scholarly journals Snag use by Foraging Black-Backed Woodpeckers (Picoides Arcticus) in a Recently Burned Eastern Boreal Forest

The Auk ◽  
2003 ◽  
Vol 120 (2) ◽  
pp. 505-511 ◽  
Author(s):  
Antoine Nappi ◽  
Pierre Drapeau ◽  
Jean-François Giroux ◽  
Jean-Pierre L. Savard

Abstract We studied snag use for foraging by Black-backed Woodpeckers (Picoides arcticus) one year after a fire in an eastern black spruce (Picea mariana) boreal forest in Quebec, Canada. We searched for signs of foraging (bark flaking and excavation holes) by Black-backed Woodpeckers on 6,536 snags sampled in 56 plots located in portions of the burned forest that had not been salvage logged. A logistic regression model was developed based on the presence or absence of foraging signs. Results showed that Black-backed Woodpeckers used larger snags that were less deteriorated by fire (qualified as high-quality snags). Direct field observations of individuals foraging on 119 snags also indicated that used snags corresponded to those of high predicted quality. Finally, we assessed the relationship between food availability and snag characteristics by measuring the density of wood-boring beetle larvae holes on 30 snags of different size and deterioration classes. High-quality snags contained higher prey densities (wood-boring beetle holes) than smaller and more deteriorated snags. We recommend that forest blocks characterized by large and less deteriorated trees be preserved from salvage logging in recently burned boreal forests in northeastern North America.

2003 ◽  
Vol 20 (4) ◽  
pp. 167-174
Author(s):  
Nobutaka Nakamura ◽  
Paul M. Woodard ◽  
Lars Bach

Abstract Tree boles in the boreal forests of Alberta, Canada will split once killed by a stand-replacing crown fire. A total of 1,485 fire-killed trees were sampled, 1 yr after burning, in 23 plots in 14 widely separated stands within a 370,000 ha fire. Sampling occurred in the Upper and Lower Foothills natural subregions. The frequency of splitting varied by species but averaged 41% for all species. The order in the frequency of splitting was balsam fir, black spruce, white spruce and lodgepole pine. The type of splitting (straight, spiral, or multiple) varied by species, as did the position of the split on the tree bole. Aspect or solar angle was not statistically related to the type or occurrence of splitting.


2005 ◽  
Vol 35 (3) ◽  
pp. 633-642 ◽  
Author(s):  
Marc-André Parisien ◽  
Luc Sirois ◽  
Sylvain Parent

This study examines the variability of the potential aging error for saplings (height ≤1.5 m) of black spruce (Picea mariana (Mill.) B.S.P.) in mature fire-dominated stands (n = 14 stands) of the northern boreal forest of northwestern Quebec. Age underestimation was determined by counting the number of underground bud scars of saplings. The magnitude and variability of age underestimation was compared within and among stands. The relationship between corrected ages (the sum of age underestimation and the number of growth rings at ground level) and ground-level ages was strongly linear and was therefore described with simple linear regression models. To evaluate landscape-level variability in this relationship, the regressions were compared among stands using mixed models. Despite high variability in age underestimation at the stand level, the relationship between corrected and ground-level age was highly significant (p < 0.0001) for all stands except one. However, there were many significant statistical differences between these regressions, indicating high landscape-level variability. The magnitude of age underestimation was found to be highly site specific (means of 7–26 years), the phenomenon being more marked and variable in older stands. Given high landscape-level variability, age underestimation of understory black spruce saplings in northern boreal stands must be documented for every sampled stand to apply a valid age correction in studies that involve multiple stands.


