Contrasting downed woody debris dynamics in managed and unmanaged northern hardwood stands

2008 ◽  
Vol 38 (11) ◽  
pp. 2850-2861 ◽  
Author(s):  
Mark C. Vanderwel ◽  
Hilary C. Thorpe ◽  
Jennifer L. Shuter ◽  
John P. Caspersen ◽  
Sean C. Thomas
Keyword(s):  
Matrix Model ◽  
Woody Debris ◽  
Fruiting Bodies ◽  
Northern Hardwood ◽  
Decay Class ◽  
Species Type ◽  
Downed Woody Debris ◽  
Cut Surface ◽  
Selection Silviculture

The reported effects of selection silviculture on downed woody debris (DWD) vary. To investigate the processes underlying potential management impacts on DWD stocks and fluxes, we conducted a repeated census of downed wood in selection-harvested, selectively harvested, and unmanaged (old-growth) stands in central Ontario. DWD was significantly more abundant in stands harvested within the last 20 years than in stands harvested earlier, and shifted towards more advanced decay classes over the first 20 years after harvest. These results are consistent with persistence of a harvest-related DWD pulse for up to two decades in managed stands. The transition of DWD from early and middle decay classes to more advanced decay classes proceeded more slowly in managed than unmanaged stands. Species type, identity of fungal fruiting bodies, presence of a cut surface, and plot moisture class were significant predictors of variation in decay dynamics within particular decay classes; however, these factors did not account for observed differences in decay-class transitions between managed and unmanaged stands. A decay class matrix model projected DWD half-lives of 19 years for unmanaged stands and 21 years for managed stands. Over the long term, slower decay dynamics may help somewhat in maintaining relatively high DWD abundances in stands managed under selection silviculture.

The effects of variable retention forestry on coarse woody debris dynamics and concomitant impacts on American marten habitat after 27 years

2020 ◽  
Vol 50 (9) ◽  
pp. 925-935 ◽  
Author(s):  
Ingrid Farnell ◽  
Ché Elkin ◽  
Erica Lilles ◽  
Anne-Marie Roberts ◽  
Michelle Venter
Keyword(s):  
Coarse Woody Debris ◽  
Woody Debris ◽  
Multiple Use ◽  
Mammal Species ◽  
American Marten ◽  
Habitat Features ◽  
Decay Class ◽  
Retention Forestry ◽  
The Impact

Coarse woody debris (CWD) in the form of logs, downed wood, stumps and large tree limbs is an important structural habitat feature for many small mammal species, including the American marten (Martes americana). At a long-term experimental trial in northern temperate hemlock-cedar forests of British Columbia, Canada, we analysed the impact of varying amounts of overstory basal area retention: 0% (clearcut), 40%, 70%, and 100% (unharvested) on CWD volume, decay class, and inputs from windthrow over 27 years. We used CWD attributes (diameter, length, decay class, and height above the ground) known to be favourable for martens to create an index for assessing the impact of harvesting intensity on CWD habitat features. Stands with 70% retention had CWD attributes that resulted in CWD habitat features similar to unharvested stands. Clearcuts contained pieces that were smaller, more decayed, and closer to the ground, which contributed to a habitat that was less valuable, compared with stands that had higher retention. Over the 27-year period, windthrown trees were the majority of CWD inputs, and volume change was positively related to percent retention. Our results highlight that forest management influences CWD size and input dynamics over multiple decades, and the need for consideration of these impacts when undertaking long-term multiple-use forestry planning.

