Zbornik gozdarstva in lesarstva 78, s. 97 - 122 
 
GDK: 815:176.1 Acer pseudoplatanus L.:114(045) 
Prispelo / Recived: 14. 11. 2005 Izvirni znanstveni 
lanek 
Sprejeto / Accepted: 14. 12. 2005 Original scientific paper 
 
FACTORS INFLUENCING GROWTH OF MATURE SYCAMORE 
TREES (Acer pseudoplatanus L.) ON CARBONATE BEDROCK 
 
Aleš KADUNC1, Marijan KOTAR2 
 
Abstract 
This paper presents the growth potential of sycamore (Acer pseudoplatanus L.) on four types of forest sites 
located on carbonate bedrock. The research covers sycamore sites (Aceri-Fraxinetum ill.), beech sites (Lamio 
orvalae-Fagetum), beech sites planted with Norway spruce, and silver fir-beech sites (Omphalodo-Fagetum 
aceretosum). The analyses for each forest type were carried out on five plots. Our aim was to determine the 
effect of site factors and stand parameters on sycamore growth. Site productivity (SP) is positively correlated 
with soil depth, coarse silt percentage in the cambic horizon, the content of phosphorus in leaves and, partly, 
with potassium. The effect of nitrogen supply on height growth or SP was not confirmed. Furthermore, height 
growth on sites with a higher rate of nutrient cycling, higher macronutrient supply and higher sand percentage 
in the cambic horizon is significantly faster. As to the growth of basal area, in addition to positive dependences 
of crown size, many other correlations with site factors were confirmed. 
Key words: Acer pseudoplatanus, site productivity, height increment, basal area 
increment, site factor, carbonate bedrock 
 
RASTNI DEJAVNIKI PRI ODRASLEM GORSKEM JAVORJU (Acer 
pseudoplatanus L.) NA KARBONATNI MATI
NI PODLAGI 
 
Izvle
ek 
V prispevku je obravnavan rastni potencial gorskega javorja (Acer pseudoplatanus L.) na štirih tipih gozdnih 
rastiš na karbonatni matini podlagi. V raziskavo so zajeta javorovja (Aceri-Fraxinetum ill.), bukova rastiša 
(Lamio orvalae-Fagetum), zasmreena bukova rastiša v isti gozdni združbi in jelovo bukova rastiša 
(Omphalodo-Fagetum acereretosum). Za vsak rastišni tip smo napravili analize na petih ploskvah. Namen 
raziskave je ugotoviti rastišne faktorje oziroma sestojne parametre, ki vplivajo na rast pri odraslem gorskem 
javorju. Proizvodna sposobnost je v pozitivni povezavi z globino tal, deležem grobega melja v kambinem 
horizontu, s koncentracijo fosforja v listih in deloma tudi s kalijem v listih. Vpliv preskrbe z dušikom na višinsko 
rast oziroma proizvodno sposobnost ni potrjen. Višinska rast je bila hitrejša na rastiših z hitrejšim kroženjem 
snovi, boljšo preskrbljenostjo z makrohranili in višjim deležem peska v kambinem horizontu. Glede temeljnine 
rasti smo poleg pozitivne odvisnosti od velikosti krošnje potrdili še številne povezave z rastišnimi dejavniki. 
Key words: Acer pseudoplatanus, proizvodna sposobnost rastiša, višinski 
prirastek, temeljnini prirastek, rastišni faktor, karbonatna matina 
podlaga 
                                            
1  dr. A. K., Biotehniška fakulteta, Oddelek za gozdarstvo in obnovljive gozdne vire, Ve
na pot 83, 1000 
Ljubljana, SLO, ales.kadunc@bf.uni-lj.si 
2  prof. dr. M. K., Biotehniška fakulteta, Oddelek za gozdarstvo in obnovljive gozdne vire, Ve
na pot 83, 
1000 Ljubljana, SLO, marijan.kotar@bf.uni-lj.si 
98 
Zbornik gozdarstva in lesarstva, 78 
 
VSEBINA 
CONTENTS 
 
1 INTRODUCTION............................................................................ 99 
 UVOD 
2 MATERIALS AND METHODS................................................... 100 
 OBMOJE RAZISKAVE IN METODE 
3 RESULTS........................................................................................ 106 
 REZULTATI 
4 DISCUSSION.................................................................................. 110 
 RAZPRAVA 
5 POVZETEK.................................................................................... 115 
6 REFERENCES ............................................................................... 117 
 VIRI 
 
99 
Kadunc, A., Kotar, M.: Factors influencing growth of mature sycamore … 
 
1 INTRODUCTION 
UVOD 
 
The importance of minority tree species in Central Europe has been increasing recently, 
which especially holds true for valuable broadleaves (THIES / HEIN 2000). Sycamore 
(Acer pseudoplatanus L.), the species treated in this paper, undoubtedly belongs to this 
group (ibidem.). High attractiveness of sycamore is a result of its broad ecological range 
(SPETHMANN / NAMVAR 1985), its presence in various forest site types, vast 
reproductive potential (HEGI 1927), solid growth (NAGEL 1985) and the attainability 
assortments of high value (THOROE / OLLMANN 2001). What is more, the influence of 
sycamore litterfall on soil processes and soil properties is quite favourable (HOFFMANN 
1960; NEIRYNCK et al. 2000), especially in coniferous plantations. Frequent and 
abundant fructifications resulting in dense regeneration are also an important source of 
food for many animal species, particularly deer (EIBERLE 1985).  
 
Sycamore as an admixed tree species is a valuable indicator of special (micro) conditions 
or/and events in forest stands (disturbances). 
 
