Small birches matter: Beetle diversity on burned birch and pine in boreal forests

Forest fires create substrates critical for saproxylic and fire‐favoured species, but fire suppression has reduced their availability, contributing to declines in these pyrophilous species populations. While beetle responses to fire have been commonly studied in pine‐dominated ( Pinus sylvestris ) forests, much less is known about how burned birch ( Betula pendula / pubescens ), another fire‐favoured tree species, supports beetle communities. We assess differences in beetle communities between prescribed‐burned birch and pine in boreal forests of Sweden, 0–2 years post‐fire. We analysed beetle species richness, abundance and species assemblage on birches and pines of varying diameters and used tree vitality and char height as proxies for fire severity. In general, birches hosted higher beetle species richness than pines with distinct beetle community composition, driven by their higher mortality post‐fire, whereas the number of red‐listed species was higher on pines. Neither species richness nor abundance was related to tree diameter. Beetle abundance on birch increased with char height of the trunk, whereas species richness decreased, suggesting an increase in specialized species. Implications for insect conservation: Birch, even with small diameters, contributes to the conservation of saproxylic and pyrophilous beetle diversity following prescribed burning and should be retained and promoted alongside pine in prescribed burning and post‐fire restoration planning.