scholarly journals Effect of clearcutting of boreal spruce forest on air and soil temperature conditions

1991 ◽  
Vol 0 (225) ◽  
Author(s):  
Eero Kubin ◽  
Lauri Kemppainen
Keyword(s):  
Soil Temperature ◽  
Spruce Forest ◽  
Temperature Conditions

scholarly journals Environmental factors regulating winter CO<sub>2</sub> flux in snow-covered boreal forest soil, interior Alaska

2012 ◽  
Vol 9 (1) ◽  
pp. 1129-1159 ◽  
Author(s):  
Y. Kim ◽  
Y. Kodama
Keyword(s):  
Environmental Factors ◽  
Soil Temperature ◽  
Forest Soil ◽  
Atmospheric Pressure ◽  
Co2 Emission ◽  
Black Spruce ◽  
Co2 Flux ◽  
Atmospheric Temperature ◽  
Spruce Forest ◽  
Interior Alaska

Abstract. Winter CO2 flux is an important element to assess when estimating the annual carbon budget on regional and global scales. However, winter observation frequency is limited due to the extreme cold weather in sub-Arctic and Arctic ecosystems. In this study, the continuous monitoring of winter CO2 flux in black spruce forest soil of interior Alaska was performed using NDIR CO2 sensors at 10, 20, and 30 cm above the soil surface during the snow-covered period (DOY 357 to 466) of 2006/2007. The atmospheric pressure was divided into four phases: >1000 hPa (HP: high pressure); 985<P<1000 (IP: intermediate pressure); <986 hPa (LP: low pressure); and a snow-melting period (MP); for the quantification of the effect of the environmental factors determining winter CO2 flux. The winter CO2 fluxes were 0.22 ± 0.02, 0.23 ± 0.02, 0.25 ± 0.03, and 0.17 ± 0.02 gCO2-C/m2 d−1 for the HP, IP, LP, and MP phases, respectively. Wintertime CO2 emission represents 20 % of the annual CO2 emissions in this boreal black spruce forest soil. Atmospheric temperature, pressure, and soil temperature correlate at levels of 56, 25, and 31 % to winter CO2 flux, respectively, during the snow-covered period of 2006/2007, when snow depth experienced one of its lowest totals of the past 80 years. Atmospheric temperature and soil temperature at 5 cm depth, modulated by atmospheric pressure, were found to be significant factors in determining winter CO2 emission and fluctuation in snowpack. Regional/global process-based carbon cycle models should be reassessed to account for the effect of winter CO2 emissions, regulated by temperature and soil latent-heat flux, in the snow-covered soils of Arctic and sub-Arctic terrestrial ecosystems of the Northern Hemisphere.

Root cold hardiness and native distribution of subalpine conifers

1992 ◽  
Vol 22 (7) ◽  
pp. 932-938 ◽  
Author(s):  
Mark D. Coleman ◽  
Thomas M. Hinckley ◽  
Geoffrey McNaughton ◽  
Barbara A. Smit
Keyword(s):  
Soil Temperature ◽  
Constant Temperature ◽  
Species Distribution ◽  
Electrolyte Leakage ◽  
Cold Hardiness ◽  
Soil Conditions ◽  
Conifer Species ◽  
Temperature Conditions

Root and needle cold hardiness were compared in seedlings of subalpine conifers to determine if differences existed among species originating from either cold continental climates or mild maritime climates. Abiesamabilis (Dougl.) Carr. and Tsugamertensiana (Bong.) Carr. are exclusively distributed in maritime environments, while Abieslasiocarpa (Hook.) Nutt. and Pinuscontorta Dougl. are more generally distributed in both continental and maritime environments. Because of the differing winter soil conditions of these two climatic types, special emphasis was placed on root cold hardiness. Cold hardiness for root samples, as measured by a decrease in the electrolyte leakage, was much greater for A. amabilis and A. lasiocarpa than for P. contorta and T. mertensiana (−11.4, −11.5, −7.5, and −7.5 °C, respectively). Thus, subalpine conifer species distribution was not found to be influenced by root cold hardiness. Root cold hardiness of field-grown seedlings paralleled changes in soil temperature through February. Under constant temperature conditions (3 °C) the maximum cold hardiness achieved in 6 weeks was not subsequently maintained in A. amabilis and A. lasiocarpa. Injury in unhardened roots was coincident with bulk freezing, whereas hardened roots were able to tolerate bulk freezing. Needles had more than three times the level of cold hardiness of roots when measured in December, All species except P. contorta reached needle cold hardiness levels below −40 °C.

scholarly journals Forest Floor Carbon Exchange of a Boreal Black Spruce Forest in Eastern Canada

