Linking deadwood-associated beetles and fungi with wood decomposition rates in managed black spruce forests1This article is one of a selection of papers from the International Symposium on Dynamics and Ecological Services of Deadwood in Forest Ecosystems.

2012 ◽  
Vol 42 (8) ◽  
pp. 1477-1490 ◽  
Author(s):  
Jenna M. Jacobs ◽  
Timothy T. Work
Keyword(s):  
Stand Structure ◽  
Black Spruce ◽  
Wood Decomposition ◽  
Decomposition Rates ◽  
Partial Cutting ◽  
Saprotrophic Fungi ◽  
Silvicultural Treatments ◽  
Saproxylic Beetle ◽  
Main Effects ◽  
The Relationship

Deadwood-associated insects and saprotrophic fungi are principal agents of wood decomposition in boreal forest. Silvicultural treatments that alter microclimate and availability of deadwood likely affect composition and growth rates of both insect and fungal communities, leading to changes in wood decomposition rates. Here, we relate both saproxylic beetle and dominant polypore assemblages with woody decomposition rates and environmental variables in experimental partial cuts, clearcuts, and uncut controls using a series of causal models to determine the relationship between stand structure, biodiversity, and ecosystem function in black spruce ( Picea mariana (Mill.) BSP) forests. Overall beetle and fungal composition differed between uncut stands and harvested stands. Main effects of harvesting included large increases in wood-feeding beetles and the fungus Gloeophyllum sepiarium (Wul.:Fr.) Karst. We suggest that these species were promoted by specific alterations in microhabitat conditions of deadwood. Within clearcuts specifically, changes in species composition and significantly more fungal degree-days resulted in significantly higher decomposition rates. We concluded that levels of partial cutting in the range of 15%–20% retention were not sufficient to maintain predisturbance communities but were sufficient to maintain wood decomposition rates similar to uncut stands.

scholarly journals Coefficients de distribution de la régénération, cinq ans après des coupes avec protection des petites tiges marchandes appliquées dans des sapinières et des pessières noires du Québec

2011 ◽  
Vol 87 (05) ◽  
pp. 669-683 ◽  
Author(s):  
Martin Riopel ◽  
Jean Bégin ◽  
Jean-Claude Ruel
Keyword(s):  
Black Spruce ◽  
Abies Balsamea ◽  
Balsam Fir ◽  
Annual Rainfall ◽  
Deciduous Species ◽  
Partial Cutting ◽  
Coniferous Species ◽  
Breast Height ◽  
Silvicultural Treatments ◽  
Heavy Equipment

For certain mature forests dominated by balsam fir (Abies balsamea [L.] Mill.) or black spruce (Picea mariana [Mill.] BSP), it may be preferable to harvest trees with diameter at breast height greater than 15 cm while conserving smaller ones. This treatment, called harvesting with protection of small merchantable trees, produces strips, where partial cutting is applied, alternating with corridors, which are disturbed by heavy equipment during harvesting. This project studied stocking levels five years after treatment on 4896 sub-plots of 4 m2 in 22 blocks. Stocking coefficients (SC) for coniferous and deciduous species were modeled in order to identify variables affecting stocking. The strips had well-distributed coniferous regeneration, while SC in the corridors were more variable and lower, occasionally less than 60%. Black spruce-dominated sites were not as well stocked as balsam fir-dominated sites. Stocking levels of protected coniferous merchantable trees positively influence coniferous and deciduous SC in the corridors. The presence of coniferous species is also affected by harvest season and total annual rainfall. Alternative silvicultural treatments applicable in certain corridors are presented.

scholarly journals Effect of three partial cutting practices on stand structure and growth of residual black spruce trees in north-eastern Quebec

2015 ◽  
Vol 88 (4) ◽  
pp. 471-483 ◽  
Author(s):  
Émilie Pamerleau-Couture ◽  
Cornelia Krause ◽  
David Pothier ◽  
Aaron Weiskittel
Keyword(s):  
Stand Structure ◽  
Black Spruce ◽  
Partial Cutting ◽  
North Eastern

scholarly journals A multiscale analysis of the effects of alternative silvicultural treatments on windthrow within balsam fir dominated stands

2015 ◽  
Vol 45 (12) ◽  
pp. 1739-1747 ◽  
Author(s):  
Kenneth Agbesi Anyomi ◽  
Jean-Claude Ruel
Keyword(s):  
Black Spruce ◽  
Abies Balsamea ◽  
Basal Area ◽  
Natural Disturbance ◽  
Balsam Fir ◽  
Partial Cutting ◽  
Selection Cutting ◽  
Silvicultural Treatments ◽  
Block Level ◽  
And Control

