Abstract |
- Soil respiration is a major pathway for carbon cycling in terrestrial ecosystems yet little is known about its response to natural and
anthropogenic disturbances. This study examined soil respiration response to prescribed burning and thinning treatments in an old-growth, mixed-conifer
forest on the western slope of the Sierra Nevada Mountains. Experimental treatments were applied in 2001 using a full factorial design
consisting of two levels of burning and three levels of thinning, and included: unburned–unthinned (UN), unburned–overstory thinned (US),
unburned–understory thinned (UC), burned–unthinned (BN), burned–understory thinned (BC), and burned–overstory thinned (BS).We measured
soil respiration rate (SRR), soil moisture (MS), soil temperature (TS), and litter depth (LD) for three replicates of each of three dominant patch types
(closed canopy, open canopy, and ceanothus shrub) within each of the six treatments (n = 54). The same sampling points were measured from May
to August in 2000 (pre-treatment) and in 2002, 2003, and 2004 (post-treatment). Within our sampling period there was as much as 37% variation
(p = 0.0005) between years in the undisturbed patches, which appeared to be driven by changes in precipitation. SRR also varied by year in all
treated plots (US: p = 0.0516; UC: p = 0.0006; BN: p = 0.0158; and BC: p = 0.0040), with the exception of BS (p = 0.3344). SRR response to
disturbance varied with patch type, year, and treatment type. In most cases, burning and the combination of burning and thinning had less of an
effect on mean SRR than thinning alone. Ceanothus patches appear to have recovered fastest, while treatment effects remained 3 years after
thinning in closed canopy (p = 0.0483 and 0.0333 in UC and US, respectively) and open canopy patches (p = 0.0191 in US). Open canopy patches
showed no response to any treatment aside from US. Both UC and US increased SRR in closed canopy and ceanothus patches, and US decreased
SRR in open canopy patches. BS increased SRR in 2004 in closed canopy patches (p = 0.0108), but no significant changes occurred in any patch
type in response to BN or BC treatments. Across all treatments, the relationship of SRR with temperature, moisture, and litter depth changed in
post-disturbance years. The results of this study can be used to help understand how management of Sierran mixed-conifer forests affects soil
carbon sequestration.
- Keywords: patch type, Sierra Nevada, shelterwood, CASPO, thinning, burning, management, Soil CO₂ efflux, interannual variability
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Citation |
- Concilio, A., Ma, S., Ryu, S., North, M., & Chen, J. (2006). Soil respiration response to experimental disturbances over 3 years [Electronic version]. Forest Ecology and Management, 228(1-3), 82-90.
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