2009 ◽  
Vol 6 (3) ◽  
pp. 5507-5548 ◽  
Author(s):  
O. Bergeron ◽  
H. A. Margolis ◽  
C. Coursolle
Keyword(s):  
Soil Temperature ◽  
Air Temperature ◽  
Forest Floor ◽  
Black Spruce ◽  
Ecosystem Respiration ◽  
Light Availability ◽  
Ground Cover ◽  
Spruce Forest ◽  
Eastern Canada ◽  
Shallow Soil

Abstract. This study reports continuous automated measurements of forest floor carbon (C) exchange over feathermoss, lichen, and sphagnum micro-sites in a black spruce forest in eastern North America during snow-free periods over three years. The response of soil respiration (Rs-auto) and forest floor photosynthesis (Pff) to environmental factors was determined. The seasonal contributions of scaled up Rs-auto adjusted for spatial representativeness (Rs-adj) and Pff (Pff-eco) relative to that of total ecosystem respiration (Re) and photosynthesis (Peco), respectively, were also quantified. Shallow soil temperature explained 67–86% of the variation in Rs-auto for all ground cover types, while deeper soil temperatures were related to Rs-auto only for the feathermoss micro-sites. Base respiration was consistently lower under feathermoss, intermediate under sphagnum, and higher under lichen during all three years. The Rs-adj/Re ratio increased from spring through autumn and ranged from 0.85 to 0.87 annually for the snow-free period. The Rs-adj/Re ratio was negatively correlated with the difference between air and shallow soil temperature and this correlation was more pronounced in autumn than summer and spring. Maximum photosynthetic capacity of the forest floor (Pffmax) saturated at low irradiance levels (~200 μmol m−2 s−1) and decreased with increasing air temperature and vapor pressure deficit for all three ground cover types, suggesting that Pff was more limited by desiccation than by light availability. Pffmax was lowest for sphagnum, intermediate for feathermoss, and highest for lichen for two of the three years. Pff normalized for light peaked at air temperatures of 5–8°C, suggesting that this is the optimal temperature range for Pff. The Pff-eco/Peco ratio varied seasonally from 13 to 24% and reached a minimum in mid-summer when both air temperature and Peco were at their maximum. On an annual basis, Pff-eco accounted for 17–18% of Peco depending on the year and the snow-free season totals of Pff-adj were 23–24% that of Rs-adj.

scholarly journals Effect of ablation ring and soil temperature on 3-yr spring CO<sub>2</sub> efflux along the trans-Alaska pipeline, Alaska

2014 ◽  
Vol 11 (3) ◽  
pp. 3615-3652 ◽  
Author(s):  
Y. Kim
Keyword(s):  
Climate Change ◽  
Boreal Forest ◽  
Soil Temperature ◽  
Co2 Emissions ◽  
White Spruce ◽  
Co2 Efflux ◽  
Spruce Forest ◽  
Carbon Budgets ◽  
Forest Sites ◽  
Annual Carbon

Abstract. Winter and spring soil CO2 efflux-measurements represent a significant component in the assessment of annual carbon budgets of tundra and boreal forest ecosystems, as a response to climate change in the Arctic. This study was conducted to quantify CO2 efflux using a portable chamber system at representative sites along the trans-Alaska pipeline. The sites here are characterized as three tundra, two white spruce, and three black spruce forest sites during winter and spring seasons of 2010 to 2012; study of these sites will offer a better understanding of winter and spring carbon contributions to the annual carbon budget, as well as their affecting parameters by the effect of ablation ring in spring. 3 yr spring CO2 efflux depends on soil temperature at 5 cm depth on a regional scale. At their highest, Q10 values were 4.2 × 106, within the exposed tussock tundra of the upland tundra site, as tundra soils warmed from −0.9 to 0.5 °C, involving the soil microbial activity. With the forest census (400 m2) of the two white spruce forest sites, CO2 emissions were estimated to be 35 to 145 gC day−1 in winter and 56 to 1980 gC day−1 in spring, corresponding to 1–3 and 1–27% of annual carbon, respectively. The contributions from spring CO2 emissions are likely to increase as exposed soils widen in average length (major axis) from east, west, and south, as well as north-side length (minor axis). Considering the periods of winter and spring seasons across tundra and boreal forests, average winter- and spring-seasonal CO2 contributions to annual carbon budgets correspond roughly to 14–22% in tundra and 9–24% in boreal forest sites during 2011–2012. Contributions from spring carbon comparable to growing season CO2 emissions are sensitive to subtle changes at the onset of spring and during the snow-covered period in northern high latitudes, in response to recent Arctic climate change.

scholarly journals Monitoring of soil temperatur on permafrost in natural and anthropogenic disturbed conditions in the Tunkinskaya Depression

