Corrigendum: Regional patterns of postfire canopy recovery in the northern boreal forest of Quebec: interactions between surficial deposit, climate, and fire cycle

2012 ◽  
Vol 42 (9) ◽  
pp. 1758-1758
Author(s):  
Nicolas Mansuy ◽  
Sylvie Gauthier ◽  
André Robitaille ◽  
Yves Bergeron
2012 ◽  
Vol 42 (7) ◽  
pp. 1328-1343 ◽  
Author(s):  
Nicolas Mansuy ◽  
Sylvie Gauthier ◽  
André Robitaille ◽  
Yves Bergeron

In many northern forest ecosystems, the postfire transition from a closed-crown forest to open woodland is often observed but poorly understood. This paper looks at the effect of interactions between surficial deposit, climate, and fire cycle on postfire forest recovery within a large territory (190 000 km2) of the boreal forest of eastern Canada. Postfire recovery was estimated using the time elapsed to move from the burnt stage to the regenerated stage and the young forest stage. The main objective was to determine if forests situated in dry regions (characterized by a high proportion of dry coarse surficial deposits, low precipitation, and short fire cycle) tend to reestablish more slowly after fire, obtaining a more open stand compared with wetter regions characterized by a longer fire cycle. To identify the best explanatory model for postfire recovery, multinomial logistic regressions with the Akaike information criterion were conducted using a combination of physicoclimatic factors. Our best model suggests that the most significant predictors of postfire recovery are time since fire (χ2 = 1370.06), surficial deposit type (χ2 = 651.95), the Canadian Drought Code (χ2 = 247.75), and the growing season precipitation (χ2 = 102.80). Fast recovery and dense forest regeneration are associated with subhydric till deposits only in the regions characterized by a long fire cycle (>500 years). Conversely, slow regeneration conducive to a sparse young forest was usually associated with regions characterized by a short fire cycle (<200 years) underlain by dry coarse deposits such as juxtaglacial but also mesic deposits in some cases. Our results also show that slow recovery and reduced forest regeneration are most likely to occur following fires that occurred in dry years, regardless of the deposit type and region.


2010 ◽  
Vol 19 (8) ◽  
pp. 1083 ◽  
Author(s):  
Nicolas Mansuy ◽  
Sylvie Gauthier ◽  
André Robitaille ◽  
Yves Bergeron

Spatial variations in the fire cycle of a large territory (190 000 km2) located in the boreal forest of eastern Canada were assessed using random sampling points. Our main objective was to determine if regions characterised by a large proportion of dry surficial deposit–drainage (SDD) burn more frequently than regions with a smaller proportion. Through a regionalisation of the landscape units, we analysed the effects of SDD on spatial variations of the fire cycle. A discriminant analysis involving the SDD and other physical variables (precipitation, temperature, aridity index, water bodies, elevation and slope) made it possible to identify a combination of variables characterising each region. A considerable variation in fire cycle was observed among the different SDD types (from 144 to 425 years) and between regions (from 90 to 715 years). Through the discriminant analysis, this study suggests that a combination of possible climatic top-down (precipitation R2 = 0.727, aridity index R2 = 0.663 and temperature R2 = 0.574) and bottom-up factors (xeric undifferentiated till R2 = 0.819 and humid undifferentiated till R2 = 0.691) could explain this variation at the regional scale. Implications of those results for forest protection against fire and regional development are briefly discussed.


The Condor ◽  
2003 ◽  
Vol 105 (1) ◽  
pp. 27-44 ◽  
Author(s):  
Craig S. Machtans ◽  
Paul B. Latour

