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Research Article Kastamonu Uni., Orman Fakültesi Dergisi, 2019, 19(1): 95-105
Kastamonu Univ., Journal of Forestry Faculty
Doi:10.17475/kastorman.543539
95
Determination of Some Stand and Site Parameters Influencing the
Snow Damage in Trees: A Case Study of Boyabat Forest Enterprise,
Turkey
Arif Oguz ALTUNEL
Kastamonu University, Faculty of Forestry, Department of Forest Engineering, Kastamonu, TURKEY
aoaltunel@kastamonu.edu.tr
Received Date: 07.01.2019 Accepted Date: 12.02.2019
Abstract
Aim of Study: Determination of the snow damage triggering stand and site parameter on trees.
Area of Study: Damaged compartments of Yedicam and Burnuk Forest Directorates, #234 and #116,
within Boyabat Forest Enterprise of Kastamonu Regional Directorate of Forestry.
Material and Method: Two damaged and two control compartments from each directorate were
compared to find if any site or stand parameters are related to the snow damage occurred in the area
during 2014-2015 winter. Statistical analysis were carried out to test the significance of the parameters.
Main results: Age, relative density, the number of trees, basal area and stand volume of the stand
parameters, and slope, site class, terrain roughness and soil depth of the site parameters were statistically
linked to the snow damage.
Research highlights: The climate is a force to be reckoned with. New strategies must be devised and
put into action in forest management. Studies have shown the mishaps. The lessons should be taken from
the past experiences. Apparent mistakes must gradually be eliminated.
Keywords: Snow damage, stand parameters, site parameters
Ağaçlarda Kar Zararını Etkileyen Bazı Meşcere ve Yetişme Ortamı
Değişkenlerinin Tespiti: Boyabat Orman Işletme Müdürlüğü Örneği,
Türkiye
Öz
Çalışmanın amacı: Ağaçlarda meydana gelen kar zararına etki eden meşcere ve yetişme ortamı
değişkenlerinin tespit edilmesi.
Çalışma alanı: Kastamonu Orman Bölge Müdürlüğü’ne bağlı Boyabat Orman İşletme Müdürlüğü’nün
Yediçam ve Bürnük İşletme Şefliklerinde kar zararının tespit edildiği 234 ve 116 numaralı bölmeler.
Meteryal ve Metod: 2014-2015 kış ve erken ilkbahar süresince kar zararı tespit edilen iki bölme, aynı
meşcere ve yetişme ortamı özelliklerine haiz ancak zarar görmemiş, kontrol maksatlı seçilen iki bölme ile
karşılaştırıldı, istatistiksel analizler yürütüldü.
Sonuçlar: Yaş, ağaç sıklığı, ağaç sayısı, meşcere göğüs yüzeyi ve hacmi gibi meşcere parametrelerine
ilaveten, eğim, bonited, engebelilik ve toprak derinliği gibi mevki parametrelerinin, kar zararı üzerinde
etkili oldukları tespit edildi.
Dikkat edilmesi gereken hususlar: İklim göz ardı edilmemesi gereken bir gerçektir. Bu doğrultuda,
sıkıntıların bertaraf edilebilmesi için, yeni yönetimsel tercihler, gerekli görülen yerlerde uygulamaya
alınmalıdır. Çalışmalar, aksi durumlarda karşılaşılabilecekleri göstermektedir. Geçmişte yaşananlardan
dersler çıkarılmalı, yanlış uygulamalar tekrarlanmamslıdır.
Anahtar kelimeler: Kar zararı, meşcere parametreleri, saha parametreleri
Introduction
Natural or plantation with whatever
approach have been administered to set up,
Turkish forests are managed, depending upon
the experience assembled during the last 150
years. Although the timber production seems
to be leading agenda, the ecologic as well as
the socio-cultural sensitivities are also looked
after thus the management related strategies
are shaped and varied. This way, the forests
Citation (Atıf): Altunel, A.O. (2019). Determination of some stand and
site parameters influencing the snow damage in trees: a case study of
Boyabat Forest Enterprise, Turkey. Kastamonu University Journal
of Forestry Faculty, 19 (1), 95-105.
