/N ratios in needles indicated nutrient imbalances of pine seedlings from humus R2, predominantly mycorrhizal with RL. We conclude that different N supply in raw humus under Scots pine stands can induce shifts in the EM frequency of pine seedlings, and this may lead to EM formation by fungal strains with different ability to support tree growth.

Species-specific uptake and allocation mechanisms for N are scarce, in particular when trees are cultivated in potted soil under more natural conditions than in hydroponic culture. The objective of this study was to compare specific N-uptake rates for economically and ecologically important tree species in Central European forests: pine (Pinus sylvestris), spruce (Picea abies), oak (Quercus petraea), beech (Fagus sylvatica), lime (Tilia cordata), and ash (Fraxinus excelsior) when they grow in mineral soil from an old fallow site with a pH of 6. We used an 15N-labeling method to measure tree seedling 15N uptake in potted soils (Humic Cambisol) when both N forms NH and NO were simultaneously present in the soil solution for interspecies comparison and assessment of relationships between specific 15N-uptake rates and amino acid-accumulation rates or relative growth rates (RGR). The results demonstrate that tree species varied significantly in their capacity to take up NH or NO into roots, stems, or leaves, but indicate only marginal differences in their preference for NH or NO when they grow in mineral soil. The ranking of specific 15N-uptake rates for NH and NO was oak < beech < spruce < pine < lime < ash. Fine roots of all species had the highest specific 15N-uptake rates for both N forms, followed by total roots, leaves/needles, and stems. As regards tree seedling species, we found negative relationships between glutamine (Gln)-accumulation rates in leaves/needles and total 15N-uptake rates in fine roots. Noteworthy was the fact that, at high Gln-accumulation rates, the N-uptake system in fine roots of ash was probably lower under feedback inhibition by the amino acid.

The results presented in this paper provide evidence for the role of phytochelatins (PCs) in the detoxification of arsenic in six nonhyperaccumulating plant species, Agropyron repens, Glecoma hederacea, Leonurus marrubiastrum, Lolium perenne, Urtica dioica and Zea mays, in a pot experiment with high phosphate treatment. These plants differed in their arsenic sensitivities and were selected to investigate whether PCs with longer chains in roots of arsenic-tolerant species are synthesized. Raised concentrations of total PCs were measured in plant species with a range of sensitivities to arsenic at equivalent levels of arsenic exposure, determined as the inhibition of root biomass. In addition, the production of PCs as a function of accumulated arsenic was studied. Long-term PC synthesis (over a 5-week period) was positively, but non-linearly correlated with arsenic, suggesting that probably not all As is bound by PCs. Moreover, it could be shown that the synthesis of different chain lengths of PCs is associated with differences in As tolerance. In the more tolerant grasses A. repens and L. perenne it was chiefly the dithiol PC2 which was measured. In contrast, the dominant PC species in the less tolerant plants U. dioica, G. hederacea, L. marrubiastrum and Z. mays was PC3, while PC2 and PC3 were detected as well.

The connection between the emission of atmospheric nitrogen (N) and the risk of groundwater pollution is significant for protection of the landscape with respect to the resources. The usually unknown amount of atmospheric nitrogen deposition has a high impact on N balances and on the leaching of nitrogen into the groundwater. Therefore, the present paper deals with the correlation between N emission and scenarios of potential risk assessment on N leaching into groundwater. The airborne N input into an agricultural landscape between the Saxon towns Taucha and Eilenburg (near Leipzig, Saxony) was measured by using the bulk N deposition method, the total atmospheric N deposition method with the ITNI system, and the bark sampling method, by focusing the results on the measurement of N input (punctual and regionalized) and on extrapolations to the risk of N leaching for planning purposes. On the forest measurement point the airborne N input is approximately twice as high as that on the 'open land' measurement point (about 15 kg N ha-1 yr-1). Two scenarios were calculated using different results of N deposition measurements; the measurement methods are described in the paper. For scenario 1, an annual potential N leaching of up to 11.5 kg/ha-1yr-1 could be modelled by using regionalized nitrate-N deposition and ammonium-N deposition data for open land. For scenario 2, because of the much higher measured inputs of 59.7 kg N ha-1yr-1 following the results of the ITNI system, the N discharge is excessively higher with up to 25 kg N ha-1yr-1. Both scenarios have been produced on the basis of a regional N balance with a surplus of 28.8 kg ha-1yr-1 (period 1998-2003) including original data from farms. The regionalization of the total atmospheric N deposition offers a new way to integrate the nowadays-unknown components of the N deposition into the estimation of potential risks of N leaching into the groundwater. The results are of high importance for groundwater protection.

