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.

Canada's oldest permanent sample plots — thinning in white and red pine

1998 ◽  
Vol 74 (4) ◽  
pp. 606-616 ◽  
Author(s):  
Darwin Burgess ◽  
Craig Robinson
Keyword(s):  
Woody Debris ◽  
Basal Area ◽  
Wildlife Habitat ◽  
Red Pine ◽  
Major Influence ◽  
Residual Volume ◽  
Annual Increment ◽  
Permanent Sample Plots ◽  
Stand Management ◽  
Set Up

Two of the oldest permanent sample plots (PSPs) in Canada were set up at Petawawa, Ontario (45° 57′ N, 77° 34′ W) to examine the effect of thinning on the development of natural white (Pinus strobus L.) and red pine (Pinus resinosa Ait). Field data were collected periodically, starting in 1918 when the stand was 40 years old and continuing for 71 years. Six thinning treatments were completed, beginning in 1918, and then in 1933, 1941, 1959, 1969 and 1989. The intensity of thinning varied through time with 14, 27, 38, 8, 30, and 7% of the basal area removed. The sawlog volume mean annual increment for the thinned plot remained stable at about five m3 ha−1 yr−1, but the sawlog volume periodic annual increment for the control declined markedly during the last 10-year measurement period to less than 2 m3 ha−1 yr−1. The residual volume was higher in the control; but, if the harvested sawlog volume (264.5 m3 ha−1) was added to the residual sawlog volume (301.3 m3 ha−1) for PSP one, then the sawlog production on the thinned plot has been about the same and its residual volume concentrated on fewer, larger and more valuable trees. The level of natural mortality in the control plot (129.7 m3 ha−1 of sawlog volume) was greater than 10 times that in the thinned plot, thereby adding more coarse woody debris to improve wildlife habitat. These two approaches had a major influence on stand development. The approach used will depend on specific stand-level management objectives. Key words: white pine, red pine, natural stand management, shelterwood system, permanent sample plots.

scholarly journals Erratum

1998 ◽  
Vol 74 (6) ◽  
pp. 811-811 ◽  
Keyword(s):  
Woody Debris ◽  
Basal Area ◽  
Wildlife Habitat ◽  
Red Pine ◽  
Major Influence ◽  
Residual Volume ◽  
Annual Increment ◽  
Permanent Sample Plots ◽  
Stand Management ◽  
Set Up

Two of the oldest permanent sample plots (PSPs) in Canada were set up at Petawawa, Ontario (45° 57′ N, 77° 34′ W) to examine the effect of thinning on the development of natural white (Pinus strobus L.) and red pine (Pinus resinosa Ait.). Field data were collected periodically, starting in 1918 when the stand was 40 years old and continuing for 71 years. Six thinning treatments were completed, beginning in 1918, and then in 1933,1941,1959,1969 and 1989. The intensity of thinning varied through time with 14, 27, 38, 8, 30, and 7% of the basal area removed. The sawlog volume mean annual increment for the thinned plot remained stable at about five m3 ha−1 yr−1, but the sawlog volume periodic annual increment for the control declined markedly during the last 10-year measurement period to less than 2 m3 ha−1 yr−1. The residual volume was higher in the control; but, if the harvested sawlog volume (264.5 m3 ha−1) was added to the residual sawlog volume (301.3 m3 ha−1) for PSP one, then the sawlog production on the thinned plot has been about the same and its residual volume concentrated on fewer, larger and more valuable trees. The level of natural mortality in the control plot (129.7 m3 ha−1 of sawlog volume) was greater than 10 times that in the thinned plot, thereby adding more coarse woody debris to improve wildlife habitat. These two approaches had a major influence on stand development. The approach used will depend on specific stand-level management objectives. Key words: white pine, red pine, natural stand management, shelterwood system, permanent sample plots

Essais de jardinage sans martelage dans des peuplements irréguliers de sapin baumier et d’épinette noire

2010 ◽  
Vol 86 (4) ◽  
pp. 498-510 ◽  
Author(s):  
Jérôme Cimon-Morin ◽  
Jean-Claude Ruel ◽  
Marcel Darveau ◽  
Jean-Martin Lussier ◽  
Philippe Meek ◽  
...  
Keyword(s):  
Black Spruce ◽  
Woody Debris ◽  
Abies Balsamea ◽  
Basal Area ◽  
Shannon Index ◽  
Simplified Approach ◽  
Selection Cutting ◽  
Quadratic Mean Diameter ◽  
Downed Woody Debris ◽  
Index Tree

