Why should we care about the extent of tree cover? As it turns out, tree coverage has immense benefits not only to Baltimore City residents, but also to surrounding communities. U.S. Forest Service and related research has demonstrated that there can be a beneficial correlation between trees and public safety (more trees, less violent crime and crimes against property), regardless of socioeconomic factors. Urban forests have positive impacts on human health (reduced asthma and other respiratory problems) and economic development (increased property values and business performance), while exposure to nature can relieve ADHD symptoms and improve academic performance. Further, trees improve water quality and reduce flooding by acting as purifiers and sponges during and after rainfall, filtering fertilizers, pesticides and pollution that washes off roads and other impervious surfaces. Increasing porous cover by investing in trees and green space has water quality benefits for the Chesapeake Bay and downstream communities. This is especially essential in cities like Baltimore, where sidewalk storm water drains connect directly to the bay.