Pittsburgh Part of First Ever “Urban Forest Inventory”


TreesThis month, the city of Pittsburgh and the USDA Forest Service’s Forest Inventory and Analysis (FIA) Program began a first-ever urban inventory of trees, green space, and ground cover on public and private land for the greater Pittsburgh metropolitan area.

“More than 80 percent of the Nation’s population lives in urban areas, where urban forests are helping clean the air, reduce energy costs, and give people a vital connection to nature,” said Tony Ferguson, Acting Director of the Northern Research Station and the Forest Products Laboratory. “The Forest Service’s Urban FIA Program is expanding to deliver knowledge that everyone engaged in urban nature resources can use to make forests healthy and sustainable.”

The Forest Inventory and Analysis Program, often called “The Nation’s Forest Census,” has been monitoring the current status and past trends of the nation’s rural forests for nearly 80 years. Recognizing the value of trees in cities, the FIA program is expanding the census to include the nation’s urban metropolitan areas. Forest Service research has documented that urban trees benefit communities and people in a variety of ways, including benefiting human health by removing air pollution, providing shade that helps reduce energy consumption, and providing areas for recreation.

Just as FIA analysts have provided states with statistics on trees for decades, the program will now provide annual statistical updates for cities, with annual updates and more comprehensive analytical reports published online every 5 years.

Two hundred Forest Inventory and Analysis plots will be inventoried in Pittsburgh, with each plot measuring about 98 feet in diameter. Inventory plots are selected randomly without regard to ownership in an effort to ensure that the inventory is free from bias and reflects the true condition of a city’s urban forest resources.

In mid-June, USDA Forest Service personnel began contacting selected landowners in the greater Pittsburgh metropolitan area by mail, email, phone, or in person to ask permission to monitor trees and ground vegetation on their property. Participating in the Urban FIA program is voluntary. If permitted access to property, Forest Service staff (all of whom will be carrying identification cards) will be on site from between half an hour to 10 hours depending on the amount and condition of vegetation within the sample area. A variety of forest health factors will be monitored in the urban inventory, including:

  • Tree species – What trees species exist and what are most abundant?
  • Tree numbers and tree size – Is the urban area losing or gaining trees, and how quickly are trees growing?
  • Tree survival and mortality – How well are trees surviving in the urban area?
  • Tree crown condition – What is the overall health of a tree, how well is it growing, and how is it affecting plants growing underneath?
  • Tree Damage – Identifying damage will contribute to effective management plans.
  • Invasive plants – What species exist, and what is their abundance, distribution and effects on urban areas?
  • Ground Cover – Are there other plants, permeable (gravel, bare soil) or  impermeable surfaces (asphalt, cement)?

The Urban FIA program will be operational in 15 cities this year.