ABSTRACTA subarctic population of Picea abies ssp. obovata in northern Sweden was retrospectively analyzed dendroecologically: tree-ring chronology (A.D. 1773–1989) and age structure. Additionally, recent canopy change and ground temperatures were assessed. Tree-ring width correlated best with the mean temperature of June, when thawing of the seasonal ground frost beneath the crowns normally takes place. Hypothetically, steeply declining radial growth since the 1950s or even earlier preconditioned substantial canopy dieback in 1987, triggered by extreme meteorological conditions associated with exceptionally late thawing and the evolution of new local permafrost. The tree-ring response to this episode had at least four equivalents, all between the 1780s and 1870s, which may indicate severe ground frost conditions. Structural features of the ground microrelief and of the spruce stand further point to previous permafrost episodes, which possibly rendered establishment of a forest stand impossible. It is hypothesized that the natural forest history is influenced by historical ground frost variations and that the northern range limit of spruce in Sweden is partially controlled by severe ground freezing, late thawing and edaphic conditions.