Estimation of soil pH with geochemical indices in forest soils

Colorimetric soil pH measurements made systematically across Burnaby Mountain in well-drained loamy soils of the rainforest of British Columbia over an 8-yr period from 1974 until 1981 showed that acidification of the subsoil increased after two consecutive drier-than-average years. This changing acidity contrasted with the relatively stable acidity of the subsoil in imperfectly drained soils, regardless of changing patterns of precipitation. Key words: pH, forests, loams, precipitation

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Variation in pH Optima of Hydrolytic Enzyme Activities in Tropical Rain Forest Soils

Applied and Environmental Microbiology ◽

10.1128/aem.00560-10 ◽

2010 ◽

Vol 76 (19) ◽

pp. 6485-6493 ◽

Cited By ~ 119

Author(s):

Benjamin L. Turner

Keyword(s):

Soil Ph ◽

Forest Soils ◽

Extracellular Enzymes ◽

Hydrolytic Enzyme ◽

Hydrolytic Enzymes ◽

Acidic Ph ◽

Acidic Soils ◽

Fluorogenic Substrates ◽

Ph Values ◽

Optimum Ph

ABSTRACT Extracellular enzymes synthesized by soil microbes play a central role in the biogeochemical cycling of nutrients in the environment. The pH optima of eight hydrolytic enzymes involved in the cycles of carbon, nitrogen, phosphorus, and sulfur, were assessed in a series of tropical forest soils of contrasting pH values from the Republic of Panama. Assays were conducted using 4-methylumbelliferone-linked fluorogenic substrates in modified universal buffer. Optimum pH values differed markedly among enzymes and soils. Enzymes were grouped into three classes based on their pH optima: (i) enzymes with acidic pH optima that were consistent among soils (cellobiohydrolase, β-xylanase, and arylsulfatase), (ii) enzymes with acidic pH optima that varied systematically with soil pH, with the most acidic pH optima in the most acidic soils (α-glucosidase, β-glucosidase, and N-acetyl-β-glucosaminidase), and (iii) enzymes with an optimum pH in either the acid range or the alkaline range depending on soil pH (phosphomonoesterase and phosphodiesterase). The optimum pH values of phosphomonoesterase were consistent among soils, being 4 to 5 for acid phosphomonoesterase and 10 to 11 for alkaline phosphomonoesterase. In contrast, the optimum pH for phosphodiesterase activity varied systematically with soil pH, with the most acidic pH optima (3.0) in the most acidic soils and the most alkaline pH optima (pH 10) in near-neutral soils. Arylsulfatase activity had a very acidic optimum pH in all soils (pH ≤3.0) irrespective of soil pH. The differences in pH optima may be linked to the origins of the enzymes and/or the degree of stabilization on solid surfaces. The results have important implications for the interpretation of hydrolytic enzyme assays using fluorogenic substrates.

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Reserves of aluminium and mineral nutrients in seeds ofEucalyptus calophylla(Myrtaceae) with reference to the globoid inclusions

Seed Science Research ◽

10.1017/s0960258500002580 ◽

1995 ◽

Vol 5 (1) ◽

pp. 53-57

Author(s):

Louise M. Egerton-Warburton ◽

Brendon J. Griffin ◽

John Kuo

Keyword(s):

Soil Ph ◽

Forest Soils ◽

Coal Mine ◽

Mineral Nutrients ◽

Soil Conditions ◽

Forest Site ◽

Parent Plant ◽

Mine Site ◽

X Ray ◽

Germinating Seeds

AbstractAmounts of mineral nutrients and aluminium (Al) were assessed in the globoid inclusions, proteinaceous matrix and druse crystals ofEucalyptus calophyllaseeds collected from trees grown in coal-mine (mean soil pH 4.3, Al 260 μg g−1) and forest soils (pH 5.3, Al 10 μg g−1). Energy-dispersive X-ray microanalysis (EDX) of bulk frozen hydrated samples indicated that significantly higher amounts of Mg, P, S, K and Ca occurred in the globoid inclusions of mine- than forest-site seeds. In both seedstocks, Al was detected in the globoid inclusions but not in the proteinaceous matrix or druse crystals. Significantly higher amounts of Al occurred in mine-site samples of dry and germinating seeds than in forest-site seeds. It was concluded that globoid inclusions may be useful as indicators of the soil conditions in which the parent plant was grown.

