Table 1.
Overview of quantitative management recommendations given in the reviewed studies to provide suitable conditions for cavity‐nesting birds. Included were all studies that provided recommendations on potential nest‐tree DBH values
| Forest type (location) | Potential nest‐tree DBH (study focus) | Amount of potential nest trees per ha | Source |
|---|---|---|---|
| Coniferous (California) | 87% of trees: DBH ≥ 40 cm, mean DBH: ≥70 cm (live and dead trees) | – | Milne and Hejl (1989) |
| Coniferous (Oregon) | >54 cm, 33% limbs and bark left, slightly decayed (live and dead trees) | – | Bull (1987) |
| Coniferous (California) | >38 cm, especially white fir (dead trees) | 11 soft snags (≥15 years)/ha | Raphael & White (1984) |
| Coniferous (Oregon) | ≥28 cm, hardness 3–4 = 19–125 years after death of tree; stage definitions from Cline, Berg, and Wight (1980), only for clearcuts (dead trees) | ≥14 soft snags (≥19 years)/ha with bark cover ≥10% | Schreiber and deCalesta (1992) |
| Coniferous (Washington) | ≥25 cm, for more species: >48 cm (dead trees) | 15–35 snags (≥25 cm)/ha | Haggard and Gaines (2001) |
| Coniferous (Oregon) | >23 cm (dead trees) | – | Wightman et al. (2010) |
| Coniferous (Idaho) | ≥23 cm (dead trees) | ≥204 snags (DBH ≥23 cm)/ha | Saab et al. (2009) |
| Coniferous (Quebec) | >20 cm (dead trees) | Patches of mature/old‐growth burned forest (size: ≥20 ha) | Nappi and Drapeau (2011) |
| Mixed (Quebec) | ≥27 cm for a 50% probability of selection (live and dead trees) | In cutblocks ≤10 live and dead trees/ha with a DBH ≥27 cm (for a 50% probability of selection); in two‐story or irregular forests ≥200 dead trees (with crown and most bark remaining, DBH ≥9 cm)/ha (for a 50% probability of selection) | Tremblay et al. (2015) |