The effects of acid rain are most prominent in aquatic environments such as lakes, rivers, creeks and marches. However, acid precipitation is increasingly damaging forest ecosystems through the leeching of soil nutrients and weakening of trees' natural defenses.
Chronic and episodic acidification leads to an increase in acidity of bodies of water and reduces the amount of nutrients available in an aquatic environment. Many plant and fish species are sensitive to pH changes in the environment and therefore cannot survive in acidic water. If they do adapt, the reduction of nutrients weakens the fish and other plant and animal life. Acid rain also causes bodies of water to absorb aluminum, which makes the water toxic to the species living in it. This damaging effect to fish and plant life travels up the food chain to birds and other animals.
Acid rain is highly detrimental to forest ecosystems. Especially at higher elevations, acid precipitation can damage trees and weaken their natural defenses to diseases and bugs. The decline of spruce-fir trees in the eastern United States is credited to acid rain. Acid rain deposits also leech key nutrients from the soil, such as calcium and magnesium, and it can release aluminum in the soil, which makes it difficult for trees to soak up the water they need to survive. Acid rain also leads to an excess amount of nitrogen in a forest ecosystem, which is not immediately damaging, but does eventually lead to the overgrowth of algae in nearby lakes and streams.