Growth comparison of different poplar clones, planted on lowlands of west Guilan

Trials of exotic variaties of Poplar species and their wood production potential at Guilan province (Caspian region) of Iran have been started after 1960s. Some ecological requirements and exceptions might positively od negatively affect the poplar's adaptation process. The trial was conducted under statistical desighn of Randomized Complete Blocks with three poplar clones (three treatments) including: P.deltoides 69.55, P. eurameracana 214 and P. deltoids 9.51 and four poplar plantation sites (four replicates) located at lowlans of west Guilan province, including: Tolaroud, Shanderman, Gisum and Haft-daghanan. Popar plantation was made in plots with 2000 m2 area (50 x 40 m.) and 3 x 4 m. spacing. The measured and calculated popolar characteristics consisted of: diameter at breast height (dbh), survival, total height and volume. Results showed that there were significant differences between the poplar clones and the poplar sites in respect to growth characteristics (ρ< 0.01). The greatest volume increment at Tolaroud site with sandy loam soil belonged to P. euramericana 214, at Shanderman site with clay sandy loam soil belonged to P. d. 79.51, at Gisum with sandy soil belonged to P. d. 79.51 and at Haft-daghanan site with loamy soil belonged to P.d. 69.55 (20.31, 23.5, 24.2, 25.4 and 26.9 m3/ha/year, respectively). Poplar and site classification, based on volume, diameter, height and basal area data showed that the first rank achieved by Haft-daghanan and Tolaroud sites and P. d. 79.51 clone, respectively. The best rate of quality achieved by P. d. 69.55 clone at Gisum site.