Contributions of harvest slash to maintaining downed woody debris in selection-managed forests

2010 ◽  
Vol 40 (8) ◽  
pp. 1680-1685 ◽  
Author(s):  
Mark C. Vanderwel ◽  
Hilary C. Thorpe ◽  
John P. Caspersen
Keyword(s):  
Size Distribution ◽  
Woody Debris ◽  
Basal Area ◽  
Managed Forests ◽  
Projection Model ◽  
Permanent Sample Plots ◽  
Decay Class ◽  
Class 1 ◽  
Selection Harvesting ◽  
Downed Woody Debris

Harvest slash can represent a major source of downed woody debris (DWD) in selection-managed forests. In this study, we analyze the volume, cover, size distribution, and decay-class distribution of DWD input by selection harvesting in central Ontario, Canada. Selection harvesting input 23.9 m3 DWD·ha–1 (0.013 m2 DWD·m–2), with cut basal area explaining 46% and 30% of the respective within-stand variation in cover and volume, respectively. The size distribution of the slash was similar to that of DWD in permanent sample plots (including old-growth stands and stands that have not been recently harvested), countering a common assumption that harvesting inputs only small-sized material. Harvest-origin DWD was bimodally distributed across decay classes, with the first peak (decay class 1) associated with fresh harvest slash and a second smaller peak (decay class 3) likely representing dead trees and branches that were felled or broken during harvest operations. A matrix projection model showed that slash can maintain DWD levels in managed, uneven-aged stands comparable with those in unmanaged stands, but the mean decay class increases steadily over a 20-year period after harvest. Our results underline the importance of harvest inputs for maintaining DWD pools in selection-managed forests and provide baseline information against which to compare forests managed with higher utilization standards.

Estimates of downed woody debris decay class transitions for forests across the eastern United States

2013 ◽  
Vol 251 ◽  
pp. 22-31 ◽  
Author(s):  
Matthew B. Russell ◽  
Christopher W. Woodall ◽  
Shawn Fraver ◽  
Anthony W. D’Amato
Keyword(s):  
United States ◽  
Woody Debris ◽  
Eastern United States ◽  
Decay Class ◽  
Downed Woody Debris

Long-term snag and downed woody debris dynamics under periodic surface fire, fire suppression, and shelterwood management

2009 ◽  
Vol 39 (9) ◽  
pp. 1709-1721 ◽  
Author(s):  
Mark C. Vanderwel ◽  
Jay R. Malcolm ◽  
Sandy M. Smith
Keyword(s):  
Coarse Woody Debris ◽  
Fire Suppression ◽  
Woody Debris ◽  
Periodic Surface ◽  
Surface Fire ◽  
Harvest Residues ◽  
Partial Harvesting ◽  
Fire Scenarios ◽  
Downed Woody Debris

There are pronounced differences in the processes that act to determine the type and amount of standing and downed coarse woody debris present under partial harvesting versus other noncatastrophic disturbances. To evaluate long-term differences in snag and downed woody debris (DWD) dynamics, we developed a simulation model to project snag density and DWD volume by size and decay class in white pine ( Pinus strobus L.) and red pine ( Pinus resinosa Ait.) dominated stands under (i) a high-retention shelterwood system, (ii) periodic surface fire, and (iii) fire suppression. Snag densities under a high-retention shelterwood system were consistently lower than those in the fire-suppression and surface-fire scenarios, even if no large snags were felled at the time of harvest. Regular inputs from harvest residues were important in maintaining the total volume of DWD, but this material tended to be concentrated in a narrow range of decay classes at any given time. Preserving existing DWD at harvest was less influential than the level of inputs from harvest residues. Active measures for snag creation and staggering of harvest stages among adjacent stands may help minimize differences in the overall supply and temporal variation of coarse woody debris between managed and both naturally disturbed and old-growth stands.

