Urban ecosystem ecology has emerged as a crucial proving ground in the development of transdisciplinary approaches to both the study of coupled human natural systems and the effective management of human-dominated systems. A comprehensive socio-ecological theory of urban ecosystems still eludes the field, though application of a variety of integrating concepts such as ecosystem metabolism and ecosystem services has led to important progress. To address this need, the Urban Long-Term Research Area (ULTRA) program has generated a new network of research sites funded by the National Science Foundation and the US Forest Service. Teams of scientists and practitioners are conducting interdisciplinary research on the dynamic interactions between people and natural ecosystems in sub/urban settings in ways that advance both fundamental and applied knowledge. This 2-hour, evening workshop follows a full day of presentations about the exploratory Urban Long Term Ecosystem Research Areas established by the National Science Foundation and the US Forest Service. The workshop will be a forum for all the ULTRA participants, and other interested parties, to discuss potential collaborative efforts and common research elements in preparation for long-term opportunities. Representatives from each of the 20 ULTRA projects (confirmed with Symposia), the National Science Foundation, and the US Forest Service will also be present.