Abstract Songbird communities in the boreal forest of the Liard Valley, Northwest Territories, Canada, are described after three years of study. Point count stations (n = 195) were placed in six types of forest (mature deciduous, coniferous, and mixedwood; young forests; wooded bogs; clearcuts) in a 700-km2 area. Vegetation characteristics at each station were also measured. Eighty-five species of birds (59 passerine species) occurred in 11 647 detections. Mixedwood forests had the highest richness of songbirds (∼41 species per 800 individuals) of the six forest types, and contained approximately 30% more individuals than nearly pure coniferous or deciduous forests. Species richness and relative abundance was 10–50% lower than in comparable forests farther south and east, and the difference was most pronounced in deciduous forests. Communities were dominated by a few species, especially Tennessee Warbler (Vermivora peregrina), Magnolia Warbler (Dendroica magnolia), Swainson's Thrush (Catharus ustulatus), Yellow-rumped Warbler (Dendroica coronata) and Chipping Sparrow (Spizella passerina). White-throated Sparrow (Zonotrichia albicollis), a dominant species in boreal forests farther south, was notably scarce in all forests except clearcuts. Clearcuts and wooded bogs had the simplest communities, but had unique species assemblages. Canonical correspondence analysis showed that the bird community was well correlated with vegetation structure. The primary gradient in upland forests was from deciduous to coniferous forests (also young to old, respectively). The secondary gradient was from structurally simple to complex forests. These results allow comparisons with other boreal areas to understand regional patterns and help describe the bird community for conservation purposes. Comunidades de Aves Canoras de Bosques Boreales del Valle de Liard, Territorios del Noroeste, Canadá Resumen. Luego de tres años de estudio, se describen las comunidades de aves canoras de bosques boreales del Valle de Liard, Territorios del Noroeste, Canadá. Se ubicaron estaciones de conteo de punto (n = 195) en seis tipos de bosque (maduro caducifolio, conífero y de maderas mixtas; bosques jóvenes; pantanos arbolados; zonas taladas) en un área de 700 km2. Las características de la vegetación en cada estación también fueron medidas. Se registraron 85 especies de aves (59 especies de paserinas) en 11 647 detecciones. Los bosques mixtos presentaron la mayor riqueza de aves canoras (∼41 especies por 800 individuos) de los seis tipos de bosque, y contuvieron aproximadamente 30% individuos más que los bosques de coníferas y los caducifolios. La riqueza de especies y la abundancia relativa fue 10–50% menor que en bosques comparables más al sur y al este, y la diferencia fue más pronunciada en los bosques caducifolios. Las comunidades estuvieron dominadas por unas pocas especies, especialmente Vermivora peregrina, Dendroica magnolia, Catharus ustulatus, Dendroica coronata y Spizella passerina. Zonotrichia albicollis, una especie dominante en bosques boreales más al sur, fue notablemente escasa en todos los bosques, excepto en las zonas taladas. Las áreas taladas y los pantanos arbolados tuvieron las comunidades más simples, pero presentaron ensamblajes únicos. Análisis de correspondencia canónica mostraron que la comunidad de aves estuvo bien correlacionada con la estructura de la vegetación. El gradiente primario en bosques de zonas altas fue de bosque caducifolio a conífero (también de joven a viejo, respectivamente). El gradiente secundario fue de bosques estructuralmente simples a bosques complejos. Estos resultados permiten hacer comparaciones con otros bosques boreales para entender los patrones regionales y ayudar a describir las comunidades de aves con fines de conservación.


2010 ◽  
Vol 19 (8) ◽  
pp. 1099 ◽  
Author(s):  
Christelle Hély ◽  
C. Marie-Josée Fortin ◽  
Kerry R. Anderson ◽  
Yves Bergeron

Wildfire simulations were carried out using the Prescribed Fire Analysis System (PFAS) to study the effect of landscape composition on fire sizes in eastern Canadian boreal forests. We used the Lake Duparquet forest as reference, plus 13 forest mosaic scenarios whose compositions reflected lengths of fire cycle. Three fire weather risks based on duff moisture were used. We performed 100 simulations per risk and mosaic, with topography and hydrology set constant for the reference. Results showed that both weather and landscape composition significantly influenced fire sizes. Weather related to fire propagation explained almost 79% of the variance, while landscape composition and weather conditions for ignition explained ∼14 and 2% respectively. In terms of landscape, burned area increased with increasing presence of shade-tolerant species, which are related to long fire cycles. Comparisons among the distributions of cumulated area burned from scenarios plus those from the Société de Protection des Forêts contre le Feu database archives showed that PFAS simulated realistic fire sizes using the 80–100% class of probable fire extent. Future analyses would best be performed on a larger region as the limited size of the study area could not capture fires larger than 11 000 ha, which represent 3% of fires but 65% of the total area burned at the provincial scale.