An integrated model for snag and downed woody debris decay class transitions

2006 ◽  
Vol 234 (1-3) ◽  
pp. 48-59 ◽  
Author(s):  
Mark C. Vanderwel ◽  
Jay R. Malcolm ◽  
Sandy M. Smith
Keyword(s):  
Woody Debris ◽  
Integrated Model ◽  
Decay Class ◽  
Downed Woody Debris

scholarly journals Long-term effects of timber harvesting on coarse woody debris dynamics and marten habitat

2021 ◽  
Author(s):  
◽  
Ingrid Farnell
Keyword(s):  
Laser Scanning ◽  
Woody Debris ◽  
Timber Harvesting ◽  
Long Term Effects ◽  
Habitat Features ◽  
Airborne Laser ◽  
Decay Class ◽  
Harvesting Intensity ◽  
The Impact

At a long-term experimental trial in northern British Columbia, Canada, I analysed the impact of varying amounts of timber retention: 0% (clearcut), 40%, 70%, 100% (unharvested) on CWD volume, decay class, and inputs from windthrow over 27 years. I used attributes (diameter, length, decay class, and height above the ground) known to be favourable to marten to create an index for assessing the impact of harvesting intensity on CWD habitat features. I then used airborne laser scanning (ALS) to predict CWD volume, habitat value, and piece attributes over the landscape. Stands with 70% retention had CWD attributes that resulted in CWD habitat features similar to unharvested stands. Clearcuts contained pieces that were smaller, more decayed, and closer to the ground, which contributed less valuable habitat, compared to stands with higher retention. Windthrown trees were the majority of CWD inputs and volume change was positively related to percent retention.

A STAGE-BASED MATRIX MODEL FOR DECAY-CLASS DYNAMICS OF WOODY DEBRIS

2002 ◽  
Vol 12 (3) ◽  
pp. 773-781 ◽  
Author(s):  
Nicholas Kruys ◽  
Bengt Gunnar Jonsson ◽  
Göran Ståhl
Keyword(s):  
Matrix Model ◽  
Woody Debris ◽  
Decay Class

scholarly journals Variation in fuel structure of boreal fens

2016 ◽  
Vol 46 (5) ◽  
pp. 683-695 ◽  
Author(s):  
T.J. Schiks ◽  
B.M. Wotton ◽  
M.R. Turetsky ◽  
B.W. Benscoter
Keyword(s):  
Woody Debris ◽  
Front Propagation ◽  
Fuel Load ◽  
Organic Layer ◽  
Fuel Loads ◽  
Boreal Peatlands ◽  
Downed Woody Debris ◽  
Northern Alberta ◽  
Fuel Components

Wildfire frequency and severity in boreal peatlands can be limited by wet fuel conditions, but increases in burn severity can occur when lower water table positions cause drying of fuels. To date, most studies on northern peatland fires have focused on ombrotrophic bogs. Though minerotrophic fens are the most common type of peatland in North America, the influence of fuel structure and loading on potential fire behaviour in boreal fens is poorly understood. To investigate the potential for widespread flame front propagation across boreal fens, we quantified the fuel components present in three generalized boreal fen types (open, shrub, and treed fens) in northern Alberta, Canada. The loadings of aerial fuels, tall shrubs, and downed woody debris varied significantly among fen types. Fuel loads tended to be smallest in the open fens and largest in the treed fens. Open and shrub fens had larger loads of total surface fuels relative to treed fens, with short-statured shrubs being the dominant contributor to surface fuel load. Based on our observations of available fuel loads, each of the fen types may support moderate- to high-intensity fire following long-term drying, which may not only consume some fraction of the aboveground biomass, but also provide a substantial downward pulse of energy to initiate smouldering in the organic layer.

scholarly journals Assessing Coarse Woody Debris Nutrient Dynamics in Managed Northern Hardwood Forests Using a Matrix Transition Model

Ecosystems ◽  
2019 ◽  
Vol 23 (3) ◽  
pp. 541-554
Author(s):  
Adam Gorgolewski ◽  
Philip Rudz ◽  
Trevor Jones ◽  
Nathan Basiliko ◽  
John Caspersen
Keyword(s):  
Coarse Woody Debris ◽  
Nutrient Dynamics ◽  
Woody Debris ◽  
Hardwood Forests ◽  
Transition Model ◽  
Northern Hardwood Forests ◽  
Northern Hardwood
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