This work is licensed under a Creative Commons
Attribution-NonCommercial 4.0 International
License.
Kastamonu Uni., Orman Fakültesi Dergisi, 2019, 19(1): 95-105 Altunel
Kastamonu Univ., Journal of Forestry Faculty
96
are maintained, periodically tended,
protected and made sure that they reach the
end of their planned rotation age when the
optimum earnings are guaranteed (Nguyen
and Nghiem, 2016). Such forests parts also
called as the stands are renewed by the new
generations growing underneath as they
mature, so the cycle keeps on going by
sticking to the principles of sustainability.
Rotation periods vary between 50-60 and
100-120 years in fast and slow growing tree
species, respectively. When the vigor of the
trees or the stands are prematurely hampered
due to some unexpected phenomenon,
predominantly economic as well ecologic
and socio-cultural repercussions follow. Fire,
storm, snow, insect and disease can be
regarded as such. Above all, Kastamonu
Regional Directorate Forestry (KRDF)
experienced one such disaster in the form of
an early spring windstorm in March 2013.
The damage alone resulted in 1580000 m3 of
timber loss spread around a large geography
within the directorate. Lesser in frequency
and extend, snow is another factor affecting
the liveliness of the trees and stands. It is
impossible to list the leading factors
exacerbating the results of heavy snow-loads
on tress, however, there are published studies
elaborating the relationships between the
snow-load and the tree and stand
characteristics, topographic and soil factors,
silvicultural tending prescriptions, etc.
Snow damage has long been the subject
of numerous studies looking into its effects
on the forests. Especially in Scandinavian
countries, the US, Canada and other
countries having mountain forests, heavy
snow cause considerable damage on the
forests (Hanewinkel, Breidenbach, Neeff, &
Kublin, 2008). In the continental Europe, 4
million m3 of annual timber loss are
associated with the snow damage (Nykanen,
Peltola, Quine, Kellomaki & Broadgate,
1997). The aging, also know as the mature
forest structuring accounted to be one of the
major factors behind various damage types
(Spathelf, Maaten, Maaten-Theunissen,
Campioli & Dobrowolska, 2014).
Additionally, the damaged trees/forests were
reported to be more susceptible to insect and
fungus infestations (Schreoder and Lindelow,
2002). Strong winds are usually considered
as the leading cause worsening the outcome
of heavy snow (Petty and Worrell, 1981).
However their role can be different. On one
hand they can disperse the snow accumulated
on trees (Solantie, 1994) and on the other
they can freeze the already accumulated
snow by further worsening the additional
load on them, which could lead to uprooting,
breaking or bending (Peltola, Nykanen &
Kellomaki, 1997). The geographical
locations of the lands on which the forests
reside, and the lands’ topographical
structuring (terrain roughness) are also the
critical factors affecting the degree of abiotic
damage factors on trees (Gardiner and Quine,
2000). Forests residing on the coastal and
mid to high elevated terrains are generally
hard hit from the snow loads because snow
tends to accumulated on tree branches and
canopies (Zhu et al., 2006). It can be said that
the slope gradient has not been found as
relevant as once thought, and the aspect has
not been fully studied to establish a definitive
relationship. Tree stem form and the canopy
structuring were reported to be the leading
factors defining the survivability of a tree.
Asymmetric stem and canopy, and
perpendicular branching are reported as tree
characteristics increasing the snow damage
risk (Valinger and Fridman, 1997). However,
it must be noted that those are typical
attributes of competition-free growing.
