Kooperativer Bibliotheksverbund

Berlin Brandenburg

and
and

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Language: English
    In: Catena, April 2016, Vol.139, pp.9-18
    Description: Riparian woodlands consist of different landscape units characterized by different hydroecomorphological site conditions that are reflected in the distribution of soils and tree species. These conditions are determined by flooding frequency and duration, distance to river channels, elevation and water flow velocity. The influence of these environmental drivers on the stabilization of soil organic matter (SOM) has as yet not been investigated. Hence, the aim of our study is to link soil formation and its drivers with stabilizing processes of SOM in riparian floodplain forests. We investigated soils and sediments at two sites in the ash–maple–elm–oak alluvial forest zone (AMEO sites) and two sites in the willow-poplar alluvial forest zone (WiP sites) within the riparian zone of the Danube near Vienna (Austria). Sediments and soils were characterized based on texture, contents of organic carbon (OC), nitrogen, Fe oxides, and soil pH. Density fractionation was used to separate OC fractions in terms of stabilization process and resulting organic matter (OM) turnover time: the free light fraction (fast turnover), the light fraction occluded in aggregates (intermediate turnover) and the heavy fraction of OM associated tightly to mineral surfaces (slow turnover). At both sites, soil and sediment properties reflect the hydroecomorphological site conditions for formation of the landscape units in the riparian zone: Soils at AMEO sites develop during constant deposition of fine-textured sediment while water flow velocity is low. Progressing soil development causes a continuous decrease in OC content with increasing soil depth, mainly from fractions with fast and intermediate turnover. As a consequence the heavy fraction clearly dominates with around 90% of OC. Temporally variable flooding conditions with occurring turbulences found at WiP sites result in a discontinuous change of soil properties with increasing soil depth. Former topsoil horizons buried by huge amounts of sediments seem to keep the OC fractionation typical for topsoil horizons with extraordinarily high amounts of light fraction OM (free and occluded) representing 20–40% of total OC. The presented results confirm that sedimentation and soil formation are simultaneous processes at AMEO sites. At WiP sites both processes seem uncoupled with alternate phases of sedimentation and soil formation. Thus, the frequent burial of topsoil material formed at WiP sites seems to enable the conservation of unstable organic matter fractions at this part of active floodplains.
    Keywords: Fluvisol Formation ; Soil Organic Matter ; Density Fractionation ; Riparian Floodplains ; Soil Aggregates ; Riparian Forests ; Sciences (General) ; Geography ; Geology
    ISSN: 0341-8162
    E-ISSN: 1872-6887
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Language: English
    In: Hydrology and Earth System Sciences Discussions, 11/30/2018, pp.1-23
    ISSN: Hydrology and Earth System Sciences Discussions
    E-ISSN: 1812-2116
    Source: CrossRef
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Language: English
    In: Plant and Soil, 2018, Vol.427(1), pp.53-69
    Description: Background and aims Phosphorus (P) availability is crucial for forest ecosystem productivity and soil organic matter (SOM) is an important source for P. This study was conducted to reveal carbon (C), nitrogen (N) and P distributions in functional SOM fractions. We hypothesised that (1) most of the organic P (P.sub.org) is part of the particulate SOM, (2) particulate SOM stores increasing share of P with decreasing soil P content and (3) the C:P.sub.org ratio of mineral-associated SOM is smaller than that of particulate SOM. Methods We analysed soil samples from five temperate forest sites (Fagus sylvatica) under different geological parent material with a wide range of total P concentrations. Density fractionation was used to separate free light fraction (fLF), particulate SOM occluded within soil aggregates (occluded light fraction; oLF), and mineral associated SOM (heavy fraction; HF). We determined the mass balance of P in these fractions, in addition to the C and N concentrations. Additionally, the P speciation of the topsoil was analysed by X-ray absorption near edge structure (XANES) spectroscopy at the P K-edge. Results The fLF contained 18-54% and the oLF 1-15% of total P (P.sub.tot). High percentage of P in these light fractions was associated to soil minerals. Phosphorous in particulate SOM within aggregates tend to increase with decreasing soil P. The HF containing mineral-associated OM, comprised 38-71% of P.sub.tot and their C:P.sub.org ratios were consistently lower than those of the fLF irrespective of the P status of the soil. Conclusions We show that all three functional SOM fractions contain variable amount of both organic and inorganic P species. The free light fraction shows no response to changing P stocks of soils.. Despite physically protected particulate SOM, oLF, becomes increasingly relevant as P cache in soils with declining P status.
