scholarly journals Snag abundance 20, 30, and 40 years following fire and harvesting in boreal forests

2003 ◽  
Vol 79 (3) ◽  
pp. 541-549 ◽  
Author(s):  
Steven H Ferguson ◽  
Philip C Elkie
Keyword(s):  
Forest Management ◽  
Boreal Forests ◽  
Woody Debris ◽  
Ecological Factors ◽  
Basal Area ◽  
Natural Disturbance ◽  
Timber Harvest ◽  
Stem Density ◽  
Dead Trees ◽  
Diameter Classes

The retention of standing dead trees (snags) has become an important conservation concern, especially when forest management efforts attempt to emulate natural disturbance. We investigate the abundance of snags within Ontario's boreal forest following 10–20, 21–30, and 31–40 years of both fire and forest harvest disturbance over a 24 000-km2 area. Fire frequency varied considerably, with 90% of the fires in the study area occurring in the 1970s. We did not detect differences in basal area of snags (m2/km2) between burned and harvested stands. However, differences occurred in dead-stem density (number/km2); the burned stands produced more snags in the 21- to 30-year post-disturbance class and the harvested stands produced more snags in the 31- to 40-year post-disturbance class. Similarly, the distribution of diameter classes of snags differed between the burned and harvested stands. In size classes greater than 32 cm (diameter at breast height), we found more snags in the harvested forests 21–40 years following disturbance. We did not find differences in the basal area of snags between disturbance types, whether they were hardwood or softwood. However, hardwood snags occurred in greater abundance in the larger diameter classes. Our findings are limited by the changing timber harvest treatments (selective harvest, clearcut, and ecological cut), the small number of disturbance events, and the variety of stand compositions. More research is required on the ecological factors influencing snag abundance to improve development of local forest management plans and to design landscapes that conserve forest structure and biodiversity. Key words: biodiversity, clearcut, conservation, coarse woody debris, dead trees, forest management, landscape, snags, wildlife

scholarly journals Impacts of Alternative Harvesting and Natural Disturbance Scenarios on Forest Biomass in the Superior National Forest, USA

Forests ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 491 ◽  
Author(s):  
Matthew Russell ◽  
Stephanie Patton ◽  
David Wilson ◽  
Grant Domke ◽  
Katie Frerker
Keyword(s):  
Forest Management ◽  
Forest Biomass ◽  
Natural Disturbance ◽  
Timber Harvest ◽  
Timber Harvesting ◽  
Volume Control ◽  
National Forest ◽  
Total Biomass ◽  
Natural Disturbances ◽  
Project Area

The amount of biomass stored in forest ecosystems is a result of past natural disturbances, forest management activities, and current structure and composition such as age class distributions. Although natural disturbances are projected to increase in their frequency and severity on a global scale in the future, forest management and timber harvesting decisions continue to be made at local scales, e.g., the ownership or stand level. This study simulated potential changes in natural disturbance regimes and their interaction with timber harvest goals across the Superior National Forest (SNF) in northeastern Minnesota, USA. Forest biomass stocks and stock changes were simulated for 120 years under three natural disturbance and four harvest scenarios. A volume control approach was used to estimate biomass availability across the SNF and a smaller project area within the SNF (Jeanette Project Area; JPA). Results indicate that under current harvest rates and assuming disturbances were twice that of normal levels resulted in reductions of 2.62 to 10.38% of forest biomass across the four primary forest types in the SNF and JPA, respectively. Under this scenario, total biomass stocks remained consistent after 50 years at current and 50% disturbance rates, but biomass continued to decrease under a 200%-disturbance scenario through 120 years. In comparison, scenarios that assumed both harvest and disturbance were twice that of normal levels and resulted in reductions ranging from 14.18 to 29.85% of forest biomass. These results suggest that both natural disturbances and timber harvesting should be considered to understand their impacts to future forest structure and composition. The implications from simulations like these can provide managers with strategic approaches to determine the economic and ecological outcomes associated with timber harvesting and disturbances.

