Black Spruce Bog Research Articles

Trapped Greenhouse Gases in the Permafrost Active Layer: Preliminary Results for Methane Peaks in Vertical Profiles of Frozen Alaskan Soil Cores

Degradation of organic carbon stored in permafrost may represent an additional source of atmospheric greenhouse gases (GHGs) in a warming climate. However, there is no clear understanding of how seasonal freeze–thaw affects gas permeability and emission of methane in permafrost soils, in part due to the lack of chemical and physical characterisation of the soils. Here, we report vertical profiles of CO2, CH4 and other soil properties with resolutions of 0.05–0.1 m depth from five soil cores, drilled to 0.9 m depth, in Alaskan permafrost during the early spring of 2013, when the ground was frozen under snow cover. Two cores from tundra and black spruce bog showed sudden increases in methane concentration (up to 416 µmol litre−1soil), indicating excess CH4 trapped in gas-impermeable soil layers during the freezing period. Active-layer cooling in late autumn, producing a frozen surface and relatively warm sub-surface, may have allowed underground microbial activity and facilitated CH4 production, while the upward transport of CH4 was hampered by the frost. Our preliminary results show that estimating annual GHG efflux from permafrost regions can be complicated because of heterogeneous distributions of trapped methane within soil columns. Copyright © 2016 John Wiley & Sons, Ltd.

Radionuclides in the terrestrial ecosystem near a Canadian uranium mill--Part I: Distribution and doses.

Soils, vegetation, small mammals, and birds were measured for uranium series radionuclides at three sites near the operating Key Lake uranium mill in northern Saskatchewan. Sites, impacted by windblown tailings and mill dust, had significantly higher concentrations of uranium, 226Ra, 210Pb, and 210Po in soils, litter, vegetation, tree needles and twigs, small mammals, and birds, compared to a control site. Samples were collected from both upland jackpine and black spruce bog habitats in triplicate at each site. Both habitats were similar in radionuclide accumulation. Absorbed doses averaged 0.92, 8.4, and 4.9 mGy y(-1) to small mammals and 2.0, 5.8, and 2.8 mGy y(-1) to Lincoln's sparrows at the control, tailings, and mill sites, respectively. These doses do not include doses from short-lived radon progeny. The majority of the dose increment at the tailings and mill sites was due to 226Ra, whereas it was 210Po at the control site. Thus, use of a radiation weighting factor of 20 for alpha radiation raised equivalent doses (in mSv y(-1)) by nearly a factor of 20.

An Identification of Environmental Disturbances from Road Developments in Subarctic Muskeg

The location, nature, and magnitude of some environmental changes associated with the introduction of a road across a muskeg in the discontinuous permafrost zone are identified from examination of near-infrared Landsat images. Impedance of natural surface drainage by the presence of a roadbed is hypothesized to transmit upstream hydro-thermal changes through the muskeg terrain, which in turn cause change in the muskeg vegetation community. Differences among the near-infrared spectral reflectances of fen, black spruce bog, and Sphagnum bog communities are found sufficiently large for use as indices of differences in the actual biophysical natures of the muskegs. Key words: environmental impact, northern Canada, muskegs, hydrology, Landsat interpretation, permafrost, road design

Lichen Decomposition in a Black Spruce Bog

AbstractNylon mesh litter bags containing Parmelia caperata, P. flaventior, P. subrudecta, Evernia nesomorpha, Hypogymnia physodes and Umbilicaria muehlenbergii were placed on the floor of a black spruce bog in northern Minnesota to study the rates of decomposition. P. caperata and E. mesomorpha had decomposed after 10 months. Most of the lichens had completely decayed after 13 months but a few thalli of some species placed on top of hummocks were still alive. The species with usnic acid decayed as rapidly as those without. Lichens decompose rapidly but not more rapidly than some vascular plants.