It is increasingly accepted that silviculture must now try to maintain complex stands. In this context, selection cutting has been suggested as an option for irregular boreal stands. However, selection cutting in virgin stands could prove difficult to apply at a reasonable cost. In an attempt to reduce harvesting costs, two selection cutting patterns were implemented, avoiding tree marking. The efficacy of this approach was evaluated by comparing the results of plots harvested without tree marking to those with tree marking. To proceed in the absence of tree marking, silvicultural types were defined as well as a rule for the selection of stems to harvest; the final choice of stems to fell was therefore left to the operator upon harvesting. The effects of the different silvicultural and tree marking treatments were examined in relation to their ability to maintain the main structural and functional attributes of irregular boreal stands. A follow-up was conducted with regards to structure, composition, residual stand basal area, abundance of woody debris and mortality. The absence of marking did not affect the performance of selection cutting treatments in terms of basal area, quadratic mean diameter and Shannon index. Tree vigour was not modified by harvesting, both with and without tree marking. Stand composition was not influenced by the absence of marking. Snag abundance was reduced to similar levels regardless of marking. Tree marking did not influence the abundance of downed woody debris. As a consequence, it seems possible to apply a simplified approach of selection cutting, without compromising the success of the treatment in these stands.Key words: black spruce, Picea mariana, balsam fir, Abies balsamea, irregular stand, selection cutting, ecosystem management, forest attributes

Coarse woody debris and forest floor respiration in an old-growth coniferous forest on the Olympic Peninsula, Washington, USA

1994 ◽  
Vol 24 (9) ◽  
pp. 1811-1817 ◽  
Author(s):  
James L. Marra ◽  
Robert L. Edmonds
Keyword(s):  
Coarse Woody Debris ◽  
Forest Floor ◽  
Woody Debris ◽  
Large Diameter ◽  
Small Diameter ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Respiration Rates ◽  
Decay Class ◽  
Class 1

Carbon dioxide evolution rates for downed logs (coarse woody debris) and the forest floor were measured in a temperate, old-growth rain forest in Olympic National Park, Washington, using the soda lime trap method. Measurements were taken every 4 weeks from October 22, 1991, to November 19, 1992. Respiration rates for Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) and western hemlock (Tsugaheterophylla (Raf.) Sarg.), logs were determined for decay classes 1–2, 3, and 5 in two diameter classes. Overall, western hemlock logs respired at a rate 35% higher (4.37 g CO2•m−2•day−1) than Douglas-fir logs (3.23 g CO2•m−2•day−1). Respiration rates for decay class 1–2 logs of both species were similar to decay class 5 logs (4.46 and 4.07 g CO2•m−2•day−1, respectively), but decay class 3 logs respired at a lower rate (3.23 g CO2•m−2•day−1). Seasonal patterns of respiration rates occurred, particularly for decay class 1 and 2 western hemlock logs where monthly averages ranged from a low of 2.67 g CO2•m−2•day−1 in February 1992 to a high of 8.30 g CO2•m−2•day−1 in September 1992. Rates for decay class 1–2 western hemlock logs were greater than those from the forest floor, which ranged from 3.42 to 7.13 g CO2•m−2•day−1. Respiration rates were depressed in late July and August compared with fall and spring owing to the summer drought characteristic of the Pacific Northwest. Large-diameter western hemlock logs in decay class 1–2 had higher respiration rates than small-diameter logs, whereas large-diameter decay class 3 western hemlock logs had lower respiration rates than small-diameter logs.

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.

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

Amount of downed woody debris and its prediction using stand characteristics in boreal and mixedwood forests of Ontario, Canada

2008 ◽  
Vol 38 (8) ◽  
pp. 2189-2197 ◽  
Author(s):  
Michael T. Ter-Mikaelian ◽  
Stephen J. Colombo ◽  
Jiaxin Chen
Keyword(s):  
Populus Tremuloides ◽  
Pinus Banksiana ◽  
Sugar Maple ◽  
Woody Debris ◽  
Constant Factor ◽  
Stand Age ◽  
White Birch ◽  
Permanent Sample Plots ◽  
Mixedwood Forests ◽  
Downed Woody Debris

We analyzed data on downed woody debris (DWD) from 435 permanent sample plots in boreal and mixedwood forests of Ontario seeking empirical relationships to predict DWD quantity from stand attributes. In each permanent sample plot, data were collected along three transects, including diameter, tree species, and degree of decomposition of DWD pieces with diameter greater than or equal to 7.5 cm at the point of intersection with the transect. Amounts of DWD in sample plots ranged from 0.7 to 402.7 m3·ha–1 and from 0.1 to 103.4 t·ha–1. Mean DWD values were 65.4 m3·ha–1 and 15.9 t·ha–1 in softwood- and 61.9 m3·ha–1 and 16.5 t·ha–1 in hardwood-dominated plots. Our analysis revealed no relationship between DWD and stand age, site index, or stocking for plots dominated by black spruce ( Picea mariana (Mill.) BSP), eastern white pine ( Pinus strobus L.), sugar maple ( Acer saccharum Marsh.), and red oak ( Quercus rubra L.) and weak relationships for plots dominated by jack pine ( Pinus banksiana Lamb.), red pine ( Pinus resinosa Ait.), trembling aspen ( Populus tremuloides Michx.), and white birch ( Betula papyrifera Marsh.). We submit that DWD in Ontario’s forests should be treated as a constant factor until the relationship between the amount of DWD and present stand condition is better understood and discuss considerations for future studies on DWD.

