Effects of silvicultural treatments on post-harvesting residual tree mortality

Abstract Forests in Europe and North America are being affected by large and severe outbreaks of bark beetles, which have caused widespread concern about forest health and have led to proposals for tree removal in affected or susceptible forests. Any such intervention, as well as broader decisions of whether any active interventions are appropriate, should be based on the best scientific data. This is true for all forests, including those whose purposes include timber production, watershed protection, biogeochemical function and recreation, and especially protected and conservation areas as the latter often provide particularly unique and important cultural, social, scientific and other ecosystem services. Here, I summarize peer-reviewed literature on the effects of bark beetle outbreaks and on silvicultural treatments aimed at mitigating beetle-induced tree mortality. From an objective scientific perspective, beetle outbreaks do not destroy forests. Instead, in many cases they play an important role in promoting wildlife, biodiversity and other ecological services. The best available data indicate that logging in conservation areas is unlikely to stop ongoing bark beetle outbreaks and instead may be more ecologically detrimental to the forests than the outbreaks themselves. If the purpose of a forest is timber production, then logging is desirable and can be planned based on appropriate analyses of timber yield and economic profit. However, in areas in which conservation is the determined goal, it is recommended that cutting trees be limited to removing hazards, such as trees that might fall in areas of high human activity in order to limit property damage and personal injury. Based on extensive research in Europe and North America, logging beetle-affected forests is inconsistent with most conservation goals.

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Fire-caused tree mortality in thinned Douglas-fir stands in Patagonia, Argentina

International Journal of Wildland Fire ◽

10.1071/wf12107 ◽

2013 ◽

Vol 22 (6) ◽

pp. 810 ◽

Cited By ~ 5

Author(s):

Maria M. Godoy ◽

Guillermo E. Defossé ◽

Lucas O. Bianchi ◽

Miguel M. Davel ◽

Tomás E. Withington

Keyword(s):

Untreated Control ◽

Tree Mortality ◽

Growth Parameters ◽

Stand Density ◽

Douglas Fir ◽

Fire Behaviour ◽

Growing Seasons ◽

Silvicultural Treatments ◽

Crown Scorch ◽

Stand Density Index

In 2003 in a municipal park near Esquel, Patagonia, Argentina, plots within a 21-year-old Douglas-fir (Pseudotsuga menziesii) afforested area were subjected to three silvicultural treatments (thinning to Reineke’s Stand Density Index (SDI) of 900, 700, 500). In March 2007 all plots were burned by a wildfire that presented extreme fire behaviour. Three weeks after the wildfire we assessed mortality, height of scorch and percentage of crown scorch, and during three subsequent growing seasons we measured mortality and growth parameters. At the end of the study, mortality differed significantly among treatments and an untreated control, and ranged from 100% in the untreated control to 25, 10 and 5% in the SDI 900, 700 and 500 treatments. The highest growth parameters and lower mortality rates were achieved at SDI indices of 700 or 500 (i.e. in the least dense plots). Trees thinned to these densities not only appear to withstand extreme fires, at least under the conditions presented, but also to achieve the highest growth rates.

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The Focus of Intensive Silvicultural Research on Coastal Douglas-Fir Over the Last 20 Years

Western Journal of Applied Forestry ◽

10.1093/wjaf/22.1.21 ◽

2007 ◽

Vol 22 (1) ◽

pp. 21-28 ◽

Cited By ~ 5

Author(s):

Andrew Moores ◽

Klaus Puettmann ◽

Doug Maguire

Keyword(s):

