Park, J-H; Matzner, E: Controls on the release of dissolved organic carbon and nitrogen from a deciduous forest floor investigated by manipulations of aboveground litter inputs and water flux, Biogeochemistry, 66, 265-286 (2003)
Abstract:
Although dissolved organic matter (DOM) released from the forest floor plays a crucial role in transporting carbon and major nutrients through the soil profile, its formation and responses to changing litter inputs are only partially understood. To gain insights into the controlling mechanisms of DOM release from the forest floor, we investigated responses of the concentrations and fluxes of dissolved organic carbon (DOC) and nitrogen (DON) in forest floor leachates to manipulations of throughfall (TF) flow and aboveground litter inputs (litter removal, litter addition, and glucose addition) at a hardwood stand in Bavaria, Germany. Over the two-year study period, litter manipulations resulted in significant changes in C and N stocks of the uppermost organic horizon (Oi). DOC and DON losses via forest floor leaching represented 8 and 11% of annual litterfall C and N inputs at the control, respectively. The exclusion of aboveground litter inputs caused a slight decrease in DOC release from the Oi horizon but no change in the overall leaching losses of DOC and DON in forest floor leachates. In contrast, the addition of litter or glucose increased the release of DOC and DON either from the Oi or from the lower horizons (Oe + Oa). Net releases of DOC from the Oe + Oa horizons over the entire manipulation period were not related to changes in microbial activity (measured as rates of basal and substrate-induced respiration) but to the original forest floor depths prior to manipulation, pointing to the flux control by the size of source pools rather than a straightforward relationship between microbial activity and DOM production. In response to doubled TF fluxes, net increases in DOM fluxes occurred in the lower forest floor, indicating the presence of substantial pools of potentially soluble organic matter in the Oe + Oa horizons. In contrast to the general assumption of DOM as a leaching product from recent litter, our results suggest that DOM in forest floor leachates is derived from both newly added litter and older organic horizons through complex interactions between microbial production and consumption and hydrologic transport. Keywords Dissolved organic carbon, Dissolved organic matter, Dissolved organic nitrogen, Forest floor, Litter manipulation, Resource availability, Water flux
Upcoming ...



BayCEER Colloquium:
Th. 2019-11-28
Rates and Dates in Alpine geosystems - Monitoring and reconstruction of geomorphologic processes
Conferences:
Fr. 2019-11-22 now
Geoökologie-Tagung 2019
Ecological-Botanical Garden:
Su. 2019-11-24
Mikroplastik in der Umwelt
Su. 2019-12-01
Grün motiviert: Pflanzen fürs Büro und Zuhaus
SFB Mikroplastik:
We. 2019-11-27
Microbial Degradation of Plastics: Searching the Needle in the Haystack
BayCEER Blog
24.05.2019
Stoichiometric controls of C and N cycling
07.05.2019
Flying halfway across the globe to dig in the dirt – a research stay in Bloomington, USA
07.05.2019
EGU – interesting research and free coffee
16.04.2019
Picky carnivorous plants?
RSS Blog as RSS Feed
Weather research site
Luftdruck (356m): 964.8 hPa
Lufttemperatur: 5.9 °C
Niederschlag: 0.0 mm/24h
Sonnenschein: 5 h/d
Wind (Höhe 17m): 9.5 km/h
Wind (Max.): 25.6 km/h
Windrichtung: SO

...more
Globalstrahlung: 3 W/m²
Lufttemperatur: 2.7 °C
Niederschlag: 0.0 mm/24h
Sonnenschein: <1 h/d
Wind (Höhe 32m): 18.2 km/h

...more
This site makes use of cookies More information