Management related silvicultural
prescriptions on the other hand, can be
considered as interventions negatively or
positively affecting the results of possible
risks. The snow damage in stand level, does
not only concern the timber losses or quality,
but also forces the forest administration to
apply not-projected salvage operations, and
to deviate from the management plan
dictated targets. The stands’ stabilities
against the snow and the wind were reported
to be related to the basal area in hectare (ha),
the trees’ spacing and slenderness ratios
(Martin_Alcon, G-Olabarria & Coll, 2010;
Castedo-Dorado, Crecente-Campo, Alvarez-
Alvarez & Barrio-Anta, 2009; Wang, Tits &
LeMay, 1998). Heavy timber losses were
observed especially on the thinned edges of
Scots pine forests when the snow loads were
further increased by strong winds (Peltola,
1996). Besides, in places where the trees
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could not well anchor themselves to the
ground - i. e., shallow soil depth or extreme
slope, extensive damage resulting from either
wind or snow in individual trees was
observed (Zubizarreta-Gerendiain, Pellikka,
Garcia-Gonzalo, Ikonen & Peltola, 2012).
The snow accumulations appeared to be
concentrated in the stands’ interiors where
even under light snow, Scots pines with low
slenderness ratios, were seriously damaged
(Pellika and Jarvenpaa, 2003). Although
short in height, the trees with large diameter
at breast height (dbh) were more subjected to
branch or stem breakages rather than
uprooting (Peltola, Kellomaki, Hasinen &
Granander, 2000). During the planned
rotation cycles, if the level of intermittent
silvicultural or management related
interventions was inadvertently exaggerated
in some parts of the stands, it was observed
that in the following years, the possibility of
those parts to be adversely affected from the
snow raised considerably (Fridman and
Valinger, 1998). The snow damage is a
phenomenon faced in anytime, depending
upon the severity of the winter and
precipitation regimes in the Turkish forests.
Since it has long been experienced as
sporadic occurrences here and there, no
particular attention has been given to find the
underlining causes. The snow damages
investigated in this study occurred
extensively in two forest sub-compartments
of Yedicam and Burnuk forest directorates in
Boyabat Forest Enterprise (BFE) within
KRDF during the winter of 2014-2015.
It was the objective of this particular
study to find if the stand and site
characteristics triggering the snow damage
here but not there vary within these
parameters.
Material and Methods
Study Area
The study was conducted in two forest
directorates of the BFE, Turkey. Two
compartments, 234 and 116 of the forest
directorates, Yedicam and Burnuk, which
registered unusually extensive snow damage
during the winter of 2014-2015 were selected
for this study (Yellow dots inside the
directorates of BFE in Figure 1). BFE is one
of five such administrative units within the
former Sinop Regional Directorate of
Forestry (SRDF). Since the October, 2011,
SRDF has become part of the neighboring
KRDF. The heavily forested geography has a
standing volume of 195 million (mil) m3 and
an approximate annual increment of 5.7 mil
m3. 2054000 m3 of industrial timber was
produced in 2017, and BFE’s contribution
was 137000 m3. The pure and mixed stands
including species such as Fir (Abies
nordmanniana subsp. equi-trojani), Scots
pine (Pinus sylvestris), Corsican pine (Pinus
nigra), Red pine (Pinus brutia), Beech
(Fagus orientalis) and Juniper (Juniperus
communis) form the forests of BFE.
Topography is rather treacherously broken
inside the Isfendiyar and east Ilgaz mountain
chains; there are riverbeds, occasional level
plains and high plateaus. The characteristics
of the terrestrial climate reign all over the
enterprise with hot summers and cold
winters. Precipitation in the form of rain is
concentrated around the spring months; the
number of average annual rainy/snowy days
is 80, and the amount of average annual
precipitation varies between 300-500 mm.
Kastamonu Uni., Orman Fakültesi Dergisi, 2019, 19(1): 95-105 Altunel
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98
Figure 1. Location of the study area
Material and Methodology
This study was realized, depending upon
the data collected from four compartments of
BFE. One seriously damaged compartment
from both Yedicam and Burnuk forest
directorates was compared to a similarly
conditioned and structured control
compartment in the respected directorate.
Thirty 800 m2 circular sample plots were
randomly selected from each compartment,
and the following parameters were measured
and computed;
- Quadratic mean diameter (dq, cm), was
calculated for each sample plot after the
diameter at breast height (dbh, cm) had
been measured for all the trees included
within the sample plots,
- Stand age (t, year) was determined through
the averaging of number of tree rings from
increment cores acquired from eight to ten
trees within the sample plots,
- For each sample plot, aspect, slope,
elevation and terrain roughness values
were extracted from digital elevation
model(s) (Altunel, 2018) – i. e. flat, east,
west, north, south; 0-10% (1), 10-30% (2),
>30% (3); 1000-1200m (1), 1200-1400m
(2) and less rough (1), rough (2) more
rough (3), respectively. Terrain roughness
was calculated as a function of the slope.
