Plant, animal, and other living organisms in an ecosystem are influenced not only by each other, but also by nonliving factors such as the chemistry of the air, soils, and water. At Allegheny Portage Railroad NHS, monitoring of the air and water protect the natural integrity of the park and provide information about the ground and air chemistry of the surrounding area. Efforts are also made to correct the inadvertent shifts in the natural communities that came about as a result of mining and nonnative species introduction. Natural plant communities are restored and preserved by combating exotic, invasive species that infest the park.