Disturbance history affects dead wood abundance in Newfoundland boreal forests

2006 ◽  
Vol 36 (12) ◽  
pp. 3194-3208 ◽  
Author(s):  
Martin T Moroni
Keyword(s):  
Boreal Forests ◽  
Dead Wood ◽  
Black Spruce ◽  
Woody Debris ◽  
Abies Balsamea ◽  
Natural Disturbance ◽  
Diameter Distribution ◽  
Natural Disturbances ◽  
A Minor ◽  
Almost All

Dead wood (dead standing tree (snag), woody debris (WD), buried wood, and stump) abundance was estimated in Newfoundland balsam fir (Abies balsamea (L.) Mill.) and black spruce (Picea mariana (Mill.) BSP) forests regrown following natural and anthropogenic disturbances. Although harvesting left few snags standing, natural disturbances generated many snags. Most were still standing 2 years after natural disturbance, but almost all had fallen after 33–34 years. Snag abundance then increased in stands aged 86–109 years. Natural disturbances generated little WD 0–2 years following disturbance. Harvesting, however, immediately generated large amounts of WD. Thirty-two to forty-one years following disturbance, most harvesting slash had decomposed, but naturally disturbed sites had large amounts of WD from collapsed snags. Harvested sites contained less WD 32–72 years following disturbance than naturally disturbed sites. Amounts of WD in black spruce regrown following harvesting and fire converged 63–72 years following disturbance, despite significant initial differences in WD quantities, diameter distribution, and decay classes. Abundance of WD increased from sites regrown 32–72 years following disturbance to older sites. Precommercial thinning had a minor impact on dead wood stocks. Stumps contained minor biomass. Buried wood and WD biomass were equivalent at some sites.

Wood-inhabiting cryptogams on dead Norway spruce (Picea abies) trees in managed Swedish boreal forests

1999 ◽  
Vol 29 (2) ◽  
pp. 178-186 ◽  
Author(s):  
Nicholas Kruys ◽  
Clas Fries ◽  
Bengt Gunnar Jonsson ◽  
Tomas Lämås ◽  
Göran Ståhl
Keyword(s):  
Picea Abies ◽  
Norway Spruce ◽  
Boreal Forests ◽  
Woody Debris ◽  
Large Diameter ◽  
Managed Forests ◽  
Red Lists ◽  
Dead Trees ◽  
Utilization Patterns ◽  
Specific Species

We surveyed the quantity and quality of dead Norway spruce (Picea abies (L.) Karst.) trees and wood-inhabiting cryptogams in a managed boreal forest landscape in northern Sweden. Size and decay of dead trees was related to substrate utilization by wood-inhabiting species. Coarse woody debris (CWD) was surveyed along 34 strip transects. CWD and wood-inhabiting cryptogams were surveyed in eight circular plots at each site. A total of 6195 spruce CWD units occurred along strip transects and 809 spruce CWD units in circular plots. On average 2.2 m3/ha spruce CWD was found on the plots. The majority (63%) of the transect CWD units were <10 cm diameter and in early to intermediate decay stages. Sixty-eight wood-specific species of fungi, lichens, mosses, and hepatics occurred on the plots. Of these, 13 occurred on [Formula: see text]5% of the 809 CWD units surveyed for wood-inhabiting species. Eight species occur on the Swedish red lists, indicating that such species are indeed uncommon in managed forests. Red-listed species showed strong preferences for large diameter CWD and CWD in late decay stages, i.e., substrates that are poorly represented in managed forests. Frequently occurring species, however, showed utilization patterns that correspond with the distribution of the substrate types.

scholarly journals Harvest volumes and carbon stocks in boreal forests of Ontario, Canada

2021 ◽  
Vol 97 (02) ◽  
pp. 168-178
Author(s):  
Michael T. Ter-Mikaelian ◽  
Stephen J. Colombo ◽  
Jiaxin Chen
Keyword(s):  
Forest Management ◽  
Forest Ecosystem ◽  
Boreal Forests ◽  
Natural Disturbance ◽  
Carbon Stocks ◽  
Wood Products ◽  
Ecosystem Carbon ◽  
Harvest Volume ◽  
Unmanaged Forest ◽  
Ecosystem Carbon Stocks