The digital elevation models constructed
for four compartments (2 damaged, 2
control) were first converted to slope
models. Rasterized slope models composed
of a number of neighboring cells assigned
with a slope value. Every cell within the
model was compared to its surrounding 8
cells. The variability within these 9 cells
was the roughness value for the cell in
question. If all the slope values across the 9
cells matched, the particular cell got the
roughness value as 1. The more the
variability within the questioned cells, the
higher the terrain roughness (Riley,
DeGloria & Elliot, 1999). Although a direct
connection linking this particular parameter
to the damage could not be established
through the recent literature, the successful
previous studies were convincing enough to
evaluate it as a possible factor (Hanna,
1981). Thus, a nine class terrain roughness
map was first produced, it was then
consolidated into 3 classes for the analysis.
- The number of trees (N/ha), basal area
(m2/ha) and stand volume (m3/ha) were
calculated through the sample plots,
- Soil depth(s) and major soil type(s) (MST)
were extracted from the vectorized
provincial soil classification maps – i.e. 0-
30cm (1), 30-50cm (2), >50cm (3) and
brown forest soil, cambisol, which had a
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certain emphasize on silt (M) and on gravel
(G),
- Relative stand density (RD) was determined
according to Curtis, Clendenan & Demars
(1981),
- Site class (absolute), crown closure, and
age class (for cross validation with
increment cores) were determined through
the databases pertaining to the current
forest management plans – i. e. best (1),
good (2), fair (3), bad (4); 40-70% and
>70%, and 40-60 years, 60-80 years and
>80 years, respectively,
- In the plots including both the damaged and
not-damaged trees, the ratios of the number
of damaged trees, their basal areas and
volumes in comparison to the overall
number of trees, their basal areas and
volumes were separately computed.
Kolmogorov-Smirnov test was applied to
assess the normality of the quadratic mean
diameter, stand age, relative density, the
number of trees, basal area and volume
computed for the sample plots, as well as the
proportional damage ratios with regard to the
number of trees, basal area and stand
volume. The test confirmed that the latter
mentioned damage ratios did not manifest
normal distribution (p<0.05), whereas the
others did (p>0.05). Student’s t-test was used
to assess if a significant difference was
present between the damaged and control
plots in terms of the quadratic mean diameter
stand age, relative density, the number of
trees, basal area and volume. Additionally,
Spearman Correlation test was utilized to
determine if there was any correlation
between the proportional damage ratios of
the computed parameters. Finally, Chi-square
test was used to evaluate the distribution of
the site parameters – i. e. aspect, slope,
roughness, elevation, site class, crown
closure and age class across the damaged and
control plots. ArcGIS 10.3 and IBM SPSS
Statistics 23 software were used for the
analysis.
Results
The means of the stand age, relative
density, number of trees, stand basal area and
stand volume were significantly different
between the damage and the control groups,
however mean diameter did not register any
difference because it was almost the same in
both the damaged and control groups (Table
1).
Table 1. Comparisons between snow damage groups for stand parameters
Stand parameter
Damaged (n=36)
Control (n=84)
p
Mean diameter (dq, cm)
28.8 (±3.7)a
27.6 (±3.1)
0.073ns
Stand age (t, year)
82.1 (±7.2)
68.9 (±19)
< 0.001*
Relative density (RD)
3.60 (±0.82)
2.8 (±0.59)
< 0.001*
Number of trees (N/ha)
294.6 (±63)
246.3 (±38.6)
< 0.001*
Basal area (m2/ha)
19.371 (±5.084)
14.808 (±3.736)
< 0.001*
Stand volume (m3/ha)
166.589 (±47.618)
125.704 (±37.416)
< 0.001*
a Mean (±Standard deviation), ns Non-significant at 0.05 level, * Significant at 0.001 level.
