ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • Articles  (2)
  • Blackwell Science Ltd  (2)
  • 2000-2004  (2)
Collection
  • Articles  (2)
Publisher
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    Oxford, UK; Malden, USA : Blackwell Science Ltd
    European journal of soil science 55 (2004), S. 0 
    ISSN: 1365-2389
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Clear-cutting of forest provides a unique opportunity to study the response of dynamic controls on dissolved organic matter. We examined differences in concentrations, fluxes and properties of dissolved organic matter from a control and a clear-cut stand to reveal controlling factors on its dynamics. We measured dissolved organic C and N concentrations and fluxes in the Oi, Oe and Oa horizons of a Norway spruce stand and an adjacent clear-cutting over 3 years. Aromaticity and complexity of organic molecules were determined by UV and fluorescence spectroscopy, and we measured δ13C ratios over 1 year.Annual fluxes of dissolved organic C and N remained unchanged in the thin Oi horizon (∼ 260 kg C ha−1, ∼ 8.5 kg N ha−1), despite the large reduction in fresh organic matter inputs after clear-cutting. We conclude that production of dissolved organic matter is not limited by lack of resource. Gross fluxes of dissolved organic C and N increased by about 60% in the Oe and 40% in the Oa horizon upon clear-cutting. Increasing organic C and N concentrations and increasing water fluxes resulted in 380 kg C ha−1 year−1 and 10.5 kg N ha−1 year−1 entering the mineral soil of the clear-cut plots. We found numerous indications that the greater microbial activity induced by an increased temperature of 1.5°C in the forest floor is the major factor controlling the enhanced production of dissolved organic matter. Increasing aromaticity and complexity of organic molecules and depletion of 13C pointed to an accelerated processing of more strongly decomposed parts of the forest floor resulting in increased release of lignin-derived molecules after clear-cutting. The largest net fluxes of dissolved organic C and N were in the Oi horizon, yet dissolved organic matter sampled in the Oa horizon did not originate mainly from the Oi horizon. Largest gross fluxes in the Oa horizon (control 282 kg C ha−1) and increased aromaticity and complexity of the molecules with increasing depth suggested that dissolved organic matter was derived mainly from decomposition, transformation and leaching of more decomposed material of the forest floor. Our results imply that clear-cutting releases additional dissolved organic matter which is sequestered in the mineral soil where it has greater resistance to microbial decay.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    European journal of soil science 55 (2004), S. 0 
    ISSN: 1365-2389
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: The sequestration of dung carbon in soil depends on the location and rate at which it is immobilized in soil aggregates. Here C4 dung (δ13C = −16.1‰) or C3 dung (δ13C = −26.8‰) were applied to a temperate permanent pasture C3 soil (δ13C = −27.9‰). Triplicate samples were taken from C3 and C4 dung remaining at the surface, and in the 0–1 and 1–5 cm soil layers in the unamended control and under the C3 and C4 dung patches after 7, 14, 29, 42 and 70 days after the application of the dung. Macroaggregates (≥ 4 mm) at the lower depth (1–5 cm) were mechanically fractionated into surface and core fractions by a combination of shock freezing followed by wet sieving.Neither overall nor differential carbon isotope fractionation occurred in the dung remaining at the surface. The incorporation of C4 dung significantly increased the δ13C content of the 0–1 cm layer of the C3 soil. Dung C sequestration did not exceed 10% for the 0–1 cm layer and was only 20% for the whole soil (0–30 cm) during the 7-day experiment. Only 32–66% of the C from dung in the 1–5 cm layer was sequestered in the aggregates; the major proportion was initially preferentially attached to their surfaces, but incorporated into aggregates within the following 14 days. The majority of dung, however, soon resided between the aggregates, pointing to the important role of the inter-aggregate fraction in short-term C dynamics of dung in this pasture soil.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...