A prerequisite for successful preservation or promotion of any species is sufficient 
knowledge of its ecological demands. The establishment of a tree species is indicated by 
its growth, which has not been - in the case of sycamore - sufficiently studied (KJÖLBY / 
SABROE / MOLTESEN 1958; FAUST 1963; AREND 1982; NAGEL 1985; JÖRNS 
2000). Even less is known about the factors influencing sycamore growth (e.g. RÖHRIG 
1967; HENNECKE 1977; FELIKSIK / NIEDZIELSKA / WILCZYNSKI 2000), since 
the majority of researches study young individuals, particularly sycamore seedlings, often 
growing in artificial conditions (HELLIWELL 1965; LYR / DREYER / AUSSENAC 
1996; CORNELLISEN / CARNELLI / CALLAGHAN 1999; WEBER 1999; WEBER / 
BAHR 2000a; WEBER-BLASCHKE / CLAUS / REHFÜSS 2002). In mature stands, the 
interspecific competition was mostly researched (e.g. NÜSSLEIN 1995), taking the 
impact of site conditions into consideration only exceptionally (HEIN 2004).  
 
In addition to growth studies, some fundamental ecological research work has also been 
carried out (GADOW v. 1975; OKALI 1966a, b; BRAUN 1976; MILLARD / PROE 
1991).  
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Zbornik gozdarstva in lesarstva, 78 
 
This paper aims to determine the factors influencing sycamore growth in the mature 
phase. We are interested in the influence of stand and site conditions. Our purpose is to 
confirm the following hypotheses: 
1. Site productivity (hereafter: SP) of sycamore is influenced by nitrogen 
concentration in soil and by plant available water. Furthermore, SP is dependent 
on soil conditions only.  
2. Height increment depends solely on soil conditions. 
3. Basal area increment is only influenced by crown dimensions (HEIN 2004), site 
factors are not important. 
 
The first hypothesis is based on common quotes (e.g. GADOW v. 1975; HENNECKE 
1977; FRANC / RUCHAUD 1996; WEBER / BAHR 2000b) on the optimal conditions 
for sycamore growth: fresh, airy soil rich in nutrients, nitrogen in particular, and well-
supplied with water.  
 
This research was carried out on carbonate bedrock. Recent findings on the importance of 
sufficient base saturation for the growth and development of sycamore, known for having 
a particular sensitivity to magnesium and calcium deficiencies (WEBER 1999; WEBER / 
BAHR 2000a; WEBER / BAHR 2000b), supported by some older observations (e.g. 
KJÖLBY / SABROE / MOLTESEN 1958), led us to the reflection that the effects of 
other factors might be better expressed excluding bigger variations in base saturation. 
One way of controlling that is to restrict the study area to carbonate bedrock sites.  
 
 
2 MATERIALS AND METHODS 
OBMOJE RAZISKAVE IN METODE 
 
2.1 SITE CHARACTERISTICS 
ZNAILNOSTI LOKACIJ 
 
The study was carried out in the central and southern parts of Slovenia, in four stand-site 
conditions. The first forest type presents a beech stand with admixed sycamore on a site 
phytosociologically defined as Lamio orvalae – Fagetum (the location of Brezova reber). 
The second type appears in the same site unit, but is occupied by a spruce stand 
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Kadunc, A., Kotar, M.: Factors influencing growth of mature sycamore … 
 
(plantation) with naturally admixed sycamore (the location of Jauhe). The third type is to 
be found on the site defined as Aceri-Fraxinetum illyricum, where sycamore is the 
dominant tree species (the location of Konjice). The latter type presents mixed stands of 
beech, silver fir, spruce and sycamore in the site unit Omphalodo-Fagetum aceretosum 
(the location of Strmec).  
 
Table 1: General characteristics of research sites 
Preglednica 1:  Spošne znailnosti analiziranih lokacij 
Site / Lokacija Site descriptor /  
Rastni deskriptor Brezova reber Jauhe Konjice Strmec 
Exposition /  
Ekspozicija 
All directions / 
Vse smeri East / Vzhod 
Mainly North / 
Pretežno sever 
Mainly North /  
Pretežno sever 
Altitude (m) /  
Nadm. višina 400-450 570-670 800-950 600-800 
Inclination (°) /  
Naklon 
5 3 12 14 
Precipitation 
(mmyear-1) / Padavine 1300 1280 1150 1600 
Stoniness (%) / 
Kamnitost 14 27 11 21 
Soil type / Talni tip Luvisol on 
limestone / 
Izprana rjava 
pokarbonatna tla 
Luvisol on 
limestone / 
Izprana rjava 
pokarbonatna tla 
Brown soil on 
limestone / 
Rjava po-
karbonatna tla 
Luvisol and brown soil 
on limestone / Izprana 
in neizprana rjava 
pokarbonatna tla 
Soil parameters / 
Talni parametri  
Mean/Min/Max 
Povp./min./max. 
Mean/Min/Max 
Povp./min./max. 
Mean/Min/Max 
Povp./min./max. 
Mean/Min/Max 
Povp./min./max. 
Soil depth / Globina 0.47/0.42/0.52 0.27/0.21/0.34 0.52/0.41/0.67 0.29/0.23/0.40 
Forest floor (tha-1)/ 
Organski talni 
horizonti 
13.8/10.0/16.5 16.3/11.4/26.0 14.4/10.9/16.4 21.7/11.1/47.5 
Volume of A horizon 
(m3ha-1) (Ahor) / 
Volumen A horizonta 
985/498/1376 
 
