Aboveground Biomass and Carbon Accumulation 19 Years Post-Windthrow and Salvage Logging

Chris Peterson,Callie Oldfield

doi:10.3390/f12020173

Abstract

Natural disturbances shape forest ecosystem characteristics, including carbon storage and structure. Often, natural disturbances are compounded with anthropogenic disturbances, which may alter the trajectory of forest carbon stock recovery. Heterogeneous levels of disturbance severity in compound disturbance events add an additional layer of complexity. This paper examines the effect of a moderate-severity wind disturbance and subsequent salvage logging on forest biomass and carbon stock recovery over 19 years. We investigate the recovery of aboveground tree biomass following a wind disturbance and salvage logging and examine the role of wind disturbance severity on biomass accumulation rates. We use pre-disturbance, 3 years post-wind disturbance and 19 years post-wind disturbance measurements of tree biomass across two adjacent sites at Natchez Trace State Forest for Site A and Site B in east central Tennessee. We found no significant difference in the carbon storage at Site A (pre = 92 MgC/ha; 19 years post-disturbance = 83 MgC/ha) or Site B (pre = 66 MgC/ha; 19 years post-disturbance = 67) when comparing the pre-disturbance level of aboveground tree carbon storage with the 19-years post-disturbance levels. Furthermore, we found no evidence that salvage logging reduced the rate of live tree carbon accumulation. The corresponding rates of mean annual carbon accumulation (MgC/ha) are as follows: Site A Unsalvaged (1.07), Site A Salvaged (1.25) and Site B Salvaged (2.02). Contrary to our prediction, greater wind damage severity was weakly associated with higher rates of biomass accumulation (R2 = 0.17). While we found no negative effect of salvage logging on the aboveground tree carbon accumulation rate, salvage logging alters other carbon pools, including coarse woody debris. Salvage logging did not reduce the rate of carbon stock recovery, and a higher wind disturbance severity was associated with a greater rate of carbon stock recovery.

Highlights

Forests are major drivers of the global carbon cycle, storing 80% of aboveground terrestrial carbon [1]
While we found no negative effect of salvage logging on the aboveground tree carbon accumulation rate, salvage logging alters other carbon pools, including coarse woody debris
Salvage logging did not reduce the rate of carbon stock recovery, and a higher wind disturbance severity was associated with a greater rate of carbon stock recovery

Summary

Introduction

Forests are major drivers of the global carbon cycle, storing 80% of aboveground terrestrial carbon [1]. Disturbances causing tree damage or mortality can release carbon into the atmosphere, potentially shifting a forest from a carbon sink to a carbon source. It may take decades for a disturbed forest to fully recover to pre-disturbance levels of carbon storage [3,4,5]. Developing an understanding of how changing disturbance patterns, including return time, impact the global carbon cycle is crucial, as forests are increasingly being managed with the goal of offsetting anthropogenic carbon emissions [8,9]

Methods

Discussion

Conclusion