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| Dr. Bruno Glaser |
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Profession:
Address:
Email: |
Food chemist, medical assistant Assistant professor
University of Bayreuth, 95440 Bayreuth Universitätsstr. 30, 95447 Bayreuth ++49-921-552254 ++49-921-552246
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| SS 2002 |
Standortskundliches Geländepraktikum Burgund Seminar Biozide |
3 SWS 1 SWS |
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WS 2002/ 2003 |
Projektübungen Bodenchemie und Bodenschutz Vorbereitungsseminar zu Projektübungen Seminar Bodenchemie und Bodenschutz: Physikochemische Grundlagen Nachbereitungsseminar zum "Standortskundlichen Geländepraktikum Burgund" im SS2002 |
3 SWS 1 SWS 1 SWS 1 SWS
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| SS 2003 |
Standortskundliches Geländepraktikum Burgund Seminar Biochemie der Bodensanierung Praktikum Spezielle Arbeitstechniken Bodenkundliche Geländeübungen |
3 SWS 1 SWS 3 SWS 1 SWS |
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WS 2003/ 2004 |
Projektübungen Bodenchemie und Bodenschutz Vorbereitungsseminar zu Projektübungen Bodenklassifikation Nachbereitungsseminar zum "Standortskundlichen Geländepraktikum Burgund" im SS2003 |
3 SWS 1 SWS 1 SWS 1 SWS |
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1996 |
Kunz
Stefanie (Master thesis): |
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1998 |
Führböter
Maike (Master thesis): |
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2002 |
Schmitt,
Jochen (Master thesis): |
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2002 |
Andreas
Manhart (Master thesis): |
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2002 |
Benker
Angela (Master thesis): |
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2003 |
Richter
Merle (Master thesis): |
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2003 |
Groß
Simone (Master thesis): |
| 1996 - 1999 |
Properties and stability of soil organic matter in Red Indian Black Earths (Terra Preta) (DFG Gu 406/2-1,2) |
| 1998 - 2000 | |
| 1999 |
Reconstruction of the Late Quaternary Glaciation of the Macha Khola valley (Gorkha Himal, Nepal) |
| 2000 - 2002 |
Compound-specific isotope ratios of soil organic matter (DFG Ze 154/46-1) |
| Since 2001 |
Evaluation of soil genesis and soil ertility of the Pamir mountains, Tajikistan (DFG GL XY) |
| Since 2003 |
Assessing turnover rates of soil organic matter by means of compound-specific isotope ratios (d13C) (DFG GL 327/4-3) |
| Since 2003 |
Reconstruction of ancient use of Terra Preta using molecular markers and compound-specific stable isotope ratios (d13C) (DFG GL 327/5-1,2) |
| Since 2003 |
(BMBF) |
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Summary Within
the Oxisol and Ultisol landscape of the Brazilian Amazon region, patches of
highly fertile and sustainably anthropogenic soils, known as Terra Preta occur.
Terra Preta soils are characterised by a large and stable soil organic matter
(SOM) pool and by high stocks of nutrients such as N, P, and Ca. These soils
are favoured by the local farmers because of they enable high crop yields. The
establishment of stable SOM seems to be decisive for the sustainable soil
fertility. Frequent charcoal findings provided evidence that black carbon is
responsible for the SOM stability in these soils. For this reason the main
objective of the current work was to verify if and to which extent black
carbon contributes to SOM of Terra Preta soils. Futhermore organo-mineral and
physical stabilisation of SOM was investigated, accompanied by an assessment
of labile SOM pools and N- and P-availability. Black
carbon was analysed in the fine-earth and in particle-size and density
fractions of Terra Preta soils and surrounding Oxisols with a novel technique
using benzenecarboxylic acids (BCA) as molecular markers for black carbon. The
analytical procedure includes acid digestion, oxidation, sample cleanup,
derivatization, and gas chromatography. BCA were not produced upon oxidation
of model humic substances. SOM
of Terra Preta consists up to 35% of black carbon, which remains as residue
after incomplete burning of biomass. Terra Preta (16 to 122 Mg ha-1
m-1) contains up to 35 times more black carbon than adjacent
Oxisols (3 to 13 Mg ha-1 m-1). More than 50% of black
carbon is located in the silt and clay fraction indicating organo-mineral
complexation. An increase of the black carbon content in the clay fraction
with increasing soil depth indicates leaching. Density fractionation, however,
shows that the highest concentrations and absolute amounts of black carbon are
located in the fraction < 2.0 g cm-3, even in 40 cm soil depth.
This SOM fraction is assumed to be of particulate nature and corroborates the
chemical and biological inertness of black carbon. This favours the theory of
transport by turbation into deeper soil horizons. Another part of
black carbon is involved into organo-mineral complexation. This could
be the reason for the high cation exchange capacities of Terra Preta soils,
although particulate black carbon could be carboxylated also at the surface. A
small part of black carbon is embedded within plaques on the surface of
minerals, isolated with the heavy fraction.
