Inventory

The Penn State Forestland Management Office develops and conducts forest inventories that efficiently and precisely answer the following questions:
What vegetation is present?
What is the size (whether it be total height, merchantable height, or DBH)?
What is the condition?
What is the value (whether it be ecological, commercial, or recreational)?
The collected forest inventory data is analyzed to develop/amend our 50-year sustainable forest management plans.

Overstory inventories utilize a fixed area plot or point sample method implementing a 10 or 20 BAF (basal area factor) prism to determine 'tally' stems.

Understory inventories utilize three concentric fixed-area plots:
1/1000th acre, a count of all woody stems by species and height class that are less than 0.5" DBH
1/100th acre, a count of all saplings between 0.5" and 4.5" DBH by species and diameter class
1/20th acre, an ocular estimate of shrub and herbaceous vegetation by species and height class

The acronym “DBH” stands for Diameter at Breast Height. DBH of a tree is measured at 4.5’ above ground level.

Old Inventory Method	Current Inventory Method
Equipment Utilized by Penn State Forestland Management Office Staff to Conduct Forest Inventories Prior to the Year 2000	Equipment Utilized by Penn State Forestland Management Office Staff to Conduct Forest Inventories Since the Year 2000

An experienced two-person crew using the Penn State Forestland Management Office current inventory method can collect statistically sound data on 30 forest inventory plots in an 8-hour workday.