We used models to project forest carbon stocks for a series of harvesting scenarios for 29 boreal forest management units totalling 23.3 million ha in Ontario, Canada. Scenarios evaluated for 2020 to 2050 ranged from a no harvesting option to annual harvesting of 2% of the total merchantable volume present in 2020. For each scenario, we estimated the following carbon quantities: (a) forest ecosystem carbon stocks, (b) sum of carbon stocks in forest ecosystem and harvested wood products (HWP) minus emissions associated with HWP production and decomposition, and (c) net greenhouse gas (GHG) effects of harvesting estimated as (b) combined with emissions avoided by substituting HWP for non-wood materials. The average of each carbon quantity for 2020 to 2050 was linearly dependent on the annual harvest volume. The developed relationships were used to estimate harvest volumes for which the three carbon quantities would equal equilibrium forest ecosystem carbon stocks for a pre-suppression natural disturbance cycle. These estimates indicate the range of harvest volumes for which resulting carbon stocks would equal or exceed those in an unmanaged forest. Also discussed are possible criteria for determining annual harvest volume.

scholarly journals Vegetation management on private forestland can increase avian species richness and abundance

The Condor ◽  
2020 ◽  
Author(s):  
Jesse M Wood ◽  
Amy K Tegeler ◽  
Beth E Ross
Keyword(s):  
South Carolina ◽  
Species Richness ◽  
Forest Management ◽  
Management Practices ◽  
Basal Area ◽  
Timber Harvest ◽  
Avian Species ◽  
Active Management ◽  
Private Lands ◽  
Species Richness And Abundance

Abstract Conservation efforts on private lands are important for biodiversity conservation. On private lands in South Carolina, in the southeastern United States, forestry management practices (prescribed burning, thinning, herbicide application) are used to improve upland pine habitat for wildlife and timber harvest and are incentivized through U.S. Department of Agriculture Farm Bill cost-share programs. Because many forest-dependent avian species have habitat requirements created primarily through forest management, data are needed on the effectiveness of these management activities. We studied privately owned loblolly pine (Pinus taeda) stands in the South Carolina Piedmont region. Our objective was to understand how management practices influence avian species richness and abundance at local (forest stand) and landscape levels in relatively small stands (average ~28 ha). We surveyed 49 forest stands during 2 bird breeding seasons with traditional point counts and vegetation surveys. We evaluated the effects of management on pine stand characteristics, avian species richness, and abundance of state-designated bird species of concern. Repeated burning and thinning shifted stand conditions to open pine woodlands with reduced basal area and herbaceous understories. Stands with lower basal area supported greater avian species richness. Some species increased in abundance in response to active management (e.g., Brown-headed Nuthatch [Sitta pusilla] and Indigo Bunting [Passerina cyanea]), but relationships varied. Some species responded positively to increases in forest quantity at a landscape scale (1–5 km; e.g., Northern Bobwhite [Colinus virginianus]). We found species-rich avian communities and species of conservation concern on working timber lands, indicating that incentivized forest management on private lands can provide valuable habitat for wildlife.

The aftermath of tree death: coarse woody debris and the topography in four tropical rain forests

2000 ◽  
Vol 30 (9) ◽  
pp. 1489-1493 ◽  
Author(s):  
Neil Gale
Keyword(s):  
Coarse Woody Debris ◽  
Woody Debris ◽  
Basal Area ◽  
Slope Position ◽  
Tropical Rain Forests ◽  
Rain Forests ◽  
Dead Tree ◽  
Dead Trees ◽  
Relationship Of ◽  
The Relationship

The relationship of coarse woody debris (CWD) was examined with respect to topography and site in four lowland tropical rain forests in northern Borneo and western Ecuador. In total, 1914 dead trees [Formula: see text]20 cm diameter at breast height were enumerated in 46 ha. The basal area per hectare of dead trees varied strongly with both site and slope position. Dead basal area and its correlate dead tree density increased moving up the topographic gradient from the valleys to the ridges. Site estimates for CWD volume ranged from 96 to 154 m3·ha-1. Mean standing CWD volume was four times higher on the ridge tops (54 m3·ha-1) compared with the valley and cross-terrain areas (both 13 m3·ha-1). In contrast, downed volume did not vary with slope position. The proportions of CWD present as standing wood were two to three times higher in the Bornean sites compared with Hoja Blanca. These topographical and site differences in CWD were linked to differences in mode of tree death as well as the distribution of live trees per hectare.

