Sphagnum mosses limit total carbon consumption during fire in Alaskan black spruce forests

2008 ◽  
Vol 38 (8) ◽  
pp. 2328-2336 ◽  
Author(s):  
Gordon Shetler ◽  
Merritt R. Turetsky ◽  
Evan Kane ◽  
Eric Kasischke
Keyword(s):  
Organic Matter ◽  
Forest Floor ◽  
Black Spruce ◽  
High Water ◽  
Total Carbon ◽  
Organic Layer ◽  
Sphagnum Mosses ◽  
Spruce Forests ◽  
Feather Moss ◽  
Soil Organic Layer

The high water retention of hummock-forming Sphagnum species minimizes soil moisture fluctuations and might protect forest floor organic matter from burning during wildfire. We hypothesized that Sphagnum cover reduces overall forest floor organic matter consumption during wildfire compared with other ground-layer vegetation. We characterized variability in soil organic layer depth and organic matter stocks in two pairs of burned and unburned black spruce ( Picea mariana (Mill.) BSP) stands in interior Alaska. In the unburned stands, microsites dominated by Sphagnum had more than twice as much soil organic matter·m–2 as microsites dominated by feather moss and (or) lichens. Whereas 20% of soil organic matter was consumed during fire in microsites dominated by Sphagnum, 45% was consumed in microsites dominated by the feather moss and (or) lichens. Across 79 recently burned black spruce stands, unburned moss abundance (primarily remnant Sphagnum hummocks), landscape position (backslope, flat upland, flat lowland classes), and the interaction among these variables explained 60% of postfire organic soil depths. We suggest that “Sphagnum sheep” could serve as a useful visual indicator of variability in postfire soil carbon stocks in boreal black spruce forests. Sphagnum mosses are important ecosystem engineers not only for their influence on decomposition rates, but also for their effect on fuel consumption and fire patterning.

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.

Soil organic layer combustion in boreal black spruce and jack pine stands of the Northwest Territories, Canada

2018 ◽  
Vol 27 (2) ◽  
pp. 125 ◽  
Author(s):  
Xanthe J. Walker ◽  
Jennifer L. Baltzer ◽  
Steven G. Cumming ◽  
Nicola J. Day ◽  
Jill F. Johnstone ◽  
...  
Keyword(s):  
Northwest Territories ◽  
Boreal Forests ◽  
Black Spruce ◽  
Jack Pine ◽  
Fire Intensity ◽  
Organic Layer ◽  
Complete Combustion ◽  
Soil Organic Layer ◽  
Pine Stands ◽  
Burn Depth

Increased fire frequency, extent and severity are expected to strongly affect the structure and function of boreal forest ecosystems. In this study, we examined 213 plots in boreal forests dominated by black spruce (Picea mariana) or jack pine (Pinus banksiana) of the Northwest Territories, Canada, after an unprecedentedly large area burned in 2014. Large fire size is associated with high fire intensity and severity, which would manifest as areas with deep burning of the soil organic layer (SOL). Our primary objectives were to estimate burn depth in these fires and then to characterise landscapes vulnerable to deep burning throughout this region. Here we quantify burn depth in black spruce stands using the position of adventitious roots within the soil column, and in jack pine stands using measurements of burned and unburned SOL depths. Using these estimates, we then evaluate how burn depth and the proportion of SOL combusted varies among forest type, ecozone, plot-level moisture and stand density. Our results suggest that most of the SOL was combusted in jack pine stands regardless of plot moisture class, but that black spruce forests experience complete combustion of the SOL only in dry and moderately well-drained landscape positions. The models and calibrations we present in this study should allow future research to more accurately estimate burn depth in Canadian boreal forests.

