Environmental controls on soil CO2 flux following fire in black spruce, white spruce, and aspen stands of interior Alaska

2002 ◽  
Vol 32 (9) ◽  
pp. 1525-1541 ◽  
Author(s):  
Katherine P O'Neill ◽  
Eric S Kasischke ◽  
Daniel D Richter
Keyword(s):  
Soil Temperature ◽  
Populus Tremuloides ◽  
Picea Glauca ◽  
Environmental Changes ◽  
Co2 Flux ◽  
Seasonal Temperature ◽  
Carbon Exchange ◽  
Soil Co2 Flux ◽  
Surface Moisture ◽  
Environmental Controls

Boreal forests contain large amounts of stored soil carbon and are susceptible to periodic disturbance by wildfire. This study evaluates the relationship between post-fire changes in soil temperature, moisture, and CO2 exchange in paired burned and control stands of three Alaskan forest systems: Picea mariana (Mill.) BSP, Picea glauca (Moench) Voss, and Populus tremuloides Michx. In these systems, the environmental factor that most directly controlled rates of carbon exchange varied depending upon burn status and soil drainage. In mature unburned stands, CO2 flux was highly correlated with seasonal patterns of soil temperature. Following fire, these soils became significantly warmer, and carbon exchange became more sensitive to fluctuations in surface moisture conditions. The effect of fire on soil climate was most pronounced in the P. mariana stands, which experienced a mean seasonal temperature increase of 5–8°C in the upper 1 m of the soil profile, a 200% increase in the rate of active layer thaw, and a reduction in mean surface moisture potential. Evidence from soil CO2 profiles suggests that these environmental changes may have resulted in enhanced decomposition of carbon previously immobilized by permafrost, potentially transforming a landscape that was once a net sink for carbon into a carbon source.

Characteristics of prescribed burns and resultant short-term environmental changes in Populus tremuloides woodland in southern Ontario

1978 ◽  
Vol 56 (15) ◽  
pp. 1782-1791 ◽  
Author(s):  
D. W. Smith ◽  
T. D. James
Keyword(s):  
Soil Temperature ◽  
Short Duration ◽  
Populus Tremuloides ◽  
Environmental Changes ◽  
Fire Severity ◽  
Small Magnitude ◽  
Prescribed Burns ◽  
Southern Ontario ◽  
Environmental Controls ◽  
Soil Temperatures

In a series of prescribed burns of low intensity and short duration in southern Ontario, wind speed, amount of fuel, and fuel moisture were important environmental controls of fire severity. A heterogenous pattern of burning, related to clumping in the vegetation and to a hummock–hollow microtopography presumably affected and was perpetuated in the reestablishing postfire vegetation.Removal of vegetation cover and surface litter plus surface albedo changes resulted in increased soil temperature 2 months after burning. These increases were short-lived and soil temperatures were close to those of unburned areas 4 months after the prescribed fires. Despite their small magnitude and short duration, the soil temperature increases could have an important stimulatory effect on regenerating vegetation.Significant increases in levels of readily available forms of phosphorus, potassium, calcium, and magnesium at surface soil depths immediately after burning could have been depleted through uptake by vegetation and microorganisms. Portions of the nutrients were removed, also, by erosion of fly ash during burning, leaching to subsurface depths, and through fixation in unavailable form.

The effect of ectomycorrhizae on water relations in aspen (Populus tremuloides) and white spruce (Picea glauca) at low soil temperatures

2002 ◽  
Vol 80 (6) ◽  
pp. 684-689 ◽  
Author(s):  
Simon M Landhäusser ◽  
Tawfik M Muhsin ◽  
Janusz J Zwiazek
Keyword(s):  
Stomatal Conductance ◽  
Soil Temperature ◽  
Water Uptake ◽  
Water Relations ◽  
Populus Tremuloides ◽  
Picea Glauca ◽  
White Spruce ◽  
Hydraulic Conductance ◽  
Root Hydraulic Conductance ◽  
Soil Temperatures

Low soil temperatures, common during the growing season in northern forests, have the potential to impede plant growth. In this study, water uptake, water relations, and growth characteristics were examined in aspen (Populus tremuloides) and white spruce (Picea glauca) seedlings that were inoculated with ectomycorrhizal fungi and grown at 20°C daytime air temperatures and low soil temperatures of 4°C and 8°C. Mycorrhizal associations had little effect on root and shoot biomass at both soil temperatures. Root hydraulic conductance (Kr) was higher in both mycorrhizal plant species compared to nonmycorrhizal plants, but there was no soil temperature effect on Kr in either species. Mycorrhizae also increased shoot water potential (Ψw) in Populus tremuloides but had no effect on Ψw in Picea glauca. The increases in Kr and Ψw were not reflected by changes in stomatal conductance (gs) and transpiration rates (E), suggesting that the reduction of water flow in seedlings exposed to low soil temperature was not likely the factor limiting gs in both plant species.Key words: boreal forest, root hydraulic conductance, root growth, stomatal conductance, water uptake.

