MODEL COMPUTATIONS ON THE IMPACT OF CHANGING CLIMATE ON NATURAL REGENERATION OF SCOTS PINE IN FINLAND

Based on model computations, the regeneration of Scots pine (Pinus syl vestris L.) in southern (60 degrees N) and northern (66 degrees N) Fin land was studied in relation to an elevating temperature. The temperat ure elevation increased flowering and the subsequent seed crop, partic ularly in northern Finland, with a decrease in the frequency of zero c rops. In southern Finland, the number of seedlings produced by each se ed crop increased when applying wide spacing, but decreased when apply ing narrow spacing of parent trees. This was due to a decrease in soil moisture induced by the increasing evaporative demand and transpirati on of the parent trees. In northern Finland, temperature elevation sub stantially increased the success of regeneration in terms of seedlings produced by each seed crop regardless of the spacing of parent trees. In terms of the density of seedling stands and the height and diamete r growth of seedlings, the establishment of a seedling stand within a given period of time was substantially improved under the improved tem perature conditions in both southern and northern Finland.