Evaluation of the composite burn index for assessing fire severity in Alaskan black spruce forests

2008 ◽  
Vol 17 (4) ◽  
pp. 515 ◽  
Author(s):  
Eric S. Kasischke ◽  
Merritt R. Turetsky ◽  
Roger D. Ottmar ◽  
Nancy H. F. French ◽  
Elizabeth E. Hoy ◽  
...  
Keyword(s):  
Black Spruce ◽  
Fire Severity ◽  
Strong Predictor ◽  
Mineral Soil ◽  
Fire Regimes ◽  
Quadratic Equation ◽  
Organic Layer ◽  
Layer Depth ◽  
Spruce Forests ◽  
Substrate Layer

We evaluated the utility of the composite burn index (CBI) for estimating fire severity in Alaskan black spruce forests by comparing data from 81 plots located in 2004 and 2005 fire events. We collected data to estimate the CBI and quantify crown damage, percent of trees standing after the fire, depth of the organic layer remaining after the fire, depth of burning in the surface organic layer (absolute and relative), and the substrate layer exposed by the fire. To estimate pre-fire organic layer depth, we collected data in 15 unburned stands to develop relationships between total organic layer depth and measures of the adventitious root depth above mineral soil and below the surface of the organic layer. We validated this algorithm using data collected in 17 burned stands where pre-fire organic layer depth had been measured. The average total CBI value in the black spruce stands was 2.46, with most of the variation a result of differences in the CBI observed for the substrate layer. While a quadratic equation using the substrate component of CBI was a relatively strong predictor of mineral soil exposure as a result of fire (R2 = 0.61, P < 0.0001, F = 60.3), low correlations were found between the other measures of fire severity and the CBI (R2 = 0.00–0.37). These results indicate that the CBI approach has limited potential for quantifying fire severity in these ecosystems, in particular organic layer consumption, which is an important factor to understand how ecosystems will respond to changing climate and fire regimes in northern regions.

Variation in postfire organic layer thickness in a black spruce forest complex in interior Alaska and its effects on soil temperature and moisture

2005 ◽  
Vol 35 (9) ◽  
pp. 2164-2177 ◽  
Author(s):  
Eric S Kasischke ◽  
Jill F Johnstone
Keyword(s):  
Soil Temperature ◽  
Fuel Consumption ◽  
Fire History ◽  
Black Spruce ◽  
Mineral Soil ◽  
Stand Age ◽  
Organic Layer ◽  
Layer Depth ◽  
Interior Alaska ◽  
Soil Temperature And Moisture

This study investigated the relationship between climate and landscape characteristics and surface fuel consumption as well as the effects of variations in postfire organic layer depth on soil temperature and moisture in a black spruce (Picea mariana (Mill.) BSP) forest complex in interior Alaska. Mineral soil moisture and temperature at the end of the growing season and organic layer depth were measured in three burns occurring in different years (1987, 1994, 1999) and in adjacent unburned stands. In unburned stands, average organic layer and humic layer depth increased with stand age. Mineral soil temperature and moisture varied as a function of the surface organic layer depth in unburned stands, indicating that as a stand matures, the moisture content of the deep duff layer is likely to increase as well. Fires reduced the depth of the surface organic layers by 5 to 24 cm. Within each burn we found that significant variations in levels of surface fuel consumption were related to several factors, including mineral soil texture, presence or absence of permafrost, and timing of the fires with respect to seasonal permafrost thaw. While seasonal weather patterns contribute to variations in fuel moisture and consumption during fires, interactions among the soil thermal regime, surface organic layer depth, and previous fire history are also important in controlling patterns of surface fuel consumption.

scholarly journals 15N natural abundances in two podsol soils of two spruce forests differing in their atmospheric N deposition conditions

2011 ◽  
Vol 51 (No. 9) ◽  
pp. 416-422 ◽  
Author(s):  
S.P. Sah
Keyword(s):  
Mineral Soil ◽  
Vertical Gradient ◽  
N Deposition ◽  
Climatic Conditions ◽  
Organic Layer ◽  
Atmospheric N Deposition ◽  
Spruce Forests ◽  
Humus Layer ◽  
N Enrichment ◽  
Deposition Conditions

