Provenance trials of Scots pine in Estonia
2000
Kurm, M. (Estonian Agricultural Univ., Tartu (Estonia). Forest Research Inst.)
An overview is given of the trial geographical plantations of Scots pine established under the supervision of Prof. E. Pihelgas in the Jaervselja Study and Experimental Forest District in 1964 and 1965. To establish the trial seeds were ordered from different regions of the former Soviet Union; a total of 34 seed shipments were received. Also presented are the preliminary findings from the study of progeny trials. According to E. Pihelgas, after eight years of growth the height of progeny correlated with the growth of the seedlings (r=0,67) and the P2O5 content of the seedlings needles (r=0,66). After twelve years of growth it appeared that the subspecies P. sylvestris L. subsp. hamata and P. sylvestris. subsp. sibirica were utterly unif for our circumstances. An extremly slow growth rate was also manifested by P. sylvestris. subsp. lapponica, with its tree height and supply constituting up to 80 per cent of the respective figures for the other trial plantations in Jaervselja at the age of 30. The data presented by A. Silla revealed that an increase in latitude by 1 deg caused a decrease in tree height by 7.5 cm and in breast-height diameter by 1.61 mm. The correlation coefficient between breast-eight diameter and latitude was high (r=0,80). E. Mustonen and J. Roosniit confined their study to the 1965 progeny trials. They found that the differences between provenances were greatest in breast-height diameter. The equation used to establish correlation between stem diameter and latitude revealed that an increase in latitude by 1 deg correlated with a decrease in breast-height diameter by 2.50 mm. The correlation between latitude and progeny supply was also of medium value (r=0,39)
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