Investigation into the Stabilization of Soil Organic Matter by Microbes

Abstract

A better understanding of below ground carbon (C) flux is of fundamental importance to predict how changing climate will influence the C balance of forest (and other) ecosystems [1]. The root system of higher plants is associated not only with soil environment composed of inorganic and organic matter, but also with a vast community of metabolically active microorganisms. Rhizosphere is the zone of soil immediately surrounding the plant roots, with the microbial population considerably higher than that of root free soil environment. Soil organic carbon pools are often defined either as labile or as recalcitrant, referring to its stability against decomposition of soil organic matter (SOM). We studied the microbial role in production and stabilization of SOM in laboratory setup of column-grown Pinus resinosa mesocosm systems [2], by (a) imaging by light and electron microscopy, with (b) high resolution chemical analysis by Fourier transform ion cyclotron resonance-mass spectroscopy (FTICR-MS), and (c) crystallographic X-ray analyses of the microbially-induced mineral weathering, to determine SOM resistance to decomposing activities.