This study aims to investigate the changes in isotope ratios in foliage and soils of the two spruce forests [Picea abies (L.) Karst.] differing greatly in their atmospheric N deposition and climatic conditions. As expected, both N concentrations and <sup>15</sup>N values in both needles and litter were found to be significantly higher in the Solling stand (N-saturated) compared to the Hyytial&auml; stand (N-poor). For the N-limited site (Hyytial&auml; plot), a typical vertical gradient of the soil <sup>15</sup>N-enrichment (both in organic and mineral soil) was observed. The N-saturated site (Solling) differs from the N-limited site (Hyytial&auml;) with respect to the <sup>15</sup>N abundance trend in organic layer. In the upper organic layer up to O-f horizon, i.e. mor layer (0&ndash;3.5 cm depth) of Solling plot, there is almost a trend of slight soil <sup>15</sup>N-depletion with increasing depth, and then there is a <sup>15</sup>N-enrichment from O-h horizon (humus layer) of organic layer to mineral soil horizons. This is explained by the presence of prominent NO<sub>3</sub><sup>&ndash;</sup> leaching at this plot

scholarly journals Contrasting Root System Structure and Belowground Interactions between Black Spruce (Picea mariana (Mill.) B.S.P) and Trembling Aspen (Populus tremuloides Michx) in Boreal Mixedwoods of Eastern Canada

Forests ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 127 ◽  
Author(s):  
Claudele Ghotsa Mekontchou ◽  
Daniel Houle ◽  
Yves Bergeron ◽  
Igor Drobyshev
Keyword(s):  
Nutrient Uptake ◽  
Resource Use ◽  
Root Biomass ◽  
Competitive Exclusion ◽  
Fine Root ◽  
Black Spruce ◽  
Mineral Soil ◽  
Organic Layer ◽  
Mixed Stands ◽  
Boreal Mixedwoods

This study explored the underground interactions between black spruce and trembling aspen in pure and mixed stands to understand how their soil resource use help these species coexist in the boreal mixedwoods of Western Quebec. We analyzed species-specific fine root foraging strategies (root biomass and root tissue density) along three soil layers (organic, top 0–15 cm, and bottom 15–30 cm mineral soil), using 180 soil cores. We collected cores in three sites, each containing three 20 × 50 m2 plots of pure spruce, pure aspen, and mixed spruce and aspen stands. Spruce had a shallow rooting, whereas aspen had a deep rooting in both types of stands. Compared to pure spruce stands, spruce had a lower fine root biomass (FRB) and a higher root tissue density (RTD) in the organic layer of mixed stands. Both patterns were indicative of spruce’s more intensive resource use strategy and competitive advantage over aspen in that layer. Aspen FRB in the organic soil did not differ significantly between pure and mixed stands, but increased in the mineral soil of mixed stands. Since we did not observe a significant difference in the nutrient content of the mineral soil layer between pure aspen and mixed stands, we concluded that aspen may experience competitive exclusion in the organic layer by spruce. Aspen exhibited an extensive nutrient uptake strategy in the organic layer of mixed stands: higher FRB and lower RTD than spruce. In mixed stands, the differences in aspen rooting patterns between the organic and mineral layers suggested the use of contrasting nutrient uptake strategies along the soil profile. We speculate that the stronger spatial separation of the roots of spruce and aspen in mixed stands likely contribute to a higher partitioning of their nutrient uptake along the soil profile. These results indicate the competitive exclusion of aspen by spruce in boreal mixedwoods, which likely occurs in the soil organic layer.