Response of abiotic soil CO2 flux to the difference in air-soil temperature in a desert

2021 ◽  
Vol 785 ◽  
pp. 147377
Author(s):  
Yang Gao ◽  
Zhong Zhao ◽  
Yuqing Zhang ◽  
Jiabin Liu
Keyword(s):  
Soil Temperature ◽  
Co2 Flux ◽  
Soil Co2 ◽  
Soil Co2 Flux ◽  
The Difference

scholarly journals Growth of White Spruce, Picea glauca, Seedlings in Relation to Microenvironmental Conditions in a Forest-Prairie Ecotone of Southwestern Manitoba

2007 ◽  
Vol 121 (2) ◽  
pp. 191 ◽  
Author(s):  
Sophan Chhin ◽  
G. Geoff Wang
Keyword(s):  
Soil Temperature ◽  
Populus Tremuloides ◽  
Picea Glauca ◽  
Carbon Allocation ◽  
White Spruce ◽  
Height Growth ◽  
Tree Canopy ◽  
Morphological Adaptation ◽  
Southern Limit ◽  
Temperature Conditions

The influence of microenvironmental conditions on the growth performance (i.e., diameter and height growth) of White Spruce [Picea glauca (Moench) Voss] seedlings was examined within three contrasting habitats: White Spruce tree islands, open prairies and Trembling Aspen (Populus tremuloides Michx.) groves. These habitats exist within a disjunct occurrence of White Spruce at its southern limit of distribution in three mixed-grass prairie preserves in the Spruce Woods Provincial Park within the forest-prairie ecotone of southwestern Manitoba. Microenvironmental measurements (i.e., light, temperature, relative humidity, soil moisture) were obtained on 10 sites in each of the three habitats and growth characteristics of 60 White Spruce seedlings were measured in each of three habitats. Higher light and soil temperature conditions occurred within the open prairie. In contrast, lower light and soil temperature conditions occurred under the tree canopy of aspen groves and the northern aspect of spruce islands, which moderated the effect of the dry regional climate. Height growth did not vary significantly among the three habitats. The greater diameter growth and decreased slenderness of White Spruce seedlings in the open versus the shaded habitats appears to be a result of increased photosynthesis at higher light intensity and may also represent a morphological adaptation to withstand the effect of increased wind exposure. The increased slenderness of White Spruce in the shaded habitats appears to be a morphological adaptation of increasing carbon allocation towards height growth and thus maximizing effective competition for light.

scholarly journals Effects of multiple environmental factors on CO<sub>2</sub> emission and CH<sub>4</sub> uptake from old-growth forest soils

2010 ◽  
Vol 7 (1) ◽  
pp. 395-407 ◽  
Author(s):  
H. J. Fang ◽  
G. R. Yu ◽  
S. L. Cheng ◽  
T. H. Zhu ◽  
Y. S. Wang ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Soil Temperature ◽  
Co2 Emission ◽  
Co2 Flux ◽  
Soil Co2 ◽  
Old Growth ◽  
Soil Co2 Flux ◽  
Old Growth Forest ◽  
Old Growth Forests ◽  
Ch4 Uptake

Abstract. To assess contribution of multiple environmental factors to carbon exchanges between the atmosphere and forest soils, four old-growth forests referred to as boreal coniferous forest, temperate needle-broadleaved mixed forest, subtropical evergreen broadleaved forest and tropical monsoon rain forest were selected along eastern China. In each old-growth forest, soil CO2 and CH4 fluxes were measured from 2003 to 2005 applying the static opaque chamber and gas chromatography technique. Soil temperature and moisture at the 10 cm depth were simultaneously measured with the greenhouse gas measurements. Inorganic N (NH4+-N and NO3−-N) in the 0–10 cm was determined monthly. From north to south, annual mean CO2 emission ranged from 18.09 ± 0.22 to 35.40 ± 2.24 Mg CO2 ha−1 yr−1 and annual mean CH4 uptake ranged from 0.04 ± 0.11 to 5.15 ± 0.96 kg CH4 ha−1 yr−1 in the four old-growth forests. Soil CO2 flux in the old-growth forests was mainly driven by soil temperature, followed by soil moisture and NO3−-N. Temperature sensitivity (Q10) of soil CO2 flux was lower at lower latitudes with high temperature and more precipitation, probably because of less soil organic carbon (SOC). Soil NO3− accumulation caused by environmental change was often accompanied by an increase in soil CO2 emission. In addition, soil CH4 uptake decreased with an increase in soil moisture. The response of soil CH4 flux to temperature was dependent upon the optimal value of soil temperature in each forest. Soil NH4+-N consumption tended to promote soil CH4 uptake in the old-growth forests, whereas soil NO3−-N accumulation was not conducive to CH4 oxidation in anaerobic condition. These results indicate that soil mineral N dynamics largely affects the soil gas fluxes of CO2 and CH4 in the old-growth forests, along with climate conditions.