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The sorption potential for SO42- in humus layer samples from field sites along a deposition gradient was determined experimentally in batch experiments. The Freundlich equation was used to quantify the sorption of added SO42- in humus layer samples and to determine site-dependent sorption parameters. SO42- sorption in humus layers is a concentration-dependent process. The linearity of isotherms reveals that SO42- is reversibly bound in the organic surface layer, as long as soil solution concentrations remain above 26 to 44 mg SO42- L-1. Natural isotope variations of sulfur in SO42- were analysed to investigate the degree of sorption of dissolved atmospheric and added SO42-. Both sulfate species differed significantly in their isotope composition. The pattern of delta(34)S values for SO42- in all equilibrium solutions confirm the findings from sorption isotherms, showing a close relationship between the sulfur isotope ratios of SO42- in soil solutions and the amount of SO42- sorbed at the humus layer matrix. Stored atmospheric SO42- in humus layers is released at sites where sulfate concentration in throughfall drops below 26 mg SO42- L-1. Concentration of soluble Fe decreased with increasing sulfate sorption, thus supporting the assumption that active Fe for example is important. Iron probably stabilizes the reactive surface of humus complexes and therefore has a positive influence on the SO42- sorption in humus layers.

The natural isotope composition (delta(34)S and delta(18)O values) of sulfate (SO42-) was determined in humus layers and needles from adult Scots pine stands at three sites between 1993 and 2001, which differed markedly regarding both mean SO2 concentrations and annual mean throughfall rates of SO42--S (Neuglobsow

Multivariate statistical methods were used to analyse the vitality of Scots pines (Pinus sylvestris L.) by means of various biochemical, physiological, and nutritional characteristics, irrespective of tree age and without site-specific information. The vitality model was developed in three steps. First, artificial neural networks were used to select a minimal set of biomarkers as input variables with respect to the output variable circular surface increment (regression problem). In the second step, vitality states were classified by using the selected biomarkers (cluster analysis). Finally, discriminant analysis was applied to assign Scots pines to one of four classified vitality states. Sulfate sulfur (SO42--S), non-protein-nitrogen (NPN), arginine (Arg), and chlorophylla (Chla) proved to be the best dynamic input variables to reliably determine the vitality of Scots pines. As the results of regression problem solutions showed, the optimized neural network found growth responses to the driving variables that are valid for both young and mature pine stands. However, the sensitivity analysis of the neural network also indicated that of the four variables, sulfate is the least sensitive. Nevertheless, the sulfate response of the network can be successfully used to analyze the specific effects of multiple exposure on the vitality of Scots pines. To summarize final vitality model enables the vitality of Scots pines to be evaluated without reference to tree age or knowing the specific forest conditions.

Measurements of the radon concentration in a column (1 m2 x 2 m) consisting of a homogenous mixture of dry sand and uranium tailings have been performed to obtain information on the radon transport under well defined conditions. The dependence of the radon concentration has been exclusively studied on the soil/air temperature gradient and on the wind speed. The soil moisture content has been kept constant. Significant diurnal variations of the radon concentration were detected in the uppermost soil layer and at the soil/air interface. Such a behavior was not found in 30 cm and deeper soil layers. It is argued that the diurnal radon variation in the uppermost soil layer is mainly associated with the diurnal inversion of the soil/air temperature gradient giving rise to a convective soil gas migration additional to the common upward diffusion processes, whereas the diurnal variation of the radon concentration at the soil/air interface is caused by the interplay of the temperature gradient and the wind speed. No impact of atmospheric pressure variations on the radon migration has been observed.

