Study of Silvicultural development in the middle aged loblolly pine plantation in Gilan province
2009
Gorji Bahri, Yousef
In order to study the tree growth and natural regeneration of loblolly pine in a 33-year-old plantation in Pylambra region (Gilan province), 1.5 hectare of well stocked stand selected. The layout of trial was Randomized complete block design with 4 Replications and 3 treatments as: T1, low density (15m2 basal area ha-1 ), T2, middle density ( 20m2 basal area ha-1 ) and T3, high density (25m2 basal area ha-1 ). Soil surface scarification was carried out at the first year. Diameter at breast height, total height of trees in each plot (100m2), number and height of pine regenerations in 10 m2 regeneration counting area in plots annually measured. At the end of 5 years results show tree growth are increased in the 4th life decade but less than before. It is concluded that the Loblolly pine annual volume growth increased in high density treatment compared with the low density and differences are significant at 1%. Pine regeneration with a height range of 10-150 cm was measured in different treatments but in terms of the number no statistical significant difference was observed.
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