The annual number of stands (total n = 21) assumed to have established from seed was related to: (1) summer temperature of the year preceding germination, possibly affecting seed set (mean = 10.0 °C, SE = 0.14); (2) annual precipitation of the current year, possibly affecting germination and seedling survival (mean = 314 mm, SE = 5.99); (3) moth damage to birch during the year of germination, possibly affecting aspen seed bed availability and seedling survival; high positive values point to increased damage (mean = -0.03 negative birch-minus-pine indices, SE = 0.03).