893/549/1600 
 
2008/1296/3300 
 
1019/474/1404 
 
pH (Ahor) 4.7/4.1/5.0 4.7/4.1/5.8 5.7/4.7/6.5 5.0/4.3/6.5 
C/N (Ahor) 13.2/11.5/14.2 16.3/9.7/19.9 12.5/11.3/14.1 13.2/10.0/18.1 
V (%) (Ahor) 29.8/15.3/40.7 40.7/26.9/63.1 55.9/34.8/74.0 38.2/15.6/72.9 
 
For each forest type, five research plots measuring 30 × 30 m (0.09 ha) were established 
(Table 1). On bigger plots, the homogeneity of site conditions would in most cases 
deteriorate. The plots included in the research were sampled by the principles of quota 
sampling, since the correct random sampling would be very expensive and time-consuming 
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Zbornik gozdarstva in lesarstva, 78 
 
work. On the appropriate macrolocation for a particular forest type, only those five plots 
which best fulfilled the conditions (mature stand, appropriate tree species composition, at 
least four dominant sycamore trees per plot, expressiveness of site conditions and absence 
of severe injuries on trees and soil) were included into the research.  
 
The analysed forest types differ importantly in the past management or silvicultural 
treatments. The most intensively managed location was Brezova reber, followed by the 
locations of Strmec and Jauhe. On the location Konjice, only salvage fellings were 
carried out. The actual intensity of management actions is impossible to reconstruct due 
to small surfaces of the analysed plots.  
 
2.2 METHODS 
METODE 
 
This study is based on several methodological complexes.  
The stand structure was analysed by means of measurements on 20 sample plots (30 × 30 
m). Diameter at breast height (hereafter: DBH), tree height, crown base height (from the 
lowest primary branch with a diameter of at least 3 cm) and eight radii of the crown 
projection area were measured for each tree (with a DBH above 10 cm) on each plot.  
 
The density of crown cover was calculated as a sum of crown projections of all the trees 
on each plot. This parameter is expressed as a ratio between the sum of crown projections 
and plot surface in percentages.  
 
For each tree crown on every plot, the mean diameter, surface and volume were 
calculated. When calculating the last two parameters, we relied on the procedure and 
species specific coefficients, as proposed by PRETZSCH (2002, p. 207).  
 
We dug out a soil profile on each plot, determined the soil horizons and examined them 
by means of pedological analysis. In the laboratory the following parameters were 
examined: pH (CaCl2), P2O5, K2O, organic matter, C %, N %, texture, exchangeable 
cations, exchangeable hydrogen, the sum of cations, cation exchange capacity (CEC) and 
base saturation.  
 
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Kadunc, A., Kotar, M.: Factors influencing growth of mature sycamore … 
 
The gathered soil data enabled us to model the values of air capacity (expressed in % of 
soil volume), plant available water and field capacity for each soil horizon on all the 
plots. The model was based on the procedure developed by FINNERN et al. (1994). The 
water-soil characteristics were modelled for cambic horizons (hereafter: Bhor). These 
horizons are most appropriate for the comparison of the plots, since they are highly 
objective with regard to water-soil characteristics.  
 
Furthermore, the soil depth on each plot was measured by means of 25 systematically 
scattered points. The maximum depth of penetration was 80 cm. If stones or rocks 
stopped the probing before reaching a depth of 80 cm, we recorded the maximum depth 
that had been reached. In this research, variable depth is defined as the share of soil 
without rocks to a depth of 80 cm. Moreover, the surface stoniness of plots was 
determined through estimations of stoniness in percentages on 25 subplots - measuring 1 
square meter each - arranged systematically on each plot. 
 
Additionally, the quantity of soil organic layers (hereafter: forest floor) on each plot was 
systematically sampled (26 points per plot; at each point the material was sampled within 
the square of 25 x 25 cm). The material was dried at 105 ºC and weighed.  
 
Four litter traps were put out on each plot in order to perform litter sampling. The inner 
surface of litter traps totalled 0.5 m2. The litter from the four traps on one plot was put 
together and then dried at 105 ºC and weighed.  
 
At the end of November we put bags with cellulose (bleached cellulose of beech) 
systematically under the forest floor in order to specify the speed of decomposition on 
two plots of each location (8 plots altogether). Nine bags per plot were sampled after 12 
months. By weighing the cellulose before putting it on plots and after picking it up, we 
were able to determine the share of non-decomposed cellulose. 
 
For foliar analyses the procedure was based on methods proposed by UN ECE-ICP 
(1994). In the second half of August and in the first days of September (before yellowing 
of sycamore leaves), the leaves of five thickest sycamore trees from each plot were 
sampled. The share of an individual tree in the composite sample of each plot was in 
proportion to its share in the total crown surface. The crown surface of each tree was 
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Zbornik gozdarstva in lesarstva, 78 
 
calculated with the formula for the surface of a quadratic paraboloid, using mean crown 
diameter and crown length in calculations.  
 
The concentrations of C, N, Ca, Mg, K and P in leaves were determined in the laboratory 
using the methods proposed by ECE-ICP (1993).  
 
To indicate the nutrient cycling rate, Olson's formula, which represents the ratio between 
the annual litter and the quantity of forest floor, was used. The inverse ratio is called the 
turnover time. 
 
For growth analyses, four thickest sycamore trees were cut down on each plot. A stem 
analysis was made for each analysed tree. Moreover, stem discs taken at breast height 
were also dendrochronologically analysed. Dendrochronological analyses were 
performed with digital positiometer (produced by L. Kutschenreiter) in four directions on 
each stem disc.  
 