Dynamics and morphology of giant circular patterns of low tree density in black spruce stands in northern Quebec

2001 ◽  
Vol 79 (4) ◽  
pp. 420-428 ◽  
Author(s):  
Jean-François Giroux ◽  
Yves Bergeron ◽  
Jean J Veillette
Keyword(s):  
Surface Water ◽  
Picea Mariana ◽  
Black Spruce ◽  
Mineral Soil ◽  
Tree Density ◽  
Surface Elevation ◽  
Organic Layer ◽  
Spruce Stands ◽  
Spruce Mortality ◽  
Soil Measurements

Giant circular patterns of low tree density in black spruce (Picea mariana) stands were investigated in the Abitibi region of Quebec. We used dendrochronological techniques to test the hypotheses that ring patterns of low tree density are caused either by radial changes in spruce mortality or productivity. Seven circles were sampled. We found no gradient in the age of spruce along circle radii suggesting that rings of low tree density do not expand radially, that is, they are not spatially dynamic entities. The results indicate, however, that spruce trees were less dense and productive within the rings due to excessive moisture in the soil. Measurements of surface elevation, thickness of the organic layer and elevation of the mineral substrate across the circles revealed that a depression in the mineral soil beneath the rings traps the surface water and this area of poor drainage seems to prevent the establishment of black spruce within the rings. The origin of the ring-shaped depressions was attributed to geological or geomorphological causes.Key words: black spruce, Picea mariana, mortality, productivity, rings, geomorphology.

Influence of recent fire season and severity on black spruce regeneration in spruce–moss forests of Quebec, Canada1This article is one of a selection of papers from the 7th International Conference on Disturbance Dynamics in Boreal Forests.

2012 ◽  
Vol 42 (7) ◽  
pp. 1316-1327 ◽  
Author(s):  
Mélanie Veilleux-Nolin ◽  
Serge Payette
Keyword(s):  
Organic Matter ◽  
Organic Material ◽  
Black Spruce ◽  
Fire Severity ◽  
Mineral Soil ◽  
Thick Layer ◽  
Fire Season ◽  
Eastern Canada ◽  
Postfire Regeneration ◽  
Crown Forest

Postfire regeneration problems compromise the maintenance of closed-crown forests of eastern Canada, often shifting toward lichen woodlands. Compounded disturbances like successive fires or insect outbreaks followed by fire may be responsible for this shift. Leaving behind unfavourable seedbeds for the germination of black spruce ( Picea mariana (Mill.) B.S.P.) seeds, low-severity fires may also be involved in this transformation. The severity of recent fires and their impact on black spruce regeneration were evaluated using 13 stands burned in spring or summer within the closed-crown forest in Quebec during the last 20 years. Two ecological indicators were used to characterize fire severity: thickness of residual organic material and recovery of plant species. Regardless of the season, the ground of all burned stands was covered with a thick layer of residual organic matter. Blackened organic matter and ericaceous vegetation, indicating the passage of a low-severity fire, were widespread in all sites whereas acrocarpous mosses and bare mineral soil, indicating the passage of a severe fire, were uncommon. The preponderance of the thick layer of residual organic material blackened at the surface can explain the failure of regeneration in most studied sites. Low-severity fires are thus among factors probably involved in the expansion of lichen woodlands within the closed-crown forest.

Paludification dynamics in the boreal forest of the James Bay Lowlands: effect of time since fire and topography

2009 ◽  
Vol 39 (3) ◽  
pp. 546-552 ◽  
Author(s):  
Martin Simard ◽  
Pierre Y. Bernier ◽  
Yves Bergeron ◽  
David Paré ◽  
Lakhdar Guérine
Keyword(s):  
Organic Matter ◽  
Boreal Forest ◽  
Black Spruce ◽  
Forest Productivity ◽  
Organic Layer ◽  
Layer Depth ◽  
Potential Productivity ◽  
Organic Matter Accumulation ◽  
Soil Organic Layer ◽  
Time Since Fire

In many northern forest ecosystems, soil organic matter accumulation can lead to paludification and forest productivity losses. Paludification rate is primarily influenced by topography and time elapsed since fire, two factors whose influence is often confounded and whose discrimination would help forest management. This study, which was conducted in the black spruce ( Picea mariana (Mill.) BSP) boreal forest of northwestern Quebec (Canada), aimed to (1) quantify the effect of slope and time since fire on paludification rates, (2) determine whether soil organic layer depth could be estimated by surface variables that can potentially be remotely sensed, and (3) relate the degree of paludification to tree productivity. In this study, soil organic layer depth was used as an estimator of the degree of paludification. Slope and postfire age strongly affected paludification dynamics. Young stands growing on steep slopes had thinner organic layers and lower organic matter accumulation rates compared with young stands growing on flat sites. Black spruce basal area and Sphagnum cover were strong predictors of organic layer depth, potentially allowing mapping of paludification degree across the landscape. Tree productivity was negatively related to organic layer depth (R2 = 0.57). The equations developed here can be used to quantify forest productivity decline in stands that are undergoing paludification, as well as potential productivity recovery given appropriate site preparation techniques.