    Keywords: Ecosystem nutrition ; Density fractions ; Soil organic matter ; C:N:P ratio ; Phosphorus ; P K-edge XANES
    ISSN: 0032-079X
    E-ISSN: 1573-5036
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Language: English
    In: Journal of Plant Nutrition and Soil Science, December 2018, Vol.181(6), pp.894-904
    Description: Sonication is widely used for disruption of suspended soil aggregates. Calorimetric calibration allows for determining sonication power and applied energy as a measure for aggregate disrupting forces. Yet other properties of sonication devices (., oscillation frequency and amplitude, sonotrode diameter) as well as procedure details (soil‐to‐water ratio, size, shape, and volume of used containers) may influence the extent of aggregate disruption in addition to the applied energy. In this study, we tested potential bias in aggregate disruption when different devices or procedures are used in laboratory routines. In nine laboratories, three reference soil samples were sonicated at 30 J mL and 400 J mL. Aggregate disruption was estimated based on particle size distribution before and after sonication. Size distribution was obtained by standardized submerged sieving for particle size classes 2000–200 and 200–63 µm, and by dynamic imaging for particles 45 W). Thus, these sonication device properties need to be listed when reporting on sonication‐based soil aggregate disruption. The overall small differences in the degree of disruption of soil aggregates between different laboratories demonstrate that sonication with the energies tested (30 and 400 J mL) provides replicable results despite the variations regarding procedures and equipment.
    Keywords: Disaggregation ; Particle Size Fractions ; Reproducibility ; Round‐Robin Test ; Ultrasound
    ISSN: 1436-8730
    E-ISSN: 1522-2624
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Language: English
    In: Hydrology and Earth System Sciences Discussions, 05/17/2019, pp.1-24
    ISSN: Hydrology and Earth System Sciences Discussions
    E-ISSN: 1812-2116
    Source: CrossRef
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    In: European Journal of Soil Science, May 2019, Vol.70(3), pp.454-465
    Description: Soil structural traits provide links between soil structure and ecosystem functioning. The size and stability of soil aggregates are assumed to provide information on aggregate formation and turnover. A standard method to analyse these traits is to determine the mass distribution on sieves. The major drawback of this method is the small size resolution because of a small number of size classes. A promising, yet still unexplored, method for size distribution analysis in soil science, is dynamic image analysis, which foremost allows a much larger diameter resolution and the assessment of both size and shape distributions. The aim of our study was to validate the applicability of dynamic digital image analysis in combination with sonication to characterize the size and shape distribution and the stability of aggregates. We used two different heterogeneous reference materials and three different soil samples with different aggregate stabilities to test this method. The soil samples were chosen based on increasing clay, humus and calcium carbonate contents. The method yielded reproducible results for diameter and shape distributions for both reference materials and soil samples. The most important improvement compared to well‐established methods was the extremely large size resolution. This allows specification of the pattern of diameter‐dependent breakup curves by relating them to specific soil properties. The information on sphericity adds supplementary information on the aggregates released. We found much lower sphericity of 1‐mm aggregates mobilized from topsoil samples formed from the activity of living organisms than aggregates mobilized from subsoil samples formed mainly by physicochemical processes. Highlights Our aim was to validate dynamic digital image analysis to characterize soil aggregates.Dynamic image analysis allows high resolution and shape analysis compared to established methods.The method yielded reproducible results for diameter and shape distributions.We established high‐resolution disruption patterns of aggregates enabling new approaches in future research.
    Keywords: Aggregate Breakdown Dynamics ; Particle‐Size Distribution ; Ultrasonic Dispersion
    ISSN: 1351-0754
    E-ISSN: 1365-2389
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Language: English
    In: Geoderma
    Description: Aggregation assembles different size mixtures of soil particles into a larger architecture. Such mixtures impede resolving which particles build aggregates and how these control the accumulation of soil organic matter (OM). Here we present an approach to differentiate the size distributions of soil fractions in the size range of microaggregates (〈250 μm) from their dispersible particle-size distribution using dynamic image analysis. This approach enabled us to differentiate the magnitude and preferential size ranges of aggregates and non-aggregated particles. Wet sieving was used to isolate free microaggregate-sized fractions. Larger soil structures 〉250 μm were sonicated to isolate occluded size fractions 〈250 μm. To investigate the impact of soil texture, we analyzed topsoil samples of an arable site on Cambisol soils with a gradient in clay content of 16–37% and organic carbon concentrations of 10–15 g kg . Our results demonstrate how soil texture governs aggregate size distributions: most water-stable microaggregates were found to be of approximately 30 μm diameter, independent of the clay content gradient. High-clay soils contain more water-stable macroaggregates (〉250 μm) and larger microaggregates in the 50–180 μm size range. The low-clay soils, on the other hand, contained more non-aggregated sand-sized particles 〉100 μm which probably hampered the buildup of larger aggregates. The size distribution of particles 〈100 μm in size fractions 〈250 μm showed a similar prevailing soil texture pattern, with approximately 24% clay, 59% silt, and 17% sand-sized particles at all clay contents. In contrast to the prevailing texture pattern along the clay content gradient, 4% more clay-sized particles helped build up water-stable macroaggregates. In the low-clay soils, the aggregates were smaller and the size fractions 〈53 μm had higher OM concentrations. This indicates that the low-clay soils held most of their OM in smaller microaggregates. Such arrangement of OM in smaller microaggregates demonstrates that soil texture may control OM stabilization mostly indirectly via the distribution of OM in different aggregate fractions. The occlusion of microaggregates in larger structures led to lower alkyl:O/N-alkyl ratios in C nuclear magnetic resonance (NMR) spectroscopy, indicating increased preservation.