For regression analyses of height and diameter growth, the function of Chapman-Richard 
(ZEIDE 1993) was used.  
 
The statistical analyses were carried out in an SPSS program (version 12.0.1 for 
Windows). The level of statistical significance is 5 % (P = 0.05).  
 
Before making any correlation analysis between growth and stand-site factors, the 
influence of different ages and different past management actions should be eliminated 
(i.e. using partial correlation).  
 
2.3 GROWTH DESCRIPTORS 
RASTNI DESKRIPTORJI 
 
The average height of four thickest sycamore trees on each plot at 80 years of age (site 
index at 80 years of age; hereafter: SI80) was used as a growth descriptor for the 
collective of trees, which indicate SP. 80 years was the highest age achieved (rounded 
off) by the analysed trees on all the plots. As additional descriptors (growth descriptors) 
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Kadunc, A., Kotar, M.: Factors influencing growth of mature sycamore … 
 
we used the height and basal area increment for trees (mean value of four individuals per 
plot) in the last 10 years (hereafter: HI10 and BAI10).  
 
As to obvious differences in the age of sycamore on the plots (Table 2), we tested the 
statistical significance in growth descriptors between the locations by using the 
covariance analysis (hereafter: Covar; age is the covariate). All the descriptors 
significantly differ between locations (SI80, P = 0.003; HI10, P = 0.000 and BAI10, P = 
0.001). Furthermore, after the exclusion of stand density influence (Nha-1; this variable 
and the age were covariates), we again ascertained significant differences between 
locations for all growth descriptors (SI80, P = 0.006; HI10, P = 0.001 and BAI10, P = 
0.003).  
 
Table 2: Basic parameters of growth descriptors and age of sycamore by 
analysed location  
Preglednica 2: Osnovni parametri rastnih deskriptorjev in starosti po lokacijah 
Growth descriptor / 
Rastni deskriptor 
Parameter Brezova 
reber 
Jauhe Konjice Strmec 
Mean / Povpreje 26.21 24.23 25.64 22.66 
Std. Dev. / St. odklon 3.9720 0.7170 1.3328 3.4752 
Std. Error / St. napaka 1.7763 0.3207 0.5960 1.5542 
SI80 
(m) 
Min / Max 22.60/30.61 23.41/25.34 23.67/27.15 18.98/26.72 
Mean / Povpreje 2.11 1.67 1.80 1.33 
Std. Dev. / St. odklon 0.2528 0.1861 0.3943 0.2615 
Std. Error / St. napaka 0.1131 0.0832 0.1763 0.1169 
HI10  
(m/10year) 
Min / Max 1.79/2.36 1.53/1.99 1.32/2.28 1.11/1.66 
Mean / Povpreje 1.71 1.55 3.17 1.43 
Std. Dev. / St. odklon 0.4532 0.2771 0.8220 0.5526 
Std. Error / St. napaka 0.2027 0.1239 0.3676 0.2471 
BAI10  
(dm2/10year) 
Min / Max 1.05/2.18 1.18/1.89 2.34/4.08 0.87/2.17 
Mean / Povpreje 95.7 90.0 130.7 129.5 
Std. Dev. / St. odklon 13.471 1.961 6.093 42.152 
Std. Error / St. napaka 6.0246 0.8768 2.7249 18.8509 
Age / Starost 
(year) 
Min / Max 80.3/107.0 88.0/93.3 122.5/137.5 90.7/193.3 
 
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Zbornik gozdarstva in lesarstva, 78 
 
3 RESULTS 
REZULTATI 
 
3.1 INFLUENCE OF STAND PARAMETERS ON GROWTH POTENTIAL 
VPLIV SESTOJNIH PARAMETROV NA RASTNI POTENCIAL 
 
In order to establish which stand parameter influences growth descriptors most strongly, 
we tested the relations (partial correlations; age is the covariate) between growing stock 
(m3ha-1), basal area (m2ha-1), stand density (Nha-1), crown projection area (%) and growth 
descriptors. Only two significant correlations were confirmed. The relationship between 
BAI10 and stand density (r = -0.587; P = 0.008) is quite logical (fewer trees means larger 
crowns, larger crowns provide for higher increment), while the correlation between SI80 
and stand density (r = -0.622; P = 0.004) is probably a result of certain favourable site 
conditions on the plots with low density (despite the lowest felling intensities, which 
were found on valuable-broadleaved tree-species sites). Otherwise, low stand density 
destimulates height growth, which is reflected in lower site indices. 
 
Furthermore, the correlation between growth descriptors and age was tested. Only one 
significant relationship was confirmed by the exclusion of stand density influence (partial 
correlation). The negative connection between age and SI80 (r = -0.758; P = 0.000; 
locations with low or high mean site index are equally distributed among younger and 
older collectives) signifies that younger collectives of dominant sycamore trees achieved 
higher site indices.  
 
Before testing the correlations between growth descriptors and crown parameters, the 
influence of age and different stand densities on the plots was eliminated (Table 3). The 
last column on the right includes information about (non)significant differences of crown 
parameters between locations.  
 