The
high SOM levels in Terra Preta soils promote soil aggregation, which leads to
higher physical protection of SOM in Terra Preta soils compared to surrounding
Oxisol but contributes also higher labile SOM, resulting in higher
mineralization rates in Terra Preta soils. Terra
Preta soils contain 2 to 3 times higher N stocks than adjacent Oxisols. In all
soils, N is predominantly associated with the clay fraction and is mineralised
more slowly but more continuously in Terra Preta soils indicating a more
sustainable N supply than in the Oxisols. By means of wet chemical analysis in
both soil types only 30% of total N could be identified, which consisted of 18
to 25% amino acid N, 4 to 7% amino sugar N and 1 to 2 % inorganic N. P
stocks are 4 to 5 times higher in Terra Preta soils compared to surrounding
Oxisols, which affect the immediately available but also the more stable and
resistant P pools. A predominance of inorganic P indicates fixation to iron
and aluminium oxides. A low contribution of diester-P provide evidence of high
mineralisation rates both in Terra Preta soils and Oxisols. Organic P was
dominated by monoester-P, which is predominantly fixed to iron and aluminium
oxides. A
key factor for the genesis of Terra Preta is the input of large amounts of
black carbon, which improves sustainably the SOM quality by providing a higher
cation exchange capacity. The higher stocks of N, P, and Ca are probably due
to human excrements and biomass accumulation from the surroundings. The
mineralized nutrients could be stored sustainably. Higher biomass production
on Terra Preta soils still result in higher C and N inputs into the topsoil.
Publications
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Summary Changes in soil management practices influence the amount, quality and turnover of soil organic matter (SOM). Our objective was to study the effects of deforestation followed by pasture establishment on SOM quantity, quality and turnover in mountain soils of the Sui Checti valley in the Alay Range, Kyrgyzia. This objective was approached by analysis of total organic C (TOC), N, lignin-derived phenols, and neutral sugars in soil samples and primary particle-size separates. Pasture installation led to a loss of about 30% TOC compared to the native Juniperus turkestanica forests. The pasture soils accumulated about 20% N, due to inputs via animal excrements. Land use change from forest to pasture affected principally SOM bound to silt fraction, observing a higher microbial decomposition in pasture than in forest silt fraction, as indicated by lower yields of lignin and carbohydrates, but also by a more advanced oxidative lignin side chain oxidation and higher values of plant to microbial sugar ratios. The ratio of arabinose to xylose was characteristic for evaluating the replacement of carbohydrates of the original forest by pasture, and we conclude that it can be used as an indicator for deforestation. The accumulation of lignin and its low humification within the forest floor could be due to the extremely cold winter and dry summer climate. Publications
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Reconstruction of the Late Quaternary Glaciation of the Macha Khola valley (Gorkha Himal, Nepal)
Summary In order to reconstruct the late Quaternary glacier fluctuations in the Macha Khola valley (Gorkha Himal, Nepal), geomorphologic and pedologic studies were undertaken. According to the geomorphologic situation, four moraine complexes could be identified. With respect to the results of radiocarbon analyses and relative dating techniques, these moraines indicate historical (< 1,7 Ka BP), Neoglacial (5,5-1,7 Ka BP), Late Glacial (17-10 Ka BP), and Last Glacial Maximum (LGM, 17/18 - 60? Ka BP) glacier advances. No relics of Middle or Early Pleistocene glaciations were found. The LGM glacier advanced to an altitude of at least 2150 m a.s.l. corresponding to an ELA depression of approximately 1300 m. It remains unclear whether the maximum of the Late Pleistocene glaciation occurred during Oxygen Isotope Stage 4 or 2. Our results show that the LGM Macha Khola glacier retreated some time before 15 Ka BP. Between the retreat and 15 Ka BP the vegetation probably consisted of C4 tundra grasses as indicated by d13C values of about –15 ‰. During the Late Glacial the Macha Khola glacier descended to altitudes between 2450 m and 3400 m a.s.l. After ca. 15 Ka BP, the d13C values decreased to about –25 to - 28 ‰ indicating reforestation. The Neoglacial ice advances were much stronger than the historical ones. Dendrochronological data of Abies spectabilis suggested several periods of unfavourable growth conditions which were especially pronounced around 1820 and at the beginning of the 20th century Publications
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Compound-specific stable isotope ratios of soil organic matter (Ze 154/46-1)
Summary The motivation for the determination of compound specific isotope ratios in soil organic matter is based on the fact that in soils and their chemical and physical fractions many different organic substrates for microbes exist. The analysis of stable carbon isotopes (12C, 13C) of such bulk samples results in a mean isotopic signal (d13C) which does not allow a differentiation between labile and stable carbon in organic compounds. To differentiate between differently available C-sources or to recognize specific pathways for the heterotrophic use of these sources, the compound specific analysis of the d13C ratio by means of gas chromatography - combustion - isotope ratio mass spectrometry (GC-C-IRMS) is necessary. Our approach is based on the analysis of the d13C ratio of biomarkers such as lignin phenols, amino acids, amino sugars and benzenecarboxylic acids in soil samples and their physical fractions. In this project we adapted methods developed at the Bayreuth Institute of Soil Science and Soil Geography for the quantification of the above mentioned biomarkers for the analysis of compound specific isotope ratios by means of GC-C-IRMS and identified and eliminated method induced isotope discriminations. Publications