The strongest correlation between the
damage and the computed stand parameter
was obvious in relative density (r; 0.507).
Positive relationship between the older
conifers and the damage was validated (Zeng
et al., 2004) Although getting weaker, all the
remaining stand parameters, which were the
result of forest management related
interventions, manifested some degree of
positive correlation (Table 2).
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Table 2. Correlations between damage ratios and stand parameters
Stand parameter
Damage ratio for
the number of
trees
Damage ratio for
basal area
Damage ratio for
stand volume
r
P
r
p
r
p
Mean diameter (dq, cm)
0.241
0.008**
0.228
0.012*
0.226
0.013*
Stand age (t, year)
0.339
< 0.001***
0.335
< 0.001***
0.333
< 0.001***
Relative density (RD)
0.507
< 0.001***
0.514
< 0.001***
0.512
< 0.001***
Number of trees (N/ha)
0.464
< 0.001***
0.481
< 0.001***
0.482
< 0.001***
Basal area (m2/ha)
0.479
< 0.001***
0.482
< 0.001***
0.481
< 0.001***
Stand volume (m3/ha)
0.458
< 0.001***
0.458
< 0.001***
0.456
< 0.001***
* Significant at 0.05 level, ** Significant at 0.01 level, *** Significant at 0.001 level.
In Table 3, slope appeared to be a rather
significant factor in the occurrence of snow
damage. The results showed the snow
damage considerably increased as the slope
gradient got bigger. The age class showed the
same tendency. As the stands got mature, the
snow damage risk grew simultaneously. Four
distinct site classes were present across the
sample plots, and the analysis results showed
as the site classes deteriorated, the snow
damage risk increased. The crown closure
was another site parameter showing
relationship with the snow damage.
However, there were only two classes 40-
70% and >70% for comparison, and not
enough sample point coincided with the first
class to come up with a definitive result to
claim this relationship as a fact.
Additionally, positive correlation of all stand
parameters in terms of the snow damage
ratios in Table 2 with respect to the number
of trees, basal area and stand volume was
also nullifying such an inference. The soil
depth was also showing strong relationship
with the snow damage. Apparently, as the
tree roots found enough soil depth to anchor
the above tree mass to the ground firmly,
they could better withstand the climatic
anomalies. Interestingly, terrain roughness
also showed significance in terms of snow
damage. The results confirmed that as the
terrain roughness registered bigger, the snow
damage risk also rose.
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Table 3. Comparisons between snow damage groups for site parameters
Site parameter
Class
Damaged (n=36)
Control (n=84)
p
Aspect
Flat (n=15)
3 (20%)
12 (80%)
0.323ns
North (n=44)
15 (34.1%)
29 (65.9%)
East (n=38)
8 (21.1%)
30 (78.9%)
South (n=3)
1 (33.3%)
2 (66.7%)
West (n=20)
9 (45%)
11 (55%)
Slope
0-10% (n=24)
4 (16.7%)
20 (83.3%)
0.003**
10-30% (n=59)
13 (22%)
46 (78%)
>30% (n=37)
19 (51.4%)
18 (48.6%)
Elevation
<1200 m (n=40)
8 (20%)
32 (80%)
0.091ns
>1200 m (n=80)
28 (35%)
52 (65%)
Age class
40-60 years (n=32)
1 (3.1%)
31 (96.9%)
0.001**
60-80 years (n=52)
20 (38.5%)
32 (61.5%)
>80 years (n=36)
15 (41.7%)
21 (58.3%)
Site class
1 (n=3)
0 (0%)
3 (100%)
0.006**
2 (n=19)
0 (0%)
19 (100%)
3 (n=88)
31 (35.2%)
57 (64.8%)
4 (n=10)
5 (50%)
5 (50%)
Crown closure
40-70% (n=10)
6 (60%)
4 (40%)
0.031*
>70% (n=110)
30 (27.3%)
80 (72.7%)
Terrain
roughness
1 (n=34)
6 (17.6%)
28 (82.4%)
0.043*
2 (n=53)
15 (28.3%)
38 (71.7%)
3 (n=33)
15 (45.5%)
18 (54.5%)
Soil depth
0-30 cm (n=30)
19 (63.3%)
11 (36.7%)
< 0.001***
30-50 cm (n=60)
17 (28.3%)
43 (71.7%)
>50 cm (n=30)
0 (0%)
30 (100%)
MST
M (n=60)
19 (31.7%)
41 (68.3%)
0.690ns
G (n=60)
17 (28.3%)
43 (71.7%)
* Significant at 0.05 level, ** Significant at 0.01 level, *** Significant at 0.001 level,
ns Non-significant at 0.05 level.
