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Soil Acidity in Loblolly Pine Stands with Interval Burning
Author(s) -
Binkley Dan
Publication year - 1986
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1986.03615995005000060041x
Subject(s) - acid neutralizing capacity , forest floor , loblolly pine , environmental science , soil ph , titratable acid , agronomy , chemistry , soil water , zoology , forestry , botany , soil science , pinus <genus> , acid deposition , biology , biochemistry , geography
Prescribed burning of loblolly pine ( Pinus taeda L.) stands every 2 yr for 24 yr increased soil pH by 0.3 to 0.9 units. Measurements of total acidity (titratable to pH 8.2) in the forest floor showed about a 14 to 21 kmol H + ha −1 decrease in burned plots. Burning increased the acid neutralizing capacity per gram of forest floor material, but the reduction in forest floor biomass largely offset the difference. Titration curves indicated that the burned forest floor would require only about 0.6 kmol H + ha −1 to lower its pH to the level of the control plots. Total acidity in the 0 to 10 cm mineral soil was more variable; one burned plot showed no decrease relative to controls, but a more intensely burned plot decreased by about 95 kmol H + ha −1 . Despite this large reduction in total acidity, titration curves indicated that only 25 kmol H + ha −1 would lower the pH to the control level. This increase in acid neutralizing capacity is about 50 times the current annual H + input in rain. However, other major components of the ecosystem's H + budget would need to be quantified to assess the importance of fire in relation to acid deposition impacts.