scholarly journals EFICIÊNCIA DE TRATAMENTOS SILVICULTURAIS POR ANELAMENTO NA FLORESTA DO JARI, AMAPÁ

FLORESTA ◽  
2012 ◽  
Vol 42 (2) ◽  
pp. 315 ◽  
Author(s):  
Celso Paulo de Azevedo ◽  
José Natalino Macedo Silva ◽  
Cintia Rodrigues de Souza ◽  
Carlos Roberto Sanquetta
Keyword(s):  
Mortality Rate ◽  
Native Species ◽  
Basal Area ◽  
Important Variation ◽  
Area Reduction ◽  
Silvicultural Treatments ◽  
Silvicultural Treatment ◽  
Dead Trees ◽  
Different Levels ◽  
Diameter Classes

 O anelamento é um tratamento silvicultural aplicado nas florestas tropicais com o objetivo de manter ou até aumentar a produtividade das espécies exploradas comercialmente para o próximo ciclo de corte. Neste trabalho, analisou-se o efeito de diferentes níveis de exploração e tratamentos silviculturais sobre a dinâmica da floresta remanescente na região do Jari/AP. O tratamento silvicultural foi realizado em 1994, aplicando-se dois tipos de desbaste: desbaste sistemático, com intensidades de redução da área basal original de 30% e 50% e o desbaste seletivo (anelamento com entalhes e aplicação de arboricida). Na aplicação do tratamento, foram aneladas em média 18,3 árvores.ha-1, 2,1 m2.ha-1 de área basal e 25,1 m3.ha-1 de volume, com total de 495 indivíduos anelados (de 93 espécies). A quantidade de árvores mortas em consequência do anelamento variou consideravelmente entre os tratamentos. De maneira geral, o anelamento com a aplicação do arboricida mostrou maior efeito em função da espécie do que com o tamanho das árvores. Espécies com troncos sulcados apresentaram baixa mortalidade. Árvores com diâmetro inferior a 50 cm apresentaram mortalidade de 61 a 90%. Nas classes diamétricas superiores, a taxa de mortalidade foi semelhante, em torno de 69 a 100%.Palavras-chave: Espécies nativas; tratamentos silviculturais; exploração florestal; Amazônia. AbstractEfficiency of silvicultural treatments by girdling in the Jari Forest, Amapá. The girdling is a silvicultural treatment applied in tropical forests in order to maintain or even increase the productivity of commercially exploited species to the next cutting cycle. In this research we analyzed effects of different levels of exploitation and silvicultural treatments on the dynamics of remaining forest in the Jari region/AP. The silvicultural treatment was improved in 1994 and applied to two types of thinning: systematic thinning, with intensities of original basal area reduction of 30% and 50% and selective thinning (with girdling slots and applying arboricida). In the application of treatment it were ringed on average 18.3 trees.ha-1, 2,1 m2.ha-1 of basal area and 25.1 m3.ha-1 of volume, total of 495 treated individuals (93 species). The amount of dead trees as a result of girdling had important variation between treatments. In general, the girdling with application of arboricida presented greater effect in relation to the species than to trees sizes. Species with furrowed trunks presented low mortality. Trees with less than 50 cm of diameter had a mortality rate of 61 to 90 percent. In superior diameter classes the mortality rate was similar, around 69 to 100 percent.Keywords: Native species; silvicultural treatments; forest exploration; Amazonia. 

Do biomass removal and structure-enhancing treatments influence deadwood characteristics following commercial thinning in spruce plantations in New Brunswick, Canada?

