Recommended Conferences

International Conference on Climate Change Global Warming

Berlin, Germany
Related Subjects
 

Photo-and bio-reactivity patterns of dissolved organic matter from biomass and soil leachates and surface waters in a subtropical wetland

Author(s): Chen M, Jaffé R

Abstract

Dissolved organic matter (DOM) reactivity plays a central role in ecosystem function and the global carbon cycle. In this study, a suite of biomass and soil leachates together with surface water samples from the Florida coastal Everglades (FCE) were investigated to quantitatively assess the photo- and bio-reactivity of DOM via dissolved organic carbon (DOC), ultraviolet–visible absorbance (UV–Vis) measurements, and excitation-emission matrix (EEM) fluorescence combined with parallel factor analysis (PARAFAC). The decomposition patterns observed were diverse, but dominated by first order decay for most of the samples studied. The reactivity rate constants obtained based on a first order multi-pool kinetic model, suggest that the DOM in the Everglades is largely refractory on time scales relevant to this ecosystem (2 months). The relative reactivity of different fluorescent DOM pools determined as labile, semi-labile and refractory were in the order of biomass leachate > soil leachate > surface water. Photo-reactivity was found to be a more important process in controlling the fate of FDOM in this system, while FDOM was mainly refractory to bio-degradation. Degradation patterns and rate constants for samples of different origin displayed vast differences for the same PARAFAC component, suggesting a complex and heterogeneous composition of fluorophores for each component, most likely the result of different structures, speciation and conformation, and molecular weight distribution. In addition, a terrestrial humic-like and two protein-like components were found to have the potential to serve as indicators of photo-degradable and bioavailable DOM.

Similar Articles

Estimating global "blue carbon" emissions from conversion and degradation of vegetated coastal ecosystems

Author(s): Pendleton L, Donato DC, Murray BC, Crooks S, Jenkins WA, et al.

Major role of marine vegetation on the oceanic carbon cycle

Author(s): Duarte CM, Middelburg JJ, Caraco N

Seagrass community metabolism: Assessing the carbon sink capacity of seagrass meadows

Author(s): Duarte CM, Marbà N, Gacia E, Fourqurean JW, Beggins J, et al.

Seagrass sediments as a global carbon sink: Isotopic constraints

Author(s): Kennedy H, Beggins J, Duarte CM, Fourqurean JW, Holmer M, et al.

Distribution of Terrestrially Derived Dissolved Organic Matter on the Southeastern U

Author(s): Moran MA, Pomeroy LR, Sheppard ES, Atkinson LP, Hodson RE

Fluorescence spectroscopy and multi-way techniques

Author(s): Murphy KR, Stedmon CA, Graeber D, Bro R

Limnol Oceanography 50: 686-697

Author(s): Stedmon CA, Markager S  (2005a) Resolving the variability in dissolved organic matter fluorescence in a temperate estuary and its catchment using PARAFAC analysis

Limnol Oceanography 50: 1415-1426

Author(s): Stedmon CA, Markager S (2005b) Tracing the production and degradation of autochthonous fractions of dissolved organic matter by fluorescence analysis