Date of Award


Document Type

Campus Access Dissertation

Degree Name

Doctor of Philosophy in Forest Science (PhD)

Administrative Home Department

College of Forest Resources and Environmental Science

Advisor 1

Andrew J. Burton

Committee Member 1

Trista Vick-Majors

Committee Member 2

Evan S. Kane

Committee Member 3

Martin F. Jurgensen

Committee Member 4

Carl C. Trettin


Deadwood is a major forest carbon (C) pool, yet, little is known regarding the ultimate amounts of deadwood-derived C moved into labile versus stable soil pools, and as mediated by deadwood type, site conditions and decomposing organisms during decomposition. The lack of information on deadwood-derived C incorporation into soil may negatively impact global C reporting and monitoring. Furthermore, data is lacking on the capacity of tropical forest soils to sequester C despite their recognized role in climate change mitigation. This research provided information on the proportions of wood-derived C moving into labile (FLF), occluded (OCC) and protected (HF) C fractions of surface and subsoils from 13C-labeled trembling aspen, paper birch and loblolly pine logs decomposing in bioclimatically-diverse US forests, and in plots with or without termites, as well as soil C storage for intact and degraded forest cover types in tropical forests of Ghana. During 8 years of log decomposition, early stages of decay led to wood C movement to surface soil labile pools that were vulnerable to further decomposition. However, in the longer term, C moved into more stable HF in both surface and subsoils. During 9 years of decomposition in three bioclimatically diverse sites, log C moving into soil to a 50 cm depth varied by site and species, with greater movement of log C occurring in a warm, moist forest site, and with aspen contributing more C to soil than pine. Though log C primarily resided in surface soil, significant portions were in HF increasing its protection against further decompostion. Wood C movement into soil pools was not greatly affected by subterranean termites, as comparable proportions of log C moved into soil with and without termites at riparian and upland locations. Meanwhile, in the tropics, we found that disturbed or degraded forests of Ghana lose little soil C if forests maintain vegetative cover of some type following disturbance. Overall, this research confirmed deadwood-derived C movement into soil pools, including stable HF, and variation related to deadwood type and site. The outcomes will help refine terrestrial C modeling and inform management efforts seeking to increase soil C sequestration.

Available for download on Saturday, August 31, 2024