Chemical and pedogenetic effects of simulated acid precipitation on two eastern Canadian forest soils. II. Metals

1985 ◽  
Vol 15 (5) ◽  
pp. 848-854 ◽  
Author(s):  
G. K. Rutherford ◽  
G. W. VanLoon ◽  
S. F. Mortensen ◽  
J. A. Hern
Keyword(s):  
Extreme Values ◽  
Mineral Soil ◽  
Base Cations ◽  
Titratable Acidity ◽  
Molar Ratio ◽  
Organic C ◽  
Free Iron ◽  
Podzolic Soils ◽  
Exchange Cations ◽  
Field Evidence

A study to determine the effects of simulated acid rain on two Canadian Shield podzolic soils was performed on field plots and reconstructed profiles. Soils were irrigated with deionized water and HNO3 and H2SO4 (1:2 molar ratio) solutions at pH 3.5 and 2.0. Pore–water concentrations of Na, K, Mg, Ca, Fe, Mn, and Al were measured at 15–60 cm over 2 years. Half the reconstructed profiles were dismantled after 1 year. Total organic C, exchange cations Ca, Mg, K, and Na, and titratable acidity were measured and three different extraction procedures were used to determine soil free iron and aluminum oxides. Al mobilization high in the profiles, with extreme values up to 40 mg/L at pH 2.0, was followed by redeposition lower in the profile. Up to threefold enhancement of Ca and Al leaching was observed under the most acidic conditions, particularly in the field. Evidence in the present study suggests that anion affinity of the mineral soil reduces the leaching of base cations. A significant decrease in free iron oxides just below the Ae horizon was observed in one of the soils.

How do forest harvesting methods compare with wildfire? A case study of soil chemistry and tree nutrition in the boreal forest

2007 ◽  
Vol 37 (9) ◽  
pp. 1658-1668 ◽  
Author(s):  
Evelyne Thiffault ◽  
Nicolas Bélanger ◽  
David Paré ◽  
Alison D. Munson
Keyword(s):  
Pinus Banksiana ◽  
Sustainable Forest Management ◽  
Black Spruce ◽  
Base Cations ◽  
Natural Disturbance ◽  
Forest Harvesting ◽  
Exchange Capacity ◽  
Molar Ratio ◽  
Organic C ◽  
Tree Nutrition

An important tenet of the natural disturbance paradigm as a basis for sustainable forest management is that impacts of interventions fall within the range of natural variation observed for the disturbance in question. We evaluated differences in soil nutrients, soil acid–base status, and tree nutrition between two harvesting methods (whole-tree (WTH) and stem-only (SOH)) and wildfire, 15–20 years after disturbance, to assess whether these harvesting methods have biogeochemical impacts that are within the natural range of variation caused by wildfires in boreal coniferous stands of Haute-Mauricie (Quebec). Both SOH and WTH created conditions of forest floor effective cation-exchange capacity, exchangeable Ca and K concentrations, base saturation, Ca:Al molar ratio, and organic C concentrations that were lower than the range of values for wildfires. We hypothesize that the immediate deposition of soluble base cations and the incorporation of recalcitrant organic matter that characterize wildfires generate biogeochemical conditions that are not emulated by either harvesting method. The improved soil nutritional environment after wildfire compared with SOH and WTH was reflected in jack pine ( Pinus banksiana Lamb.) foliar nutrient composition but not in black spruce ( Picea mariana (Mill.) BSP) foliage. The results raise uncertainties about the long-term base nutrient availability of the harvested sites on Boreal Shield soils.

The effects of simulated acid precipitation in the surface horizons of two eastern Canadian forest Podzol soils

1987 ◽  
Vol 17 (9) ◽  
pp. 1138-1143 ◽  
Author(s):  
D. J. Thacker ◽  
G. K. Rutherford ◽  
G.W. Vanloon
Keyword(s):  
Mineral Soil ◽  
Acid Precipitation ◽  
Exchange Capacity ◽  
Soil Core ◽  
X Ray Diffraction ◽  
Total N ◽  
Organic C ◽  
Podzolic Soils ◽  
Humus Layer ◽  
Organic Horizons

