Issue: Data and analysis capacity for understanding current conditions of U.S. forests and trees on agricultural and urban lands is underdeveloped. At the same time, the values provided by these resources to society and the need to sustain them are increasingly being recognized, as is the need to manage these forests within the context of broader landscapes incorporating both wildlands and developed areas.

Background: The USDA Forests Service’s Forest Inventory and Analysis (FIA) Program produces a detailed and statistically robust inventory of conventional forests across the U.S., and reports such as the RPA Assessment and the National Report on Sustainable Forests present national assessments of these same forests based in part on FIA data. The purpose of the current report is to explore ways to develop a similar assessment capacity for agricultural and urban forest resources using forest sustainability criteria and indicators (C&I) as a touchstone. This report has undergone peer review and was compiled and edited by USFS R&D’s Sustainability Assessment Program. It relies on substantial contributions from FIA, the National Agroforestry Center and FS R&D urban forestry experts.

Report Key Findings:

• Agricultural and urban forests are important. This point is obvious but deserves to be emphasized. The various and specific ways in which these resources benefit (and sometimes cost) human society are discussed in detail throughout the report.
• Agricultural and urban forests represent a vast and varied resource. Urban and agricultural lands in the United States total more than one billion acres. Tree cover on urban lands is currently estimated at 35 percent. National measures of forest cover on agricultural lands are not available, but the sheer extent of agricultural lands ensures that the total amount of forests in this category is immense. These resources span the various ecoregions existing across the United States and play an essential role in all the landscapes in which they are found.
• Data on agricultural and urban forests are relatively scarce. Forest inventory activities have long been applied coast to coast for conventional forests, and the resulting information forms the backbone of forest assessment and sustainability reporting in the United States. Similar inventory and reporting activities are sorely lacking for agricultural and urban forests at the national level.
• Data availability is improving. Satellite imagery and related remote sensing techniques have allowed for forest cover estimates for urban forests; tools facilitating the digital collection and consolidation of urban forest data are being developed and used; and pilot inventory projects, including a wall-to-wall inventory in the upper Midwest, are building experience in inventorying agricultural and urban forests in an integrated fashion.
• A national urban forest inventory under FIA is in its initial stages of implementation. The 2014 Farm Bill directs the Forest Service’s FIA to extend its inventory activities into urban areas. Pilot inventories have been established in a number of cities across the U.S. This effort builds on years of preparatory work performed by FIA. Sampling protocols and related details for the program have been established and will further evolve as FIA and its collaborators gain more experience in inventorying urban trees and forests at the national scale.
• A comprehensive inventory of agricultural and urban forests is feasible at a relatively modest cost. Based on lessons learned from the newly instituted urban forest inventory and using a combination of remote-sensing and plot-sampling strategies, a wall-to-wall inventory measuring the physical characteristics of trees and forests on agricultural and urban lands could be developed, likely at a fraction of the annual cost currently devoted to inventorying conventional forests. Building the institutional arrangements and devising a consistent sampling protocol spanning these different land use types, however, will require considerable effort.
• Addressing the social and economic aspects of forest sustainability in agricultural and urban settings will still be problematic. A comprehensive physical inventory will go a long way in helping us understand the dimensions of this resource, but many important data gaps will remain, especially in regard to quantifying the benefits, uses, and values these forests supply to U.S. citizens.