Nitrogen transformations in feather moss and forest floor layers of interior Alaska black spruce ecosystems

1984 ◽  
Vol 14 (2) ◽  
pp. 278-290 ◽  
Author(s):  
M. G. Weber ◽  
K. Van Cleve
Keyword(s):  
Forest Floor ◽  
Black Spruce ◽  
Vascular Plant ◽  
N Uptake ◽  
Nitrogen Transformations ◽  
Organic Matter Quality ◽  
Available N ◽  
Moss Species ◽  
Feather Moss ◽  
Interior Alaska

Permafrost-free and permafrost-dominated black spruce (Piceamariana (Mill.) B.S.P.) ecosystems in interior Alaska were treated with low addition levels of high enrichment isotope (<1% of the total nitrogen pool with 99 at.% excess 15N) to describe nitrogen dynamics through pools of selected forest floor components. A thick carpet of mosses, made up primarily of the feather moss species Hylocomiumsplendens (Hedw.) B.S.G. and Pleuroziumschreberi (B.S.G.) Mitt, seemed to play a vital role in the nitrogen economy of the forest floor. Nitrogen, quickly immobilized in the moss layers (green, brown) and retained there, was released very slowly to the lower organic layers (021 + 022) where most of the vascular plant roots were located. 15N uptake by the vascular understory was minimal, as was15Nexport via the soil solution. Periodic mineralization episodes, more frequent and dynamic at the permafrost-free site (where C/N ratios were lower), were largely restricted to the moss layers since available N fractions in deeper forest floor layers incorporated little label over the 3-year period. In the lower layers of the forest floor (021 + 022) temperature rather than organic matter quality appeared to be the overriding factor controlling N flow.

Nutrient cycling in relation to decomposition and organic-matter quality in taiga ecosystems

1983 ◽  
Vol 13 (5) ◽  
pp. 795-817 ◽  
Author(s):  
P. W. Flanagan ◽  
K. Van Cleve
Keyword(s):  
Organic Matter ◽  
Nitrogen Content ◽  
Forest Floor ◽  
Fungal Biomass ◽  
Microbial Respiration ◽  
Black Spruce ◽  
Litter Fall ◽  
Substrate Quality ◽  
Respiration Rates ◽  
Forest Floors

A variety of evergreen and deciduous forests in the taiga of interior Alaska were studied over a 5-year period to examine how the chemical quality of forest-floor organic matter affected its rate of decomposition and mineral cycling within and outside the tree vegetation. Litterbag and respiration studies were used to monitor decomposition. Natural forest-floor substrates and others altered by addition of N, P, and K fertilizer and glucose as a carbon source were studied in the laboratory and field for rates of weight loss and O2 consumption. Forest floors differing in C/N ratios, including those deficient in N, were used to measure substrate quality influences on seedling growth, nutrient content, and tannin content. Microbial (bacteria and fungi) biomass was measured across a range of forest types along with pH, base saturation total pool sizes of N and P, and annual mineralization of organic matter per square metre. Under identical moisture and temperature conditions average respiration rates in evergreen forest-floor L, F, and H substrates were 1.8, 2.8, and 2.0 times less than in the corresponding deciduous forest horizons, respectively. Birch L and F horizons had respiration rates 11.5 times higher than the corresponding black spruce layers. Weight losses in birch L, F, and H horizons were 6, 3, and 2 times higher, respectively, than in the corresponding black spruce substrates. Substrates had a quality-dependent decay rate which did not change when they were relocated within or between sites indicating that measured field climatic differences were not as influential on decay rates as substrate quality components. Fungal biomass was significantly correlated with the quantity of organic matter in all sites (n = 15, r = 0.62) but correlations were better for deciduous (n = 9, r = 0.89), and evergreen (n = 6, r = 0.82) forests separately. Strong correlations exist also between grams of organic matter decayed per square metre per year and fungal biomass (n = 13, r = 0.86), and fungal biomass and grams of N and P mineralized per square metre per year (n = 14, r = 0.95) and (n = 11, r = 0.94, respectively). Seedlings on mineral-deficient substrates produced more tannins than the controls, and seedlings on substrates with widening C/N ratios had successively less tissue with lower N content, and proportionally more roots. Nitrogen content of litter fall in increasingly nitrogen-poor forest floors was correspondingly lower. Nitrogen content of litter fall on N rich forest floors and N fertilized forest floors was proportionately higher. Nitrogen withdrawal in leaves at senescence was inversely correlated with grams N mineralized per square metre per year in forest floors. Fertilization did not influence microbial processes in the field, though lab studies indicated a negative influence of NH4, P, and K on microbial respiration. Glucose added in the laboratory and field markedly increased forest-floor microbial respiration. In vitro glucose-induced increases in respiration were not influenced by addition of ammonium nitrate and were significantly depressed by addition of P and K. In the field, fertilization had no effect on either glucose-induced respiration or microbial biomass.