Undisturbed 18-cm soil cores of the L, F, H, Ae, and upper Bhf horizons of Ferro-Humic Podzols from the Turkey Lake Watershed (Ontario) and Montmorency Forest (Quebec) were treated in the laboratory with 10 m of simulated acid precipitation at pH 5.7, 3.5, and 2.0 over approximately 1 year. Leachate samples were collected from the bottom of the humus layer and the bottom of the soil core and the soils were analyzed at the completion of leaching. The soils from the two sites behaved similarly. Anion concentrations in the leachates adjusted to input levels after approximately 2 m of simulated rainfall. Leaching generally produced an initial flush of cations followed by lower concentrations. The pH 2.0 treatment caused major changes in some soil properties; the pH 3.5 and 5.7 treatment had a more modest effect. Base saturation was markedly reduced following the pH 2.0 treatment, slightly reduced following the pH 3.5 treatment, and slightly increased following the distilled water treatment. Cation exchange capacity was reduced only in the organic horizons receiving pH 2.0 treatment. Organic C, total N, and C/N ratios showed no changes on acidification. Leaching of Fe and Al was only substantial with the pH 2.0 treatment and much more Al than Fe was mobilized. Bicarbonate – extractable P in the mineral soil was doubled by the pH 2.0 treatment compared with the other treatments. X-ray diffraction of clays indicated a loss of hydroxyaluminum interlayers with increasing acidity, which is a stage in the acidic transformation of micaceous to smectite-like materials in Podzolic soils.

A conceptual model for nutrient availability in the mineral soil-root system

1996 ◽  
Vol 76 (2) ◽  
pp. 125-131 ◽  
Author(s):  
George R. Gobran ◽  
Stephen Clegg
Keyword(s):  
Organic Matter ◽  
Conceptual Model ◽  
Norway Spruce ◽  
Mineral Soil ◽  
Organic Matter Content ◽  
Base Cations ◽  
Titratable Acidity ◽  
Matter Content ◽  
Bulk Soil ◽  
Soil Fractions

We propose a conceptual model based on our results from rhizospheric studies of a Norway spruce stand growing on a nutrient poor Podzol in Southwest Sweden. We assume that dynamic linkages exist between three soil fractions: bulk soil, rhizosphere (Rhizo) and soil root interface (SRI). The soil fractions were characterized by organic matter content, electrical conductivity, pH, and soluble and exchangeable cations. Analyses showed great differences among the three soil fractions, especially the properties of the SRI. Cation exchange capacity and base saturation were higher in the rhizosphere and SRI than in the bulk soil. We attribute this to accumulation of organic matter (OM) in the rhizosphere and SRI. Moreover, the rhizosphere and SRI fractions had lower pH and higher titratable acidity than the bulk soil. Any possible negative effects of Al to the roots could be offset by accumulated organic matter and base cations (BC). The calcium-aluminum balance followed a consistent trend: bulk < rhizo < SRI. The results suggest that soil around the roots exhibits a different chemical composition than that of the root-free (bulk) soil, indicating more favorable conditions for roots. We suggest that trees growing on nutrient-poor acid soils invest their energy around roots to create a favorable microenvironment for both roots and microorganisms. Our results suggest that existing models which attempt to connect tree growth to soil acidification need modification. Such modification would include horizontal variation (bulk soil, rhizo and SRI) besides the vertical ones normally emphasized. It is possible that the conceptual model may enable a better understanding and description of naturally existing relationships between soil and plants under normal and stressed conditions. Key words: Conceptual model, organic matter, rhizosphere, soil root interface, acidification and growth models, Norway spruce

scholarly journals Linking the lithogenic, atmospheric, and biogenic cycles of silicate, carbonate, and organic carbon in the ocean

2009 ◽  
Vol 6 (4) ◽  
pp. 6579-6599
Author(s):  
S. V. Smith ◽  
J.-P. Gattuso
Keyword(s):  
Carbon Storage ◽  
Chemical Weathering ◽  
Dissolved Inorganic Carbon ◽  
North Pacific Ocean ◽  
Atmospheric Co2 ◽  
Molar Ratio ◽  
Co2 Uptake ◽  
Organic C ◽  
Co2 Gas ◽  
The Relationship

