Fire and retention island remnants have similar deadwood carbon stock a decade after disturbances in boreal forests of Alberta

Abstract

In an attempt to reconcile wood extraction and forest biodiversity in managed boreal forests, ecosystem-based forest management (EBM) has become the de facto management approach. Retention forestry represents one prominent way that EBM is implemented in many parts of the world. Retention patches commonly left after harvesting serve as analogues of fire island remnants, which are patches of unburned forests in the burned forest matrix. Although the persistence of retention patches has been questioned, few studies have attempted to quantitatively compare forest attributes in both burned and harvested forests. As part of a larger program examining multiple aspects of ecosystem function in fire and harvest island remnants, we investigated the impact of disturbance type (fire/harvest) and forest edges on C stock in snags and coarse woody debris (CWD) found in island remnants in mixedwood boreal forests of Alberta, Canada. Total C stock (in snags and CWD) was similar between the two disturbance types and edge plots had similar total deadwood C stocks to interiors. The edges of island remnants had about two-fold more snag C stock than their interiors in both disturbance types, but C stock in CWD was unaffected by edge effects and disturbance type. Our results suggest that deadwood C dynamics in island remnants in fire and harvest disturbed boreal forests were similar, thus lending support for the continued implementation of retention forestry in Alberta.