Veli Pohjonen , Timo Pukkala

Cupressus lusitanican tuotos Etiopiassa

Pohjonen V., Pukkala T. (1993). Cupressus lusitanican tuotos Etiopiassa. Silva Fennica vol. 27 no. 3 article id 5511. https://doi.org/10.14214/sf.a15672

Abstract

Yield of Cupressus lusitanica Mill. was modelled by predicting the diameter distribution of trees at given stand ages. The beta distribution was used as a theoretical distribution. The models used for the calculation of diameter distribution were based on 66 temporal sample plots with varying age, site and stand density. The growing sites of Cupressus lusitanica were divided into four classes on the basis of age and dominant height. Using the stand models developed in the study, the yield and profitability of different thinning schedules was evaluated by a simulation technique. In the simulated treatment regimes, the mean annual increment varied from 6.6 m³/ha in the poorest site class to 16.6 m³/ha in the best class with rotation lengths ranging from 25 years (best sites) to 34 years (poorest sites). With typical planting densities (1,600 trees/ha), thinnings increase the total harvest by a few percentage points and improved the profitability of plantation forestry.
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Keywords
distribution; plantation; diameter; yield, models; yield tables; Cupressus lusitanica; thinning regimes

Published in 1993

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Available at https://doi.org/10.14214/sf.a15672 | Download PDF