Boreal ecosystem functioning is largely controlled by disturbance dynamics. There have been efforts at adapting forest management approaches to emulate natural disturbance effects, as this is expected to maintain ecosystem resilience. In many instances, this involves resorting to partial cutting strategies that are likely to increase windthrow losses. The objective of this study was to determine the effects of alternative silvicultural practices on windthrow damage and how these effects vary with the scale of treatment. The study was conducted in the Quebec North Shore region (Canada), an area dominated by balsam fir (Abies balsamea (L.) Mill.) and accompanied by black spruce (Picea mariana (Mill) B.S.P.). Four different silvicultural treatments (overstory removal, heavy partial cutting, and two patterns of selection cutting) and control areas were implemented in 2004 and 2005. The experiment used a nested approach where treatment at the plot level was independent and yet nested within the block-level treatment. At the block level, treatments were applied over 10–20 ha units, leaving a small portion of the block for a smaller application of each treatment (plot scale, 2500 m2). Inventory was carried out before harvesting and monitoring was done yearly after harvesting, with the aim to better understand the plot- and block-level factors that drive windthrow damage levels and the effects of alternative silvicultural treatments. Results after 6–7 years show that basal area proportion windthrown differs substantially between treatments, as well as between treated sites and control sites. Windthrow levels were higher under heavy cuts relative to selection cuts and also increased with balsam fir proportion. Windthrow proportions were better correlated to block-level treatment than plot-level treatment, showing that the environment surrounding the treated plot can have an important effect on windthrow losses. Overall, the selection cutting system, particularly SC2, retains the most green-tree basal area and thus best meets the management objective of retaining old-growth attributes. A simple empirical model was calibrated that could aid in hazard rating.

scholarly journals A trait-based understanding of wood decomposition by fungi

2020 ◽  
Vol 117 (21) ◽  
pp. 11551-11558 ◽  
Author(s):  
Nicky Lustenhouwer ◽  
Daniel S. Maynard ◽  
Mark A. Bradford ◽  
Daniel L. Lindner ◽  
Brad Oberle ◽  
...  
Keyword(s):  
North America ◽  
Decomposition Rate ◽  
Extracellular Enzymes ◽  
Terrestrial Ecosystems ◽  
Extension Rate ◽  
Wood Decomposition ◽  
Decomposition Rates ◽  
Fungal Community Composition ◽  
Saprotrophic Fungi ◽  
Trade Off

As the primary decomposers of organic material in terrestrial ecosystems, fungi are critical agents of the global carbon cycle. Yet our ability to link fungal community composition to ecosystem functioning is constrained by a limited understanding of the factors accounting for different wood decomposition rates among fungi. Here we examine which traits best explain fungal decomposition ability by combining detailed trait-based assays on 34 saprotrophic fungi from across North America in the laboratory with a 5-y field study comprising 1,582 fungi isolated from 74 decomposing logs. Fungal growth rate (hyphal extension rate) was the strongest single predictor of fungal-mediated wood decomposition rate under laboratory conditions, and accounted for up to 27% of the in situ variation in decomposition in the field. At the individual level, decomposition rate was negatively correlated with moisture niche width (an indicator of drought stress tolerance) and with the production of nutrient-mineralizing extracellular enzymes. Together, these results suggest that decomposition rates strongly align with a dominance-tolerance life-history trade-off that was previously identified in these isolates, forming a spectrum from slow-growing, stress-tolerant fungi that are poor decomposers to fast-growing, highly competitive fungi with fast decomposition rates. Our study illustrates how an understanding of fungal trait variation could improve our predictive ability of the early and midstages of wood decay, to which our findings are most applicable. By mapping our results onto the biogeographic distribution of the dominance-tolerance trade-off across North America, we approximate broad-scale patterns in intrinsic fungal-mediated wood decomposition rates.

scholarly journals The Difficulty of Predicting Eastern Spruce Dwarf Mistletoe in Lowland Black Spruce: Model Benchmarking in Northern Minnesota, USA

Forests ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 843
Author(s):  
Ella R. Gray ◽  
Matthew B. Russell ◽  
Marcella A. Windmuller-Campione
Keyword(s):  
Stand Structure ◽  
Black Spruce ◽  
Forest Health ◽  
Basal Area ◽  
Predictive Performance ◽  
Stand Age ◽  
Management Decisions ◽  
Dwarf Mistletoe ◽  
Growing Seasons ◽  
Model Interpretation

Insects, fungi, and diseases play an important role in forest stand development and subsequently, forest management decisions and treatments. As these disturbance agents commonly occur within and across landscapes, modeling has often been used to inform forest planning and management decisions. However, models are rarely benchmarked, leaving questions about their utility. Here, we assessed the predictive performance of a Bayesian hierarchical model through on–the-ground sampling to explore what features of stand structure or composition may be important factors related to eastern spruce dwarf mistletoe (Arceuthobium pusillum Peck) presence in lowland black spruce (Picea mariana (Mill.) B. S. P.). Twenty-five state-owned stands included in the predictive model were sampled during the 2019 and 2020 growing seasons. Within each stand, data related to the presence of eastern spruce dwarf mistletoe, stand structure, and species composition were collected. The model accurately predicted eastern spruce dwarf mistletoe occurrence for 13 of the 25 stands. The amount of living and dead black spruce basal area differed significantly based on model prediction and observed infestation, but trees per hectare, total living basal area, diameter at breast height, stand age, and species richness were not significantly different. Our results highlight the benefits of model benchmarking to improve model interpretation as well as to inform our understanding of forest health problems across diverse stand conditions.

