But a new study suggests that the ecosystems affected by acid rain aren't recovering as quickly as people once hoped. The study resulted from ten independent scientists working with data from the Hubbard Brook Experimental Forest, a long-term research site in the White Mountains of New Hampshire. First noticed in northern New Hampshire about thirty years ago, acid rain is caused when sulfur and nitrogen emissions from power plants and automobiles mix with atmospheric water. As these toxic emissions travel across the land via the movement of large air masses, they eventually fall as acid rain. The acid rain that falls across the northeast, for example, is largely a result of emissions from midwestern power plants.
Acid rain can harm ecosystems in a variety of ways.
The results of the new report suggest that northeastern ecosystems are still suffering these affects. It can also help to chemically release a toxic form of aluminum in soil that can harm forests and aquatic creatures. Many bodies of water in the northeast continue to show reduced aquatic life and species diversity. As a result, they may be at higher risk for damage by climate change or insect stress. The good news is that because of policy changes and reductions in sulfur and nitrogen emissions, acid rain appears to be declining somewhat.