Long-Term Effect of Prescribed Burning Regimes and Logging on Coarse Woody Debris in South-Eastern Australia

Mitchell Stares,Kristine French,Bradley Law,Luke Collins

doi:10.3390/f9050242

Abstract

Coarse woody debris (CWD) is vital within forest ecosystems for an array of fauna. Forest management practices, such as prescribed burning and logging, influence the creation or loss of CWD. We examined the effect of long-term prescribed burning and logging on (i) the abundance of hollow-bearing CWD, (ii) the volume of CWD in different decay classes, (iii) the probability of hollow presence, and (iv) the size of hollows at a long-term (28 years) experimental site. Volume of CWD in moderate and advanced stages of decomposition decreased with increasing fire frequency while moderately decomposed material was higher in logged plots. The likelihood of a hollow being present increased with diameter and decreased when CWD was extensively charred. Hollow size was smaller when material was externally charred but larger when charring affected a pre-existing hollow. Increases in moderately decayed CWD reflect a pulse input of unmerchantable timber following the one-off logging event 28 years ago, though future loss of mature trees may lead to reduced input rates of woody debris in the future. Charring effects on hollow formation, increasing hollow size but decreasing overall presence, demonstrate the complex effect of fire on this resource. Our research highlights the need to develop a fundamental understanding of CWD input and loss dynamics in response to fire and logging in order to predict changes to this resource under a broad range of management scenarios.

Highlights

Fallen coarse woody debris (CWD) is an important habitat resource for a large range of taxa, including small mammals, birds, reptiles, fungi, and invertebrates [1,2]
Collins et al [9] found a higher likelihood of CWD containing hollows in areas experiencing ‘low’ compared to ‘high’ fire frequencies, though this study examined a mixed regime of both prescribed burning and wildfire in which burning was not experimentally manipulated
The intercept-only model had the lowest AICc for the abundance of hollow-bearing CWD, indicating that there was no effect of fire frequency or logging on abundance

Summary

Introduction

Fallen coarse woody debris (CWD) is an important habitat resource for a large range of taxa, including small mammals, birds, reptiles, fungi, and invertebrates [1,2]. Hollows in CWD are used as shelter and breeding dens by mammals, amphibians, and reptiles [6,7]. Decayed CWD are foraging sites for insectivores and fungivores [1,6], and CWD provides movement pathways for mammals and reptiles [2]. Forest management practices, such as prescribed burning and logging, may create or remove CWD, potentially altering the availability of this resource [8,9,10].

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Conclusion