This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. ; Thesis: M.C.P., Massachusetts Institute of Technology, Department of Urban Studies and Planning, 2015 ; Cataloged from PDF version of thesis. ; Includes bibliographical references (pages 50-53). ; New York City's "emerald empire" is much more than its street trees. The city contains over 10,000 acres of forests within the five boroughs, including several examples of old growth forests. These natural areas are at risk--from their vulnerability to climate impacts, to development pressures, to a lack of support for and information about managing urban forests. Urban forests will only become more crucial to quality of life in cities into the future, as their ecological, health, and psychological benefits become increasingly critical to mitigating the impacts of climate change on cities and their residents. In New York City, half of residents full experience of "nature" happens within the five boroughs. ; Without access to urban forests and other natural areas, millions of New Yorkers would not have any opportunity to access the well-documented physical and mental health benefits of contact with nature, nor have the experience of learning about and appreciating the important ecosystems that exist in and support the life of the city. Old growth forests are particularly significant and exceedingly rare, especially in dense urban environments. Old growth forests have been documented to support more biodiversity, can store more carbon, and have more positive impacts on improving water and air quality than younger natural areas. There are multiple old growth forests within the five boroughs of New York City, which have somehow managed to persist over hundreds of years, if not more in the case of some areas. ; Learning from these rare and increasingly important spaces--how and why they survived, what unique benefits they provide and challenges they face, and what roles they have played in surrounding communities historically and into the future--will be important to ensuring both their long-term sustainability and can provide lessons for managing other urban forests. This thesis explores the historical, contemporary, and future importance of healthy, old growth forest ecosystems in cities and how they can provide more benefits than individual trees, and a greater variety of them. ; by Rachel Finkelstein. ; M.C.P. ; M.C.P. Massachusetts Institute of Technology, Department of Urban Studies and Planning