When people think of ecology, they usually imagine studies out in the country. The next thing they think of is studies involving the relationship of plants and animals to one another. They also imagine studies that show how organisms relate to the physical environment -- air, water, and soil. People and cities usually don't come to mind when ecology is mentioned. But ecologists now realize that it is important to understand cities and suburbs, because about three quarters of the people in the United States live in metropolitan areas. More people are also moving to cities throughout the world. So ecologists want to know how organisms and environments in and around cities are affected by the buildings and paved surfaces, the things that people do, and the new environments that cities create. To do that ecologists have to work with other researchers who understand people. That means more than just knowing how many people there are in an area. Understanding the urban environment requires that we understand how people are interact as groups and organizations that make decisions. What people do and build in and around cities affect the environment and the plants and animals for many miles around What is the Long Term Ecological Research Network? The Baltimore Ecosystem Study is one of 24 research programs established by the National Science Foundation to study ecological systems over long time periods. Ecological processes often take long times to occur, and so scientists must collect and use data that span long time periods. The projects that make up the Long-Term Ecological Research Network span different kinds of sites of interest to ecologists and decision makers. There are sites in the Arctic, in Antarctica, in moist coniferous forests, deciduous forest, coastal areas, grasslands and deserts. BES represents the particularly dynamic and patchy ecosystem type found in and around cities, and enhances ecological understanding by including an ecosystem type rarely studied by ecologists. http://www.lternet.edu The Baltimore Ecosystem Study is a long-term ecological research project. It is funded by the National Science Foundation and the Environmental Protection Agency to learn how an urban area works as an ecological system. We want to know the ecological interactions in the whole range of habitats -- from the center city of Baltimore, out into the surrounding rural areas. We are conducting research on the soil, the plants and animals on land and in the streams, the water quality, and condition of the air in and around Baltimore. For that information to make sense, we are also studying how families, associations, organizations and political bodies make decisions that affect ecological processes. In other words, we are treating the whole collection of urban, suburban and rural areas as an ecological system that includes people and their activities. This is a really unusual approach to ecology because it combines with social sciences, physical sciences, and education to understand a big metropolitan area as an ecological system. Saying that an urban area is a system just means that we are concerned with the interactions between wild and domestic organisms, people and their organizations, and the natural and built environment all affect one another. It is these relationships that determine the quality of the environment we experience in the places where we live, work and relax. The research project is long-term, because conditions in the past affect the urban environment we experience now, and we also need to be able to say what environmental effects the things we are doing now in and around our cities will affect the environment in the future. This information can help people, including individuals, families, organizations and government agencies, to make decisions that have the environmental effects that they want. We will try to keep people informed through this publication, through meetings and workshops, through school and community interactions, and through the web. We're young, and growing rapidly. We look forward to keeping in touch with you.