caa a22 4500 60551710X CHVBK 20210128100718.0 cr unu---uuuuu 210128e20150301xx s 000 0 eng 10.1007/s10533-014-0051-6 doi (NATIONALLICENCE)springer-10.1007/s10533-014-0051-6 Optimization of method to quantify soil organic matter dynamics and carbon sequestration potential in volcanic ash soils [Elektronische Daten] [Susan Crow, Mataia Reeves, Olivia Schubert, Carlos Sierra] Volcanic ash-derived soils are important globally for their C sequestration potential and because they are at risk of compaction and degradation due to land use change. Poorly or non-crystalline minerals impart enormous capacity for soils to store and stabilize C, but also unusual chemical and physical properties that make quantifying meaningful soil C pools challenging. Here, we optimize a soil physical fractionation method to effectively assess soil organic matter dynamics in volcanic ash soils by first comparing three common methods for Andisols of the same soil series under three land uses. Components of those methods that (1) effectively isolated C pools of different size and turnover and (2) demonstrated potential sensitivity to land use change were then modified for a final, combined method. The isolation of C pools corresponding to fundamental mechanisms of protection within aggregates and organo-mineral control on the stabilization of C, which often function to the extreme in volcanic ash soils, underlie these modifications. Combined application of ultrasonic energy to disrupt aggregates and the removal of light fractions with sequential high density fractionation successfully isolated multiple C pools that ranged in radiocarbon-based turnover time from 7 to 1,011year in the surface 0-15cm of mineral soil in an undisturbed, native forest. Soil C accumulates as a result of high, continuous input that cycles through a transitional (century-scale) organo-mineral pool and then either becomes occluded and protected within aggregates (multiple centuries) or enters a continuum of organo-mineral and non-crystalline mineral-dominated pools (from centuries to millennium-scale). Comparison of relative C pool sizes and C isotope signature among soils from native forest, grazed pasture, and managed Eucalyptus plantation revealed the potential for making accurate, direct measurements of soil C change over time with land use and management change or disturbance regime. Springer International Publishing Switzerland, 2014 Andisol nationallicence Carbon cycle nationallicence Carbon sequestration nationallicence Land use change nationallicence Physical fractionation nationallicence Volcanic ash soil nationallicence Crow Susan Natural Resources and Environmental Management Department (NREM Department), University of Hawaii Manoa, 1910 East-West Road, Sherman Lab 101, 96822, Honolulu, HI, USA aut Reeves Mataia Natural Resources and Environmental Management Department (NREM Department), University of Hawaii Manoa, 1910 East-West Road, Sherman Lab 101, 96822, Honolulu, HI, USA aut Schubert Olivia Natural Resources and Environmental Management Department (NREM Department), University of Hawaii Manoa, 1910 East-West Road, Sherman Lab 101, 96822, Honolulu, HI, USA aut Sierra Carlos Max Planck Institute for Biogeochemistry, Hans Knöll Straβe 10, 07745, Jena, Germany aut Biogeochemistry Springer International Publishing 123/1-2(2015-03-01), 27-47 0168-2563 123:1-2<27 2015 123 10533 https://doi.org/10.1007/s10533-014-0051-6 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10533-014-0051-6 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Crow Susan Natural Resources and Environmental Management Department (NREM Department), University of Hawaii Manoa, 1910 East-West Road, Sherman Lab 101, 96822, Honolulu, HI, USA aut NATIONALLICENCE 700 1- Reeves Mataia Natural Resources and Environmental Management Department (NREM Department), University of Hawaii Manoa, 1910 East-West Road, Sherman Lab 101, 96822, Honolulu, HI, USA aut NATIONALLICENCE 700 1- Schubert Olivia Natural Resources and Environmental Management Department (NREM Department), University of Hawaii Manoa, 1910 East-West Road, Sherman Lab 101, 96822, Honolulu, HI, USA aut NATIONALLICENCE 700 1- Sierra Carlos Max Planck Institute for Biogeochemistry, Hans Knöll Straβe 10, 07745, Jena, Germany aut NATIONALLICENCE 773 0- Biogeochemistry Springer International Publishing 123/1-2(2015-03-01), 27-47 0168-2563 123:1-2<27 2015 123 10533