Kelman Wieder - Academia.edu (original) (raw)
Papers by Kelman Wieder
AGU Fall Meeting Abstracts, Dec 1, 2012
2014 AGU Fall Meeting, Dec 16, 2014
Biogeosciences, Mar 8, 2010
An 18-month reciprocal peat transplant experiment was conducted between two peatlands in the Czec... more An 18-month reciprocal peat transplant experiment was conducted between two peatlands in the Czech Republic. Both sites were 100% Sphagnum-covered, with no vascular plants, and no hummocks and hollows. Atmospheric depositions of sulfur were up to 10 times higher at the northern site Velke jerabi jezero (VJJ), compared to the southern site Cervene blato (CB). Forty-cm deep peat cores, 10-cm in diameter, were used as transplants and controls in five replicates. Our objective was to evaluate whether CO 2 and CH 4 emissions from Sphagnum peat bogs are governed mainly by organic matter quality in the substrate, or by environmental conditions. Emission rates and δ 13 C values of CO 2 and CH 4 were measured in the laboratory at time t = 18 months. All measured parameters converged to those of the host site, indicating that, at least in the short-term perspective, environmental conditions were a more important control of greenhouse gas emissions than organic carbon quality in the substrate. Since sulfate reducers outcompete methanogens, we hypothesized that the S-polluted site VJJ should have lower methane emissions than CB. In fact, the opposite was true, with significantly (p <0.01) higher methane emissions from VJJ. Additionally, as a first step in an effort to link C isotope composition of emitted gases and residual peat substrate, we determined whether multiple vertical δ 13 C profiles in peat agree. A high degree of within-site homogeneity in δ 13 C was found. When a specific vertical δ 13 C trend was seen in one peat core, the same trend was also seen in all the remaining peat cores from the wetland.
Biogeochemistry, Apr 1, 1999
One important assumption in applying 210 Pb-dating is that atmospherically deposited 210 Pb is im... more One important assumption in applying 210 Pb-dating is that atmospherically deposited 210 Pb is immobilized in the peat or sediment column. This assumption has been challenged widely, but has never been evaluated experimentally. We evaluated Pb mobility and the chemical forms in which Pb is stabilized in peat profiles by adding either soluble or particulate Pb to intact peat cores that were maintained under different water level regimes (permanently high, permanently low, fluctuating between high and low) and were subjected to simulated precipitation over a five month period. By analyzing the behavior of stable Pb we made inferences about the expected behavior of 210 Pb. Results indicate that added soluble Pb 2+ was retained in the peat through physiochemical binding to organic matter, and as such Pb 2+ was largely immobile in peat even under conditions of a fluctuating water table. Added particulate Pb was largely (most likely by physical entrapment), but not completely, immobilized in peat. In none of the water table treatments was there evidence to support mobility of Pb by alternating formation and oxidation of sulfides, or by any other mechanism. The binding of Pb 2+ with organic matter at the peat surface, and the absence of Pb mobility lend credence to 210 Pbdating of Sphagnum-dominated peat deposits, which are over 90% organic matter throughout, and have high cation exchange capacities.
Biogeochemistry, Jun 1, 1988
Total S concentration in the top 35 cm of Big Run Bog peat averaged 9.7 pmo1.gwet mass-' (123pmol... more Total S concentration in the top 35 cm of Big Run Bog peat averaged 9.7 pmo1.gwet mass-' (123pmol.gdry mass-'). Of that total, an average of 80.8% was carbon bonded S, 10.4% was ester sulfate S, 4.5% was FeS2-S, 2.7% was FeS-S, 1.2% was elemental S, and 0.4% was SO:-S. In peat collected in March 1986, injected with 35S-SO:-and incubated at 4 "C, mean rates of dissimilatory sulfate reduction (formation of H2S + So + FeS + FeS,), carbon bonded S formation, and ester sulfate S formation averaged 3.22,0.53, and 0.36 nmo1.g wet mass-'W', respectively. Measured rates of sulfide oxidation were comparable to rates of sulfate reduction. Although dissolved S O : concentrations in Big Run Bog interstitial water (< 200pM) are low enough to theoretically limit sulfate reducing bacteria, rates of sulfate reduction integrated throughout the top 3&35 cm of peat of 9 and 34mm0l.m-~&' (at 4 "C) are greater than or comparable to rates in coastal marine sediments. We suggest that sulfate reduction was supported by a rapid turnover of the dissolved SO:-pool (average turnover time of 1.1 days). Although over 90% of the total S in Big Run Bog peat was organic S, cycling of S was dominated by fluxes through the inorganic S pools.