2012 ◽  
Vol 42 (7) ◽  
pp. 1253-1263 ◽  
Author(s):  
David W. Andison

Under the auspices of ecosystem-based management, historical disturbance patterns are promoted as a means of providing benchmarks for ecosystem sustainability. The associated research in support of this strategy in the boreal forest has substantially increased our understanding of frequencies, sizes, shapes, and severities of wildfires. However, despite the fact that different spatial definitions of wildfires exist in both research and practice, we have not considered the significance or impact of those differences on observed patterns. This study addresses this gap by conducting a sensitivity analysis on the influence of 11 spatial definitions of a wildfire on six pattern metrics for 24 wildfires in the Foothills Natural Region of Alberta. The results suggest that all pattern metrics were sensitive to changes to wildfire delineation, but in particular the total amount of remnants, wildfire shape, and the relationship between pre-burn fuel types and the probability of burning. The results also suggest that simple mortality maps do not necessarily identify multiple disturbed patches within wildfires, an attribute undocumented by previous research. These pattern differences potentially correspond to some fundamental differences in perception of how and why wildfires burn and our understanding of the associated processes and biological responses.


2008 ◽  
Vol 17 (4) ◽  
pp. 490 ◽  
Author(s):  
Karen A. Murphy ◽  
Joel H. Reynolds ◽  
John M. Koltun

During the 2004 fire season ~6.6 million acres (~2.7 million ha) burned across Alaska. Nearly 2 million of these were on National Wildlife Refuge System lands inaccessible from the state’s limited road system. Many fires burned through September, driven by unusually warm and dry temperatures throughout the summer. Using several fires from this season, we assessed the national burn severity methodology’s performance on refuge lands. Six fires, spanning 814 489 acres (329 613 ha), were sampled on five boreal forest refuges. In total, 347 sites were sampled for vegetation composition and ground-based burn severity estimates following the national protocols. The relationship between the differenced Normalized Burn Ratio (dNBR) and composite burn index (CBI) was unexpectedly weak (R2adjusted, 0.11–0.64). The weak relationship was not a result of data or image processing errors, nor of any biotic or abiotic confounding variable. The inconsistent results, and dNBR’s limited ability to discern the ecologically significant differences within moderate and high severity burn sites, indicate that the current methodology does not satisfy key Alaskan boreal forest management objectives.


2012 ◽  
Vol 42 (7) ◽  
pp. 1306-1315 ◽  
Author(s):  
Evelyn Belien ◽  
Sergio Rossi ◽  
Hubert Morin ◽  
Annie Deslauriers

The predicted climate warming and more frequent and longer droughts are expected to produce potentially severe water stresses in the boreal forest. The aim of this experiment was to study the effect of a summer drought on xylem phenology and anatomy of mature black spruce ( Picea mariana (Mill.) BSP) trees in their natural environment. The trees were excluded from rain during June–September 2010 by the installation of under-canopy roofs in four sites of the boreal forest of Quebec. Xylem phenology, stem radius variations, and physiological traits of treated and control trees were monitored at short time resolution. At the end of the growth season, cell characteristics were measured. The rain exclusion reduced the cell area of the xylem, but no significant change was observed in cell wall thickness, cell production, or phenology. Stem radius variations of the treated trees were lower but followed the same pattern as the control. After removal of the exclusion, trees and soil quickly recovered their normal water status. One summer of drought led to the formation of smaller tracheids but showed that black spruce is resistant to this rain exclusion treatment. This is likely due to the ability to collect water from sources other than the superficial soil horizon.


2016 ◽  
Vol 46 (4) ◽  
pp. 564-571 ◽  
Author(s):  
Yannick Cadorette-Breton ◽  
Christian Hébert ◽  
Jacques Ibarzabal ◽  
Richard Berthiaume ◽  
Éric Bauce

This study aimed to characterize the vertical distribution of longhorned beetle larvae in burned trees of the eastern Canadian boreal forest. Black spruce (Picea mariana (Mill.) Britton, Sterns & Poggenb.) and jack pine (Pinus banksiana Lamb.) trees burned at three severity levels were cut, and 30 cm boles were collected from the ground up to a height of 9.45 m. Boles were debarked and dissected to collect insect larvae. Results show that the three most abundant longhorned beetle species were vertically segregated among burned jack pine and black spruce trees, but the section having the highest timber value was heavily infested by woodborer larvae. Larval density distribution of Monochamus scutellatus scutellatus (Say) and of Acmaeops proteus proteus (Kirby) could be linked with bark thickness, which also depends on fire severity. Lightly burned stands of black spruce were the most heavily infested and should be salvaged only if they are easily accessible and can thus be rapidly harvested and processed at the mill. More severely burned stands should be salvaged later as they will be less affected by woodborers, as should jack pine, which is lightly infested compared with black spruce. The ecological role of stumps should be further investigated because they could still have an ecological value after salvage logging as Arhopalus foveicollis (Haldeman) uses them specifically.


