Evaluation of lodgepole pine (Pinus contorta Dougl. ex Loudon) on a provenance plot situated in a formerly air-polluted area of the Krušné hory Mts. at the age of 34 years

The article evaluates 27 provenances of three subspecies of lodgepole pine on the Kovářská research plot (Krušné hory Mts.). The plot is part of a series of three established plots in various stand conditions. Two plots were already evaluated and the findings were published. At 34 years of age, we evaluated height, DBH, trunk shape, trunk forking, branch thickness, bark type, mortality, and defoliation. A total of 1,147 trees were measured. Above-average growth was achieved predominantly by the provenances of Pinus contorta subsp. latifolia (Engelmann ex S. Watson) Critchfield from middle elevations. In the Pinus contorta subsp. contorta Douglas ex Loudon, only the 2099 Port Orford provenance from Oregon demonstrated favourable results, and in the Pinus contorta subsp. murrayana (Balfour) Engelmann it was 2098 Chemult. High mortality was demonstrated mainly in the P. c. subsp. murrayana provenance from high mountainous elevations in California and P. c. subsp. contorta from coastal regions of Oregon. Provenances from middle elevations had relatively lower mortality, especially P. c. subsp. latifolia. The pines usually were of good quality although this was not the case for defoliation and branch thickness. In comparing all plots of the series, growth was fastest at the Sofronka location in western Bohemia and slowest at the south Bohemian Mláka location. Only the best provenances of lodgepole pine can equal the domestic Scots pine (Pinus sylvestris Linnaeus).