AGU Fall Meeting Abstracts, Dec 1, 2010
Bogs of Alberta, Canada are peatlands that are both Sphagnum-moss dominated and nutrient limited.... more Bogs of Alberta, Canada are peatlands that are both Sphagnum-moss dominated and nutrient limited. Due to their ombrotrophic nature, nitrogen (N) is deposited only via atmospheric deposition (wet/dry) and biological N2 fixation. Historically, bogs of Alberta are unpolluted with low rates of atmospheric N deposition (15 kg ha-1 yr-1). Due to the extensive rich bitumen deposits under northern Alberta, however,
AGUFM, Dec 1, 2010
Water table position (WT) is an important factor in peatland ecosystem structure and function. Th... more Water table position (WT) is an important factor in peatland ecosystem structure and function. The relationship between WT and net ecosystem production (NEP) is recognized, but poorly described, especially on a microscale level where factors such as vegetation and microhabitat may influence this relationship. Over two growing seasons, fluxes of CO2 and CH4, coupled with measurements of WT, were examined
AGU Fall Meeting Abstracts, Dec 1, 2013
2015 AGU Fall Meeting, Dec 14, 2015
AGU Fall Meeting Abstracts, Dec 1, 2019
SIL Proceedings, 1922-2010, 1993
Journal of Geosciences, 1997
Previous field investigations have shown that a Sphagnum-dominated wetland had the potential to c... more Previous field investigations have shown that a Sphagnum-dominated wetland had the potential to chemically modify acid mine drainage (AMD). The authors objective was to assess the relative importance of the mechanisms by which peat removes iron from inputs of AMD water. These mechanisms include the formation of organically bound iron, iron oxides, and iron sulfides. Experimental microcosms were filled with
Soil Biology and Biochemistry, 1987
Arylsulphatase activity in peat exposed to acid precipitation. BW Jarvis, GE Lang, RK Wieder Soil... more Arylsulphatase activity in peat exposed to acid precipitation. BW Jarvis, GE Lang, RK Wieder Soil Biology and Biochemistry 19:11, 107-109, 1987. The author investigated pool sizes for total S and ester-sulphate S within the ...
AGUFM, Dec 1, 2010
Peatlands of boreal Canada represent large reservoirs of sequestered carbon (C) and nitrogen (N).... more Peatlands of boreal Canada represent large reservoirs of sequestered carbon (C) and nitrogen (N). Cycling of C and N in peatlands is intrinsically linked, especially in bogs - peatlands isolated from ground- and surface-water inputs, receiving nutrients exclusively from the atmosphere, which in the absence of N pollution, ensures an N-limited, nutrient-poor ecosystem. A growing concern associated with the development
AGU Fall Meeting Abstracts, Dec 1, 2011
ABSTRACT Nitrogen oxide and sulfur oxide emission from ongoing development of oil sands in northe... more ABSTRACT Nitrogen oxide and sulfur oxide emission from ongoing development of oil sands in northern Alberta results in regionally elevated atmospheric deposition of N and S in an area where background deposition of both N and S is exceptionally low (less than 1 kg/ha/yr). Because bogs, which represent major landforms in the Alberta oil sands region, are believed to be N-limited and potentially sensitive to S inputs, we have been investigating the effects of elevated N deposition on C, N, and S cycling in bogs, as well as the potential of bogs to serve as monitors of N and S deposition. Toward this latter end, we have measured seasonal variation (5 sampling dates between June and October 2009) concentrations of N and S, as well as δ15N value, in leaf tissues (Picea mariana (ectomycorrhizal); Ledum groenlandicum, Oxycoccos microcarpon, Vaccinium vitis-idaea (ericoid mycorrhizal); Rubus chamaemorus, and Smilacina trifolia (nonmycorrhizal), Sphagnum (S. fuscum, S. capillifolium, S. magellanicum, S. angustifolium) moss capitula (top 1-cm of plant) and lichens (Cladina mitis and Evernia