1999 ◽  
Vol 77 (8) ◽  
pp. 1185-1188 ◽  
Author(s):  
E A Johnson ◽  
K Miyanishi ◽  
N O'Brien

Climate modelling studies have predicted an increase in fire frequency with global warming as well as suggesting a longer fire season occurring later in the year. We used 160 years of fire scars in Pinus banksiana Lamb. dating from 1831 to 1948 and written fire records from 1927 to 1995 for Prince Albert National Park in the southern boreal forest to look for evidence of changes in the duration and timing of the fire season (defined as the months when large areas burn) that may have accompanied past changes in fire frequency. The Park's time-since-fire distribution had indicated two such changes: one around 1890 and the other around 1945, both in the direction of decreasing fire frequency. Both fire scars and written fire records indicated that the dominance of the spring fire season (April-June) has remained unchanged over the past 160 years. A small number of scars suggested that the fire season may have extended slightly into the summer (July) prior to 1890 when the fire cycle was much shorter and that the fire season may have shifted to a slightly earlier spring start after 1945 when the fire cycle was much longer.Key words: fire season, boreal forest, fire frequency.


Author(s):  
Joshua P. Schimel ◽  
F. Stuart Chapin III

Forest ecosystems typically occur in moderate environments where growing season rainfall is adequate to support tree growth and where nongrowing season conditions are not too extreme. The Alaskan boreal forests, however, occur at the limit of the forest biome, in an environment that is climatically extreme, with strong physical gradients. The seasonal variation in temperature is among the greatest on earth, with winter temperatures as low as –50ºC and summer growing season temperatures that can reach +30ºC (Chapter 4). The growing season is short, the climate is semi-arid, and growing season rainfall is limited. Forests exist in the region because evapotranspiration is also limited. Steep south-facing slopes can be too dry to support tree growth (Chapter 6). In contrast, in flat, low-lying areas, low evapotranspiration combined with permafrost produces wetlands despite the low rainfall. Regular drought makes the forest highly susceptible to fires. At large scales (many square kilometers), the boreal forest experiences regular, extensive fires that destroy whole stands, resetting succession (Chapter 17). This regular fire cycle produces a patchwork mosaic of forest stands in different successional stages across the landscape (Dyrness et al. 1986, Kasischke and Stocks 2000; Chapter 7). In large rivers (e.g., the Tanana), the cutting and filling of meander loops washes away some forest stands while depositing new silt bars for colonization and succession (Zasada 1986). At the landscape scale, the biogeochemical cycles in the boreal forest are therefore dominated by landscape structure (e.g., dry uplands vs. wet lowlands) and by disturbance (particularly fire). At smaller scales, however, the strong feedbacks between plant and soil processes control much of the functioning of individual forest stands, and possibly the rate of transition among successional stages. In this chapter, we discuss how microbial processes in the boreal forest produce unusual patterns of nutrient cycling that drive the overall functioning of boreal forest stands. Figure 14.1 illustrates the linkages between plant and microbial communities that dominate the functioning of the boreal forest soil system. In the feedbacks between plant and soil processes, plants drive the loop largely through inputs of organic materials.


2001 ◽  
Vol 31 (3) ◽  
pp. 384-391 ◽  
Author(s):  
Yves Bergeron ◽  
Sylvie Gauthier ◽  
Victor Kafka ◽  
Patrick Lefort ◽  
Daniel Lesieur

Given that fire is the most important disturbance of the boreal forest, climatically induced changes in fire frequency (i.e., area burnt per year) can have important consequences on the resulting forest mosaic age-class distribution and composition. Using archives and dendroecological data we reconstructed the fire frequency in four large sectors along a transect from eastern Ontario to central Quebec. Results showed a dramatic decrease in fire frequency that began in the mid-19th century and has been accentuated during the 20th century. Although all areas showed a similar temporal decrease in area burned, we observed a gradual increase in fire frequency from the west to Abitibi east, followed by a slight decrease in central Quebec. The global warming that has been occurring since the end of the Little Ice Age (~1850) may have created a climate less prone to large forest fires in the eastern boreal forest of North America. This interpretation is corroborated by predictions of a decrease in forest fires for that region of the boreal forest in the future. A longer fire cycle (i.e., the time needed to burn an area equivalent to the study area) has important consequences for sustainable forest management of the boreal forest of eastern Canada. When considering the important proportion of overmature and old-growth stands in the landscape resulting from the elongation of the fire cycles, it becomes difficult to justify clear-cutting practices over all the entire area as well as short rotations as a means to emulate natural disturbances. Alternative practices involving the uses of variable proportion of clear, partial, and selective cutting are discussed.