2015 ◽  
Vol 45 (10) ◽  
pp. 1407-1418 ◽  
Author(s):  
Kwadwo Omari ◽  
David A. MacLean
Keyword(s):  
New Brunswick ◽  
Picea Glauca ◽  
Woody Debris ◽  
Basal Area ◽  
Status Quo ◽  
Commercial Thinning ◽  
Dead Trees ◽  
Biomass Removal ◽  
The Status ◽  
Intensively Managed

Effects of commercial thinning on downed coarse woody debris (CWD) and standing dead trees (snags) were examined in six intensively managed 22- to 30-year-old white spruce (Picea glauca (Moench) Voss) plantations in northern New Brunswick, Canada. Four alternative treatments were applied: (i) an unthinned control and three commercial thinning 40% basal area removals, with (ii) slash and tops remaining on the site (status quo), (iii) most of the branches and tops extracted from the site (biomass removal), and (iv) clumps of unthinned trees left, with one-half of the trees in each clump girdled to create snags (enhanced structure). Three years after thinning, CWD volume increased by 14%–27% in the status quo and enhanced structure treatments, by 6% in the biomass removal treatment, and by 0.1% in the unthinned treatment. Mean snag volume changed little, i.e., less than 1 m3·ha−1 among treatments, and stumps of thinned trees were 4.6–4.9 m3·ha−1. The girdled trees added 0.7 m3·ha−1 of snags, and 1.3 m3·ha−1 is expected to be added from girdling the remaining live trees in the unthinned clumps in 2016. The girdled trees and future to-be-girdled trees added up to 50% of the new deadwood in the enhanced structure treatments, but thinning treatments did not significantly affect total deadwood. The results indicate that commercial thinning produced fine debris but had little effect on overall deadwood amount. Girdling trees during commercial thinning, at the intensity used in this study, is unlikely to produce sufficient snags. Leaving islands and clumps during harvest before plantation establishment would be a more effective way of adding structure.

scholarly journals Wildfires in boreal ecosystems: past, present and some emerging trends

2010 ◽  
Vol 19 (8) ◽  
pp. 991 ◽  
Author(s):  
Martin P. Girardin ◽  
Adam A. Ali ◽  
Christelle Hély
Keyword(s):  
Forest Management ◽  
Boreal Forests ◽  
Fire Risk ◽  
Natural Disturbance ◽  
Fire Frequency ◽  
Future Research ◽  
Research Activity ◽  
Research Activities ◽  
Emerging Trends ◽  
Fire Activity

With the emergence of a new forest management paradigm based on the emulation of natural disturbance regimes, interest in fire-related studies has increased in the boreal forest management community. A key issue in this regard is the improvement of our understanding of the variability in past disturbances and its linkages with climate and ecosystems. The surge in research activity has further been exacerbated by the increasing awareness of climate change, which has already exposed boreal forests to greater fire risk in recent decades. It is anticipated that further warming and drying will further enhance fire frequency and area burned in many boreal forests. Better predictions of future fire activity will contribute to better long-term forest planning in managed boreal forests. The 12 papers presented in this special issue exemplify this increased research activity by bringing together studies from diverse disciplines and presenting the latest advances regarding methodological approaches for reconstruction and modelling of past, present and future fire activity. Here we aim to summarise, evaluate and set into context some of the new insights arising from these studies and also to discuss some considerations to be taken into account in future research activities.

Cavity Trees in Sawtimber-Size Oak Stands in Central Massachusetts

1989 ◽  
Vol 6 (2) ◽  
pp. 61-65 ◽  
Author(s):  
William M. Healy ◽  
Robert T. Brooks ◽  
Richard M. DeGraaf
Keyword(s):  
Basal Area ◽  
Timber Production ◽  
Diameter Class ◽  
Silvicultural Treatment ◽  
Dead Trees ◽  
Tree Quality ◽  
Live Tree ◽  
Diameter Classes

Abstract Animals that use cavities in trees are an important component of hardwood ecosystems, but reserving cavity trees is often perceived as an impact on timber production. Cavities occurred in 4% of the live trees in even-aged, saw-timber-size oak stands with no previous silvicultural treatment. Cavity trees accounted for 8% of the total live tree basal area and occurred in all tree quality and diameter classes. Dead trees were well distributed by diameter class. On the average, unthinned stands had about 2.9 times as many cavity trees and 1.8 times as many dead trees per ha as thinned stands. It is possible to conduct thinnings that both improve stand quality and retain cavity trees because 89% of the rough cull, and 63% of the rotten cull trees did not contain cavities. North. J. Appl. For. 6:61-65, June 1989.

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