Modelling and sustainable management

Comparison of Sampling Methods Used to Evaluate Forest Soil Bulk Density

volume: 39, issue: 2

The objective of this study was to compare forest soil bulk density values obtained through
conventional sampling methods such as the volumetric ring (VR: diameter 5 cm, length 10 cm)
and paraffin sealed clod (PSC), with a variation of the VR, where rectangular boxes (RB) of
four different dimensions were used. Sampling transects were established on a machine operating
trail located in a beech (Fagus orientalis Lipsky) stand in Northern Iran. At each
transect, three soil samples were collected at three different locations. Samples from different
methods were spaced by a 50 cm distance to avoid direct interactions. The soil class of our
study area was Combisols according to the WRB classification with a clay texture. Soil bulk
density differed significantly between the three sampling methods. The lowest values were
obtained with the RB (average 1.25 g cm-3), followed by the VR (average 1.40 g cm-3), and
lastly the PSC (average 1.52 g cm-3). The values obtained with four variations of the RB
method ranged from 1.22 to 1.28 g cm-3 and were not found significantly different. When soil
bulk density was calculated after the removal of the weight and volume of roots included in
the samples, the values were determined to be higher than before but with the same range of
magnitude. The lowest coefficient of variation was found for RB4 (CV=2.3%), while the highest
values were observed for VR and RB1 (CV=5.7%).

Root Tensile Force and Resistance of Several Tree and Shrub Species of Hyrcanian Forest, Iran

volume: 39, issue: 2

Shallow landslides are a frequently recurring problem in some parts of Iran, including the
Hyrcanian forest. In addition to traditional civil engineering measures, a potential solution
for this problem is the application of soil bioengineering techniques. The mechanical reinforcement
effect of plant roots is one of the major contributions of vegetation to the mitigation of
shallow landslides. Given the lack of information on the mechanical properties of common
Hyrcanian forest species, the present study assessed the root strength of 10 common species
of this forest. Eight tree species occurring in natural regeneration sites (Carpinus betulus,
Fagus orientalis, Parrotia persica and Quercus castaneifolia) and plantations (Acer velutinum,
Alnus glutinosa, Fraxinus excelsior and Picea abies) and two shrub species
(Crataegus microphylla and Mespilus germanica) were selected. Fresh roots were collected
and mechanical tests were carried out on 487 root samples. The ranges of root diameter,
tensile force, and root resistance were 0.29–5.90 mm, 3.80–487.20 N, and 2.41–224.35 MPa,
respectively. Two different algorithms, including the nonlinear least square method and logtransformation,
were used to obtain power regressions for diameter-force and diameter-resistance
relationships. The results of the two algorithms were compared statistically to choose
the optimal approach for soil bioengineering applications. The nonlinear least square method
resulted in lower Akaike information criteria and higher adjusted R2 values for all species,
which means that this model can more efficiently predict tensile force and resistance based on
root diameter. Log-transformation regressions generally underestimate tensile force and resistance.
Significant differences were found among mean root tensile force (ANCOVA;
F=37.36, p<0.001) and resistance (ANCOVA; F=34.87, p<0.001) of different species. Also,
root diameter was significant as a covariate factor in tensile force (F=1453.77, p<0. 001) and
resistance (F=274.26, p<0.001). Shrub species and trees in natural regeneration sites had
higher tensile force and resistance values, while trees from plantation stands had lower values.
The results of this study contribute to the knowledge on the root force and resistance characteristics
of several shrub and tree species of the Hyrcanian forest and can be used in evaluating
the efficiency of different species for bioengineering purposes.

Impacts of a High-Capacity Truck Transportation System on the Economy and Traffic Intensity of Pulpwood Supply in Southeast Finland

volume: 40, issue: 1

High-capacity transportation (HCT) of roundwood is a road transport concept that is currently
being demonstrated in Finland and Sweden. In Finland, HCT trucks are in most cases
unable to access roadside storages, but they are expected to bring cost savings in highway
transportation between transshipment terminals and mill yards. Evaluating the optimal solutions
is challenging due to the complexity of the transportation systems. This paper presents a
dynamic simulation model, SimPulp, which was developed to generate information about the
impacts of substituting HCT for a part of the present pulpwood transportation system. A case
study in the area of the most intensive pulpwood use in Finland was conducted. The results
indicate that HCT has potential for reducing transport costs and especially the traffic intensity
of roundwood procurement in the studied area. The economic advantages of pulpwood HCT
could be more significant in a larger area or in the use of inter-terminal backhauling.

Multi-Criteria Decision Analysis (MCDA) in Forest Operations – an Introductional Review

volume: 40, issue: 1

Decision making in forestry is very complex and requires consideration of trade-offs among
economic, environmental, and social criteria. Different multi-criteria decision analysis
(MCDA) methods have been developed for structuring and exploring the decision-making
process of such problems. Although MCDA methods are often used for forest management
problems, they are rarely used for forest operation problems. This indicates that scholars and
practitioners working with forest operations are either unaware of MCDA methods, or see no
benefit in using these methods. Therefore, the prime objective of this review was to make
MCDA methods more intelligible (compared with current level of understanding) to novice
users within the field of forest operations. For that purpose, basic ideas as well as the strengths
and limitations of selected MCDA methods are presented. The second objective was to review
applications of MCDA methods in forest operations. The review showed that MCDA applications
are suitable for forest operation problems on all three planning levels – strategic, tactical,
and operational – but with least use on the operational level. This is attributed to: 1) limited
availability of temporally relevant and correct data, 2) lack of time (execution of MCDA
methods is time consuming), and 3) many operational planning problems are solved with
regards to an economic criterion, with other criteria serving more as frames. However, with
increased importance of environmental and social aspects, incorporating MCDA methods into
the decision-making process on the operational planning horizon (e.g., by developing MCDAbased
guidelines for forestry work) is essential.


Web of Science Impact factor (2017): 1.714
Five-years impact factor: 1.775
Next issue: January 2019

Subject area

Agricultural and Biological Sciences