mesomorpha) at 5 bogs at distances ranging from 14 to 300 km from the heart of the oil sands mining area. Averaged across all sites and sampling dates, N concentrations in ectomycorrhizal, ericoid mycorrhizal, nonmycorrhizal, Sphagnum, and lichens was 8.6 + 0.2, 11.9 + 0.2, 26.3 + 0.6, 10.2 + 0.1, 7.2 + 0.2 mg/g, respectively; δ15N values were -10.3 + 0.1, -6.0 + 0.1, 1.7 + 0.2, -5.3 + 0.1, -4.7 + 0.1 mg/g, respectively, and S concentrations were 1.07 + 0.2, 1.31 + 0.2, 1.94 + 0.6, 1.46 + 0.2, 1.11 + 0.3 mg/g, respectively. Plant functional groups and individual species behaved differently with respect to both seasonal variation and site differences, often with significant interactions when analyzed using two-way analyses of variance. Some species exhibited seasonal variation in some aspects of plant tissue chemistry, while others did not; when a species did exhibit seasonal variation, the variation was rather consistent between sites. More importantly, however, canonical discriminant analysis (with potential variables of C, N, or S concentrations, C:N, C:S, or N:S ratios, and δ15N values) indicated that the five sites can be differentiated based on plant tissue chemistry, most clearly separating the site closest and the site farthest from the oil sands mining area. The first canonical axis explained between 66 and 91 percent of the overall variation, but the variables that were significantly correlated with the first canonical axis differed between species. We conclude that plant tissue chemistry exhibited a significant variation between plant functional groups, between species, between sites, and seasonally. Some of this variation appears to be related to distance from the heart of oil sands mining activity in northern Alberta, possibly reflecting regionally elevated atmospheric deposition of N and S. Bog plants, through analysis of tissue chemistry, have the potential to serve as biomonitors of the anticipated spread of elevated atmospheric N and S deposition as oil sands development continues to grow in northern Alberta.
AGU Fall Meeting Abstracts, Dec 1, 2013
AGU Fall Meeting Abstracts, Dec 1, 2012
2014 AGU Fall Meeting, Dec 16, 2014
Biogeosciences, Mar 8, 2010
An 18-month reciprocal peat transplant experiment was conducted between two peatlands in the Czec... more An 18-month reciprocal peat transplant experiment was conducted between two peatlands in the Czech Republic. Both sites were 100% Sphagnum-covered, with no vascular plants, and no hummocks and hollows. Atmospheric depositions of sulfur were up to 10 times higher at the northern site Velke jerabi jezero (VJJ), compared to the southern site Cervene blato (CB). Forty-cm deep peat cores, 10-cm in diameter, were used as transplants and controls in five replicates. Our objective was to evaluate whether CO 2 and CH 4 emissions from Sphagnum peat bogs are governed mainly by organic matter quality in the substrate, or by environmental conditions. Emission rates and δ 13 C values of CO 2 and CH 4 were measured in the laboratory at time t = 18 months. All measured parameters converged to those of the host site, indicating that, at least in the short-term perspective, environmental conditions were a more important control of greenhouse gas emissions than organic carbon quality in the substrate. Since sulfate reducers outcompete methanogens, we hypothesized that the S-polluted site VJJ should have lower methane emissions than CB. In fact, the opposite was true, with significantly (p <0.01) higher methane emissions from VJJ. Additionally, as a first step in an effort to link C isotope composition of emitted gases and residual peat substrate, we determined whether multiple vertical δ 13 C profiles in peat agree. A high degree of within-site homogeneity in δ 13 C was found. When a specific vertical δ 13 C trend was seen in one peat core, the same trend was also seen in all the remaining peat cores from the wetland.