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Evaluation of soil genesis and soil fertility of the Pamir mountains, Tajikistan (GL XY)
Summary The aims of this project are to evaluate a detailed chronology of the Holocene and Pleistocene climate fluctuations in the surroundings of the Fedschenko glacier, the largest glacier of Eurasia by means of soil genetic properties, relative (weathering indices, clay mineralogy) and absolute dating (radiocarbon, cosmogenic nuclides). Additionally, potential and limitation of land-use of the Pamir mountains will be evaluated with special emphasis to agriculture and pasture. This will be achieved by establishing soil maps with general soil fertility parameters as well as nutrient contents of plants and nutrient delivery potential of soil organic matter. Publications
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Assessing turnover rates of soil organic matter by means of compound-specific stable carbon isotope ratios (d13C) (GL 327/4-3)
Summary The aim of this project is the assessment of turnover rates of soil organic matterconstituents by means of compound-specific stable carbon isotope ratio determination (d13C) using Gas Chromatography - Combustion - Isotope Ratio Mass Spectrometry (GC-C-IRMS). In a former project-phase, well established analytical methods for biomarker determination such as lignin, amino acids, benzenepolycarboxylic acids) were optimized for GC-C-IRMS analysis and method-induced isotope fractionation identified and eliminated. In the current project period, special emphasis is made to microbial biomarkers such as phospholipid fatty acids, amino sugars and neutral sugars. A main focus lies on further method optimization, especially the reduction of the foreign-carbon addition during derivatization. The optimized GC-C-IRMS methods will be applied to a set of different experiments working with artificial and natural isotope labeling such as agricultural soils incubated with labeled glucose under controlled conditions, C3 grassland soils incubated with maize slurry in the field. Furthermore, the effects of elevated atmospheric CO2 concentrations on soil organic matter turnover will be evaluated using the Zurich Free Air Carbon dioxide Enrichment facility.
Publications
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Reconstruction of ancient use of Terra Preta using molecular markers and compound-specific stable isotope ratios (d13C) (GL 327/5-1,2)
Summary In Amazonia, nutrient-poor Oxisols and Ultisols predominate which are hardly usable in a sustainable way. However, within this landscape, a mosaic of highly fertile soils occur, known as Terra Preta (do Indio), which are the product of sustainable land management of pre-Columbian Indians. Our previous examinations showed that the high and stable soil organic matter stocks of these soils were decisively attributed to pyrogenen carbon. However, input of nutrient-poor charred residues does not explain the high nutrient contents (particular N, P, about, Mg) of Terra Preta soils. Thus, the goal of the present research project is it therefore, to gain insight into pre-Columbian land-use through small-scale analysis of different phosphorus forms, stable biomarkers and their stable isotope ratios. Especially, one should distinguish between the entry of human and animal excrements as well as between aquatic and terrestrial biomass. From the results of this research, we expect information on the enrichment of Terra Preta with nutrients as well as the heterogeneity of the entry-paths.
Publications
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Summary
The objective of this project is to study the effects of fragmentation on 1) soil biodiversity (structure, function) and 2) soil sustainability. Both are closely correlated. In agreement with the Brazilian and German partners the following habitats, which are the result of fragmentation, will be compared: relics of primary forest, large fragments of secondary forests, small fragments of secondary forests, forest plantations, agricultural land, and hydromorphic sites. The research plots within these habitats will be characterised pedologically, thus contributing to the data bank on the regional abiotic conditions. The data on soil biodiversity and sustainability will be evaluated together with results of other subprojects, in order to model building, recommendations for management practices and land use planning in respect to biodiversity conservation.
Publications
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Zech, W., Barbosa, P. de Camargo, Glaser, B., Schramm, A., Ullrich, T., Bähr, E., Förster, M. Fiedler, S., Schreitmüller, I, Puzzi, P. (2003)
Does fragmentation influence soil biodiversity and thus soil sustainability? Plans for a case study at the Atlantic Plateau of São Paulo (Brazil). In: Sustainable use and conservation of biological diversity. A challenge for society. Report International Symposium 1-4 December 2003, Berlin, 345.