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Kadunc, A., Kotar, M.: Factors influencing growth of mature sycamore … 
 
Table 3: Partial correlation coefficients between growth descriptors and crown 
parameters  
Preglednica 3: Parcialni korelacijski koeficienti med rastnimi deskriptorji in parametri 
krošnje 
 
Growth descriptor / Rastni 
deskriptor 
Crown parameter / Parameter 
krošnje 
SI80 HI10 BAI10 
Covar (age and stand density are 
covariates) / Kovarianca (starost 
in gostota sestoja sta kovariati) 
Mean diameter (m) / Povp. premer 0.392 0.022 0.743*** 0.010** 
Surface (m2) / Površina 0.306 0.059 0.782*** 0.010** 
Volume (m3) / Volumen 0.317 0.054 0.787*** 0.026* 
Length (m) / Dolžina 0.181 0.112 0.722*** 0.024* 
Ratio surface/volume (m2m-3) / 
Razmerje površina/volumen -0.242 -0.186 -0.572* 0.114 
 
Obviously, only basal area increment correlates with each and every crown parameter 
(Table 3). The conclusion from the results is that the influence of different past 
management actions - reflected in different stand densities - should only be eliminated in 
further correlations with basal area increment, since only this descriptor significantly 
correlates with crown parameters. Therefore, in the following analyses the age factor will 
be excluded in correlations to all growth descriptors, while the stand density factor will 
be eliminated only in correlations with basal area increment.  
 
In addition, the differences between locations with regard to crown dimensions 
considering the eliminated age and density are quite astonishing. Evidently, the crown 
dimensions of sycamore are at least partly dependent on site characteristics. 
 
3.2 INFLUENCE OF NUTRIENT SUPPLY AND RATE OF NUTRIENT 
CYCLING ON GROWTH POTENTIAL 
VPLIV PRESKRBE S HRANILI IN HITROSTI KROŽENJA SNOVI NA 
RASTNI POTENCIAL 
 
Evidently, only phosphorus concentration indicates higher SP (SI80) and even higher 
recent basal area increment (Table 4). Interestingly enough, in spite of similar soil types 
there are significant differences in calcium supplies between locations. 
 
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Zbornik gozdarstva in lesarstva, 78 
 
Moreover, the higher rate of nutrient cycling (higher values of ratio annual litter/forest 
floor) and higher values of annual litter per growing stock (in some way representing the 
dynamics of nutrient cycling as well) indicate faster height growth.  
 
Table 4: Partial correlation coefficients between growth descriptors and 
macronutrient concentrations in leaves or indicators of nutrient cycling 
rate 
Preglednica 4: Parcialni korelacijski koeficienti med rastnimi deskriptorji in 
koncentracijami makrohranil v listih oziroma indikatorji hitrosti 
kroženja hranil 
Growth descriptor / Rastni 
deskriptor 
Macronutrient or indicator of nutrient 
cycling rate / Makrohranilo oziroma 
indikator hitrosti kroženja snovi SI80 HI10 BAI10 
Covar (age = 
covariate) / 
Kovarianca (starost 
je kovariata) 
N % 0.047 0.278 0.040 0.003** 
P % 0.494* 0.231 0.601** 0.002** 
K % 0.446 0.111 0.130 0.313 
Ca % -0.056 0.431 0.123 0.024* 
Mg % 0.040 0.014 0.127 0.456 
% of non-decomposed cellulose after 12 
months / % nerazgrajene celuloze po 12 
mesecih 
-0.014 -0.298 -0.664 0.961a 
Annual litter per growing stock (tm-3) / Letni 
opad glede na lesno zalogo 0.055 0.462* 0.156 0.172 
Ratio annual litter/forest floor (%) / 
Razmerje letni opad/organski talni horizonti 0.048 0.482* -0.066 0.051 
a – Kruskal-Wallis test 
 
Furthermore, we tested the existence of correlations between growth descriptors and the 
following nutrient relations or ratios: C/N, N/P, N/K, N/Mg, N/Ca, P/Mg, Ca/K, Ca/Mg, 
Ca+Mg, K+P, N+P, N+K, Mg+Ca+K, N+P+K, Mg+Ca+K+P, Mg+Ca+K+P+N. Due to 
the extensive list of correlated pairs of variables, only the significant ones are given 
below: 
- SI80 and N/P (r = -0.550; P = 0.015), 
- SI80 and K+P (r = 0.505; P = 0.028), 
- HI10 and Mg+Ca+K+P+N (r = 0.463; P = 0.046), 
- BAI10 and N/P (r = -0.520; P = 0.027). 
 
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Kadunc, A., Kotar, M.: Factors influencing growth of mature sycamore … 
 
A great importance of nitrogen/phosphorus ratio is detected from the results. Lower 
values of this ratio are reflected in higher basal area growth, as well as in higher site 
indices. Moreover, the positive importance of potassium for SI80 is indicated. The most 
unclear connections concern height growth. It is quite likely that the analysed stands are 
too old for a sensitive reaction of height increment to nutrient supply.  
 
3.3 INFLUENCE OF SOIL PROPERTIES ON GROWTH POTENTIAL 
VPLIV LASTNOSTI TAL NA RASTNI POTENCIAL 
 
The relation between growth descriptors and the most important parameters of the A 
horizon (hereafter: Ahor) was tested. The influence of Ahor parameters on the growth 
process of mature sycamore trees in the analysed locations is small (Table 5). The 
positive influence of calcium or base saturation on recent basal area increment, however, 
is an exception.  
 