    Keywords: Soil Aggregation ; Aggregate Size Distributions ; Soil Texture ; Organo-Mineral Associations ; Dynamic Image Analysis ; Agriculture
    ISSN: 0016-7061
    E-ISSN: 1872-6259
    Source: ScienceDirect Journals (Elsevier)
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Description: Mineral soils in riparian floodplains are known for large organic carbon (OC) stocks in both top and sub soil. Soil forming conditions unique in these landscapes, mainly determined by flooding and sedimentation, contribute to these large stocks compared to other mineral soils in temperate climates. With regard to the position of soils in the carbon cycle, knowledge on stabilization mechanisms for soil organic matter (SOM) in addition to soil OC stocks is crucial to assess the function of riparian floodplain soils as sinks or sources of carbon. In this thesis, both aspects were investigated in the area of the “National Park Donau-Auen” which is one of the biggest remaining near-natural riparian floodplains in central Europe. In the soils sampled in the study area a mean OC stock of 177 t ha-1 was determined and confirms the assumption that riparian floodplain soils are characterized by large OC stocks. Within the study area, soil OC stocks differed with regard to the hydroecomorphological site conditions, which are the result of the site-specific flooding dynamics. These are supposed to change along a gradient with increased distance from the river channel and are indicated by different vegetation types. Sites close to the river dominated by... ; Mineralische Böden in Flussauen sind für ihre hohen Vorräte an organischem Kohlenstoff sowohl im Ober- als auch im Unterboden bekannt. Hierzu tragen die außergewöhnlichen Bedingungen für die Bodenbildung in Flussauen bei. Diese sind maßgeblich bestimmt durch wiederkehrende Überflutung und Sedimentation. In Anbetracht der Funktion von Böden im Kontext des Klimawandels sind Kenntnisse über Stabilisierungsmechanismen von organischer Bodensubstanz neben der Bemessung der Vorräte an organischem Kohlenstoff unabdingbar für die Bewertung von Auenböden in Bezug auf ihre Senken- oder Quellenfunktion für Kohlenstoff. In dieser Arbeit wurden daher beide Aspekte in einer der letzten und größten sowie annähernd natürlich entwickelten Flussauenlandschaft in Mitteleuropa, dem Nationalpark Donau-Auen nahe Wien (Österreich), untersucht. Der mittlere Kohlenstoffvorrat in den untersuchten Böden betrug 177 t ha-1 und bestätigt damit die Annahme, dass sich Böden in Auenlandschaft durch hohe Kohlenstoffvorräte auszeichnen. Innerhalb des Untersuchungsgebietes unterschieden sich die bestimmten Vorräte jedoch in Hinblick auf die jeweiligen hydroökomorphologischen Standortbedingungen, welche von der dort vorherrschenden Überflutungs- und Sedimentationsdynamik bestimmt werden. Es wird weithin angenommen, dass diese sich entlang eines Gradienten mit steigender Entfernung vom Fluss verändern und durch unterschiedliche Standortvegetation angezeigt werden. An Weichholzauenstandorten in Flussnähe wurden im Mittel geringere Kohlenstoffvorräte im Boden (154 t ha-1) festgestellt als an Hartholzauenstandorten (186 t...
    Keywords: Ddc::500 Naturwissenschaften Und Mathematik::550 Geowissenschaften, Geologie::550 Geowissenschaften ; Soil Organic Matter ; Aggregates ; Floodplains ; Ultrasound ; Soil ; Organische Bodensubstanz ; Aggregate ; Flussauen ; Ultraschall ; Boden
    Source: DataCite
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. Further information can be found on the KOBV privacy pages