scholarly journals The Distribution and Migration of 137Cs in Oak (Quercus serrata) and Cedar (Cryptomeria japonica) Forest Organic Fractions

Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1045
Author(s):  
Akwasi Dwira Mensah ◽  
Hiroto Toda ◽  
Sonoko Dorothea Bellingrath-Kimura ◽  
Hiroaki Kato ◽  
Dongsu Choi
Keyword(s):  
Organic Matter ◽  
Forest Soil ◽  
Cryptomeria Japonica ◽  
Quercus Serrata ◽  
Total Carbon ◽  
Organic Layer ◽  
Soil Columns ◽  
137Cs Inventory ◽  
Organic Fractions ◽  
And Migration

To analyse the 137Cs distribution and migration under various fractions of organic matter layers, this study investigated easily recognizable, originally shaped organic L-fractions, and not easily recognizable, early fermented and fragmented organic F-fractions, of both oak (Quercus serrata) and cedar (Cryptomeria japonica) sampled from Osawa watershed sites at Nihonmatsu City, Fukushima Prefecture, Japan. The organic materials were put on top of soil columns from Field Museum (FM) Tamakyuryo in Hachioji City, Tokyo. The 137Cs vertical distribution in forest soil profiles was analyzed using the relaxation mass depth, ho (kg m−2). Soil columns with both L and F- organic layer fractions of both oak and cedar, labelled as Oak-L, Oak-F, Cedar-L and Cedar-F with four replications (n = 16), were set up by the laboratory column-based method and kept under five months’ incubation period. Soil columns after incubation were sampled at depths of 0–1 cm, 1–2 cm, 2–5 cm and 5–10 cm. Results of 137Cs inventory in the organic fractions showed that 86% (oak and cedar) of the total organic layer fractions 137Cs inventory accumulated within the F-layer, indicating that the transformation of litter is a huge source for potentially mobile 137Cs, especially the oak F-layer (67% 137Cs inventory) and further continuous transfer into the forest soil mineral layers. A higher ho in L treated soils (Oak-L and Cedar-L) compared to the F treatments implied that the low 137Cs amounts penetrated faster and deeper due to their water-soluble nature. Furthermore, Cedar-F showed a higher ho of 24.3 kg m−2 than Oak-F of ho, 14.0 kg m−2, and a significant positive relationship between 137Cs retention and total carbon (TC) (p < 0.05) suggested the influence of soil organic matter on 137Cs penetration and retention. The C/N (carbon nitrogen ratio) results revealed that organic matter fractions of high C/N including 137Cs, as observed in Cedar-F, in which decomposition does not advance, penetrates soil depths while the organic matter fraction of low C/N, observed in Oak-F, showed that decomposition advanced to release 137Cs which was held by adsorption unto the RIP (radiocesium interception potential) of soil surface. In addition, infiltration by water as a transportation process was suggested to largely influence the downward migration and retention of 137Cs at lower depths of Cedar-F.

scholarly journals Mechanical site preparation: Key to microsite creation success on Clay Belt paludified sites

2015 ◽  
Vol 91 (02) ◽  
pp. 187-196 ◽  
Author(s):  
Mohammed Henneb ◽  
Osvaldo Valeria ◽  
Nicole J. Fenton ◽  
Nelson Thiffault ◽  
Yves Bergeron
Keyword(s):  
Organic Matter ◽  
High Water ◽  
Site Preparation ◽  
Tree Regeneration ◽  
High Water Content ◽  
Organic Layer ◽  
Forest Sector ◽  
Mechanical Site Preparation ◽  
Rooting Zone ◽  
Before And After