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Scots pine (Pinus sylvestris L.) bark samples were collected at two field sites (Neuglobsow, Rösa) and in different years between 1987 and 1996 in the east of Germany. The barks were analyzed with respect to the following inorganic and organic substances: Al, As, B, Ca, Cd, Ce, Cr, Cu, Fe, Hg, Mo, NH4 +, Ni, NO3-, PO43-, Pb, Sr, SO42-, Ti, V, W, Zr, Zn, benzo(a)pyrene, fluoranthene, pyrene, a-hexachlorocyclohexane (a-HCH) and dichlorodiphenyltrichloroethane (DDT). In addition to bark samples from the site Rosa, 53 test sites were investigated in the Nature Park Dübener Heide. Here, the analysis of the barks aimed at discovering spatial patterns of the abovementioned substances. Since 1991, most of the determined substances (e.g. sulfate, nitrate, calcium, lead, benzo(a)pyrene, a-HCH) show decreased concentration values in bark samples from both sites. Temporal variations reflect substantial infra-structural changes in eastern Germany, especially at Rosa and in the industrial region around the cities Leipzig, Halle, and Bitterfeld. Moreover, nitrate concentrations in barks are increasing since 1995. The trend can be explained with increased nitrogen emissions from motor traffic and livestock farms. Spatial patterns of sulphate and ammonia reflect inputs from power plants and agriculture in pine stands of the Nature Park Dübener Heide. The results show that barks of pine trees can be used as biomonitoring tools to indicate and characterize depositions of airborne organic and inorganic pollutants.

A total of 273 pine bark samples collected from various pine stands in Central and East Germany, South Norway, Poland, and Russia was analyzed with respect to 20 inorganic and organic substances (sulphate, nitrate, ammonia, calcium, 3 PAHs, 5 heavy metals, 9 other elements). Multivariate statistics were applied to characterize the multiple exposure of airborne pollutants in terms of major sources, deposition types and impact levels. The former was studied with factor analysis, whilst the latter two were addressed by applying cluster and discrimination analysis. Factor analysis of the concentration values suggest separation into three factors with the following characteristics: Factor 1 shows higher contributions from sulphate and calcium, factor 2 from fluoranthene, benzo(a)pyrene as well as from pyrene, and factor 3 from nitrate and ammonia, respectively. According to results from the cluster analysis, three major deposition types can be identified: "Industry and House heating", "Motor traffic", and "Agriculture". The first deposition type is characterized by high contents of sulphate and calcium. The other two deposition types contain specific composition profiles for nitrogen-containing components and PAHs. Impact levels are separately classified with the characteristic variables of main deposition types. Finally, discriminant analysis is used to allocate new bark samples to the classified deposition types and impact levels. The results demonstrate the usefulness of multivariate statistical techniques to characterize and evaluate multiple exposure patterns of airborne pollutants in forest ecosystems.

Scots pine (Pinus sylvestris L.) bark samples were collected at two field sites (Neuglobsow, Rösa) and in different years between 1987 and 1996 in the east of Germany. The barks were analyzed with respect to the following inorganic and organic substances: Al, As, B, Ca, Cd, Ce, Cr, Cu, Fe, Hg, Mo, NH4 +, Ni, NO3-, PO43-, Pb, Sr, SO42-, Ti, V, W, Zr, Zn, benzo(a)pyrene, fluoranthene, pyrene, a-hexachlorocyclohexane (a-HCH) and dichlorodiphenyltrichloroethane (DDT). In addition to bark samples from the site Rosa, 53 test sites were investigated in the Nature Park Dübener Heide. Here, the analysis of the barks aimed at discovering spatial patterns of the abovementioned substances. Since 1991, most of the determined substances (e.g. sulfate, nitrate, calcium, lead, benzo(a)pyrene, a-HCH) show decreased concentration values in bark samples from both sites. Temporal variations reflect substantial infra-structural changes in eastern Germany, especially at Rosa and in the industrial region around the cities Leipzig, Halle, and Bitterfeld. Moreover, nitrate concentrations in barks are increasing since 1995. The trend can be explained with increased nitrogen emissions from motor traffic and livestock farms. Spatial patterns of sulphate and ammonia reflect inputs from power plants and agriculture in pine stands of the Nature Park Dübener Heide. The results show that barks of pine trees can be used as biomonitoring tools to indicate and characterize depositions of airborne organic and inorganic pollutants.

