Forest Inventory of a Northern Hardwood Forest: Bird Area at the Hubbard Brook Experimental Forest, 1981

The forest inventory surveys in the bird area were
initiated in 1981 and transects were made permanent in 1991.
The inventory is representative of approximately 2.5
km-squared of mid elevation northern hardwood forest. It
consists of a total inventory of all trees >=10 cm dbh,
within each of four 10 m wide belt transects. The parallel
transects are placed approximately 200 m apart and run
roughly in an east-west direction for 2200 to 2900 m. In
1991, each live stem >=10 cm dbh was tagged with a unique
number. Tree vigor is assessed every two years and diameter
is remeasured every ten years. Every two years, new tags are
placed on stems that have grown into the 10 cm diameter
class. A survey of smaller trees (>=2 to <10 cm dbh)
was first taken in 1991 and is resurveyed every ten years.
This dataset includes the initial inventory values measured
in 1981 These data were gathered as part of the Hubbard Brook
Ecosystem Study (HBES). The HBES is a collaborative effort at
the Hubbard Brook Experimental Forest, which is operated and
maintained by the USDA Forest Service, Northern Research
Station.