Peat Temperature Regime of a Minnesota Bog and the Effect of Canopy Removal

Peat bogs occupy approximately 6 000 000 ha in the cool sub-humid northern Lake States of the U.S.A. These peatlands are intimately associated with the regional water resources, often serving as the source of streamfiow. They also represent unique wetland ecosystems. Temperature is an important characteristic both of the bog environment and the quality of streamflow water. Alteration of peat temperature could result in changes in the surface vegetation and changes in microbial activity, so affecting the amount of organic matter accumulated (Clymo 1965; Lather & Cragg 1967; Moore & Bellamy 1974) and the quality of streamfiow water. Therefore, it is necessary to determine the temperature regimes of peat bogs in both undisturbed and disturbed situations prior to any large-scale alterations of management and energy input. Accordingly, temperature regimes were determined in a strip-cut black spruce bog to evaluate the effect of canopy removal. METHODS The study bog, located in northern Minnesota on the Marcell Experimental Forest (c. 47032'N, 93028'W), is approximately 560 m long and 140 m wide with the long axis oriented north and south. The peat profile of this lake-filled, forested bog has been described by Boelter (1964). The bog is isolated from the regional groundwater system. Precipitation and run-off from the adjacent uplands comprise the water input to the bog. Outflow is primarily as intermittent surface streamflow from the south end of the bog. In the winter of 1968-69, 30-m-wide strips were clear-cut, in an east-west direction, leaving 45-m-wide strips of sixty-two-year-old black spruce (Picea mariana (Mill.) B.S.P.). The crown closure of the forested strips was& approximately 7500. The strips were logged when snow cover was ample, so that disturbance of the surface vegetation was negligible, and a luxuriant sedge cover rapidly established in the following summer (Brown 1972). Eight temperature stations were located at the south end of the bog and eight at the north end. Two stations were located in the centre of clear-cut strips, two were in the centre of the forested strips and four were on the boundaries between strips. Peat depth at the temperature stations ranged from 2 to 2-8 m. Each temperature station consisted of a series of copper-constantan thermocouples, located at depths of 0-025, 0 3, 1 and 2 m below the interface of the living sphagnum moss and the organic soil material. The thermocouples were inserted through a wooden stake 2-5 x 2-5 cm and 2 m long; the stake was pushed into the peat to the desired depth. Air temperatures were measured at two locations in the clear-cut strips and two locations in the non-cut strips by shaded thermocouples 1 m above the bog surface. Temperatures were read with a portable potentiometer. A battery-operated resistance heating unit was

Water Level Fluctuation in a Northeastern Ontario Peatland

Depths to water level and changes due to local climate were dissimilar in five peatland conditions in northeastern Ontario. The deepest water level and the greatest fluctuations occurred in an ombrotrophic black spruce bog site. The sedge-dominated poor fen site was submerged following every heavy rain. Waterlogged conditions remained within 6 cm of the surface at all times because of the influence by the water level of Dai Lake. The water level of Dai Lake varied within a narrow range because the loss of water was primarily dependent on slow seepage and evaporation. The lagg site was affected by continuous inflow, high water levels, and fast run-off, therefore, a larger fluctuation of water level prevailed at this site.

Studies on the Bryophytes of Southern Manitoba. VII. Distribution of Terrestrial Bryophytes in a Black Spruce Bog in Bird's Hill Provincial Park

The seventeen most common terricolous bryophytes in calcareous black spruce bog forest occur in three distinct groups occupying different microtopographic sites. The chief factors governing the distribution of these groups are moisture availability, shade, and competition. There have been few attempts to study in detail the ecology of terrestrial bryophytes in coniferous bog forests. Even the studies of Bevis (1960), Jeglum (1971), Reichle and Doyle (1965), and Sjors (1961) have little quantitative information relating bryophyte species to microsite factors, although in other respects they provide much useful data on the bryophytes of bog forests and bogs. Bevis (1960) used transects in his phytosociological study on bogs and bog forests, but his rather large sampling units (2 X 2 m quadrats) were not intended to sample the mosaic of microsites. According to Kil'dyushevskii (1964), a study of the distribution of species in the immediate soil cover with respect to the elements of the microrelief can reveal much concerning the biology and ecology of these species. With this observation in mind, we undertook this study in an attempt to elucidate the microtopographic distribution of bryophytes in hummocky black spruce bog forest, and to find how microenvironmental factors might account for these distribution patterns. The site chosen was in Bird's Hill Provincial Park, an area of coniferous and mixedwood forest some 36 hectares in extent approximately 25 km northeast of downtown Winnipeg. The park lies in the transition zone between the Aspen-Oak and Manitoba Lowlands sections of the Boreal Forest Region (Rowe, 1959). On Bird's Hill itself, white spruce (Picea glauca) with some jack pine (Pinus banksiana) are associates of the dominant oak (Quercus macrocarpa) and aspen (Populus tremuloides). However, most of the coniferous forest is in wet, poorly drained areas, where bog forests of black spruce (Picea mariana) and tamarack (Larix laricina) have developed, usually on deep layers of peat. We will report in separate publication other aspects of our work on the bryophytes of the park, which have not previously been studied.