Discussion and Conclusion
The Black sea region of Turkey can
unquestionably be regarded as the Mecca of
the forests in the country. It is further
emphasized within the Western part of the
region. In terms of the acreage, growing
stock, annual increment and production, the
region including the provinces of
Kastamonu, Zonguldak and Bolu, along with
their namesake regional forest directorates,
produces a considerable amount of the
country’s timber need. The natural
characteristics are suitable for tree growth in
this region, however the effects of climate
change have started to unprecedentedly
change the dynamics even in forestry sector
(Tayanc, Im, Dogruel & Karaca, 2009;
Ozcan, Musaoglu & Turkes, 2018). The
never before seen forest fires have started to
hit the region, and the strategies are devised
to cope with the problem (Kucuk, Topaloglu,
Altunel & Cetin, 2017). KRDF was ravaged
by a wind-storm in March 2013, causing 1.5
million m3 timber loss (Torun, 2018). The
objective of this particular study, the snow
damage is a phenomenon frequently seen in
sporadic occurrences during the winter and
early spring in the region. Type of the
damage has long been so coincidental that no
study has so far looked into the underlying
reasons. On the other hand, the extent of the
damage analyzed in BFE was rather
extensive and concentrated to deserve a
comprehensive study. The most active and
prevalent method of lessoning the damage
caused by the wind and snow on forests is to
avoid the silvicultural and management
related practices which have been proven to
adversely affect the outcome. It was
recommended that the stands reaching the
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critical stages should be strategically
managed (Hirvela and Hynynen, 1990).
Slope, site class, terrain roughness and soil
depth were the site parameters which were
found as statistically significant factors in the
definition of snow damage in this study,
however aspect, elevation and major soil
type were not. The nature of the damage was
already pointing the slope as one possible
factor because the damage was concentrating
on slopes in both damaged compartments
(Figure 2). Although the past studies showed
that both the slope and the aspect were found
rather less related and inconclusive (Nykanen
et al. 1997) as factors influencing snow
damage on trees, they can still be considered
as important on soil fertility (Scholten et al.,
2017) and morphology (Valtera, Samonil,
Svoboda & Janda, 2015). Since these are
crucial factors on tree growth, slope might
very well be a decisive parameter negatively
affecting the proper formation of such
factors. Slope and aspect were extracted from
digital elevation models. They were
categorized into individual classes, for ease
of convenience and evaluation. The statistical
analysis showed one as an important
topographical parameter among the snow
damage triggering factors, however, it is very
obvious that there are apparently much more
to this conclusion than referring the slope as
a percent figure.
Figure 2. The locations of the snow damaged trees in compartments, 116 and 234
Soil formation, preservation and fertility
get worsen as the percentage of the slope
increases (Fang, Sun & Tang, 2014). Not
enough soil leads to poor site class and soil
depth. Besides, if the topography is
treacherous increasing the terrain roughness,
the ground becomes not-ideal to support the
trees because soil fertility was drastically
influenced by the topographical factors
(Scholten et al., 2017). Despite these
adversities, as long as the climatic conditions
progresses favorable, trees can still grow just
fine until the unexpected occurs. Snow is one
such anomaly adding considerable weight
over trees which have precariously anchored
to the soil (Zubizarreta-Gerendiain et al.,
2012).
