Effects of fires on carbon cycling in North American boreal peatlands

1998 ◽  
Vol 6 (1) ◽  
pp. 13-24 ◽  
Author(s):  
S C Zoltai ◽  
L A Morrissey ◽  
G P Livingston ◽  
W J Groot
Keyword(s):  
North America ◽  
Fire Frequency ◽  
Return Periods ◽  
Peat Layer ◽  
Raised Bogs ◽  
Boreal Peatlands ◽  
Carbon Release ◽  
Moisture Conditions ◽  
Carbon Losses ◽  
Surface Peat

Boreal peatlands occupy about 1.14 x 106 km2 in North America. Fires can spread into peatlands, burning the biomass, and if moisture conditions permit, burning into the surface peat. Charred layers in peat sections reveal that historically bogs in the subhumid continental regions and permafrost peatlands of the subarctic regions have been the most susceptible to fires. Fire return periods were estimated from the numbers and ages of the charred peat layers. Based on average moisture conditions of the surface, about 0.5% of the peatlands (6420 km2) can be expected to burn annually, but the surface peat layer is expected to burn only in a small portion of this area (1160 km2). Carbon losses from aboveground combustion, in the form of CO2, CO, CH4, and nonmethane hydrocarbons, are the highest in forested swamps at 2.03 Tg C ·year-1. Carbon losses due to combustion of surface peat is the highest in the driest peatlands (e.g., raised bogs underlain by permafrost) at 5.82 Tg C ·year-1. The total estimated carbon release due to aboveground combustion is 2.92 Tg C ·year-1 and due to belowground peat combustion is 6.72 Tg C ·year-1. These estimates of direct carbon emissions to the atmosphere due to wildfires suggest a globally significant, but relatively small source in contrast with emissions from wildfires in uplands. The effects of a possible climate change are expected to be most prominent in the continental and northern parts of North America. A lower water table would result in increased CO2 but decreased CH4 emissions from the peatlands. A drier climate may mean increased fire frequency and intensity, resulting in more fires in peatlands and an increased probability of the fires consuming part of the peat.Key words: fire, peatlands, carbon, boreal, permafrost, gas flux.

Wildfires in the southern Canadian Rocky Mountains and their relationship to mid-tropospheric anomalies

1993 ◽  
Vol 23 (6) ◽  
pp. 1213-1222 ◽  
Author(s):  
E.A. Johnson ◽  
D.R. Wowchuk
Keyword(s):  
North America ◽  
Rocky Mountains ◽  
Large Scale ◽  
Fire Frequency ◽  
Fuel Moisture ◽  
Large Fire ◽  
Canadian Rocky Mountains ◽  
Area Burned ◽  
Upper Level ◽  
Moisture Conditions

In this paper we present evidence for a large-scale (synoptic-scale) meteorological mechanism controlling the fire frequency in the southern Canadian Rocky Mountains. This large-scale control may explain the similarity in average fire frequencies and timing of change in average fire frequencies for the southern Canadian Rocky Mountains. Over the last 86 years the size distribution of fires (annual area burned) in the southern Canadian Rockies was distinctly bimodal, with a separation between small- and large-fire years at approximately 10–25 ha annual area burned. During the last 35 years, large-fire years had significantly lower fuel moisture conditions and many mid-tropospheric surface-blocking events (high-pressure upper level ridges) during July and August (the period of greatest fire activity). Small-fire years in this period exhibited significantly higher fuel moisture conditions and fewer persistent mid-tropospheric surface-blocking events during July and August. Mid-tropospheric surface-blocking events during large-fire years were teleconnected (spatially and temporally correlated in 50 kPa heights) to upper level troughs in the North Pacific and eastern North America. This relationship takes the form of the positive mode of the Pacific North America pattern.

The role of temperate zone forests in the global carbon cycle

1980 ◽  
Vol 10 (1) ◽  
pp. 53-60 ◽  
Author(s):  
Thomas V. Armentano ◽  
C. W. Ralston
Keyword(s):  
World War Ii ◽  
North America ◽  
Western Europe ◽  
Fossil Fuels ◽  
Carbon Sink ◽  
Forest Growth ◽  
Temperate Zone ◽  
Carbon Release ◽  
Annual Carbon ◽  
Limited Basis

Recent growth and harvest trends in commercial timberlands of the temperate zone suggest that these forests have been serving as a net sink for about 1.0 × 109 to 1.2 × 109 t of carbon annually over the past 3 decades. This is 20 to 60% of the annual carbon release from combustion of fossil fuels over the period, indicating that recovery transients in temperate zone forests apparently have been partially dampening the increase in atmospheric CO2 caused by fossil fuel combustion and tropical forest reduction. Net forest growth is occurring throughout the temperate zone with principal carbon sinks found in North America and in Siberia. Timber inventories for North America show an excess of growth over harvest equivalent to over 5 × 1015 g of C since the 1950. Limited data suggest that in Siberia there is a large stock of slowly growing conifers that are underexploited, forming a sink equivalent to that of North America. Reafforestation in western Europe has expanded forest area by 5% since World War II. Similar recovery may now be occurring in temperate Asia. Problems of data reliability, particularly for the U.S.S.R., and the limited basis for estimating carbon balance in entire forests, suggest a severalfold uncertainty in the carbon sink estimates.