Pacific Northwest ◽

Tree Mortality ◽

Current Knowledge ◽

Growth Yield ◽

Forest Productivity ◽

Douglas Fir ◽

Interactive Effects ◽

Extensive Literature ◽

Silvicultural Treatments ◽

Current Knowledge Base

Abstract Silvicultural regimes are becoming more intensive in the US Pacific Northwest, incorporating a multitude of treatments over the length of the rotation. Therefore, there is a need to understand not only how individual treatments affect forest productivity, but also how these treatments interact to determine productivity. To help launch the Planted Forest Productivity and Value Enhancement Program at Oregon State University, an extensive literature search was conducted over 9 different classes of silvicultural treatments and 10 different categories of measured responses. The objective was to examine the scope of our current knowledge base about intensive silvicultural practices in the Pacific Northwest, particularly the mechanisms by which various treatment combinations or regimes control the productivity of coastal Douglas-fir stands. The literature, 1984 through 2004, shows that studies were more likely to focus on a combination of silvicultural treatments or practices if they were applied during similar times of stand development. Very little documented research addressed the interactive effects of treatments applied sequentially over the rotation. Although most studies monitored growth, yield, and tree mortality, fewer studies investigated environmental, physiological, and morphological responses that are key to understanding and predicting how both tested and untested silvicultural regimes will affect forest productivity.

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Harvest Impacts in Uneven-Aged and Even-Aged Missouri Ozark Forests

Northern Journal of Applied Forestry ◽

10.1093/njaf/21.4.187 ◽

2004 ◽

Vol 21 (4) ◽

pp. 187-193 ◽

Cited By ~ 1

Author(s):

John P. Dwyer ◽

Daniel C. Dey ◽

William D. Walter ◽

Randy G. Jensen

Keyword(s):

Surface Area ◽

Forest Stand ◽

Individual Tree ◽

Silvicultural Treatments ◽

Potential Damage ◽

Residual Tree ◽

The Individual ◽

Forest Managers

Abstract Forest managers are concerned about the potential damage to residual trees and site from cyclic harvest re-entries into the same forest stand. This study summarizes logging and felling damage resulting from the harvesting of silvicultural treatments on a large landscape experiment in southern Missouri that is designed to compare impacts of even-aged, uneven-aged and no management on a wide array of ecosystem components. Although damage levels to bole and crown of leave trees was low for all treatments, the individual tree selection (uneven-aged) treatment did show: (1) higher levels of surface area skidder impact; (2) higher percentage of leave trees with one or more bole wounds; (3) higher number of bole wounds; (4) higher percentage of wounded trees in the dominant and co-dominant crown classes; and (5) the highest percentage of leave trees impacted by logging activity. Preharvest planning that involves the layout and discussion with the skidder operator(s) will reduce the area impacted by skidding to less than 12%. Also, the probability of a bole wound to a residual tree can be reduced to less than 5% if skid trails are kept 30 ft or more from the leave tree. North. J. Appl. For. 21(4):187–193.

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GROWTH OF Manilkara huberi AND Manilkara paraensis AFTER LOGGING AND SILVICULTURAL TREATMENTS IN THE MUNICIPALITY OF PARAGOMINAS, PARÁ, BRAZIL

FLORESTA ◽

10.5380/rf.v44i3.29423 ◽

2014 ◽

Vol 44 (3) ◽

pp. 485 ◽

Cited By ~ 3

Author(s):

Deivison Venicio Souza ◽

João Olegário Pereira de Carvalho ◽

Fernanda Da Silva Mendes ◽

Lia De Oliveira Melo ◽

José Natalino Macedo Silva ◽

...

Keyword(s):