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A total of 273 pine bark samples collected from various pine stands in Central and East Germany, South Norway, Poland and Russia was analyzed with respect to 20 inorganic and organic substances (sulphate, nitrate, ammonia, calcium, 3 PAHs, 5 heavy metals, 9 other elements). Multivariate statistics were applied to characterize the multiple exposure of airborne pollutants in terms of major sources, deposition types and impact levels. The former was studied with factor analysis, whilst the latter two were addressed by applying cluster and discrimination analysis. Factor analysis of the concentration values suggest separation into three factors with the following characteristics: Factor 1 shows higher contributions from sulphate and calcium, factor 2 from fluoranthene, benzo(a)pyrene as well as from pyrene, and factor 3 from nitrate and ammonia, respectively. According to results from the cluster analysis, three major deposition types can be identified: 'Industry and House heating', 'Motor traffic' and 'Agriculture'. The first deposition type is characterized by high concentrations of sulphate and calcium. The other two deposition types are contain specific composition profiles for nitrogen-containing components and PAHs. Impact levels are separately classified with the characteristic variables of main deposition types. Finally, discriminant analysis is used to allocate new bark samples to the classified deposition types and impact levels. The results demonstrate the usefulness of multivariate statistical techniques to characterize and evaluate multiple exposure patterns of airborne pollutants in forest ecosystems.

A total of 273 pine bark samples collected from various pine stands in Central and East Germany, South Norway, Poland, and Russia was analyzed with respect to 20 inorganic and organic substances (sulphate, nitrate, ammonia, calcium, 3 PAHs, 5 heavy metals, 9 other elements). Multivariate statistics were applied to characterize the multiple exposure of airborne pollutants in terms of major sources, deposition types and impact levels. The former was studied with factor analysis, whilst the latter two were addressed by applying cluster and discrimination analysis. Factor analysis of the concentration values suggest separation into three factors with the following characteristics: Factor 1 shows higher contributions from sulphate and calcium, factor 2 from fluoranthene, benzo(a)pyrene as well as from pyrene, and factor 3 from nitrate and ammonia, respectively. According to results from the cluster analysis, three major deposition types can be identified: "Industry and House heating", "Motor traffic", and "Agriculture". The first deposition type is characterized by high contents of sulphate and calcium. The other two deposition types contain specific composition profiles for nitrogen-containing components and PAHs. Impact levels are separately classified with the characteristic variables of main deposition types. Finally, discriminant analysis is used to allocate new bark samples to the classified deposition types and impact levels. The results demonstrate the usefulness of multivariate statistical techniques to characterize and evaluate multiple exposure patterns of airborne pollutants in forest ecosystems.

The large surface area of barks from many tree species enables the effective accumulation of pollutants. Therefore, the analysis of bark material will provide useful information about the degree of pollution of a certain region. The determination of main, minor, and trace elements (Al, Ca, Cd, Ce, Cr, Cu, Fe, Mn, P, Pb, S, Ti and Zn) in bark was performed with an Nd:YAG laser coupled to an ICP-MS system. Bark standards for the calibration by laser ablation ICP-MS were prepared from different bark layers which differ for some relevant elements in concentrations. Four digestion procedures for the decomposition of the standard pellets, the numbers of laser shots per sample and of samples per region necessary have been investigated. Representative results were obtained for 5 or more samples taken from different individuals of one species of a sampling area and the averaged element concentrations of 10 separately placed laser shots for each sample. Laser ablation ICP-MS was applied for the characterization of real bark samples from different regions with high and low pollution burden. It was shown that the method is well suited to characterize different degrees of environmental impact. Anthropogenic sources were responsible for the higher concentrations of most of the elements under investigation.

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The depositions of airborne pollutants (SO2, NOx, SO42-, NO3, NH4+) on old pine stands is studied at three differently polluted locations (Neuglobsow, Taura, Rösa) by means of various effect parameters (biomarkers) of the C-, N-and S-metabolism and of the antioxidative decontamination system. The findings (hark analysis) concerning multiple contamination show that between 1991 and 1997 the input of sulphate at all three locations significantly decreased. A comparable trend was also found for ammonium and nitrate until the mid-1990s. However, the input of N has significantly risen in pine stands since 1995 and is becoming the main form of deposition contamination in the forest ecosystems in the lowlands of north-eastern Germany. The differences between the locations and the changes over time of depositions are clearly reflected in the reactions of the biomarkers. The sulphate levels in the needles correlate especially closely with the changes in the SO2 concentration in the ambient air. By contrast, the levels of the soluble non-protein-N (NPN) fraction and the parameters of biomarkers of related metabolic areas (phosphoenolpyruvate carboxylase, glucose, organic phosphor fraction, glucathione reductase) underwent low or no change over time. Using multivariate statistical models (factor analysis, cluster analysis, discriminance analysis), close relations are detected between various biomarkers, and the pines' vitality states are characterised depending on the multiple pollution situation.