Table 5: Partial correlation coefficients between growth descriptors and 
parameters of Ahor 
Preglednica 5: Parcialni korelacijski koeficienti med rastnimi deskriptorji in parametri 
A horizonta 
Growth descriptor / Rastni deskriptor Soil parameter (Ahor) / Talni 
parameter (Ahor)  SI80 HI10 BAI10 
ANOVA between locations / 
ANOVA med lokacijami 
Volume (m3ha-1) / Volumen 0.362 0.081 0.199 0.013* 
pH 0.409 -0.043 0.436 0.109 
C/N ratio / C/N razmerje -0.337 -0.243 0.225 0.139 
N (%) 0.122 0.139 0.365 0.286 
P2O5 (mgg
-1) -0.234 0.077 -0.010 0.710 
K2O (mgg
-1) 0.188 -0.031 0.415 0.807 
Ca (eq mmol H/100g) 0.193 -0.063 0.491* 0.125 
Mg (eq mmol H/100g) 0.341 0.176 0.381 0.434 
K (eq mmol H/100g)  0.331 -0.097 0.420 0.466 
Na (eq mmol H/100g) 0.159 0.099 0.167 0.367 
V (%) 0.352 -0.071 0.474* 0.132 
 
Furthermore, we tried to ascertain the influences of soil depth, surface stoniness and the 
most important parameters of Bhor. Except for three texture classes, soil depth is the only 
parameter that significantly differs between locations (Table 6). This parameter strongly 
influences SP (SI80). Surprisingly enough, surface stoniness does not influence growth, in 
spite of its correlation with soil depth (r = -0.514; P = 0.020). Basal area increment is 
110 
Zbornik gozdarstva in lesarstva, 78 
 
dependent on the ratio between air capacity and plant available water in Bhor. The share of 
sand positively correlates with recent height increment, and the share of coarse silt is in 
positive connection with SI80, while the share of fine silt negatively influences recent 
basal area increment.  
 
Table 6: Partial correlation coefficients between growth descriptors and soil 
depth, surface stoniness and parameters of Bhor  
Preglednica 6: Parcialni korelacijski koeficienti med rastnimi deskriptorji in globino 
tal, površinsko skalovitostjo in parametri B horizonta  
Growth descriptor / Rastni deskriptor Soil parameter / Talni parameter 
SI80 HI10 BAI10 
ANOVA between locations 
/ ANOVA med lokacijami 
Soil depth / Globina tal 0.642** 0.363 0.436 0.000*** 
Surface stoniness (%) / Površinska 
skalovitost -0.303 -0.256 0.414 0.139 
Air capacity (%); Bhor / Kapaciteta 
tal za zrak  -0.103 -0.040 -0.458 0.133 
Plant available water (%); Bhor / 
Rastlinam dostopna voda 0.096 -0.116 -0.009 0.076 
Ratio air capacity of soil/plant 
available water; Bhor / Razmerje 
med kapaciteto tal za zrak in 
rastlinam dostopno vodo 
-0.217 0.010 -0.532* 0.678 
V (%); Bhor 0.004 -0.118 0.304 0.141 
Sand (%); Bhor / Pesek  -0.125 0.573* -0.104 0.306 
Coarse silt (%); Bhor / Grobi melj 0.572* 0.066 0.428 0.001*** 
Fine silt (%); Bhor / Fini melj -0.026 -0.040 -0.568* 0.022* 
Clay (%); Bhor / Glina  -0.223 -0.288 0.354 0.002** 
 
 
4 DISCUSSION  
RAZPRAVA 
 
4.1 ESTIMATION OF SITE PRODUCTIVITY 
OCENJEVANJE PROIZVODNE SPOSOBNOSTI 
 
SP is basically defined as timber production potential on a particular site type for a 
particular tree species or forest type in one rotation period (SPIECKER et al. 1994). 
There are two problems that make this research approach to establish SP regarding 
sycamore rather impossible. First, unmanaged (virgin) forests, particularly on better sites, 
are an exceptional rarity in Central Europe, where destructive analyses are forbidden for 
111 
Kadunc, A., Kotar, M.: Factors influencing growth of mature sycamore … 
 
understandable reasons. Second, sycamore is mostly an admixed tree species, its pure 
stands are rather small and restricted to special (micro)sites, therefore it is hard to study 
SP indicators at the stand level.  
 
SP can be estimated by using different methods or approaches (KIMMINS 1997; 
SPIECKER et al. 1994). Total volume production of woody mass at the culmination 
point of mean volume increment of a stand, whose structure was not influenced by man, 
is theoretically an optimal indicator. Other indicators of SP are as follows: top height at 
definite age (usually 100 years), estimations based on maximum densities, soil properties 
(often in combination with topographic and climatic factors), tree nutrient supply, 
(quantified) ground vegetation, and fertilization trials in combination with visual 
symptoms estimation (KIMMINS 1997; SPIECKER et al. 1994). Along with these 
methods, the growth characteristics (trends, correlations with stand or site parameters 
etc.) can be analysed by means of permanent plots, dendroecological analyses (single tree 
data) and inventory data (SPIECKER et al. 1996). A very promising approach to 
understanding the (dynamic) relationships between growth and site is to relate changes in 
nutrient availability and uptake with growth variables (REHFUESS et al. 1999). 
Unfortunately, the majority of these options were not available to us.  
 
In order to study the relationship between growth and stand or site characteristics, the top 
height of dominant sycamore trees seemed to be the best available method to estimate SP. 
Another promising and available method is the evaluation of ground vegetation as a 
bioindicator of productivity, but unfortunately it is not improved enough at present 
(KADUNC 2003). It turned out that on the plots with admixed sycamore only four trees 
of the studied species per plot (they were also the thickest sycamores) belonged to the 
collective of dominant trees in stand canopies.  
 
