Post-fire forest recovery at high latitudes: tree regeneration dominated by fire-adapted, early-seral species increases with latitude

RUGGIRELLO, MATTHEW JOSEPH; BUSTAMANTE, GIMENA; RODRIGUEZ, PAULA; CRUZ-ALONSO, VERÓNICA; SOLER, ROSINA

Annals of Forest Science

Annals of Forest Science

Año: 2023 vol. 80

Key message Above 40° N/S, increasing latitude is linked to greater post‑fire tree regeneration. However, speciesdominance shifts from conifers to short‑lived deciduous trees, which may negatively impact flora, fauna, and eco‑system services dependent on coniferous forests. These results were primarily driven by studies from North America,highlighting the need for more research that directly measures post‑fire forest recovery in other high‑latitude regions.Context As the size and frequency of wildfires increase across many regions, high‑latitude forests may be at particu‑lar risk for decreases in regeneration and state shifts post‑fire.Aims Through this systematic review, we sought to determine the general relationship between post‑fire tree regen‑eration densities and latitude in forests above 40° N/S. We expected regeneration densities post‑fire would decreasewith increasing latitude, and that forest regeneration would be negatively impacted by high burn severities, forestmanagement, harsh site conditions, and unprotected microsites. We also anticipated that light‑demanding specieswith adaptations to fire would replace shade‑tolerant species that lack such adaptations post‑fire.Methods We conducted a literature search that returned over 4500 articles. We selected those that directlymeasured post‑fire regeneration at or above 40° N/S and retained 93 articles for analysis. Fire characteristics, pre‑and post‑fire tree species compositions and regeneration densities, and regeneration predictors were then extractedfrom the retained articles. We fit linear mixed models to post‑fire regeneration density with latitude and species traitsas explanatory variables and also explored the significance and magnitude of predictors that informed post‑fire treespecies response.Results Contrary to our expectations, post‑fire regeneration increased significantly with latitude. High burn severitiesand unprotected microsites had negative impacts on post‑fire regeneration; higher elevations and more prolific pre‑or post‑fire reproduction were positively correlated with post‑fire regeneration, while management of any type didnot have an impact.Conclusion Although forests are regenerating after wildfires at the most extreme latitudes included in this study(above 55° N), regeneration is often limited to only a handful of genera: aspen (Populus) and birch (Betula), for exam‑ple. Regeneration was less abundant at the lower range of our study area. Certain lower latitude forests that occupy .