scholarly journals Biomass Procurement in Boreal Forests Affected by Spruce Budworm: Effects on Regeneration, Costs and Carbon Balance

2020 ◽  
Author(s):  
Daniel Gouge ◽  
Evelyne Thiffault ◽  
Nelson Thiffault
Author(s):  
Marc Rhainds ◽  
Ian DeMerchant ◽  
Pierre Therrien

Abstract Spruce budworm, Choristoneura fumiferana Clem. (Lepidoptera: Tortricidae), is the most severe defoliator of Pinaceae in Nearctic boreal forests. Three tools widely used to guide large-scale management decisions (year-to-year defoliation maps; density of overwintering second instars [L2]; number of males at pheromone traps) were integrated to derive pheromone-based thresholds corresponding to specific intergenerational transitions in larval densities (L2i → L2i+1), taking into account the novel finding that threshold estimates decline with distance to defoliated forest stands (DIST). Estimates of thresholds were highly variable between years, both numerically and in terms of interactive effects of L2i and DIST, which limit their heuristic value. In the context of early intervention strategy (L2i+1 > 6.5 individuals per branch), however, thresholds fluctuated within relatively narrow intervals across wide ranges of L2i and DIST, and values of 40–200 males per trap may thus be used as general guideline.


Author(s):  
Olalla Díaz-Yáñez ◽  
Timo Pukkala ◽  
Petteri Packalen ◽  
Manfred J Lexer ◽  
Heli Peltola

Abstract Boreal forests produce multiple ecosystem services for the society. Their trade-offs determine whether they should be produced simultaneously or whether it is preferable to assign separate areas to different ecosystem services. We use simulation and optimization to analyse the correlations, trade-offs and production levels of several ecosystem services in single- and multi-objective forestry over 100 years in a boreal forest landscape. The case study area covers 3600 ha of boreal forest, consisting of 3365 stands. The ecosystem services and their indicators (in parentheses) considered are carbon sequestration (forestry carbon balance), biodiversity (amount of deadwood and broadleaf volume), economic profitability of forestry (net present value of timber production) and timber supply to forest industry (volume of harvested timber). The treatment alternatives simulated for each of the stands include both even-aged rotation forestry (thinning from above with clear cut) and continuous cover forestry regimes (thinning from above with no clear cut). First, we develop 200 Pareto optimal plans by maximizing multi-attribute utility functions using random weights for the ecosystem service indicators. Second, we compare the average level of ecosystem services in single- and multi-objective forestry. Based on our findings, forestry carbon balance and the amount of deadwood correlate positively with each other, and both of them correlate negatively with harvested timber volume and economic profitability of forestry. Despite this, the simultaneous maximization of multiple objectives increased the overall production levels of several ecosystem services, which suggests that the management of boreal forests should be multi-objective to sustain the simultaneous provision of timber and other ecosystem services.


Ecosystems ◽  
2019 ◽  
Vol 22 (8) ◽  
pp. 1838-1851 ◽  
Author(s):  
Zelin Liu ◽  
Changhui Peng ◽  
Louis De Grandpré ◽  
Jean-Noël Candau ◽  
Timothy Work ◽  
...  

2017 ◽  
Vol 47 (2) ◽  
pp. 246-256 ◽  
Author(s):  
Ane Zubizarreta-Gerendiain ◽  
Timo Pukkala ◽  
Heli Peltola

This study presents a new method for considering the risk of wind damage in forest planning and for predicting the amount of damage and its effects on timber production, economic profitability and carbon balance of forestry. The effects of wind damage on the optimal management of boreal forests under current and changing climatic conditions were analyzed by comparing four forest management plans. A reference plan maximized net present value (NPV) with even-flow harvesting constraints. The second plan minimized height differences between adjacent stands, the third minimized height differences while simultaneously maximizing NPV, and the fourth maximized height differences between adjacent stands. To obtain damage-adjusted results, schedules that belonged to the optimal management plans were simulated with wind damage, taking into account the shelter provided by adjacent stands. Maximizing NPV and simultaneously minimizing height differences resulted in the highest damage-adjusted NPV. Increasing wind damage increased carbon balance of forest soil but decreased the total carbon balance of forestry as it decreased the carbon balances of living forest biomass and wood-based products. Climate change slightly improved the total carbon balance of forestry. If wind damage was ignored in calculations, NPV, total carbon balance of forestry, and timber production were overestimated.


2019 ◽  
Vol 489 (2) ◽  
pp. 195-198
Author(s):  
A. V. Ptichnikov ◽  
D. V. Karelin ◽  
V. M. Kotlyakov ◽  
Y. A. Pautov ◽  
A. Y. Borovlev ◽  
...  