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EFFECTS OF AIR-DRYING ON THE MEASUREMENT OF SOIL pH IN ACIDIC FOREST SOILS OF QUEBEC, CANADA

Soil Science ◽

10.1097/00010694-199507000-00006 ◽

1995 ◽

Vol 160 (1) ◽

pp. 56-68 ◽

Cited By ~ 15

Author(s):

FRANÇOIS COURCHESNE ◽

SYLVAIN SAVOIE ◽

ALAIN DUFRESNE

Keyword(s):

Soil Ph ◽

Forest Soils ◽

Air Drying

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Chemical and pedogenetic effects of simulated acid precipitation on two eastern Canadian forest soils. I. Nonmetals

Canadian Journal of Forest Research ◽

10.1139/x85-136 ◽

1985 ◽

Vol 15 (5) ◽

pp. 839-847 ◽

Cited By ~ 10

Author(s):

J. A. Hern ◽

G. K. Rutherford ◽

G. W. vanLoon

Keyword(s):

Pore Water ◽

Soil Ph ◽

Forest Soils ◽

Microbial Processes ◽

Molar Ratio ◽

Soil N ◽

Total Soil ◽

Treatment Conditions ◽

Ammonium Production ◽

Total Soil N

An experiment involving the addition of simulated acid rain to two Canadian Shield orthic humo-ferric podzolic forest soils was carried out in the field and in the laboratory. Soils were subjected to treatments of pH 5.7, 3.5, and 2.0 water containing added nitric and sulphuric acids in a 1:2 molar ratio. Pore-water concentrations of H+, [Formula: see text], [Formula: see text], [Formula: see text], and Cl− were monitored at depths of 15–60 cm for up to 2 years. Some of the laboratory columns were dismantled after 1 year and total soil N, S, soil pH, and S adsorption characteristics were measured. Half the columns were sterilized in an attempt to assess the relative importance of microbial processes. Considerable H+ buffering by the soils was indicated, with soil pH unchanged even under the most acidic treatment. Nitrate but not ammonium production was suppressed under highly acid treatment conditions in the laboratory, while in the field only small concentrations of both nitrogen species were detected in pore water. No change in total soil N was detected. Sulphur retention was assessed, with major amounts retained by the soil just below the Ae horizon where iron and aluminum oxides along with organic matter accumulate. Sterile column data indicates microbial processes are also of considerable importance in the immobilization of S inputs.

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VARIATIONS OF pH WITH ANNUAL CUMULATIVE PRECIPITATION IN ACID FOREST SOILS

Canadian Journal of Soil Science ◽

10.4141/cjss80-042 ◽

1980 ◽

Vol 60 (2) ◽

pp. 385-387 ◽

Cited By ~ 3

Author(s):

C. B. CRAMPTON

Keyword(s):

British Columbia ◽

Soil Ph ◽

Forest Soils ◽

Rain Forest ◽

Ph Measurements ◽

Ph Values ◽

Acid Forest Soils ◽

Normal Increase ◽

Cumulative Precipitation

Colorimetric soil pH measurements made systematically across Belcarra Mountain in the rain-forest of British Columbia over the 4-yr period 1975 to 1978 showed summer (June or July) values to increase somewhat with total cumulative precipitation (previous November to July). After dry winters, lower pH values in both A and B horizons were recorded, the increase in acidification being so marked on the sandy Podzols as compared to the less light-textured Brunisols that the normal increase in pH down the profile was reversed. The causes of such variations are discussed along with their significance when characterizing Orthic Humo-Ferric Podzols of the region.

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Determination of exchangeable hydrogen ions in boreal shield soils of Quebec

Canadian Journal of Soil Science ◽

10.4141/s05-034 ◽

2006 ◽

Vol 86 (3) ◽

pp. 513-521 ◽

Cited By ~ 6

Author(s):

N. Bélanger ◽

J D MacDonald ◽

D. Paré ◽

E. Thiffault ◽

Y. Claveau ◽

...