2011 ◽  
Vol 41 (5) ◽  
pp. 994-1003 ◽  
Author(s):  
Antoine Nappi ◽  
Pierre Drapeau

Burned forests represent high-quality habitats for many deadwood-dependent species. Yet, post-fire conditions may vary greatly within and among burns and thereby may affect habitat suitability for these species. We studied habitat selection of nesting black-backed woodpeckers ( Picoides arcticus Swainson) in recently burned spruce-dominated boreal forests. Our objectives were to (i) identify factors involved in snag selection for both nesting and foraging and (ii) examine selection of nest sites within the burned landscape. A total of 92 nests and 1612 foraging observations were used to investigate snag selection. Our results show that both pre-fire forest conditions and fire severity are important in determining the quality of burned forests for black-backed woodpeckers. This species selected large snags for both nesting (>20 cm DBH) and foraging (>15 cm DBH). Woodpeckers selected deciduous and degraded “pre-fire” snags for nesting whereas black spruce snags that had been created by fire and that were moderately burned were preferred for foraging. Nest sites were concentrated in burned mature stands and supported higher densities of large snags (e.g., >15 cm DBH). Our results suggest that burned forest patches of at least 20 ha and composed mainly of burned mature and old-growth forests should be maintained during post-fire harvesting. The decrease in the amount of late seral stands in managed forest landscapes raises concerns about the future availability of high-quality burned forests for this species.


Author(s):  
Caius Ribeiro-Kumara ◽  
Cristina Santín ◽  
Stefan H. Doerr ◽  
Jukka Pumpanen ◽  
Greg Baxter ◽  
...  

Fires are an important perturbation for the carbon (C) dynamics of boreal forests, especially when they are stand-replacing. In North American boreal forests, crown fires are predominant and, therefore, the most studied. However, surface fires can also lead to major tree mortality with substantial implications for the C balance. Here, we assess the short- (hours – days) to medium-term (1 – 3 years) effects of the different fire types (surface vs. crown) on the postfire soil C effluxes in jack pine and black spruce forest stands in the Northwest Territories, Canada. We found that while trees were instantly killed by the four crown fires studied, trees also died within one year after two of three surface fires studied. Associated with this tree mortality, soil autotrophic respiration decreased after both fire types, although at different timings. The soil heterotrophic respiration was either lower or unchanged when measured 1 – 3 years after either fire type, but was increased when measured immediately after a surface fire, possibly due to the interaction between ash generation and wetting performed to suppress the fire. Our results suggest that both fire types can thus substantially alter C fluxes in the short- to medium-term, both through changes in vegetation and the soil environment.


2004 ◽  
Vol 80 (1) ◽  
pp. 67-74 ◽  
Author(s):  
A. Nappi ◽  
P. Drapeau ◽  
J -P.L. Savard

In recent years, the increase in wood demand, the reduction in the availability of timber resources and the northern expansion of timber harvesting, along with the general perception that wildfires create ecological disasters, have favoured an increase in salvage logging in burned boreal forests. Concurrently, pioneer studies have shown that these post-fire forests may represent important habitats for several wildlife species and that intensive salvage logging, by removing standing snags, has several impacts on wildlife. However, the effects of salvage logging on biodiversity have yet to be considered in post-fire management plans. We examine the issue of salvage logging for wildlife in the boreal forest, with particular reference to Québec as an example. We describe our current state of knowledge on the use of burned forests by some wildlife and on the impacts of salvage logging on these habitats. We conclude that snag retention at multiple spatial and temporal scales in recent burns, which will be salvage-logged, is a prescription that must be implemented to meet the principles of sustainable forest management and the maintenance of biodiversity in the boreal forest. Key words: boreal forest, post-fire forests, salvage logging, snags, wildlife, birds, cavity-nesting birds, woodpeckers, mammals, invertebrates, xylophagous insects, biodiversity


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