In this paper, we analyze applicability of Land degradation neutrality (LDN) concept of the UN Convention to Combat Desertification for Russian boreal forests. In this regard, it is necessary to adapt the three global LDN indicators (land cover, land productivity, and carbon stocks) to the assessment of land degradation processes of boreal forests in Russia and around the world. The proposed study concludes that landscapes with different types of forest restoration dynamics can be viewed as the object in forest land dynamic studies. The proposed research also suggests the set of LDN indicators adapted for boreal forests conditions. In order to assess LDN proxies we calculated the retrospective and projected net carbon balance in the middle taiga zone of Noshulskoye forest domain (Komi Republic, Russia) using the CBM CFS model. Here we explored 3 scenarios of forest net carbon balance under the three different felling regimes. It was shown that the net carbon balance cannot be applied as an independent LDN indicator, since it does not take into account changes in species diversity and primary productivity. We also suggest that industrial felling should imitate natural types of restoration dynamics in order to achieve LDN targets. It can be reached through minimization of forest felling at sites with fireless types of succession, which accumulate maximum stocks of dead phytomass matter and serve as forest refuges supporting biodiversity.


Forests ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 850 ◽  
Author(s):  
Janie Lavoie ◽  
Miguel Montoro Girona ◽  
Hubert Morin

Spruce budworm (Choristoneura fumiferana) is the main defoliator of conifer trees in North American boreal forests, affecting extensive areas and causing marked losses of timber supplies. In 2017, spruce budworm affected more than 7 million ha of Eastern Canadian forest. Defoliation was particularly severe for black spruce (Picea mariana (Mill.) B.S.P.), one of the most important commercial trees in Canada. During the last decades, intensive forest exploitation practices have created vast stands of young balsam fir (Abies balsamea (L.) Mill.) and black spruce. Most research focused on the impacts of spruce budworm has been on mature stands; its effects on regeneration, however, have been neglected. This study evaluates the impacts of spruce budworm on the defoliation of conifer seedlings (black spruce and balsam fir) in clearcuts. We measured the cumulative and annual defoliation of seedlings within six clearcut black spruce stands in Quebec (Canada) that had experienced severe levels of defoliation due to spruce budworm. For all sampled seedlings, we recorded tree species, height class, and distance to the residual forest. Seedling height and species strongly influenced defoliation level. Small seedlings were less affected by spruce budworm activity. As well, cumulative defoliation for balsam fir was double that of black spruce (21% and 9%, respectively). Distance to residual stands had no significant effect on seedling defoliation. As insect outbreaks in boreal forests are expected to become more severe and frequent in the near future, our results are important for adapting forest management strategies to insect outbreaks in a context of climate change.


2014 ◽  
Vol 44 (10) ◽  
pp. 1165-1176 ◽  
Author(s):  
François Girard ◽  
Louis De Grandpré ◽  
Jean-Claude Ruel

As climate changes, boreal forest ecosystems may become subject to disturbances that were previously uncommon in some regions. In recent decades, large tracts of northeastern boreal forest of Canada have been affected by different types of climatic events causing a lot of partial and some total stand mortality. Since these disturbances may become more important drivers of forest dynamics, there is a need to document their impact on forest structure. The objectives of this study were to describe temporal dynamics of partial windthrows and determine the effect of partial windthrow on stand composition and understory vegetation. The study was conducted in the North-Shore region of Quebec (Canada). Eighteen plots in closed forests were paired with 18 adjacent windthrow areas, in which trees experienced similar edaphic and climatic conditions. Dendroecological analyses, combined with vegetation sampling, were conducted on each site to determine stand structure and vegetation development through time. Significant increases in balsam fir and shade-tolerant species were observed in windthrow gaps. Tree mortality in windthrown stands was a slow process until the mid-1990s, a period during which spruce budworm defoliation may have played a role in weakening trees and making them more vulnerable to partial windthrow. Greater mortality observed following the mid-1990s was most certainly related to a regional storm. The initial composition of stands plays an important role in driving postwindthrow succession, as balsam fir is more susceptible to treefall. As opposed to stand-replacing windthrow and spruce budworm outbreaks that generate various postdisturbance responses, partial windthrow appears to only create opportunities for pre-established balsam fir to undergo release in gaps.


1995 ◽  
Vol 5 (2) ◽  
pp. 437-451 ◽  
Author(s):  
Eric S. Kasischke ◽  
N. L. Christensen ◽  
Brian J. Stocks

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