Paludification is the accumulation of partially decomposed organic matter over saturated mineral soils. It reduces tree regeneration and growth, mainly because of low temperatures and high water content in the rooting zone, reduced organic matter decomposition, and hence, low nutrient availability. On the Clay Belt of western Québec and eastern Ontario, forests tend to paludify naturally but this process might be promoted by logging methods. Our objective was to identify which of two commonly used mechanical site preparation (MSP) techniques is best adapted to reduce organic layer thickness (OLT) and generate favourable planting microsites post-harvest in paludified sites. Nine experimental blocks (between 20 ha–61 ha each) were delimited within a 35 km2 forest sector with variable levels of paludification. The forest sector was harvested by careful logging to protect advance growth and soils and subsequently the nine experimental blocks were treated with either forest harrowing, disc trenching (T26) or left as untreated controls (harvesting only) with three replicate blocks per treatment. We measured OLT before and after MSP and determined planting microsite quality within each block. Results revealed significant differences in OLT between MSP treatments and harvesting only. Overall, harrowing was the best technique, as it reduced OLT more than T26 scarification and generated the highest percent of good microsites, except where initial OLT was 44 cm–56 cm. Our results contribute to the successful use of MSP in paludified forests.

scholarly journals Increasing fire and the decline of fire adapted black spruce in the boreal forest

2021 ◽  
Vol 118 (45) ◽  
pp. e2024872118
Author(s):  
Jennifer L. Baltzer ◽  
Nicola J. Day ◽  
Xanthe J. Walker ◽  
David Greene ◽  
Michelle C. Mack ◽  
...  
Keyword(s):  
Climate Change ◽  
North America ◽  
Black Spruce ◽  
Wildlife Habitat ◽  
Ecosystem Functions ◽  
Organic Layer ◽  
Complete Combustion ◽  
Postfire Regeneration ◽  
Soil Organic Layer ◽  
Compositional Changes

Intensifying wildfire activity and climate change can drive rapid forest compositional shifts. In boreal North America, black spruce shapes forest flammability and depends on fire for regeneration. This relationship has helped black spruce maintain its dominance through much of the Holocene. However, with climate change and more frequent and severe fires, shifts away from black spruce dominance to broadleaf or pine species are emerging, with implications for ecosystem functions including carbon sequestration, water and energy fluxes, and wildlife habitat. Here, we predict that such reductions in black spruce after fire may already be widespread given current trends in climate and fire. To test this, we synthesize data from 1,538 field sites across boreal North America to evaluate compositional changes in tree species following 58 recent fires (1989 to 2014). While black spruce was resilient following most fires (62%), loss of resilience was common, and spruce regeneration failed completely in 18% of 1,140 black spruce sites. In contrast, postfire regeneration never failed in forests dominated by jack pine, which also possesses an aerial seed bank, or broad-leaved trees. More complete combustion of the soil organic layer, which often occurs in better-drained landscape positions and in dryer duff, promoted compositional changes throughout boreal North America. Forests in western North America, however, were more vulnerable to change due to greater long-term climate moisture deficits. While we find considerable remaining resilience in black spruce forests, predicted increases in climate moisture deficits and fire activity will erode this resilience, pushing the system toward a tipping point that has not been crossed in several thousand years.

Dynamics of moisture content in spruce–feather moss and spruce–Sphagnum organic layers during an extreme fire season and implications for future depths of burn in Clay Belt black spruce forests

2014 ◽  
Vol 23 (4) ◽  
pp. 490 ◽  
Author(s):  
Aurélie Terrier ◽  
William J. de Groot ◽  
Martin P. Girardin ◽  
Yves Bergeron
Keyword(s):  
Climate Change ◽  
Moisture Content ◽  
Mixed Model ◽  
Linear Mixed Model ◽  
Black Spruce ◽  
Weather Conditions ◽  
Fire Disturbance ◽  
Fire Season ◽  
Organic Layer ◽  
Feather Moss

High moisture levels and low frequency of wildfires have contributed to the accumulation of the organic layer in open black spruce (Picea mariana)–Sphagnum dominated stands of eastern boreal North America. The anticipated increase in drought frequency with climate change could lead to moisture losses and a transfer of the stored carbon back into the atmosphere due to increased fire disturbance and decomposition. Here we studied the dynamics of soil moisture content and weather conditions in spruce–feather moss and spruce–Sphagnum dominated stands of the boreal Clay Belt of eastern Canada during particularly dry conditions. A linear mixed model was developed to predict the moisture content of the organic material according to weather, depth and site conditions. This model was then used to calculate potential depth of burn and applied to climate model projections to determine the sensitivity of depth of burn to future fire hazards. Our results suggest that depth of burn varies only slightly in response to changes in weather conditions in spruce–Sphagnum stands. The reverse holds true in spruce–feather moss stands. In conclusion, our results suggest that spruce–Sphagnum stands in the boreal Clay Belt may be resistant to an increase in the depth of burn risk under climate change.

