Pine high yield performance occurs once in three years on the average in the Preob boreal forests of the Altai area. Periodicity of seed-bearing is characterised with different reasons including the effect of weather conditions on bud-setting, development of generative structures and successful pollination. The task of our investigations was also the analysis of common pine ( Pinus sylvestris L.) seed yield performance dependence on terrestrial air temperature and precipitation level in natural and forest-seed plantations (FSOs) in the Preob boreal forests of the Altai area (forest-steppe zone). Seed-bearing intensity of natural plantations was estimated on the total seed number obtained at the teasle driary of the Ozersk forestry unit. Seed-bearing intensity of FSOs was determined experimentally during joint investigations with V.V. Tarakanov for the period of 1998-2003. Studying the correlations between seed-bearing and weather conditions for this period proves some regularities described in scientific literature. At the same time, positive dependence of seed-bearing on average annual temperature for 2 years till the yield was revealed (r=0.6...0.7; P<0.05 ), and it was not reported on in earlier investigations. The obtained data can be used for a preliminary yield prognosis in FSOs and natural plantations. Some rearrangement of correlational dependences between seed-bearing and weather conditions dynamics is discussed regarding the data on global climatic warming.

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