Effect of Clearcutting a Black Spruce Bog on Net Radiation

Effect of Clearcutting a Black Spruce Bog on Net Radiation

Geobotanical Processes in the Saskatchewan River Delta

The interactions of substrate, soil frost, groundwater levels, vegetation, and ongoing landscape-forming processes were studied in a portion of the Saskatchewan River Delta. Representative field transects were used to relate vegetation types to differences in relief and seasonal water table elevation. Seasonal soil temperatures were recorded from common community types, and peat stratigraphy was determined along several field transects.Vegetation zonations, extending from mixed forest on river levees to open lake water obviously reflect moisture gradients. However, increasing moisture availability is paralleled by declining nutrient availability, away from the levees, as peat accumulation prevents rooting in the mineral soil. Nutrient status and type and degree of peat accumulation are thus dependent on landform and water circulation. Three main physiographic divisions were recognized as a means of discussing the dynamics of vegetation/environment interrelationships; alluvial levees, open drainage basins, and closed drainage basins.Alluvial levees, paralleling stream channels, are generally well drained, nutrient-rich, and covered by mixed forest and tall shrub communities. Open drainage basins are characterized by slow circulation of mineral waters, favoring growth of minerotrophic fens and floating sedge mats. Closed drainage basins are more or less completely surrounded by raised levees. Their source of water is limited runoff from the encircling levees and precipitation falling onto the basins. Deep peat deposits are characteristic of these sites. Nutrient levels are lower than in open basins and sphagnum moss commonly occurs above the fen peat deposits. The slightly raised centers of these closed basins often support black spruce bog communities.

La tourbière à sphaignes Mer Bleue près d'Ottawa. II. Quelques facteurs écologiques

Mer Bleue is an ombrotrophic sphagnum and black spruce bog near Ottawa, Ontario. Its 5000 ac offer a vegetation composed of 10 associations and 3 subassociations. Day temperature in the bog is 2.7°F higher and night temperature 3.2°F lower than at Uplands Airport 7 mi away. Relative humidity is also higher. The black spruce stand is the most humid and the coolest of all plant associations and its water table is the highest, while Polytrichum association is the dryest and the warmest. Black spruce stands also have the most stable climate.Temperature at 1 ft depth in the peat moss reaches a minimum of 55°F in summer. At 2 ft depth a maximum of 47°F occurs in September and a minimum of 24°F in February. The pH lies between 3.8 in ombrotrophic areas and 6.5 in minerotrophic conditions. Many other aspects are discussed.

Peridinium limbatum (Stokes) verglichen mit der tertiären Deflandrea phosphoritica eisenack

Abstract Title: Peridinium limbatum (Stokes) compared with the Tertiary Deflandrea phosphoritica Eisenack. This study is based on material from post-glacial lake sediments in a small lake, today surrounded by black spruce bog, in northeastern-Minnesota, U. S. A. These lake sediments have been subject of a pollen-analytical study (Fries 1962). The dinoflagellate shown in Fig. 1 A—D occurs abundantly in the upper layer (brown organic mud, rich in humic substances, Swedish dy) of about 1 m in the center of the lake (at about 2 m water depth) and in the sediment below a floating bog at the shore. Najas seeds do not occur in the layers with Peridinium, but farther down, and Pediastrum coenobia are here much more scattered than in the lower layers (partly claygyttja). The stratigraphic occurrence is shown in the pollen diagrams in Fries 1962. It has not been possible to verify that this microorganism now lives in the lake. However, its abundance in the uppermost layer makes it most likely that this is the case....