Modelling moss-derived carbon in upland black spruce forests

2016 ◽  
Vol 46 (4) ◽  
pp. 520-534 ◽  
Author(s):  
Kelly Ann Bona ◽  
Cindy H. Shaw ◽  
James W. Fyles ◽  
Werner A. Kurz
Keyword(s):  
Large Scale ◽  
Fire Regime ◽  
Black Spruce ◽  
Ground Cover ◽  
Tree Canopy ◽  
Canopy Openness ◽  
Organic Layer ◽  
Feather Moss ◽  
C Cycle ◽  
Scale Variation

Mosses play a key role in the carbon (C) cycle of upland black spruce (Picea mariana (Mill.) BSP) forests; however, national reporting models such as the Carbon Budget Model of the Canadian Forest Sector (CBM-CFS3) do not include mosses. This study examined whether widely available plot-level merchantable tree volume could predict, for black spruce ecosystems in Canada’s boreal forest, the relative proportions of sphagnum and feather moss ground cover and moss net primary productivity (NPP). A field study found that merchantable tree volume was significantly related to tree canopy openness (R2 = 0.61, P < 0.001), which could then be used to model the relative ground cover of feather moss (R2 = 0.5, P < 0.001) and sphagnum (R2 = 0.45, P < 0.001) and NPP of feather moss (R2 = 0.41, P < 0.001) and sphagnum (R2 = 0.28, P < 0.001). The resulting MOSS-C submodel increased the accuracy of the CBM-CFS3’s prediction of organic-horizon C five-fold and could explain large-scale variation in sites dominated by sphagnum with large organic-layer C pools but not fine-scale variation in dryer sites. To improve MOSS-C accuracy, future studies should focus on varying decomposition and fire regime parameters based on regional climate or plot-level vegetation parameters.

scholarly journals Effects of Mechanical Site Preparation on Microsite Availability and Growth of Planted Black Spruce in Canadian Paludified Forests

Forests ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 670 ◽  
Author(s):  
Mohammed Henneb ◽  
Osvaldo Valeria ◽  
Nelson Thiffault ◽  
Nicole J. Fenton ◽  
Yves Bergeron
Keyword(s):  
Organic Matter ◽  
Treatment Effectiveness ◽  
Black Spruce ◽  
Wood Fiber ◽  
Site Preparation ◽  
Planting Density ◽  
Organic Layer ◽  
Mechanical Site Preparation ◽  
Decomposition Of Organic Matter ◽  
Successful Establishment

Low productivity caused by paludification in some parts of the closed black spruce (Picea mariana (Mill.) B.S.P) dominated boreal forest threatens the provision of ecosystem services, including wood fiber production. The accumulation, over time, of organic matter in paludified soils leads to an anaerobic environment that reduces microbial activity, decelerates decomposition of organic matter, and generates nutrient-poor microsites for regeneration. Consequently, it results in significant impacts on site productivity. Considering its ability to disturb the soil, mechanical site preparation (MSP) is viewed as a potential treatment that can help restore productivity of paludified sites following harvesting. We conducted a field experiment to verify if (1) the availability of microsites conducive to reforestation varies with MSP, microtopography (slope and aspect) and initial OLT conditions; (2) the growth of planted seedlings depends on the intensity of mechanical disturbance of the organic layer, type of microsite, planting density, presence of Ericaceae, and the planting position and depth; (3) there are direct and indirect causal relationships between microsites availability after MSP, OLT, microtopography, planting quality and seedlings growth; and (4) if mechanical site preparation and microsite type exposed affect the Ericaceae cover after planting. Our results confirmed that MSP is effective in establishing conditions that permit a productive regeneration cohort on these paludified sites. To ensure successful establishment of plantations on these sites, it is necessary, however, to distinguish between those that are slightly or moderately paludified from those that are highly paludified, as treatment effectiveness of different MSP types depends on organic layer thickness. Our results also show that preference should be given to some microsite types as clay and mixed-substrate microsites for planting to ensure sufficient availability of water and nutrients for seedlings.

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