| Popis: |
At present, majority of commercial poplar plantations aimed at producing quality timbers with larger dimension are established in wider planting spacings in Turkey. The experimental poplar plantations in closer spacings were established for this study purposes in order to investigate the prospects for producing mass quantity of small dimensioned chip wood relatively in shorter period of plantation rotation rather than producing quality timber of larger dimension in longer period of rotation. Along with five various planting spacings, five different poplar clones such as “I-214”, “I-45/51”, “Samsun (I-77/51)”, “İzmit (S.307-26)” and “89.M.060” were sampled in the experimental plantation blocks which were repeated on sites of three different growth conditions. The criteria of “Net Present Value (NPV) and “Internal Rate of Return” (IRR) were used for economic analyses. The results of the analyses showed that the most suitable spacing for producing mass quantity of chip wood is “3m x 1,5m” (4,5 m2 / plant) and most promising poplar clone is “89.M.060”. The plantation rotation periods were also determined in accordance with the criteria of NPV and IRR. The period of rotation varied by the variation of the discount rate involved when the NPV criterion is used for the evaluation. The periods of rotation determined in accordance with the IRR criterion are shorter than the period determined in accordance with the NPV criterion. Therefore, the IRR criterion should be preferred for the evaluation of industrial plantation investments. According to the results of the analyses, the recommended period of plantation rotation varies between 6 to 8 years on good sites, 7 to 9 years on medium sites and 8 to 10 years on poor sites. |