Scots pine (Pinus sylvestris L.) bark samples were collected at two field sites (Neuglobsow, Rosa) and in different years between 1987 and 1996 in the east of Germany. The barks were analyzed with respect to the following inorganic and organic substances: Al, As, B, Ca, Cd, Ce, Cr, Cu, Fe, Hg, Mo, NH4+, Ni, NO3- PO43-, Pb, Sr, SO42- Ti, V, W, Zr, Zn, benzo[a]pyrene, fluoranthene, pyrene, alpha-hexachlorocyclohexane (a-HCH) and dichlorodiphenyl-trichloroethane (DDT). In addition to bark samples from the site Rosa, 53 test sites were investigated in the Nature Park Dubener Heide. Here, the analysis of the barks aimed at discovering spatial patterns of the above-mentioned substances. Since 1991, most of the determined substances (e.g. sulfate, nitrate, calcium, lead, benzo[a]pyrene, alpha-HCH) show decreased concentration values in bark samples from both sites. Temporal variations reflect substantial infra-structural changes in eastern Germany, especially at Rusa and in the industrial region around the cities Leipzig, Halle, and Bitterfeld. Moreover, nitrate concentrations in barks are increasing since 1995. The trend can be explained with increased nitrogen emissions from motor traffic and livestock farms. Spatial patterns of sulphate and ammonia reflect inputs from power plants and agriculture in pine stands of the Nature Park Dubener Heide. The results show that barks of pine trees can be used as biomonitoring tools to indicate and characterize depositions of airborne organic and inorganic pollutants.

Fluorescence measurements were carried out with the ground-based DLidaR-2 of the German Aerospace Center (DLR) in October 1994 on pine trees (Pinus sylvestris L.) located in two differently polluted areas of eastern Germany. The DLidaR-2 instrument is a far-field fluorescence lidar exciting the leaves with a doubled or tripled air-cooled Nd:YAG laser. The lidar is configured as a coaxial system with variable beam divergence in front of the receiving telescope. The detection unit is set up with several channels equipped with sensitive photomultiplier and interference and blocking filters for spectral separation. At two test sites (Neuglobsow, Rösa) as part of the SANA project, five areas including three groups with five pine trees were selected for the fluorescence lidar measurements. At each area twigs in the upper crown of the 15 selected trees were cut. The young needles (first needle age class) were prepared for pigment analysis (chlorophyll a and b), nutrition element analysis (e.g., Mg, K) and for the determination of biochemical parameters (e.g., reduced glutathione—GSH; glutathione reductase—GLR; superoxide dismutase—SOD, and soluble protein—PROT). Additional tip necroses were estimated for both needle age classes. The results show that the current year’s needles from the polluted site (Rösa) contain more SO4–S and antioxidants than those from the reference area (Neuglobsow). For both test sites a correlation between the detoxification enzyme SOD and the chlorophyll fluorescence ratio (F685/F730) is observed as well as for chlorophyll a and b concentration and the chlorophyll fluorescence ratio . The blue-green fluorescence ratio (F440/F520) is also correlated with damage symptoms as, for example, the needle damage index , which is derived from visual inspection of the needles. Taking into account that the fluorescence lidar measurements present an average over different twigs and needles of differen

The activity of glutathione S-transferase (GST, EC 2.5.1.18) was determined in needles from Scots pines (Pinus sylvestris L.) obtained from two polluted field sites. Substantial differences were found between the two sites' samples regarding the levels of soluble protein and the total GST activity in the crude extracts. GST was purified more than 90-fold using ammonium sulphate precipitation, gel filtration and affinity chromatography, resulting in 15 % recovery. The purified enzyme of both sites had a pH optimum between 7.75 and 8.0 and showed high specificity for, 1-chloro-2,4-dinitro-benzene (CDNB) as substrate while activities with 1,2-dichloro-4-nitrobenzene (DCNB) were much lower. The approximate molecular weight was determined as 54 kDa for the native enzyme and 26 kDa for the subunits. The enzyme of the two sampling sites differed in their affinity for glutathione and CDNB.