Abstract. Geochemical theory describes long term cycling of atmospheric CO2 between the atmosphere and rocks at the Earth surface in terms of rock weathering and precipitation of sedimentary minerals. Chemical weathering of silicate rocks takes up atmospheric CO2, releases cations and HCO3− to water, and precipitates SiO2, while CaCO3 precipitation consumes Ca2+ and HCO3− and releases one mole of CO2 to the atmosphere for each mole of CaCO3 precipitated. At steady state, according to this theory, the CO2 uptake and release should equal one another. In contradiction to this theory, carbonate precipitation in the present surface ocean releases only about 0.6 mol of CO2 per mole of carbonate precipitated. This is a result of the buffer effect described by Ψ, the molar ratio of net CO2 gas evasion to net CaCO3 precipitation from seawater in pCO2 equilibrium with the atmosphere. This asymmetry in CO2 flux between weathering and precipitation would quickly exhaust atmospheric CO2, posing a conundrum in the classical weathering and precipitation cycle. While often treated as a constant, Ψ actually varies as a function of salinity, pCO2, and temperature. Introduction of organic C reactions into the weathering-precipitation couplet largely reconciles the relationship. ψ in the North Pacific Ocean central gyre rises from 0.6 to 0.9, as a consequence of organic matter oxidation in the water column. ψ records the combined effect of CaCO3 and organic reactions and storage of dissolved inorganic carbon in the ocean, as well as CO2 gas exchange between the ocean and atmosphere. Further, in the absence of CaCO3 reactions, Ψ would rise to 1.0. Similarly, increasing atmospheric pCO2 over time, which leads to ocean acidification, alters the relationship between organic and inorganic C reactions and carbon storage in the ocean. Thus, the carbon reactions and ψ can cause large variations in oceanic carbon storage with little exchange with the atmosphere.

Organic C and nutrients in surface soils from some primary rainforests, derived grasslands and secondary rainforests on the Atherton Tableland in North East Queensland

Soil Research ◽  
1993 ◽  
Vol 31 (3) ◽  
pp. 343 ◽  
Author(s):  
J Maggs ◽  
B Hewett
Keyword(s):  
Metamorphic Rock ◽  
Forest Type ◽  
Mineral Soil ◽  
Chemical Properties ◽  
Primary Forest ◽  
Long Term Effects ◽  
Organic C ◽  
North East ◽  
Exchangeable Ca ◽  
Labile N

Some long term effects of (a) converting rainforest to grassland, and (b) rainforest regeneration on cleared land were investigated by comparing chemical properties of mineral soil (0-10 cm depth) from beneath primary rainforest, derived grassland and old secondary rainforest. Grasslands and secondary rainforest. were on land cleared at least 50 years ago. The study was undertaken on the Atherton Tableland in north east Queensland using soils formed on basalt, granite and metamorphic rocks. Organic C, kjeldahl N and labile N were 15-50% lower (P < 0.05) beneath grassland than primary rainforest for all soils, and were higher beneath secondary rainforest than grassland. Exchangeable Ca varied in a similar way in basaltic soils but did not differ between vegetation types in the other soils. Extractable Al was lower under grassland than either forest type for soils formed on granite and metamorphic rock. Total and organic P concentrations did not differ between primary forest and grassland, but were lowest under secondary rainforest for soils on metamorphic rock.

Cycling of acid and base cations in deciduous stands of Huntington Forest, New York, and Turkey Lakes, Ontario

1992 ◽  
Vol 22 (2) ◽  
pp. 167-174 ◽  
Author(s):  
N.W. Foster ◽  
M.J. Mitchell ◽  
I.K. Morrison ◽  
J.P. Shepard
Keyword(s):  
New York ◽  
Soil Acidity ◽  
Mineral Soil ◽  
Base Cations ◽  
Base Cation ◽  
Native Soil ◽  
Soil Solutions ◽  
Acid And Base ◽  
Turkey Lakes Watershed ◽  
Dominant Cation