Spatiotemporal evolution of paludification associated with autogenic and allogenic factors in the black spruce–moss boreal forest of Québec, Canada

2019 ◽  
Vol 91 (2) ◽  
pp. 650-664 ◽  
Author(s):  
Éloïse Le Stum-Boivin ◽  
Gabriel Magnan ◽  
Michelle Garneau ◽  
Nicole J. Fenton ◽  
Pierre Grondin ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Vegetation Dynamics ◽  
Pinus Banksiana ◽  
Fire History ◽  
Black Spruce ◽  
Mineral Soil ◽  
Abies Balsamea ◽  
Organic Layer ◽  
Coniferous Species ◽  
Topographic Depressions

AbstractPaludification is the most common process of peatland formation in boreal regions. In this study, we investigated the autogenic (e.g., topography) and allogenic (fire and climate) factors triggering paludification in different geomorphological contexts (glaciolacustrine silty-clayey and fluvioglacial deposits) within the Québec black spruce (Picea mariana)–moss boreal forest. Paleoecological analyses were conducted along three toposequences varying from a forest on mineral soil to forested and semi-open peatlands. Plant macrofossil and charcoal analyses were performed on basal peat sections (≤50 cm) and thick forest humus (<40 cm) to reconstruct local vegetation dynamics and fire history involved in the paludification process. Results show that primary paludification started in small topographic depressions after land emergence ca. 8000 cal yr BP within rich fens. Lateral peatland expansion and secondary paludification into adjacent forests occurred between ca. 5100 and 2300 cal yr BP and resulted from low-severity fires during a climatic deterioration. Fires that reduced or eliminated entirely the organic layer promoted the establishment ofSphagnumin microdepressions. Paludification resulted in the decline of some coniferous species such asAbies balsameaandPinus banksiana. The paleoecological approach along toposequences allowed us to understand the spatiotemporal dynamics of paludification and its impacts on the vegetation dynamics over the Holocene.

scholarly journals Recovery of carbon pools a decade after wildfire in black spruce forests of interior Alaska: effects of soil texture and landscape position

2018 ◽  
Vol 48 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Gregory P. Houle ◽  
Evan S. Kane ◽  
Eric S. Kasischke ◽  
Carolyn M. Gibson ◽  
Merritt R. Turetsky
Keyword(s):  
Soil Texture ◽  
Black Spruce ◽  
Mineral Soil ◽  
Carbon Stocks ◽  
Parent Material ◽  
Influential Factor ◽  
Landscape Position ◽  
Organic Layer ◽  
Fire Dynamics ◽  
Interior Alaska

We measured organic-layer (OL) recovery and carbon stocks in dead woody debris a decade after wildfire in black spruce (Picea mariana (Mill.) B.S.P.) forests of interior Alaska. Previous study at these research plots has shown the strong role that landscape position plays in governing the proportion of OL consumed during fire and revegetation after fire. Here, we show that landscape position likely influences fire dynamics in these stands through changes in mineral soil texture. The content of fine-textured materials in underlying mineral soils was positively related to OL depths measured 1 and 10 years after fire, and there was an interaction between soil texture and elevation in governing OL consumption and OL recovery a decade following fire. OL depths 10 years after fire were 2 cm greater than 1 year after fire, with a range of 19 cm of accumulation to 9 cm of subsidence. Subsidence was inversely related to the percentage of fine textures within the parent material. The most influential factor determining the accumulation of OL carbon stocks a decade following wildfire was the interaction between landscape position and the presence of fine-textured soil. As such, parent material texture interacted with biological processes to govern the recovery of soil organic layers.

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