The critical zone is the layer of the Earth surface defined from the outer edge of vegetation to the depths of groundwater. This relatively thin zone where rock, soil, water, air, and organisms evolve over time is the foundation of life for people on Earth. Studied since the 1970s and NSF-funded for nearly two decades, Penn State critical zone research at Shale Hills – a small watershed next to the Shavers Creek Environmental Center – is undergoing a transition expected to involve both ongoing and new areas of research and education, with applications that include enhanced understanding of land use impacts on water provision and water quality.