2001 ◽  
Vol 31 (8) ◽  
pp. 1462-1466 ◽  
Author(s):  
K Miyanishi ◽  
E A Johnson

A report by Ward and Tithecott (P.C. Ward and A.G. Tithecott. 1993. Ontario Ministry of Natural Resources, Aviation, Flood and Fire Management Branch, Publ. 305.) is frequently cited in the literature as providing evidence of the effects of fire suppression on the boreal forest. The study is based on 15 years of fire data and stand age data from Ontario, Canada. A re-examination of this report reveals serious flaws that invalidate the conclusions regarding effects of fire suppression on fire size and fire frequency. The fire-size data from the unprotected zone are censored in the small size classes because of detection resolution, invalidating comparisons of shapes of the distributions between the protected and unprotected zones. Use of different plotting scales gives the false appearance of large differences in the number of large fires between the two zones. Stand age data are used to show a change in fire frequency in the 20th century, and this change is attributed to fire suppression. However, no evidence is presented to conclude that this change in fire frequency is attributable to fire suppression and not to climate change. The estimate of the current fire cycle is based on too short a record to give a reliable estimate given the variation in annual area burned. Therefore, this report does not present sound evidence of fire suppression effects and should not be cited as such.


2002 ◽  
Vol 32 (11) ◽  
pp. 1996-2009 ◽  
Author(s):  
Daniel Lesieur ◽  
Sylvie Gauthier ◽  
Yves Bergeron

Fire history and forest dynamics were reconstructed for a 3800-km2 territory located in the south-central boreal forest of Quebec. Fire cycle was characterized using a random sampling strategy combined with archival data on fires that had occurred since 1923 on private land owned by Smurfit-Stone. Bioclimatic subdomain, land use, surficial deposit, and mean distance from a firebreak did not affect the fire cycle. Fire cycles have been longer since the end of the Little Ice Age (~1850). Warming after the Little Ice Age seems to have triggered a change in fire frequency. Forest dynamics were characterized by transition matrices for changes in dominant canopy composition from 344 permanent sampling plots. These permanent plots were sampled approximately every 15 years over the preceding 40 years. We observed two distinct patterns of replacement: (i) deciduous and mixed stands were replaced by balsam fir (Abies balsamifera (L.) Mill.) (and, to a lesser extent, by black spruce (Picea mariana (Mill.) BSP)) and (ii) jack pine (Pinus banksiana Lamb.) was replaced by black spruce. Analyses confirm that species replacement occurs in the eastern boreal forest of Canada when the fire-return interval is long enough and that the substrate plays an important role along with other disturbances, such as insect outbreaks. Our results also suggest that the proportion of old-growth forests (>100 years old) in the landscape should increase as a result of the lengthening of the fire cycle. More and more stands are likely to experience species replacement. From the standpoint of sustainable forest management, this perspective calls into question the widespread use of clear-cutting in the boreal forest. Regional context must be taken into account in forest management if the conservation of biodiversity and ecosystem integrity are serious objectives. Economically and ecologically sound silvicultural scenarios that emulate natural processes are discussed.


2006 ◽  
Vol 19 (8) ◽  
pp. 1437-1449 ◽  
Author(s):  
Jin-Ho Yoon ◽  
Tsing-Chang Chen

Abstract It is not unreasonable to expect that boreal forests that exist along 60°N in the Eurasian and North American continents were created and are maintained by warm seasonal rainfall. As revealed from satellite observations and various precipitation sources, zonally elongated rainbelts appear along these forests. Previous studies show that a relationship may exist between the frontal zone along the Arctic seaboard and regional patterns of high-latitude precipitation. It was observed by this study that baroclinic zones associated with strong Arctic westerlies coincide with minor storm tracks and boreal forest rainbelts only in eastern Canada. In contrast, this coincidence does not occur in northern Europe, eastern Siberia, and the Alaska–Pacific coast, because boreal forest rainbelts in these regions are located farther south of strong Arctic westerlies and ahead of high-latitude troughs over central Eurasia, the Bering Sea, the Labrador Sea, and the Norwegian Sea. Therefore, instead of baroclinicity along strong Arctic westerlies, favorable environments for the formation of minor storm tracks are developed by positive vorticity advections ahead of these high-latitude troughs. The water vapor budget analyses performed with NCEP and Goddard Earth Observing System (GEOS-1) reanalyses show that the boreal forest rainbelts are essentially maintained by the convergence of water vapor flux associated with transient disturbances at high latitudes.


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