scholarly journals Shifting environmental controls on CH<sub>4</sub> fluxes in a sub-boreal peatland

2013 ◽  
Vol 10 (12) ◽  
pp. 7971-7981 ◽  
Author(s):  
T. G. Pypker ◽  
P. A. Moore ◽  
J. M. Waddington ◽  
J. A. Hribljan ◽  
R. C. Chimner
Keyword(s):  
Soil Temperature ◽  
Net Ecosystem Exchange ◽  
P Value ◽  
Co2 Uptake ◽  
Ch4 Flux ◽  
Environmental Controls ◽  
Poor Fen ◽  
Abiotic And Biotic Factors ◽  
The Relationship ◽  
Northern Michigan

Abstract. We monitored CO2 and CH4 fluxes using eddy covariance from 19 May to 27 September 2011 in a poor fen located in northern Michigan. The objectives of this paper are to: (1) quantify the flux of CH4 from a sub-boreal peatland, and (2) determine which abiotic and biotic factors were the most correlated to the flux of CH4 over the measurement period. Net daily CH4 fluxes increased from 70 mg CH4 m−2 d−1 to 220 mg CH4 m−2 d−1 from mid May to mid July. After July, CH4 losses steadily declined to approximately 50 mg CH4 m−2 d−1 in late September. During the study period, the peatland lost 17.4 g CH4 m−2. Both abiotic and biotic variables were correlated with CH4 fluxes. When the different variables were analyzed together, the preferred model included mean daily soil temperature at 20 cm, daily net ecosystem exchange (NEE) and the interaction between mean daily soil temperature at 20 cm and NEE (R2 = 0.47, p value < 0.001). The interaction was important because the relationship between daily NEE and mean daily soil temperature with CH4 flux changed when NEE was negative (CO2 uptake from the atmosphere) or positive (CO2 losses to the atmosphere). On days when daily NEE was negative, 25% of the CH4 flux could be explained by correlations with NEE, however on days when daily NEE was positive, there was no correlation between daily NEE and the CH4 flux. In contrast, daily mean soil temperature at 20 cm was poorly correlated to changes in CH4 when NEE was negative (17%), but the correlation increased to 34% when NEE was positive. The interaction between daily NEE and mean daily soil temperature at 20 cm indicates shifting environmental controls on the CH4 flux throughout the growing season.

The effect of soil temperature and light on sprouting and rooting of root cuttings of hybrid aspen clones

2005 ◽  
Vol 35 (11) ◽  
pp. 2671-2678 ◽  
Author(s):  
N Stenvall ◽  
T Haapala ◽  
S Aarlahti ◽  
P Pulkkinen
Keyword(s):  
Soil Temperature ◽  
Populus Tremuloides ◽  
Hybrid Aspen ◽  
Light Conditions ◽  
Dark Treatment ◽  
Sand Mixture ◽  
Negative Effect ◽  
Soil Temperatures ◽  
Time Required ◽  
Better Than

Root cuttings from five clones of hybrid aspen (Populus tremula L. × Populus tremuloides Michx.) obtained from 2-year-old stock plants were grown in a peat–sand mixture (soil) at four soil temperatures (18, 22, 26, and 30 °C). Half of the cuttings were grown in light and the rest in darkness. The root cuttings that were grown at the highest soil temperature sprouted and rooted significantly better than the cuttings grown at the lower temperatures. Light did not affect the sprouting of root cuttings but did have a negative effect on their rooting. Moreover, the clones varied significantly in sprouting and rooting percentages, as well as in the time required for sprouting. In general, higher soil temperatures hastened sprouting of the cuttings. Sprouting was also faster in the light than in the dark treatment. Differences in soil temperature, light conditions, or clone had no significant effect on rooting time.

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