Keyword(s):

Cation Exchange ◽

Soil Ph ◽

Forest Soils ◽

Cation Exchange Capacity ◽

Prediction Models ◽

Exchange Capacity ◽

Data Set ◽

Linear Relationships ◽

Boreal Shield ◽

Single Data

An unbuffered BaCl2 extraction for determining effective cation exchange capacity (ECEC) and exchangeable cations is often used for acidic forest soils. However, the contribution of exchangeable H+ to ECEC cannot be assessed using this method as H+ in the extract may be produced/consumed in reactions with free Al3+ and Al-OH complexes, or H+ may be added to the extract via non-exchangeable sources. Fundamentally, any valid measure of ECEC must include some estimate of exchangeable H+ concentration or a demonstration that it is negligible. Unfortunately, this procedure is often neglected in forest soil studies. In this paper, we assessed the significance of the contribution of exchangeable H+ to ECEC for upper soil horizons of three sites of Quebec’s Boreal Shield subject to various disturbance types (i.e., recent harvest, fire and mature forest). We also investigated whether the linear relationships between exchangeable H+ concentrations and soil pH are robust enough to develop regression models capable of predicting exchangeable H+. Exchangeable H+ in the FH samples was higher than that in the podzolic B samples, but the amount of adsorbed H+ relative to ECEC was nevertheless significant in the podzolic B horizons. The general linear relationship (i.e., FH and podzolic B samples as a single data set) developed from soil pH in water explained close to 70% of the variability of log (H+/ECEC). The relationships between log (exchangeable H+) and pH in water in the FH samples were however superior (R2 ≥ 80), either for all sites, disturbance types and sampling strategies (e.g., proportions of F and H horizons in sample). The relationships developed for podzolic B samples alone were not as strong, but ECEC was used efficiently in combination with soil pH to increase prediction capabili ties (R2 ≥ 0.61). Key words: Boreal Shield forest soils, effective cation exchange capacity, exchangeable H+, fire, FH and podzolic B horizons, harvesting, prediction models, soil pH.

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Structural and functional acid-base properties of gray forest soil of Ranged Pobuzhya

Visnyk of the Lviv University. Series Geography ◽

10.30970/vgg.2013.44.1202 ◽

2013 ◽

pp. 85-90

Author(s):

Vitaliy Denys

Keyword(s):

Forest Soil ◽

Soil Ph ◽

Forest Soils ◽

Gray Forest Soil ◽

Water Extract ◽

Acid Base ◽

Structural Units ◽

Gray Forest Soils ◽

Water Ph ◽

Agricultural Use

In this work presents the results of the research of acid-base changes in the structural properties of aggregates in light gray and gray forest soils Ranged Pobuzhya. The present article describes pH of water extract and pH in saline structural units of soils of different agricultural use. Found that with decreasing size of the aggregates decreases acidity. Key words: gray forest soils, light gray forest soil, pH water, pH saline, aggregates, structure.

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Response of Atmospheric Methane Consumption by Maine Forest Soils to Exogenous Aluminum Salts

Applied and Environmental Microbiology ◽

10.1128/aem.66.9.3674-3679.2000 ◽

2000 ◽

Vol 66 (9) ◽

pp. 3674-3679 ◽

Cited By ~ 21

Author(s):

K. Nanba ◽

Gary M. King

Keyword(s):

Soil Ph ◽

Forest Soils ◽

Aluminum Chloride ◽

Atmospheric Methane ◽

Aluminum Salts ◽

Methane Consumption ◽

Ph Values ◽

Mineral Acids ◽

Sulfate Salts

ABSTRACT Atmospheric methane consumption by Maine forest soils was inhibited by additions of environmentally relevant levels of aluminum. Aluminum chloride was more inhibitory than nitrate or sulfate salts, but its effect was comparable to that of a chelated form of aluminum. Inhibition could be explained in part by the lower soil pH values which resulted from aluminum addition. However, significantly greater inhibition by aluminum than by mineral acids at equivalent soil pH values indicated that inhibition also resulted from direct effects of aluminum per se. The extent of inhibition by exogenous aluminum increased with increasing methane concentration for soils incubated in vitro. At methane concentrations of >10 ppm, inhibition could be observed when aluminum chloride was added at concentrations as low as 10 nmol g (fresh weight) of soil−1. These results suggest that widespread acidification of soils and aluminum mobilization due to acid precipitation may exacerbate inhibition of atmospheric methane consumption due to changes in other parameters and increase the contribution of methane to global warming.

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