Organic matter labile

A fraction of organic C oxidizable with 333 mM KMn04 is another measure of labile organic matter (Blair et al. 1995). This fraction encompasses all those organic components that can be readily oxidized by KMnCL including labile humic material and polysaccharides (Conteh et al. 1999). It commonly accounts for 15-20% of total soil organic C (Blair et al. 1998 Conteh et al. 1998). 

Bending GD, Putland C, Rayns F (2000) Changes in microbial community metabolism and labile organic matter fractions as early indicators of the impact of management on soil biological quality. Biol Fertil Soils 31 78-84... 

At whole lake scales, littoral zones are a major component of autochthonous DOM production and important sources of labile organic matter for aquatic bacteria. Of the approximately one billion lakes in the world, the littoral zone accounts for more than 95% of lake surface area in nearly 99.8% of all lakes (Wetzel, 1983 Fig. 3a). The importance of shallow waters is even more marked when the bounds of lakes are expanded to include wetlands. With such an expanded view, the littoral zone and wetlands comprise more than 95% of the area in 99.999% of all lakes (Fig. 3a). Clearly, shallow waters are a dominant feature of lentic ecosystems. 

Bano, N., M. A. Moran, and R. E. Hodson. 1998. Photochemical formation of labile organic matter from two components of dissolved organic carbon in a freshwater wetland. Aquatic Microbial Ecology 16 95-102. 

Keil, R. G., D. B. Monducon, F. G. Prahl, and J. I. Hedges. 1994. Sorptive preservation of labile organic matter in marine sediments. Nature 370 549-552. 

Figure 6.12. Calculated saturation states with respect to aragonite of marine pore waters undergoing anoxic diagenesis as a function of the original C/N ratio of labile organic matter. The extent of diagenesis is represented by the organic C oxidized in the sediment-pore water system, shown as inorganic carbon added to pore waters.

Borch, N.H., and Kirchman, D.L. (1999) Protection of labile organic matter from bacterial degradation by submicron particles. Aquat. Microb. Ecol. 16, 265-272. 

Hulthe, G., Hulth, S., and Hall, P.O.J. (1998) Effect of oxygen on degradation rate of refractory and labile organic matter in continental margin sediments. Geochim. Cosmochim. Acta 62, 1319-1328. 

Equilibria involving reductive dissolution reactions add to the complexity of mineral solubility phenomena in just the way that pE-pH diagrams are more complicated than ordinary predominance diagrams, like that in Fig. 3.7. The electron activity or pE value becomes one of the master variables whose influence on dissolution reactions must be evaluated in tandem with other intensive master variables, like pH or p(H4Si04). Moreover, the status of microbial catalysis under the suboxic conditions that facilitate changes in the oxidation states of transition metals has to be considered in formulating a thermodynamic description of reductive dissolution. This consideration is connected closely to the existence of labile organic matter and, in some cases, to the availability of photons.26... 

Limited quantitative information is available on the fluxes and reactivity of organic matter in soils and subsurface environments (Figure 6). With concentrations of low molecular weight (labile) organic matter (whether dissolved or solid-associated) in uncontaminated aquifers on the order of ng to p,g L, the rates of... 

---