One of the most serious impacts of acid precipitation is on forests and soils. Great damage is done when sulphuric acid falls onto the earth as rain. Nutrients present in the soils are washed away. Aluminium in the soil is freed and the roots of trees absorb this toxic element, the trees become deprived of their vital nutrients such as calcium and magnesium they then starve to death. Not all of the sulphur dioxide is converted to sulphuric acid. In fact, a substantial amount can float into the atmosphere, move over to another area and return to the soils unconverted. As this gas returns back to earth, it clogs up the stomata in the leaves, stopping photosynthesis.

Research has been carried out into whether red spruce seedlings are affected by acid rain. The results were that the stronger the acid the slower the trees grew.

Nitrogen oxide and nitric oxide, also components of acid rain, can force trees to grow even though they do not have the necessary nutrients. As well, the trees are sometimes forced to grow well into late autumn when it is actually time for them to prepare for severe frosts in the winter