Table 2.

Woodland key habitats recorded in the NFI since 2003, following the Complementary Hot-spot Inventory (CHI) methodology, with the main criteria for defining and mapping whole or parts of the 0.2 ha plot as a habitat polygon. The rightmost column gives the occurrence of the respective CHI habitats as of 2016 (inventory period 2014–2018)

CHI habitat	Main criteria for inclusion in polygon	Occurrence in productive forest (% of area)
Standing deadwood	• ≥ 40 standing dead trees·ha−1 with dbh ≥10 cm • Distance to other dead trees ≤15 m	2.7
Downed deadwood	• ≥ 40 downed dead trees·ha−1 with diameter at root end ≥10 cm • Distance to other downed dead trees ≤15 m	17.7
Trees with nutrient-rich bark	• Occurrence of maple (Acer platanoídes L.) or any tree species with bark lichens of the lobarion group • ≥ 20 trees·ha−1 of any of the above categories (60 in West and North Norway) • Distance to other trees with nutrient-rich bark ≤25 (15) m	0.3
Trees with pendant lichens	• ≥ 100 trees·ha−1 with at least 10 individuals/groups of pendant lichens of more than 10 cm length within 1 m2 of the vertical tree crown area • Occurrence of trees with lichens of the species Evernia divaricata (L.) Ach. or Usnea longissima Ach. • Only assessed for the lower 5 m of the tree	3.1
Deciduous boreal trees in late successional stage	• ≥ 40 trees·ha−1 with dbh ≥20 cm of any of the species Populus tremula L., Sorbus aucuparia L., Alnus incana L., Salix caprea L., Prunus padus L., or Betula spp. • Northern Norway: only P. tremula is considered	1.5
Old trees	• ≥ 30 standing old trees·ha−1 • Minimum age for spruce/pine = 150/200 yrs. • Deciduous trees are included dependent on dbh and species (minimum dbh is 30–40 cm for boreal species and 40–50 cm for noble hardwoods) • Distance to other old trees ≤20 m	2.5
Luxuriant ground vegetation	• Nutrient-rich forms of selected vegetation types sensu (Larsson 2005)	3.1