Acidification of Sensitive Soils: Base Saturations

Another measure of soil acidification is base saturation (the percentage of the cation exchange sites occupied by base cations). Base cations provide buffering capacity against soil pH changes. In forested soils, values of 5-15% are considered critical threshold levels. Below these levels, the loss of base cations leaves soils more susceptible to soil acidification. Although the current measure for forested soils shows a declining trend, there is a substantial margin before the base saturation threshold of 15% is reached.