Journal of Forest Science, 2020 (vol. 66), issue 11
Innovative productivity improvements in forest operations: a comparative study of the Assortment Grapple using a machine simulatorOriginal Paper
Jussi Manner, Simon Berg, Martin Englund, Back Tomas Ersson, Anders Mörk
J. For. Sci., 2020, 66(11):443-451 | DOI: 10.17221/104/2020-JFS 
Because of generally small log piles, loading forwarders during thinning is time consuming. The Assortment Grapple, an innovative grapple with an extra pair of claws which facilitates the handling of two assortments during one loading crane cycle, has been designed to decrease forwarders' loading time consumption. A standardized experiment was performed in a virtual thinning stand using a machine simulator with the objectives to form guidelines for working with the Assortment Grapple and to analyse its development potential. Four experienced operators participated in the study. According to the results, the Assortment Grapple's accumulating function...
Trade-off between shoot and root dry weight along with a steady CO2 assimilation rate ensures the survival of Eucalyptus camaldulensis under salt stressOriginal Paper
Fahad Rasheed, Rasool Bakhsh, Ihsan Qadir
J. For. Sci., 2020, 66(11):452-460 | DOI: 10.17221/44/2020-JFS
Salt stress is a major challenge for reforestation in arid to semi-arid regions. Therefore the effect of salt stress was tested in 4-months-old saplings of Eucalyptus camaldulensis under controlled conditions. Individuals were subjected to three levels of salt stress (2, 8, 16 d.Sm-1) and several traits describing growth and dry weight production/allocation, as well as physiological attributes were measured. The results showed that salt stress had no impact on plant height or stem diameter. Number of leaves, number of branches, and leaf chlorophyll content decreased significantly under high salt stress treatment. Leaf dry weight...
How different approaches to logging residues handling affected retention of nutrients at poor-soil Scots pine site after clear-cutting? A case studyOriginal Paper
Ondřej Špulák, Dušan Kacálek
J. For. Sci., 2020, 66(11):461-470 | DOI: 10.17221/143/2020-JFS
Biomass nutrient loss and retention were studied at nutrient-poor forest site dominated by Scots pine where two methods of logging residues handling after clear-cutting were compared. The experiment was conducted on nutrient-poor pine-oak forest site on deep sandy-gravel unconsolidated sediments at the altitude of 255 m. There were three treatments established such as (i) control - no harvesting, (ii) whole-tree harvesting with ca. 10% of the slash retained unintentionally on site as processing residues and (iii) stem-only harvesting when small-diameter wood and slash were left on site. The third treatment was found to retain...
Evaluation of silver birch diameter increment model based on data of the Czech National Forest InventoryOriginal Paper
Jan Kikal, Zdeněk Adamec
J. For. Sci., 2020, 66(11):471-481 | DOI: 10.17221/161/2020-JFS
In the Czech Republic, the silver birch (Betula pendula Roth.) is considered as a pioneer and a soil preparing tree species. It occurs mainly on clearcutting areas after disturbances. The aim of this study was to fit breast height diameter increment model for birch with respect to tree age, share of birch trees and forest site type (ecological series - ES and forest vegetation zones - FVZ). We used data of both cycles of National Forest Inventory of the Czech Republic. We evaluated production potential of this species. We tested Korf and Michailoff increment models in variant of nonlinear least squares model (NLS) and nonlinear mixed effects...