scholarly journals Highly Distinct Microbial Communities in Elevated Strings and Submerged Flarks in the Boreal Aapa-Type Mire

2022 ◽  
Vol 10 (1) ◽  
pp. 170
Author(s):  
Andrey L. Rakitin ◽  
Shahjahon Begmatov ◽  
Alexey V. Beletsky ◽  
Dmitriy A. Philippov ◽  
Vitaly V. Kadnikov ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Microbial Communities ◽  
16S Rrna Gene Sequencing ◽  
Rrna Gene ◽  
16S Rrna Gene Sequences ◽  
Raised Bogs ◽  
European North ◽  
Rrna Gene Sequencing ◽  
Surface Peat

Large areas in the northern hemisphere are covered by extensive wetlands, which represent a complex mosaic of raised bogs, eutrophic fens, and aapa mires all in proximity to each other. Aapa mires differ from other types of wetlands by their concave surface, heavily watered by the central part, as well as by the presence of large-patterned string-flark complexes. In this paper, we characterized microbial diversity patterns in the surface peat layers of the neighboring string and flark structures located within the mire site in the Vologda region of European North Russia, using 16S rRNA gene sequencing. The microbial communities in raised strings were clearly distinct from those in submerged flarks. Strings were dominated by the Alpha- and Gammaproteobacteria. Other abundant groups were the Acidobacteriota, Bacteroidota, Verrucomicrobiota, Actinobacteriota, and Planctomycetota. Archaea accounted for only 0.4% of 16S rRNA gene sequences retrieved from strings. By contrast, they comprised about 22% of all sequences in submerged flarks and mostly belonged to methanogenic lineages. Methanotrophs were nearly absent. Other flark-specific microorganisms included the phyla Chloroflexi, Spirochaetota, Desulfobacterota, Beijerinckiaceae- and Rhodomicrobiaceae-affiliated Alphaproteobacteria, and uncultivated groups env.OPS_17 and vadinHA17 of the Bacteroidota. Such pattern probably reflects local anaerobic conditions in the submerged peat layers in flarks.

Evaluation of Satellite-Based Optical and Thermal Trapezoid Methods for Groundwater Table Depth Monitoring in Estonian Bogs

2020 ◽  
Author(s):  
Iuliia Burdun ◽  
Valentina Sagris ◽  
Michel Bechtold ◽  
Viacheslav Komisarenko ◽  
Ülo Mander ◽  
...  
Keyword(s):  
Land Surface ◽  
Large Scale ◽  
Bare Soil ◽  
Groundwater Table ◽  
Soil Conditions ◽  
Landsat 8 ◽  
Raised Bogs ◽  
Groundwater Table Depth ◽  
Dryness Index ◽  
Moisture Conditions

<p>Groundwater table depth and peat moisture content are of crucial importance for many peatland processes, like for example their greenhouse gas budget. Thus, there is a strong need for remote sensing techniques that allow to spatially monitor these critical moisture conditions to quantify the hydrological responses to climate change and other anthropogenic disturbances. Previous studies have demonstrated the usefulness but also limitations of microwave observations for peatland moisture monitoring at the large scale. Here, we explore the potential of techniques based on optical and thermal imagery for smaller scale applications.</p><p>Satellite-derived land surface temperature (LST) as well as shortwave infrared transformed reflectance (STR) are sensitive to soil moisture conditions in mineral soils. Both data form, together with remotely sensed vegetation indices (VIs), trapezoids in the LST-VI and STR-VI space with the highest range of possible LST and STR for bare soil conditions. The lowest and highest LST and STR along the vegetation cover gradient define the wet and dry edge, respectively. In this study, we used Landsat 7 and Landsat 8 satellite data for the vegetation periods from 2008 through 2019 to calculate various VIs, LST and STR for hemiboreal raised bogs in Estonia. Two common approaches for the determination of wet and dry edges for the LST-based method were applied and compared. The first approach estimates the edges directly from the observed values of VIs and LST for each scene; while the second one relies on modelled theoretical edges for each scene. In contrast, the STR-VI trapezoid is derived from observed values from all scenes as proposed in literature. The trapezoids are used to calculate the dryness index of each Landsat pixel by linearly scaling between the wet and dry edge. These indices are evaluated with measured groundwater table depth time series. Preliminary results indicate that, for our study area, suitable LST-based trapezoids cannot be derived from satellite observations alone, indicated by the low dependency of the resulting dryness index on groundwater table depth. Evaluation of the theoretically-derived trapezoids and the STR-VI is ongoing and will be discussed.</p>