Who Speaks Up?

2021 ◽  
Author(s):  
Ming Yi ◽  
Shenghui Wang ◽  
Irene E. De Pater ◽  
Jinlian Luo
Keyword(s):  
Comparative Analysis ◽  
Big Five ◽  
Service Industry ◽  
Qualitative Comparative Analysis ◽  
Work Behavior ◽  
Employee Voice ◽  
Big Five Traits ◽  
Main Effects ◽  
The Relationship ◽  
Prohibitive Voice

Abstract. Research on the relationship between personality traits and employee voice has predominantly focused on main effects of one or more traits and has shown equivocal results. In this study, we explore relationships between configurations (i.e., all logically possible combinations) of the Big Five traits and promotive and prohibitive voice using fuzzy-set qualitative comparative analysis. Survey data from 171 employees from 10 organizations in the service industry revealed that none of the traits alone could induce promotive or prohibitive voice. Yet, we found three trait configurations that relate to promotive voice and four configurations that relate to prohibitive voice. We use the theory of purposeful work behavior to explain the different trait configurations for promotive and prohibitive voice.

scholarly journals Who can enjoy the unavoidable emotional labor

2014 ◽  
Vol 27 (4) ◽  
pp. 719-742
Author(s):  
SeungGeun Baeck ◽  
KangHyun Shin ◽  
JongHyun Lee ◽  
ChangGoo Heo
Keyword(s):  
Work Engagement ◽  
Emotional Labor ◽  
Negative Emotion ◽  
Job Burnout ◽  
Self Monitoring ◽  
Main Effect ◽  
Relationship Of ◽  
Main Effects ◽  
The Relationship ◽  
Positive Effect

The purpose of this study was to examine the positive effect of self-monitoring among emotional display rules (fostering positive emotion(FPE) & suppressing negative emotion(SNE)) and consequential work attitude (job burnout & work engagement). A sample of 191 hotel employees were participated in this study and data were analyzed by SPSS. The results are as follows. First, the main effect of FPE on work engagement was supported, but the main effect of SNE on job burnout was not. Second, the main effects of self-monitoring on engagement and burnout were supported. Third, the moderation effects of self-monitoring which buffer the relationship of SNE on burnout and which facilitate the relationship FPE on engagement were significant. Finally, the implications and limitations were discussed.

scholarly journals Gender, Marital Status and Life Satisfaction

2016 ◽  
Author(s):  
Theodore N Greenstein
Keyword(s):  
Gender Differences ◽  
Life Satisfaction ◽  
Marital Status ◽  
Employment Status ◽  
Religious Affiliation ◽  
World Values Survey ◽  
The World ◽  
Relationship Of ◽  
Main Effects ◽  
The Relationship

*This paper uses materials from the World Values Survey and the EuropeanValues Study from 2006-2014 to study the relationship of gender and maritalstatus to life satisfaction. In an analysis of 103,217 respondents from 81nations I find that while there do not seem to be main effects of gender onlife satisfaction – that is, women are no more or less satisfied with theirlives than are men -- gender moderates the effects of geographical region,age, employment status, education, religious affiliation, and attendance ofreligious services on life satisfaction. In particular, there aresubstantial differences in the effects of marital status on lifesatisfaction by gender. The gender differences in most effects are sosubstantial that I argue that it makes no sense to analyze lifesatisfaction data without performing separate analyses by gender. *

Soil and root respiration in mature Alaskan black spruce forests that vary in soil organic matter decomposition rates

2005 ◽  
Vol 35 (1) ◽  
pp. 161-174 ◽  
Author(s):  
Jason G Vogel ◽  
David W Valentine ◽  
Roger W Ruess
Keyword(s):  
Soil Respiration ◽  
Root Respiration ◽  
Forest Type ◽  
Black Spruce ◽  
Decomposition Rates ◽  
Spruce Forests ◽  
Moisture Deficit ◽  
Soil Temperatures ◽  
Boreal Ecosystem ◽  
Site Identification

Climate warming at high latitudes is expected to increase root and microbial respiration and thus cause an increase in soil respiration. We measured the root and microbial components of soil respiration near Fairbanks, Alaska, in 2000 and 2001, in three black spruce (Picea mariana (Mill) B.S.P.) forests. We hypothesized faster decomposition correlates with greater amounts of both root and microbial contributions to soil respiration. Contrary to our prediction, the site with the coolest summer soil temperatures and slowest decomposition (site identification "high-np") had significantly (p < 0.05) greater growing season soil respiration (485 g C·m–2·year–1) than the two other sites (372 and 332 g C·m–2·year–1). Spruce C allocation to root respiration was significantly greater, and fine-root N concentration was 10% and 12% greater (p < 0.05) at high-np than at the other two sites. High-np spruce foliage was also more enriched in 13C and depleted in 15N, suggesting either lower available moisture or slower N turnover. Either factor could drive greater C allocation to roots; however, a literature review suggests moisture deficit corresponds to greater C allocation to roots in black spruce forests across the boreal ecosystem. Controls on spruce C allocation need to be resolved before making the generalization that soil respiration will increase with warming in this forest type.

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