Dynamics of coarse woody debris following gap harvesting in the Acadian forest of central Maine, U.S.A.

2002 ◽  
Vol 32 (12) ◽  
pp. 2094-2105 ◽  
Author(s):  
Shawn Fraver ◽  
Robert G Wagner ◽  
Michael Day
Keyword(s):  
Coarse Woody Debris ◽  
Woody Debris ◽  
Small Diameter ◽  
Basal Area ◽  
Sampling Period ◽  
Permanent Plots ◽  
Small Scale ◽  
Decay Class ◽  
Acadian Forest ◽  
Mechanical Crushing

We examined the dynamics of down coarse woody debris (CWD) under an expanding-gap harvesting system in the Acadian forest of Maine. Gap harvesting treatments included 20% basal area removal, 10% basal area removal, and a control. We compared volume, biomass, diameter-class, and decay-class distributions of CWD in permanent plots before and 3 years after harvest. We also determined wood density and moisture content by species and decay class. Mean pre-harvest CWD volume was 108.9 m3/ha, and biomass was 23.22 Mg/ha. Both harvesting treatments increased the volume and biomass of non-decayed, small-diameter CWD (i.e., logging slash), with the 20% treatment showing a greater increase than the 10% treatment and both treatments showing greater increases than the control. Post-harvest reduction of advanced-decay CWD due to mechanical crushing was not evident. A mean of 18.48 m3 water/ha (1.85 L/m2) demonstrates substantial water storage in CWD, even during an exceptionally dry sampling period. The U-shaped temporal trend in CWD volume or biomass seen in even-aged stands may not apply to these uneven-aged stands; here, the trend is likely more complex because of the superimposition of small-scale natural disturbances and repeated silvicultural entries.

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 A comparative analysis of directed and spontaneous development of mixed forests of fir, spruce and beech on Mt. Tara

2017 ◽  
pp. 141-170
Author(s):  
Snezana Obradovic ◽  
Damjan Pantic ◽  
Milan Medarevic ◽  
Biljana Sljukic
Keyword(s):  
Comparative Analysis ◽  
Layer Structure ◽  
Self Regulation ◽  
Basal Area ◽  
Light Regime ◽  
Large Dimension ◽  
Managed Forests ◽  
Permanent Sample Plots ◽  
Functional Value ◽  
Good Living

The data of periodic complete measurements of permanent sample plots and compartments in which they were located in the period 1955/60-2005/2010 served as the basis for this research. Two sets of data from a 50-year time span enabled a comparative analysis of a number of structural and numerical elements of regularly managed selection forests of fir, spruce and beech that more or less spontaneously developed in the sample plots. The number of trees in low-diameter categories decreased in the regularly managed compartments, but it was partly compensated by regeneration and ingrowth, which amounted to 7.9 trees per year. In forests with spontaneous development, the ingrowth is either missing or minimal, and it amounts to 2.7 trees per year. From the aspect of preserving the natural composition of these forests and thus their biological stability, a significant decline in the number of beech trees is worrying, above all in the lowest-diameter categories. The accumulation of large-dimension trees is more pronounced in the sample plots in relation on the compartments with regular management. This trend resulted in high basal area values (max. was observed in compartment 131 and at the end of the analyzed period, it amounted to 37.8 m2?ha-1, and in SP-2 to 55.7 m2?ha-1) and volume (max. 605.4 m3?ha-1 was achieved in compartment 66, with a 79% share of fir, i.e. 898 m3?ha-1 in SP-2 in which the share of fir is 71%). Increase of volume in diameter catagories above 50 cm amounts to on average 120% in compartments, and in stands with spontaneous development to as much as 230%. Current volume increment is high and at the end of the period it amounted to on average 12.9 m3?ha-1 in the compartments, and 14.9 m3?ha-1 in the sample plots. In both these values the share of fir is 80%. However, increment percentage, as a more reliable indicator of vitality and good living and stand conditions decreased from 2.54% to 2.32% in the observed compartments and from 2.31% to 1.91% in the sample plots, under the conditions of spontaneous development. On the basis of the above, certain disturbances and negative trends can be identified, both in regularly managed forests and stands with spontaneous development, while they are significantly more pronounced in the latter case. This is reflected in the unfavorable spatial relationships and light regime, and consequently difficult regeneration and ingrowth (especially of beech) as well as the slowing dynamics of these forests, which finally disrupts their structure and functional value. In regularly managed forests, the reason for that is the rigid understanding of the felling ripeness diamater and lower intensity cutting of large-dimension inventory, which slowed down the dynamics and made regeneration and ingrowth difficult. More intensive operations in this part of the inventory would provide a better spatial distribution of trees (horizontal and vertical) and a a better light regime, while the development of these forests would be accelerated. This is confirmed by the fact that forests with self-regulation processes (spontaneous development) become gradually depleted in low and medium storey trees and turn into a one-layer structure with a horizontal canopy which was observed in the investigated sample plots.

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