Why do oak trees turn the surrounding soil acidic?

An analogy that comes from Stewart Brand - plants can't move. so they engage in chemical warfare to make their environment favorable for them and hostile to other species of plants. Redwood trees also do this. read more

,Oaks make the soil around them acidic by the tannin in the leaves and the acorn casings , most of the acorns get eaten .The increase in acidity often prevents other plants competing with it . Also it can drop a lot of leaves in the spring just when normal plants are beginning to grow and prevent seed germination . read more

Some soils are impossibly alkaline -- and will never grow blueberries. You may need to test your soil to make sure you do not have permanently high pH real estate. Not even sulfuric acid will lower your pH enough to grow blueberries if you do. read more

Good Soil for Pine Trees. Pine trees thrive in soil that is mildly acidic, about 5.5 pH. This frequently observed pairing may be part of the reason that pine trees are said to create acid soil. Gardeners often find it difficult to grow other plants under pine trees, and blame this on acid soil. read more