Top height or height development patterns of dominant trees in even-aged stands are little 
affected by silvicultural interventions, except by thinning from above (SPIECKER et al. 
1994). This type of thinning was applied on some locations included in the present 
research, but sycamore trees were preserved. Consequently, it can be claimed with high 
probability that the analysed trees were the thickest during all their lifetime. Moreover, 
thinning from above destimulates height growth of the released trees, because they are 
allowed to increase their crown growth in width. Our results show, however, that stands 
112 
Zbornik gozdarstva in lesarstva, 78 
 
with lower density achieved higher values of SI80, which could be explained by naturally 
lower initial stand density on high productive valuable-broadleaved sites (DIACI 1997). 
A detailed analysis at a single tree level reveals that correlations between crown diameter 
and height at 80 years of age by location (influence of age was statistically eliminated) 
are not significant in any location. On that basis the effects of crown release on top height 
development of dominant trees can be rejected, at least within this research. 
 
In the last decade, SP changes have been discussed quite intensively (e.g. SPIECKER et 
al. 1996). For Central Europe it has prevailed that in the majority of sites SP has 
increased (SPIECKER et al. 1996; DITTMAR / ZECH / ELLING 2003). Our results 
indicate positive growth trends (younger collectives had higher values of SI80), which is 
in accordance with the above-mentioned researches in European and Slovenian studies as 
well (KOTAR 2002). 
 
4.2 INFLUENCING FACTORS 
RASTNI FAKTORJI 
 
Obvious importance of phosphorus regarding SP is in agreement with the findings 
proposed by WEBER / BAHR (2000a), which pointed out the deficiency problem with 
phosphorus on carbonate rock (due to Ca-phosphates). Our results are, however, in 
contradiction with the statements made by FRANC / RUCHAUD (1996), who detected 
sycamore tolerance to phosphorus deficiency (except in forest nurseries). Furthermore, 
they stressed the importance of a good supply of potassium, which is in accordance with 
our results, and the importance of nitrates. Our research, however, did not confirm the 
explicit role of nitrogen in sycamore growth. The undetected relationship between growth 
and nitrogen could be due to methodological reasons. BAUER et al. (2000) establish that 
the net above-ground primary production of spruce and beech stands correlates with 
nitrogen content in crowns (g Nm-2), but not with nitrogen concentration in leaves.  
 
As to the first hypothesis, it is obvious that optimal nitrogen concentration depends 
mostly on available phosphorus, while the importance of sufficient water supply could be 
indirectly linked to soil depth. Deeper soil means larger water supplies and slower 
outflow of water. Nevertheless, the first hypothesis about nitrogen soil concentration and 
plant available water as the key factors for SP could not be accepted within the frames of 
113 
Kadunc, A., Kotar, M.: Factors influencing growth of mature sycamore … 
 
this research. The analysed site conditions are very likely to provide a sufficient supply of 
nitrogen. An excess nitrogen supply of trees may also be associated with a reduction in 
growth (KENNEL / WEHRMANN 1967). Moreover, no direct influence of plant 
available water was detected, despite frequent dry conditions on karst soils during 
summers. 
 
With regard to height increments, extremely few correlations were confirmed. 
HENNECKE (1977) mentions that water supply or favourable microsite conditions have 
an extremely strong influence on sycamore height growth. Similar conclusions were 
drawn by HÖLSCHER / SCHMITT / KUPFER (2002). According to them, water supply 
results in decreasing height growth of sycamore seedlings along slope gradient (upper 
parts of the slope had the poorest water supply). In addition, insufficient water supply 
restricted the uptake of soil nutrients, despite their sufficient concentrations (ibidem.). 
Our results, however, did not confirm the connection between height growth and water 
conditions in soil. The research done by WEBER / BAHR (2000a) states the importance 
of base saturation for favourable height growth of sycamore trees, which is not in 
accordance with our results. We studied growth of mature sycamore trees on a limited 
range of soil types, while the research done by WEBER / BAHR (2000a) was carried out 
on a wider range of soils and with young trees (5-10 years). Moreover, the positive 
relationship between nitrogen supply in leaves and height growth was confirmed in 
WEBER / BAHR's research (2000a) as well. Our research, however, did not confirm the 
role of nitrogen in sycamore growth. A possible explanation might be the higher age of 
analysed trees compared to the age of analysed trees included in WEBER / BAHR's 
research (2000a), despite the similarity of nitrogen concentration in leaves (1.3 – 2.6 %). 
In contrast to WEBER / BAHR (2000a), our research did not establish the role of 
magnesium in height growth, possibly due to the fact that there was no lack of 
magnesium on any of the research plots.  
 
From the results it can be concluded that the response of the height growth of mature 
sycamore trees to site factors and stand conditions is extraordinarily modest. Evidently, 
growth is in decline and it is strongly dependent on age. To conclude, the second 
hypothesis can not be accepted. 
 
114 
Zbornik gozdarstva in lesarstva, 78 
 
With regard to the growth of basal area, many significant connections were confirmed. 
Basal area increment is positively dependent on diameter, surface, volume and crown 
length. The established negative relationship between basal area increment and ratio of 
crown surface to crown volume does not correspond to the findings made by PRETZSCH 
(1992). He cites that a higher ratio of crown surface to volume positively influences the 
increment due to a better ratio between photosynthesis (surface) and respiration (volume). 
Our results could be explained by a less advantageous ratio between sunny and shady 
leaves as a response to a bigger amount of foliage. Mature sycamore is more light 
demanding and this ratio could be crucial for its growth potential. It is also well known 
that yield starts to decrease if the leaf area index (LAI) is too large (e.g. KIMMINS 1997; 
KOZLOWSKY / PALLARDY 1997; MARSCHNER 1998).  
 