Annual nutrient fluxes within two forests exposed to acidic deposition were compared for a 1-year period. Calcium (Ca2+) was the dominant cation in throughfall and soil solutions from tolerant hardwood dominated Spodosols (Podzols) at both Huntington Forest (HF), New York, and the Turkey Lakes watershed (TLW), Ontario. There was a net annual export of Ca2+ and Mg2+ from the TLW soil, whereas base cation inputs in precipitation equaled outputs at HF. In 1986, leaching losses of base cations were five times greater at TLW than at HF. A higher percentage of the base cation reserves was leached from the soil at TLW (5%) than at HF (1%). Relative to throughfall, aluminum concentrations increased in forest-floor and mineral-soil solutions, especially at HF. The TLW soil appears more sensitive to soil acidification. Deposited atmospheric acidity, however, was small in comparison with native soil acidity (total and exchangeable) and the reserves of base cations in each soil. Soil acidity and base saturation, therefore, are likely only to change slowly.

Carbon Dioxide Assimilation by Pineapple Plants, Ananas comosus (L.) Merr. I. Effects of Daily Irradiance

1980 ◽  
Vol 7 (4) ◽  
pp. 363 ◽  
Author(s):  
PJM Sale ◽  
TF Neales
Keyword(s):  
Leaf Area ◽  
Leaf Tissue ◽  
Extended Period ◽  
Titratable Acidity ◽  
Dry Weight ◽  
Co2 Assimilation ◽  
Co2 Exchange ◽  
Ananas Comosus ◽  
Molar Ratio ◽  
Weight Changes

Net carbon exchange over 24-h cycles was measured in well watered pineapple plants, using a 'minicrop' in field assimilation chambers and single leaves in a growth cabinet. Whole plants under natural light and a standard 30°C day/15°C night regime showed crassulacean acid metabolism, nearly all assimilation occurring in the dark period, with a net efflux of CO2 in the day. Assimilation, as measured by both CO2 exchange and changes in titratable acidity in the leaf tissue, was markedly dependent on the total photosynthetically active radiation incident in the previous photoperiod. The molar ratio of the maximum acidity change to maximum net nocturnal CO2 influx was 1.8 : 1. The rate of deacidification depended on the irradiance in the current photoperiod. Efflux in the photoperiod was largely independent of irradiance, but was greater at very low irradiances. Maximum rates of CO2 assimilation in the minicrop were about 15 ng cm-2 (leaf area) s-1 in the dark at the standard temperature regime, and 22 ng-2 s-1 when photoperiod assimilation was induced by a 20°C day/30°C night regime. Similar rates were recorded in the single-leaf experiments, and are higher than those previously found for pineapple. Over a 24-h period, mean rates of about 6 ng cm-2 (leaf area) s-1 were recorded, in good agreement with measured dry weight changes over an extended period. These data help to explain earlier discrepancies in the literature between measured rates of CO2 assimilation and of crop growth rates in pineapples.

Douglas-fir soil C and N properties a decade after termination of urea fertilization

2001 ◽  
Vol 31 (12) ◽  
pp. 2225-2236 ◽  
Author(s):  
Peter S Homann ◽  
Bruce A Caldwell ◽  
H N Chappell ◽  
Phillip Sollins ◽  
Chris W Swanston
Keyword(s):  
Mineral Soil ◽  
Cellulase Activity ◽  
Douglas Fir ◽  
Soil Organic C ◽  
Total N ◽  
Organic C ◽  
Soil C ◽  
Second Growth ◽  
Heavy Fractions ◽  
Urea Fertilization

Chemical and microbial soil properties were assessed in paired unfertilized and urea fertilized (>89 g N·m–2) plots in 13 second-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) stands distributed throughout western Washington and Oregon. A decade following the termination of fertilization, fertilized plots averaged 28% higher total N in the O layer than unfertilized plots, 24% higher total N in surface (0–5 cm) mineral soil, and up to four times the amount of extractable ammonium and nitrate. Decreased pH (0.2 pH units) caused by fertilization may have been due to nitrification or enhanced cation uptake. In some soil layers, fertilization decreased cellulase activity and soil respiration but increased wood decomposition. There was no effect of fertilization on concentrations of light and heavy fractions, labile carbohydrates, and phosphatase and xylanase activities. No increase in soil organic C was detected, although variability precluded observing an increase of less than ~15%. Lack of a regionwide fertilization influence on soil organic C contrasts with several site-specific forest and agricultural studies that have shown C increases resulting from fertilization. Overall, the results indicate a substantial residual influence on soil N a decade after urea fertilization but much more limited influence on soil C processes and pools.