Within a series of regular projects investigating the suitability of biochemical parameters as biomarkers for the early recognition of environmental pollution, the levels of selected phenolic compounds were determined in Scots pine needles (Pinus sylvestris L.) from young and adult trees at three field sites with different SO2 pollution (Rosa>Taura>Neuglobsow). Young trees showed no differences in the levels of soluble phenolics in case of increasing loads of SO2, whereas the concentration of the soluble phenolic component catechin in previous needles of adult trees altered significantly. In current year's needles, differences were only found in the presence of high SO2 deposition. In contrast to catechin, picein and total phenolics remained unaffected. The concentration of catechin in the previous year's needles of adult trees correlated positively with needle necroses. The phenolic components of the cell walls of pine needles were also analysed. The main phenolic compounds were identified as p-coumaric acid and ferulic acid. Differences in the levels of p-coumaric acid were detected in the needles of adult trees between the three sites, with the highest levels being measured at the site with the lowest pollution (Neuglobsow). However, changes in the p-coumaric acid content in young trees were low. No site-related differences were found regarding ferulic acid in adult and young pines. The findings are discussed and compared with data reported in the literature.

METEOR expedition M34 was carried out as part of the long-range investigations being pursued under the Special Research Project (SFB) No. 261, for the reconstruction of mass budget and current systems in the South Atlantic during the Late Quaternary. On METEOR cruise M34 samples and data were recovered from the upwelling region off Namibia, the central South Atlantic, and off North Brazil and Barbados. The cruise consisted of four legs, starting in Cape Town on January 3, 1996, and ending at Barbados on April 15, 1996. During the first leg, seismic and echographic measurements along a series of profiles as well as the sampling of surface sediments in the Cape Basin area was performed. These investigations provide basic information for a deep coring operation by the international Ocean Drilling Program, which is being prepared for by the University of Bremen. The main objective of the second leg was to investigate the biogeochemical processes in sediments of the upwelling area off Namibia. The scientific groups of the Max-Planck-Institut for Marine Microbiology and the Department of Geoscience of the University of Bremen worked closely together to produce new data for the biogeochemical reaction rates. On the third leg sediment cores were receovered to supplement the sample materials of SFB 261 in the central South Atlantic. Core-station profiles were taken from the Angola Basin to the Mid-Ocean-Ridge, and from there into the Brazil Basin. This cruise served also as a continuation of the investigations of the Institut für Meereskunde Kiel and the Traceroceanography of the University of Bremen, which are studying the spread of bottom water on the southern edge of the Brazil Basin, and determining temporal changes in the chlorofluoromethane content of the water, respectively. Three signal generator moorings were also recovered. The main objective of the fourth leg was to determine the seasonal particle sedimentaton in the western equatorial Atlantic and to extend the i

METEOR expedition M34 was carried out as part of the long-range investigations being pursued under the Special Research Project (SFB) No. 261, for the reconstruction of mass budget and current systems in the South Atlantic during the Late Quaternary. On METEOR cruise M34 samples and data were recovered from the upwelling region off Namibia, the central South Atlantic, and off North Brazil and Barbados. The cruise consisted of four legs, starting in Cape Town on January 3, 1996, and ending at Barbados on April 15, 1996. During the first leg, seismic and echographic measurements along a series of profiles as well as the sampling of surface sediments in the Cape Basin area was performed. These investigations provide basic information for a deep coring operation by the international Ocean Drilling Program, which is being prepared for by the University of Bremen. The main objective of the second leg was to investigate the biogeochemical processes in sediments of the upwelling area off Namibia. The scientific groups of the Max-Planck-Institut for Marine Microbiology and the Department of Geoscience of the University of Bremen worked closely together to produce new data for the biogeochemical reaction rates. On the third leg sediment cores were receovered to supplement the sample materials of SFB 261 in the central South Atlantic. Core-station profiles were taken from the Angola Basin to the Mid-Ocean-Ridge, and from there into the Brazil Basin. This cruise served also as a continuation of the investigations of the Institut für Meereskunde Kiel and the Traceroceanography of the University of Bremen, which are studying the spread of bottom water on the southern edge of the Brazil Basin, and determining temporal changes in the chlorofluoromethane content of the water, respectively. Three signal generator moorings were also recovered. The main objective of the fourth leg was to determine the seasonal particle sedimentaton in the western equatorial Atlantic and to extend the i