Journal of Forest Science, 2018 (vol. 64), issue 5
The development and growth of larch stands in LithuaniaOriginal Paper
Kšištof GODVOD, Gediminas BRAZAITIS, Julius BAČKAITIS, Gintaras KULBOKAS
J. For. Sci., 2018, 64(5):199-206 | DOI: 10.17221/6/2018-JFS 
Changing climate conditions and increasing demands for timber and wood products create a need to cultivate highly productive forest stands. High productivity, good wood quality and adaption to climate change make European larch a promising species for Lithuania. The aim of this research was to evaluate the productivity and sustainability of the larch stands. We tested the hypothesis that larch stands mixed with other species are more productive than the pure larch stands. In total, our study sampled 138 larch stands, mixed stands (91) and pure stands (47) that aged between 30 and 60 years old in Lithuania. We evaluated these stands using dendrologic,...
Investigation of rooting and growth characteristics of poplar clones in hydroponic and soil culturesOriginal Paper
Fatemeh AHMADLOO, Mohsen CALAGARI, Azadeh SALEHI, Gholam Reza GOODARZI
J. For. Sci., 2018, 64(5):207-215 | DOI: 10.17221/1/2018-JFS
In this study, rooting and growth characteristics of different poplar clones from six species including Populus deltoides Bartram ex Marshall clone Lux, Populus nigra subsp. betulifolia (Pursh) W. Wettstein clone 17/13, Populus euramericana (Dode) Guinier clone 561/41, P. deltoides clone Samsun, Populus alba Linnaeus clone 49/9, Populus caspica (Bornmüller) Bornmüller, and Populus euphratica Olivier in hydroponic and soil cultures have been evaluated. In hydroponic culture, poplar cuttings were grown in plastic tanks and in...
Estimating the economic life of forest machinery using the cumulative cost model and cost minimization model in Iranian Caspian forestsOriginal Paper
Mohammad HEJAZIAN, Majid LOTFALIAN, Soleiman MOHAMMADI LIMAEI
J. For. Sci., 2018, 64(5):216-223 | DOI: 10.17221/133/2017-JFS
This study was conducted in order to estimate the economic life of two models of rubber-tired skidders, namely Timberjack 450C and HSM 904, in Iranian Caspian forests. The total annual costs and average cumulative cost of skidders were calculated by life-cycle costing analysis. The economic life of the machines was estimated by both the cumulative cost model and cost minimization model. The results indicated that the economic life of Timberjack 450C and HSM 904 is 7,700 h (at the end of the 11th year) and 15,300 h (at the end of the 17th year), respectively, using the cost minimization model. Furthermore, the results indicated...
Onset of canopy closure for black pine, Turkish red pine and Scots pine forestsOriginal Paper
Ferhat KARA, Osman TOPAÇOGLU
J. For. Sci., 2018, 64(5):224-229 | DOI: 10.17221/153/2017-JFS
Canopy closure plays an important role in regeneration and management activities in forestry. Thus, determining the density at which canopy closure occurs is important for the success of silvicultural treatments. Turkish red pine (Pinus brutia Tenore), black pine (Pinus nigra J.F. Arnold) and Scots pine (Pinus sylvestris Linnaeus) forests are usually managed at a density that is near or below the canopy closure. Residual stand density during the management of these species is commonly described by stand basal area - BA (m2.ha-1), however, the BA levels for the canopy closure have not been clearly indicated...
Evaluation of distance methods for estimating population density in Populus euphratica Olivier natural stands (case study: Maroon riparian forests, Iran)Original Paper
Reza BASIRI, Mostafa MORADI, Bahman KIANI, Maryam MAASUMI BABAARABI
J. For. Sci., 2018, 64(5):230-244 | DOI: 10.17221/146/2017-JFS
The aim of this study was to determine the performance of distance methods in terms of accuracy, precision, bias, consumed time and sampling efficiency in the Maroon riparian forests, Iran. 40 estimators were used to evaluate the density of Populus euphratica Olivier trees in pure and mixed stands. Fifty quadrates (30 × 30 m) were established in each stand. To evaluate the accuracy, precision, bias, consumed time and efficiency of sampling techniques, relative root mean square error - RRMSE (%), coefficient of variation - CV (%), relative bias - RBIAS (%), t × RBIAS2, t × E2, where t...