Although reported as snow damage, it
was not clear if the damage occurred purely
based upon the snow accumulation or an
unexpected strong wind accompanied it,
making the damage even greater. Trees
growing regimes shapes around the
prevailing climatic conditions, so they
develop strength to those conditions. Other
than the above mentioned sporadic
occurrences, no previous extensive snow
damage record existed either in the
directories or in the enterprise. As the climate
change is considered, it is rather unlikely that
a similar damage would repeat itself in the
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103
future. However, when unexpected
anomalies throw conditions which the trees
and forests are not accustomed to, then such
phenomenon would continue to take place in
our forests. It is not known what kind of
silvicultural or management related
treatments were applied to these stands in the
past. The tending prescriptions can positively
as well as negatively change the risks
through the preferences of regeneration,
thinning and rotation (Nykanen et al., 1997).
The stand characteristics are all related to the
management strategies in Turkey because all
the forests and forest lands are managed
through forest management plans. Six stand
parameters were computed through field data
collected in both the damaged and the control
compartments. Student’s t-test showed that
the stand age, relative density, the number of
trees, basal area and stand volume figures
were found significantly different in the
damaged compartments compared to the
control ones (p<0.001). Mean diameter, dq,
was not found significant as a stand
parameter because in both the damaged and
the control groups, it was almost the same.
However, dbh which is a factor in the
calculation of dq in single tree evaluation is
so important as a factor in tree taper or
slenderness ratio (Diaz-Yanez, Mola-
Yudego, Gonzalez-Olabarria & Pukkala,
2017) that further study would certainly have
the potential to yield viable results. Then,
these parameters’ involvement in the damage
was checked through Spearman’s correlation
test in terms of the number of damaged trees,
basal area and stand volume. All the
evaluated stand parameters were significant,
varying in level. The thinning procedures are
implemented as selective rather than
systematic in Turkey. It is the main
intervention behind the calculated stand
parameters in this study. Thinning is a must
in forestry if the ideal bole form, good
anchoring attributes and aeration through the
stands would be met (Cameron, 2002).
However, it changes the relative density, the
number of trees, , basal area and stand
volume in any given area and leaves the
stands vulnerable to wind and snow damage
(Pellika and Jarvenpaa, 2003; Martin_Alcon
et al., 2010). It would take very many years
for a stand to compensate for the degree of
intervention and to regain its stability.
During this period, if a climatic anomaly hits
the stand(s), it is very likely that they would
suffer in unusual levels. All the
compartments, damaged and control, have
long been managed in BFE, but it is not clear
if the past interventions were excessive in the
damaged compartments, but ideal in the
control ones.
Both stand; age, relative density, the
number of trees, basal area and volume and
site; slope, site class, terrain roughness and
soil depth, parameters were found as decisive
factors in the evaluation of snow damage on
forest stands. Site is not a medium which can
be drastically altered for the forest growth, it
involves topographic and climatic
derivatives. The living organisms prefer that
site because their capabilities suit well to the
region. However, the mentioned stand
parameters are always changed as the
management strategies dictate. Today, forests
are so intertwined with the management
decisions and activities that accidentally
changing one parameter automatically affects
the other(s), leaving the stands vulnerable to
climatic anomalies. This study and many
others showed the factors affecting the
stability of forest stands against such
uncertainties, snow in this case. Forests will
grow and produce tangible goods for the
mankind, and we will intervene that cycle
with the knowledge and know-how to make
it even better. Unfortunately, there are forces
which we would probably never harness,
thus research outputs like this should be
taken seriously to see what we are up against
in the management of the forests.
Acknowledgment
I thank my dear friend and colleague
Oytun Emre SAKICI, PhD for his
unconditional support and mentoring in
shaping this paper. Additionally, I thank state
engineer Abdullah KAPUCU for his
dedication to the profession, tenacious field
work and dependable data coverage. The
making of this paper is the culmination of a
research project, KUBAP-01/2015-29,
funded by the coordinator-ship of scientific
research funds of Kastamonu University.
Kastamonu Uni., Orman Fakültesi Dergisi, 2019, 19(1): 95-105 Altunel
Kastamonu Univ., Journal of Forestry Faculty
104
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