Growth Rate ◽

Diameter Growth ◽

Terra Firme ◽

Diameter Increment ◽

Silvicultural Treatments ◽

Appropriate Treatment ◽

Post Harvesting ◽

Short Time ◽

Reduced Impact Logging ◽

Tree Girdling

AbstractThe effects of silvicultural treatments and logging on the growth rates of Manilkara huberi and Manilkara paraensis in a terra firme natural forest were evaluated. The study was performed in a Forest Management Unit (FMU) located in the municipality of Paragominas, PA. The experimental area covered 500 ha, where five treatments (100 ha each), with four replications per treatment (25 ha each), were established. The replications were randomly distributed in the 500 ha sample area of the FMU. The growth rate of trees was evaluated in the following treatments: T1 – Reduced Impact Logging (RIL) + classic liberation thinning and climber cutting; T2 – RIL + modified liberation thinning and climber cutting; T3 – RIL + climber cutting; T6 - only RIL; T7 - unlogged forest (control). Manilkara huberi and Manilkara paraensis showed good responses on diameter growth rate to the post-harvesting silvicultural treatments applied. However, considering the growth rate differences between the evaluated periods, one can say that the short time elapsed from the application of silvicultural treatments (four years) to the end of the study period does not allow to make accurate statements about the most appropriate treatment for the species, or about the intensity of the interventions to be applied.Keywords: Diameter increment; post-harvesting silviculture; tree girdling; climber cutting. ResumoCrescimento de Manilkara huberi e Manilkara paraensis após a colheita de madeira e tratamentos silviculturais, paragominas, Pará, Brasil. Foram avaliados os efeitos de tratamentos silviculturais e da colheita de madeira sobre o crescimento diamétrico das espécies Manilkara huberi e Manilkara paraensis em uma floresta natural de terra firme. A pesquisa foi conduzida em uma Unidade de Manejo Florestal (UMF), município de Paragominas, PA. A área experimental correspondeu a 500 ha, onde foram estabelecidos cinco tratamentos (100 ha cada) com quatro repetições (25 ha cada). As repetições foram distribuídas aleatoriamente na amostra de 500 ha na UMF. O crescimento das árvores foi avaliado nos seguintes tratamentos: T1 – exploração de impacto reduzido (EIR) + desbaste de liberação clássico e corte de cipós; T2 – EIR + desbaste de liberação modificado e corte de cipós; T3 – EIR + corte de cipós; T6 – apenas EIR; T7 - floresta não-explorada. Manilkara huberi e Manilkara paraensis mostraram respostas favoráveis, em termos de crescimento em diâmetro, às intervenções silviculturais pós-exploratórias aplicadas. Contudo, considerando as diferenças no incremento das árvores entre os períodos avaliados, pode-se dizer que o curto espaço de tempo decorrido da aplicação dos tratamentos silviculturais (quatro anos) ainda não permite fazer projeções precisas acerca do tratamento mais adequado às espécies, ou mesmo, da intensidade das intervenções a serem aplicadas.Palavras-chave: Incremento diamétrico; silvicultura pós-colheita; anelagem de árvores, corte de cipós.

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Post-harvesting silvicultural treatments in canopy logging gaps: Medium-term responses of commercial tree species under tending and enrichment planting

Forest Ecology and Management ◽

10.1016/j.foreco.2019.117521 ◽

2019 ◽

Vol 451 ◽

pp. 117521 ◽

Cited By ~ 3

Author(s):

Raphael Lobato Prado Neves ◽

Gustavo Schwartz ◽

José do Carmo Alves Lopes ◽

Fábio Miranda Leão

Keyword(s):

Tree Species ◽

Medium Term ◽

Silvicultural Treatments ◽

Enrichment Planting ◽

Post Harvesting

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Long-term changes in masticated woody fuelbeds in northern California and southern Oregon, USA

International Journal of Wildland Fire ◽

10.1071/wf19156 ◽

2020 ◽

Vol 29 (9) ◽

pp. 807

Author(s):

Warren P. Reed ◽

J. Morgan Varner ◽

Eric E. Knapp ◽

Jesse K. Kreye

Keyword(s):

Tree Mortality ◽

Fire Hazard ◽

Fire Intensity ◽

Fuel Loading ◽

Fire Hazards ◽

Fuels Treatment ◽

Fuel Layer ◽

Long Duration ◽

Western Us ◽

Residual Tree

Mechanical mastication is a fuels treatment that shreds midstorey trees and shrubs into a compacted woody fuel layer to abate fire hazards in fire-prone ecosystems. Increased surface fuel loading from mastication may, however, lead to undesirable fire intensity, long-duration flaming or smouldering, and undesirable residual tree mortality. Two major questions facing fuels managers are: how long do masticated fuels persist, and how does the composition of masticated fuelbeds change over time? To evaluate these changes, we measured 25 masticated sites with a range of vegetation, species masticated and time since treatment (1–16 years) in the western US. Seven of the 25 sites were sampled nearly a decade earlier, providing a unique opportunity to document fuelbed changes. Woody fuel loading ranged from 12.1 to 91.9Mg ha−1 across sites and was negatively related to time since treatment. At remeasured sites, woody fuel loads declined by 20%, with the greatest losses in 1- and 10-h woody fuels (69 and 33% reductions in mass respectively). Reductions were due to declines in number of particles and reduced specific gravity. Mastication treatments that generate greater proportions of smaller-diameter fuels may result in faster decomposition and potentially be more effective at mitigating fire hazard.