2019 ◽  
Vol 59 (4) ◽  
pp. 517-528
Author(s):  
N. N. Voropay ◽  
M. V. Kiselev ◽  
A. A. Cherkashina
Keyword(s):  
Soil Temperature ◽  
Soil Layer ◽  
Morphological Structure ◽  
Permafrost Soil ◽  
Time Interval ◽  
Spruce Forest ◽  
Freezing And Thawing ◽  
Cryogenic Soils ◽  
Soil Temperatures ◽  
Seasonal Thawing

The territory of the study is the Tunkinsky intermountain basin (South-Western Baikal region, Republic of Buryatia) which belongs to the area of sporadic (island) distribution of permafrost. Soil temperature controls many biotic and abiotic processes in it, so it is important to monitor the freezing and thawing regimes in peat and mineral soils. The object of the study is coarse-humic cryogenic soils on sandy lacustrine-alluvial sediments. The first site was represented by natural coarse-humic cryogenic soils under spruce forest, while the second site was organized on the area where in 1960s the forest had been destroyed and the soils were ploughed. At the end of XX century, the arable lands were abandoned, and now they are covered with steppe grasses (the long fallow). Both sites are located on the permafrost. The atmospheric-soil measuring complex was used to study the state of both the perennial and seasonal permafrost at these two sites. The soil temperatures were measured in automatic mode with a time interval of 1 hour from July 1, 2013 to June 30, 2017 along the soil profile from the surface down to a depth of 320 cm. Anthropogenic interference on one of the sites resulted in changes in vegetation cover, the soil moisture as well as the morphological structure and granulometric composition of the upper part of the soil layer. This caused changes in the temperature regime of the permafrost and its degradation with lowering of its upper limit. The soil on the long fallow is better warmed up and cools down faster than it takes place under the spruce forest. As a result of this, the maximum annual temperature on the surface here is higher by 10 °C, while at a depth of 320 cm – by 5 °C, and the minimum annual temperature on the surface is lower by 7 °C, while at a depth of 320 cm – by 1 °C. On the anthropogenically disturbed area, the warm period (at the soil temperature above 0 °C) on the surface is, on the average, by 22 days longer than on the natural lot. These differences are observed at all depths. As a result, the perennial permafrost is retained under the spruce forest below 130 cm throughout the year (soil temperature −0.2 ÷ −0.9 °C), while on the fallow the zero isotherm during seasonal thawing falls much deeper 320 cm, and the soil in the layer of 240–320 cm warms up to 2–5 °C.

scholarly journals Forest floor carbon exchange of a boreal black spruce forest in eastern North America

2009 ◽  
Vol 6 (9) ◽  
pp. 1849-1864 ◽  
Author(s):  
O. Bergeron ◽  
H. A. Margolis ◽  
C. Coursolle
Keyword(s):  
North America ◽  
Soil Temperature ◽  
Air Temperature ◽  
Forest Floor ◽  
Black Spruce ◽  
Ecosystem Respiration ◽  
Light Availability ◽  
Ground Cover ◽  
Eastern North America ◽  
Spruce Forest

Abstract. This study reports continuous automated measurements of forest floor carbon (C) exchange over feathermoss, lichen, and sphagnum micro-sites in a black spruce forest in eastern North America during snow-free periods over three years. The response of soil respiration (Rs-auto) and forest floor photosynthesis (Pff) to environmental factors was determined. The seasonal contributions of scaled up Rs-auto adjusted for spatial representativeness (Rs-adj) and Pff (Pff-eco) relative to that of total ecosystem respiration (Re) and photosynthesis (Peco), respectively, were also quantified. Shallow (5 cm) soil temperature explained 67–86% of the variation in Rs-auto for all ground cover types, while deeper (50 and 100 cm) soil temperatures were related to Rs-auto only for the feathermoss micro-sites. Base respiration was consistently lower under feathermoss, intermediate under sphagnum, and higher under lichen during all three years. The Rs-adj/Re ratio increased from spring through autumn and ranged from 0.85 to 0.87 annually for the snow-free period. The Rs-adj/Re ratio was negatively correlated with the difference between air and shallow soil temperature and this correlation was more pronounced in autumn than summer and spring. Maximum photosynthetic capacity of the forest floor (Pff-max) saturated at low irradiance levels (~200 μmol m−2 s−1) and decreased with increasing air temperature and vapor pressure deficit for all three ground cover types, suggesting that Pff was more limited by desiccation than by light availability. Pff-max was lowest for sphagnum, intermediate for feathermoss, and highest for lichen for two of the three years. Pff normalized for light peaked at air temperatures of 5–8°C, suggesting that this is the optimal temperature range for Pff. The Pff-eco/Peco ratio varied from 13 to 24% over the snow-free period and reached a minimum in mid-summer when both air temperature and Peco were at their maximum. On an annual basis, Pff-eco accounted for 17–18% of Peco depending on the year and the snow-free season totals of Pff-eco were 23–24% that of Rs-adj.

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