Elemental dynamics in forested bogs in northern Minnesota

1991 ◽  
Vol 69 (3) ◽  
pp. 539-546 ◽  
Author(s):  
D. F. Grigal
Keyword(s):  
Primary Productivity ◽  
Plant Uptake ◽  
Net Primary Productivity ◽  
Nutrient Status ◽  
Landscape Position ◽  
Mineralization Rate ◽  
Annual Plant ◽  
Raised Bogs ◽  
Elemental Mass ◽  
Surface Peat

Dynamics of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), and magnesium (Mg) were determined for three perched bogs, formed by lake filling, and three raised bogs, formed by landscape swamping. N and K concentrations were higher in the undergrowth of perched bogs, and Ca and Mg concentrations were higher in subsurface anaerobic peat of raised bogs. Elemental pools in vegetation were in the order N > Ca > K > Mg > P; in surface peat, N > Ca > Mg > P = K. Differences in elemental mass between the bog types were closely related to biomass differences. The atmosphere potentially supplied from 3% of annual plant uptake of K to 20% of Mg; this fraction was inversely related to uptake as a proportion of the surface peat. Vegetation on raised bogs had a greater proportion of uptake from the atmosphere (15 vs. 12%), a faster rate of elemental turnover (3.8 vs. 4.8 years), and lower net primary productivity (NPP) than on perched bogs, all indicative of a lower nutrient status. The annual mineralization rate of the surface peat for both bog types was estimated at 1.5% year−1; NPP predicted from N mineralized at this rate agrees well with observations. The better nutritional status of perched bogs may be related to landscape position, with potential inputs via runoff from adjacent uplands. The nutrient capital in both bog vegetation and substrate was similar to that in upland northern conifer forests. Key words: acrotelm, ombrotrophic, raised bogs, nutrients, peatlands, nutrient cycling.

scholarly journals Growth of Lonicera caerulea across Fertility and Moisture Conditions: Comparisons with Lonicera villosa and Invasive Congeners

HortScience ◽  
2020 ◽  
Vol 55 (2) ◽  
pp. 149-155
Author(s):  
Darren J. Hayes ◽  
Bryan J. Peterson
Keyword(s):  
North America ◽  
North American ◽  
Treatment Plant ◽  
Competitive Growth ◽  
Growth Strategies ◽  
Lonicera Caerulea ◽  
Agricultural Use ◽  
Moisture Conditions ◽  
Individual Size ◽  
Insight Into

Several species of honeysuckle from Europe and Asia have proved to be invasive in North America, with substantial impacts on native ecosystems. Although shrubby honeysuckles of Eurasian origin have appeared on banned plant lists in North America and other parts of the world, cultivars of the edible blue honeysuckle (Lonicera caerulea L.) derived from Eurasian germplasm and marketed as honeyberry, Haskap, or sweetberry honeysuckle have recently been widely developed for agricultural use in North America, with little scrutiny of invasive potential in North America despite its documented invasion of the Scandinavian Peninsula in northern Europe. To gain insight into differences in growth strategies among congeners, we compared the growth of Eurasian L. caerulea with that of a closely related congener in North America [Lonicera villosa (Michx.) R. & S.] and two known invasive congeners from Eurasia (Lonicera tatarica L. and Lonicera xylosteum L.). In Expt. 1, L. villosa, L. caerulea, and L. tatarica were grown in #1 nursery containers after top-dressing with Osmocote Pro 17–5–11 4-month controlled-release fertilizer (CRF) at rates of 5, 10, 15, 20, and 25 g CRF/container. Across all fertilizer treatments, L. caerulea outperformed L. villosa by a factor of two for root and shoot dry weights, although L. tatarica produced more growth than either of the others and was more responsive to increasing CRF. However, L. caerulea more strongly resembled L. tatarica in form, producing leaves of greater individual size and producing significantly taller primary stems than L. villosa, evidence for prioritization of competitive growth. In Expt. 2, plants of the same taxa plus L. xylosteum were grown communally in #20 nursery containers, followed by a period in which each container was subjected to regular irrigation, withheld irrigation (dry treatment), or inundation (flooded treatment). Plant growth differed substantially among taxa, but moisture treatments did not affect growth significantly. As in Expt. 1, plants of L. caerulea in Expt. 2 produced greater dry biomass than plants of L. villosa and resembled the invasive Eurasian honeysuckles more strongly in size and form. We conclude Eurasian L. caerulea is distinct in growth rate and morphology from North American L. villosa. In light of these findings, the ecology and competitive ability of Eurasian L. caerulea may not be well predicted by ecological observations of its closely related North American congener.

scholarly journals Mechanism of two-dimensional long-term subsidence in surface peat layer

2015 ◽  
Vol 1 (6) ◽  
pp. 29-34 ◽  
Author(s):  
Takuya Miki ◽  
Satoshi Nishimura ◽  
Nobutaka Yamazoe
Keyword(s):  
Two Dimensional ◽  
Peat Layer ◽  
Surface Peat
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