Biogeochemistry, Apr 1, 1999
One important assumption in applying 210 Pb-dating is that atmospherically deposited 210 Pb is im... more One important assumption in applying 210 Pb-dating is that atmospherically deposited 210 Pb is immobilized in the peat or sediment column. This assumption has been challenged widely, but has never been evaluated experimentally. We evaluated Pb mobility and the chemical forms in which Pb is stabilized in peat profiles by adding either soluble or particulate Pb to intact peat cores that were maintained under different water level regimes (permanently high, permanently low, fluctuating between high and low) and were subjected to simulated precipitation over a five month period. By analyzing the behavior of stable Pb we made inferences about the expected behavior of 210 Pb. Results indicate that added soluble Pb 2+ was retained in the peat through physiochemical binding to organic matter, and as such Pb 2+ was largely immobile in peat even under conditions of a fluctuating water table. Added particulate Pb was largely (most likely by physical entrapment), but not completely, immobilized in peat. In none of the water table treatments was there evidence to support mobility of Pb by alternating formation and oxidation of sulfides, or by any other mechanism. The binding of Pb 2+ with organic matter at the peat surface, and the absence of Pb mobility lend credence to 210 Pbdating of Sphagnum-dominated peat deposits, which are over 90% organic matter throughout, and have high cation exchange capacities.
Biogeochemistry, Jun 1, 1988
Total S concentration in the top 35 cm of Big Run Bog peat averaged 9.7 pmo1.gwet mass-' (123pmol... more Total S concentration in the top 35 cm of Big Run Bog peat averaged 9.7 pmo1.gwet mass-' (123pmol.gdry mass-'). Of that total, an average of 80.8% was carbon bonded S, 10.4% was ester sulfate S, 4.5% was FeS2-S, 2.7% was FeS-S, 1.2% was elemental S, and 0.4% was SO:-S. In peat collected in March 1986, injected with 35S-SO:-and incubated at 4 "C, mean rates of dissimilatory sulfate reduction (formation of H2S + So + FeS + FeS,), carbon bonded S formation, and ester sulfate S formation averaged 3.22,0.53, and 0.36 nmo1.g wet mass-'W', respectively. Measured rates of sulfide oxidation were comparable to rates of sulfate reduction. Although dissolved S O : concentrations in Big Run Bog interstitial water (< 200pM) are low enough to theoretically limit sulfate reducing bacteria, rates of sulfate reduction integrated throughout the top 3&35 cm of peat of 9 and 34mm0l.m-~&' (at 4 "C) are greater than or comparable to rates in coastal marine sediments. We suggest that sulfate reduction was supported by a rapid turnover of the dissolved SO:-pool (average turnover time of 1.1 days). Although over 90% of the total S in Big Run Bog peat was organic S, cycling of S was dominated by fluxes through the inorganic S pools.
AGU Fall Meeting Abstracts, Dec 1, 2010
Bogs of Alberta, Canada are peatlands that are both Sphagnum-moss dominated and nutrient limited.... more Bogs of Alberta, Canada are peatlands that are both Sphagnum-moss dominated and nutrient limited. Due to their ombrotrophic nature, nitrogen (N) is deposited only via atmospheric deposition (wet/dry) and biological N2 fixation. Historically, bogs of Alberta are unpolluted with low rates of atmospheric N deposition (15 kg ha-1 yr-1). Due to the extensive rich bitumen deposits under northern Alberta, however,
AGUFM, Dec 1, 2010
Water table position (WT) is an important factor in peatland ecosystem structure and function. Th... more Water table position (WT) is an important factor in peatland ecosystem structure and function. The relationship between WT and net ecosystem production (NEP) is recognized, but poorly described, especially on a microscale level where factors such as vegetation and microhabitat may influence this relationship. Over two growing seasons, fluxes of CO2 and CH4, coupled with measurements of WT, were examined
AGU Fall Meeting Abstracts, Dec 1, 2013
2015 AGU Fall Meeting, Dec 14, 2015
AGU Fall Meeting Abstracts, Dec 1, 2019
SIL Proceedings, 1922-2010, 1993
Journal of Geosciences, 1997
Previous field investigations have shown that a Sphagnum-dominated wetland had the potential to c... more Previous field investigations have shown that a Sphagnum-dominated wetland had the potential to chemically modify acid mine drainage (AMD). The authors objective was to assess the relative importance of the mechanisms by which peat removes iron from inputs of AMD water. These mechanisms include the formation of organically bound iron, iron oxides, and iron sulfides. Experimental microcosms were filled with
Soil Biology and Biochemistry, 1987
Arylsulphatase activity in peat exposed to acid precipitation. BW Jarvis, GE Lang, RK Wieder Soil... more Arylsulphatase activity in peat exposed to acid precipitation. BW Jarvis, GE Lang, RK Wieder Soil Biology and Biochemistry 19:11, 107-109, 1987. The author investigated pool sizes for total S and ester-sulphate S within the ...