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Armillaria Root Disease-Caused Tree Mortality following Silvicultural Treatments (Shelterwood or Group Selection) in an Oregon Mixed-Conifer Forest: Insights from a 10-Year Case Study

Western Journal of Applied Forestry ◽

10.1093/wjaf/25.3.136 ◽

2010 ◽

Vol 25 (3) ◽

pp. 136-143 ◽

Cited By ~ 7

Author(s):

Gregory M. Filip ◽

Helen M. Maffei ◽

Kristen L. Chadwick ◽

Timothy A. Max

Keyword(s):

Ponderosa Pine ◽

Group Selection ◽

Tree Mortality ◽

Douglas Fir ◽

Conifer Forest ◽

Mixed Conifer ◽

Silvicultural Treatments ◽

Mixed Conifer Forest ◽

Armillaria Root Disease

Abstract In 2005, the 10-year effects of two silvicultural treatments (group-selection and shelterwood) on tree-growth loss and mortality caused by Armillaria ostoyae were compared with no treatment in a mixed-conifer forest in south-central Oregon. Ten years after treatment, Armillaria-caused mortality varied by species and was greatest in Shasta red fir (38% of trees per acre) and white fir (31%) and much less in Douglas-fir (3%) and ponderosa pine (0%). Ten years after harvesting, leave-tree mortality caused by Armillaria root disease was not significantly different in treated than in the unharvested units, nor was there significant diameter-growth response to the harvesting even in large ponderosa pine and Douglas-fir. The silvicultural treatments did have some benefits: (1) leave-tree mortality appeared, at least, not to be exacerbated by harvesting; (2) more disease-resistant pine, cedar, and larch seedlings and saplings survived in the shelterwood-harvest stands and group-selection openings than in comparable areas that were not harvested; and (3) living wood fiber was recovered from the treated stands, as well as dying and dead fuels that could exacerbate wildfire losses. Insights into host-pathogen interactions and recommendations for silvicultural options are presented. This is a case study from a single site and should be interpreted as such.

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Conifer response to three silvicultural treatments in the Oregon Coast Range foothills

Canadian Journal of Forest Research ◽

10.1139/x04-068 ◽

2004 ◽

Vol 34 (9) ◽

pp. 1967-1978 ◽

Cited By ~ 13

Author(s):

Scott T Walter ◽

Chris C Maguire

Keyword(s):

Group Selection ◽

Tree Mortality ◽

Basal Area ◽

Coast Range ◽

Oregon Coast Range ◽

Oregon Coast ◽

Silvicultural Treatments ◽

Crown Width ◽

Previous Decade ◽

Epicormic Branching

This study assessed growth, condition, and mortality of residual trees one decade after harvest across three silvicultural treatments in thirty 85- to 125-year-old Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stands in the Oregon Coast Range foothills. Group-selection cuts had 33% of the entire stand volume extracted as patches approximately 0.20.8 ha in size; two-story regeneration harvests had 75% of the volume extracted, and 2030 residual trees/ha were left; clearcuts had all trees removed, except for 1.2 trees/ha. One decade after harvest, tree basal area, diameter, and height growth, and crown width and fullness did not differ between silvicultural treatments. In contrast, live crown ratio was largest in clearcuts (0.74), and the proportion of trees with epicormic branching was highest in two-story stands (35%). Overall, 45% of trees had more basal area growth in the decade after harvest than in the previous decade. Residual green trees in clearcuts and group-selection stands experienced the highest and lowest percentage mortality, respectively (30.6% vs. 0.2%). Our results reflect little differentiation in the characteristics of trees growing under three silvicultural conditions one decade after harvest. However, percent residual green tree mortality increased with increasing harvest intensity.

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