Journal of Forest Science, 2018 (vol. 64), issue 12

INDEX OF VOLUME 64Index

editors

J. For. Sci., 2018, 64(12):I-IV | DOI: 10.17221/11519-JFS  

An estimation strategy to protect against over-estimating precision in a LiDAR-based prediction of a stand meanOriginal Paper

Steen MAGNUSSEN

J. For. Sci., 2018, 64(12):497-505 | DOI: 10.17221/120/2018-JFS  

A prediction of a forest stand mean may be biased and its estimated variance seriously underestimated when a model fitted for an ensemble of stands (stratum) does not hold for a specific stand. When the sampling design cannot support a stand-level lack-of-fit analysis, an analyst may opt to seek a protection against a possibly serious over-estimation of precision in a predicted stand mean. This study propose an estimation strategy to counter this risk by an inflation of the standard model-based estimator of variance when model predictions suggest non-trivial random stand effects, a spatial distance-dependent autocorrelation in model predictions, or...

Effects of some properties of cedar forest soils on secondary roots of Cedrus atlantica ManettiOriginal Paper

Belkacem EL AMRANI, Mohammed BENDRISS AMRAOUI

J. For. Sci., 2018, 64(12):506-513 | DOI: 10.17221/69/2018-JFS  

The effect of textural and physicochemical characteristics of five cedar forest soils on 4- and 8-month-old seedlings of Cedrus atlantica Manetti was studied in a controlled growth chamber. During their growth, cedar seedlings show a change in the root architecture by the levels of C_org, N, P, and by the soil granulometry. The Tioumlilin soil conditions stimulate mainly the cumulative length and the number of secondary roots. However, the cedar forest soil of Tazekka predominates over most soils in its effect on growth by the balance of chemical elements and the high percentage of coarse particles. The analysis of the densities...

LAI estimation by direct and indirect methods in Scots pine stands in Northern Steppe of UkraineOriginal Paper

Viktoriia LOVYNSKA, Petro LAKYDA, Svitlana SYTNYK, Mykola KHARYTONOV, Iryna PIESTOVA

J. For. Sci., 2018, 64(12):514-522 | DOI: 10.17221/79/2018-JFS  

Leaf area index (LAI) of Scots pine (Pinus sylvestris Linnaeus) in the Northern Steppe of Ukraine was estimated. LAI estimated directly (LAI d, destructive sampling) was compared with LAI determined by digital hemispherical photography (indirect method, LAI id) in Scots pine stands. The studies to determine LAI were performed in pine stands of the age ranging from 57 to 87 years. The high coefficient of determination between needle weight and crown diameter as dependent variables and stand age as an independent variable was found at the tree level. LAI values of the stands estimated by the direct method were higher than those obtained by the...

Aboveground biomass estimation in linear forest objects: 2D- vs. 3D-dataOriginal Paper

Stefan LINGNER, Eiko THIESSEN, Eberhard HARTUNG

J. For. Sci., 2018, 64(12):523-532 | DOI: 10.17221/106/2018-JFS  

Wood-chips of linear forest objects (hedge banks and roadside plantings) are used as sustainable energy supply in wood-chip heating systems. However, wood yield of linear forest objects is very heterogeneous and hard to estimate in advance. The aim of the present study was to compare the dry mass estimation potentials of two different non-destructive data: (i) Canopy area (derived from aerial images) and mean age at stump level (2D), (ii) volume of vegetation cover based on structure from motion (SfM) via unmanned aerial vehicle (3D). These two types of data were separately used to predict reference dry mass (ground truth) in eleven...