عنوان مقاله [English]
This paper presents the results of an elimination trial of exotic needle-leaves in the form of Randomized Completely Blocks Design with three replications at three elevations of Nowshahr region: i) nine species of needle-leaves in lower altitude (450 m.a.s.l.) of Patom district, Kheiroud forest after 19 years, ii) twelve species in middle altitude (1000 m.a.s.l.) of Namkhane district, Kheiroud forest after 18 years, and iii) twelve species in higher altitude (1250 m.a.s.l.) Golband-Veysar forest after 19 years of plantation. Survival, diameter at breast height, collar diameter and total height of trees were measured every year. Final results (2008) indicated that: i) Sequoia sempervirens (origin of California- Nowshahr), Cryptomeria japonica (origin of Japan- Kelardasht) and Pinus nigra var. calabrica (origin of south France) were the promising species in the lower altitude, ii) Picea abies (origin of former Yugoslavia- Kelardasht), Abies nordmaniana (origin of Turkey) and Abies alba (origin of Bulgaria) were the promising species in the middle altitude and iii) Pseudotsuga menziensii (origin of Washington), Abies alba (origin of Bulgaria), Abies nordmaniana (origin of Turkey) and Abies bormulleriana (origin of Turkey) were the promising species in the higher elevation.