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Old growth is disappearing globally, with implications for biodiversity, forest resilience, and carbon storage; yet uncertainty remains about how much exists, partly because assessments stratify ecosystems differently, sometimes obscuring relevant patterns. This paper compares portrayals of British Columbia's (BC) old-growth forest stratified in two ways: by biogeoclimatic variant, as per policy, and by relative site productivity. Our analyses confirm provincial government claims that about a quarter of BC's forests are old growth but find that most of this area has low realized productivity, including subalpine and bog forests, and that less than 1% is highly productive old growth, growing large trees. Within biogeoclimatic variant, nearly half of high-productivity forest landscapes have less than 1% of the expected area of old forest. Low-productivity ecosystems are over-represented in protected forest. We suggest that the experiment of managing old growth solely by biogeoclimatic variant has failed and that current forest policy, in combination with timber harvesting priorities, does not maintain representative ecosystems, counter to the intent of both policy and international conventions. Stratifying old growth by relative productivity within biogeoclimatic variant seems an appropriate method to portray ecosystem representation, potentially increasing the probability of maintaining ecosystem resilience. Key words: old growth, British Columbia, forest productivity, ecosystem representation, forest policy. Les forets anciennes sont generalement en voie de disparition ce qui a des repercussions sur la biodiversite, la resilience de la foret et le stockage du carbone. Par contre, l'incertitude persiste quant a la quantite encore en existence, en partie parce que les evaluations stratifient les ecosystemes differemment, obscurcissant dans certains cas les patrons qui seraient pertinents. Cet article compare la representation des forets anciennes de la Colombie-Britannique (C.-B.) stratifiees de deux facons : selon la variante biogeoclimatique, conformement a la politique, et selon la productivite relative de la station. Nos analyses confirment les affirmations du gouvernement provincial precisant qu'environ le quart des forets de la C.-B. sont des forets anciennes. Mais nous constatons que cette superficie est effectivement peu productive, incluant les forets marecageuses et subalpines, et que moins de 1% des forets anciennes sont tres productives et contiennent de gros arbres. A l'interieure de la variante biogeoclimatique, presque la moitie des paysages forestiers a haute productivite occupent moins de 1% de la superficie presumee de foret ancienne. Les ecosystemes a faible productivite sont surrepresentes dans la foret protegee. Nous sommes d'avis que l'experimentation consistant a gerer la foret ancienne uniquement sur la base de la variante biogeoclimatique est un echec et que la politique forestiere en vigueur, combinee aux priorites de recolte de bois, ne permet pas de maintenir les ecosystemes representatifs et va a l'encontre de l'intention de la politique et des conventions internationales. La stratification des forets anciennes sur la base de la productivite relative a l'interieur de la variante biogeoclimatique semble une methode appropriee pour dresser le portrait de la representation ecosystemique, pouvant augmenter la probabilite de maintenir la resilience de l'ecosysteme. [Traduit par la Redaction] Mots-cles: foret ancienne, Colombie-Britannique, productivite forestiere, representation de l'ecosysteme, politique forestiere., Introduction Intact old-growth forest is disappearing globally (FRA 2020), with implications for biodiversity, resilience, and carbon storage (Foley et al. 2005; Watson et al. 2018). Old-growth forests are structurally complex [...]

The article discusses the views of provincial government on the need for change to British Columbia forest management, which include careers in traditional forest management recommended a fundamental change from managing timber with constraints to prioritizing ecosystem health.

Current forestry practices radically modify habitat, particularly by increasing the frequency of early seral stages. We examined the demography of two secondary cavity nesters, the Mountain Bluebird (Sialia currucoides) and the Tree Swallow (Tachycineta bicolor), with respect to landscape changes. The study area contained a mosaic of clearcuts ranging from 3 to 27 years in age. The initial distribution of both species was uneven with respect to patch age. Experimental addition of nest boxes: (1) increased the number of nesting pairs of both species, and (2) expanded the age range of occupied patches. Nest-site availability was the primary limiting factor in young patches, but vegetation structure was increasingly important in determining occupation in older patches. Mountain Bluebird patch occupation and Tree Swallow density were best predicted by the proportion of trees 1 to 3 m in height. Although some patches contained multiple pairs of Mountain Bluebirds in natural cavities, experimental patches typically contained no more than one pair, even though excess nest boxes were available. The presence of nonbreeding floaters was an indication of nest-site limitation and suggested that Mountain Bluebirds sometimes defer breeding attempts rather than nest close to conspecifics. At low densities, Tree Swallows also were over-dispersed, but pairs saturated available nest boxes as density increased. Clutch size and number of chicks fledged from successful nests did not vary with patch age for either species, although swallows initiated clutches later in younger compared with older patches. Nest predation varied consistently with patch age; mean nest predation for both species was 86% (n = 30 pairs) in the youngest patches, 37% (n = 34) in mid-age patches, and 25% (n = 22) in the oldest patches. The low densities of both species in older patches was not associated with low productivity, suggesting that habitat selection occurred independently of potential productivity in this novel habitat.