AGUFM, Dec 1, 2010
Peatlands of boreal Canada represent large reservoirs of sequestered carbon (C) and nitrogen (N).... more Peatlands of boreal Canada represent large reservoirs of sequestered carbon (C) and nitrogen (N). Cycling of C and N in peatlands is intrinsically linked, especially in bogs - peatlands isolated from ground- and surface-water inputs, receiving nutrients exclusively from the atmosphere, which in the absence of N pollution, ensures an N-limited, nutrient-poor ecosystem. A growing concern associated with the development
AGU Fall Meeting Abstracts, Dec 1, 2011
ABSTRACT Nitrogen oxide and sulfur oxide emission from ongoing development of oil sands in northe... more ABSTRACT Nitrogen oxide and sulfur oxide emission from ongoing development of oil sands in northern Alberta results in regionally elevated atmospheric deposition of N and S in an area where background deposition of both N and S is exceptionally low (less than 1 kg/ha/yr). Because bogs, which represent major landforms in the Alberta oil sands region, are believed to be N-limited and potentially sensitive to S inputs, we have been investigating the effects of elevated N deposition on C, N, and S cycling in bogs, as well as the potential of bogs to serve as monitors of N and S deposition. Toward this latter end, we have measured seasonal variation (5 sampling dates between June and October 2009) concentrations of N and S, as well as δ15N value, in leaf tissues (Picea mariana (ectomycorrhizal); Ledum groenlandicum, Oxycoccos microcarpon, Vaccinium vitis-idaea (ericoid mycorrhizal); Rubus chamaemorus, and Smilacina trifolia (nonmycorrhizal), Sphagnum (S. fuscum, S. capillifolium, S. magellanicum, S. angustifolium) moss capitula (top 1-cm of plant) and lichens (Cladina mitis and Evernia mesomorpha) at 5 bogs at distances ranging from 14 to 300 km from the heart of the oil sands mining area. Averaged across all sites and sampling dates, N concentrations in ectomycorrhizal, ericoid mycorrhizal, nonmycorrhizal, Sphagnum, and lichens was 8.6 + 0.2, 11.9 + 0.2, 26.3 + 0.6, 10.2 + 0.1, 7.2 + 0.2 mg/g, respectively; δ15N values were -10.3 + 0.1, -6.0 + 0.1, 1.7 + 0.2, -5.3 + 0.1, -4.7 + 0.1 mg/g, respectively, and S concentrations were 1.07 + 0.2, 1.31 + 0.2, 1.94 + 0.6, 1.46 + 0.2, 1.11 + 0.3 mg/g, respectively. Plant functional groups and individual species behaved differently with respect to both seasonal variation and site differences, often with significant interactions when analyzed using two-way analyses of variance. Some species exhibited seasonal variation in some aspects of plant tissue chemistry, while others did not; when a species did exhibit seasonal variation, the variation was rather consistent between sites. More importantly, however, canonical discriminant analysis (with potential variables of C, N, or S concentrations, C:N, C:S, or N:S ratios, and δ15N values) indicated that the five sites can be differentiated based on plant tissue chemistry, most clearly separating the site closest and the site farthest from the oil sands mining area. The first canonical axis explained between 66 and 91 percent of the overall variation, but the variables that were significantly correlated with the first canonical axis differed between species. We conclude that plant tissue chemistry exhibited a significant variation between plant functional groups, between species, between sites, and seasonally. Some of this variation appears to be related to distance from the heart of oil sands mining activity in northern Alberta, possibly reflecting regionally elevated atmospheric deposition of N and S. Bog plants, through analysis of tissue chemistry, have the potential to serve as biomonitors of the anticipated spread of elevated atmospheric N and S deposition as oil sands development continues to grow in northern Alberta.
AGU Fall Meeting Abstracts, Dec 1, 2013