The effect of pedogenetic processes on the distribution of phosphorus, calcium and magnesium in Gray Luvisols

1991 ◽  
Vol 71 (4) ◽  
pp. 397-410 ◽  
Author(s):  
X. J. Xiao ◽  
D. W. Anderson ◽  
J. R. Bettany
Keyword(s):  
Populus Tremuloides ◽  
Picea Glauca ◽  
Pinus Banksiana ◽  
Black Spruce ◽  
Mineral Soil ◽  
Coniferous Forest ◽  
Soil Formation ◽  
Podzolic Soils ◽  
Exchangeable Ca ◽  
Phosphorus Losses

Pedogenesis and its effect on calcium (Ca), magnesium (Mg) and phosphorus (P) was studied on a sequence of seven Gray Luvisol soils in central Saskatchewan. The soils were formed on calcareous glacial till under trembling aspen (Populus tremuloides Michx), mixedwood (aspen and white spruce) (Picea glauca (Moench) Voss)) and coniferous (black spruce and jack pine) (Picea mariana (Mill) BSP and Pinus banksiana Lamb) forests. Soils under aspen had the highest concentration of total and exchangeable Ca and Mg in litter layers and Ae horizons, and had Ae and Bt horizons that were least acidic. The most acidic Ae and Bt horizons and lowest amounts of Ca and Mg occurred under coniferous forests, whereas the soils under mixedwood stands were intermediate. The thickness of eluvial (Ae and AB) horizons increased along the aspen to coniferous sequence. All soils had about 40% less P in their A and B horizons than was calculated to have been present at the start of soil formation. The greatest decrease in P was observed in the thickest and most acidic soil under coniferous forest. The present litter layers and vegetation make up only a small proportion of the P removed from the mineral soil. Unusually large amounts of P appear to have been translocated from A and B horizons during development of Gray Luvisols, in comparison to Chernozemic or even Podzolic soils. Our hypothesis proposes that P is ineffectively retained in the solum as P-clay-humus, or iron-P complexes and that organic P moves along with the soil water, laterally and downslope through permeable Ae horizon over less permeable Bt horizons, or vertically through macropores. Key words: Boreal forest, nutrient cycling, phosphorus losses, weathering, soil formation

scholarly journals Forms, amounts and distribution of carbon, nitrogen, phosphorus and sulfur in a boreal aspen forest soil

1996 ◽  
Vol 76 (3) ◽  
pp. 373-385 ◽  
Author(s):  
W. Z. Huang ◽  
J. J. Schoenau
Keyword(s):  
Boreal Forest ◽  
Populus Tremuloides ◽  
Mineral Soil ◽  
Nutrient Storage ◽  
Organic C ◽  
C Storage ◽  
C And N ◽  
Aspen Forest ◽  
Total P ◽  
Total Organic C

The forms, amounts and distribution of carbon (C), nitrogen (N), phosphorus (P) and sulfur (S) were assessed in soil profiles under trembling aspen (Populus tremuloides Michx.) stands in the southern boreal forest of Saskatchewan, Canada. The total mass of organic C storage in the LFH horizon and mineral soil to a depth of 1 m ranged from 95 352 to 103 430 kg ha−1, with an average of 99 220 kg ha−1. Organic C and N in the LFH horizon accounted for the greatest proportion of the total storage (47.3% of C and 34.2% of N), followed by the B horizon (22.4% of C and 32.7% of N) the A horizon (17.3% of C and 18.3% of N) and the C horizon (13.0% of C and 14.8% of N). Unlike C and N, more than 96% of the total P was found in the mineral soil and only 3.5% in the LFH horizon. Much of the P stored in the mineral horizons is contained in non-labile primary minerals forms. The greatest proportion (36.5%) of organic S was found in the C horizon with 26.6% in the LFH horizon. The contribution of the LFH horizon to total organic C and N stored in boreal forest soils should not be neglected in global nutrient cycling models. Key words: Forest floor, litter, nutrient storage, organic matter

Sign in / Sign up

Export Citation Format

Share Document