Morphological investigation and physical characterization of ancient fragments of pyrogenic carbon

4th Young Researcher Meeting, Trieste 2013

Pusceddu, E.^1 ; Criscuoli, I.^2 ; Miglietta, F.^1,2

Istituto di Biometeorologia Del Consiglio Nazionale Delle Ricerche, IBIMET CNR, Via Giovanni Caproni, 8, 50145 Firenze, Italy^1

FoxLab., Fondazione E. Mach, via E. Mach 1, 38010 S. Michele all'Adige (TN), Italy^2

关键词: Abiotic oxidations;    Carbon decomposition;    Carbon mitigation;    Climate mitigations;    Incubation time;    Morphological features;    Physical characterization;    Time-scales;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/470/1/012003/pdf
DOI  :  10.1088/1742-6596/470/1/012003

来源: IOP

【 摘 要 】

In the latest years, the attention toward the use of pyrogenic carbon as a climate mitigation strategy has increasingly grown. Biochar (BC) contains substantial amount (60-90%) of pyrogenic carbon, which is a recalcitrant material and it is hardly decomposed by biotic and abiotic oxidation. The carbon mitigation potential of biochar is associated to the fact that carbon is not easily released back into the atmosphere, even after very long incubation time in the soil. Several studies have been addressing the understanding of the fate of pyrogenic carbon in the soil in a quantitative way, but only a few actually considered materials that were produced in the past and they were not fully able to estimate the fraction of carbon that was oxidized on centennial time scales. In this paper, an old deposits of biochar in soils of the Eastern Alps (Trentino, Val di Pejo) was dated at 1859 by means of a dendroanthracological approach. Carbon decomposition in those soils was then investigated to calculate the fraction of carbon that was lost over 155 years. Part of this study is focused on the morphological and physical characterization of several fragments of biochar, using a scanning electron microscope (SEM). Such study enabled the identification of specific morphological features of tracheids in the old biochar, which were tentatively associated to a differential oxidation of the structures that were created during carbonization from lignin and cellulose.