It is logical that stands with lower density provided higher basal area increments in the 
last 10 years. Our results, however, do not accord well with the conclusions of a Danish 
experiment, which points out a very restricted response of radial growth to stand density 
reductions of 40-year stands (PLAUBORG 2004). Thinning from below could be an 
explanation for the poor response of relatively young stands. 
 
The importance of base saturation and calcium concentration for recent basal area 
increment is slightly surprising due to a very narrow range of soil types included in the 
research. The role of base saturation was already stressed in WEBER's research (1999), 
but for substantially younger individuals.  
 
Evidently, basal area increment responds quite intensively to site factors and stand 
conditions. Diameter growth dies away much later than height growth does. The 
hypothesis that basal area increment depends only on crown dimensions is rejected. In 
contrast to that, HEIN (2004) does not confirm the dependence between ring width and 
site quality, which might be due to uneliminated factors (e.g. stand density).  
 
Furthermore, it also turned out that the role of soil parameters was much less evident on 
the limited range of analysed soil types than it could be on a wider group of included 
soils. In our case some other factors can be more strongly expressed. The weakness of SP 
or growth potential estimation based on soil properties is that analytical methods of soil 
115 
Kadunc, A., Kotar, M.: Factors influencing growth of mature sycamore … 
 
research only give a static picture. In addition, these methods do not include downslope 
seepage, which importantly increases SP of lower situated sites (KLINKA 1976).  
 
Finally, it must be stressed that our research was carried out in real forest conditions, 
where the great complexity of interactions is impossible to control. Consequently, the 
interpretations of results demand the highest degree of caution. The maturity of analysed 
trees and the fact that the research was restricted to carbonate bedrock sites allow only 
partial comparisons with the majority of other researches dealing with sycamore.  
 
 
5 POVZETEK  
 
Namen prispevka je ugotoviti vpliv rastiš
nih dejavnikov oziroma sestojnih parametrov 
na rast odraslega gorskega javorja (Acer pseudoplatanus L.). Raziskavo smo izpeljali na 
štirih tipih gozdnih rastiš
. Omejili smo se na karbonatno mati
no podlago. Za vsak 
rastiš
ni tip smo napravili pet ponovitev, z drugimi besedami, analizirali smo po pet 
ploskev za posamezen rastiš
ni tip. Prvi tip leži na rastiš
u združbe Aceri-Fraxinetum ill. 
(lokacija Konjice), kjer v sestoju prevladuje gorski javor. Naslednji rastiš
ni tip smo 
analizirali v fitocenozah, ki jih uvrš
amo v okvir združbe Lamio orvalae-Fagetum, v teh 
sestojih je prevladovala bukev (lokacija Brezova reber). Tudi tretji tip leži v okviru iste 
združbe, vendar v sestoju prevladuje (umetno vnešena) smreka (lokacija Jauhe). Zadnji 
tip smo analizirali na rastiš
ih združbe Omphalodo-Fagetum aceretosum (lokacija 
Strmec). Skupno smo torej zajeli 20 ploskev v velikosti 30 x 30 m.  
 
Na vseh ploskvah smo analizirali strukturo sestoja, vsem nadmerskim drevesom (prsni 
premer nad 10 cm) smo izmerili prsni premer, višino, višino pri
etka krošnje in osem 
polmerov projekcije krošnje. Na podlagi teh meritev smo izra
unali površino in volumen 
ter srednji premer krošnje. Nadalje smo na vsaki ploskvi izkopali talni profil in napravili 
klasi
no pedološko analizo po talnih horizontih. V laboratoriju smo dolo
ili: pH (CaCl2), 
P2O5, K2O, organsko snov, % ogljika, % dušika, teksturo, izmenljive katione, izmenljiv 
vodik, KIK in stopnjo nasi
enosti z bazami. Na podlagi teh podatkov smo s pomo
jo 
nemškega modela (FINNERN et al. 1994) zmodelirali vrednosti za kapaciteto tal za zrak 
in rastlinam dostopno vodo po horizontih in ploskvah. Na vseh ploskvah smo s 
sistemati
nim vzor
enjem ugotovili tudi globino tal, površinsko skalovitost, koli
ino 
116 
Zbornik gozdarstva in lesarstva, 78 
 
organskih talnih horizontov in koli
ino nadzemnega opada. S pomo
jo položenih 
vzor
nih enot celuloze smo ocenili hitrost razgradnje v tleh. Nadalje smo pri dominantnih 
gorskih javorjih s foliarnimi analizami ugotovili preskrbljenost le-teh z makrohranili. Na 
koncu smo na vsaki ploskvi podrli po štiri najdebelejše javorje in na njih opravili debelne 
analize. Tako smo ugotovili višinsko in debelinsko rast. Na podlagi doseženih višin 
gorskih javorjev pri 80 letih smo definirali proizvodno sposobnost rastiš
 za obravnavano 
drevesno vrsto. Kot indikator rasti pri odraslem javorju smo izbrali višinski prirastek v 
zadnjih 10 letih (HI10), temeljni
ni prirastek v zadnjih 10 letih (BAI10) in povpre
no 
višino analiziranih štirih osebkov na ploskvi pri 80 letih (rastiš
ni indeks; SI80).  
 
Ker se je starost dreves razlikovala med ploskvami in lokacijami in ker se lokacije 
razlikujejo glede preteklega gospodarjenja (jakost poseganj), smo vpliv teh spremenljivk 
(starost in gostota sestoja) odstranili, kjer je bilo to primerno.  
 
Po pri
akovanju smo potrdili pozitivni vpliv premera, površine, volumna in dolžine 
krošnje na temeljni
ni prirastek. Razmerje med površino in volumnom krošnje pa vpliva 
negativno na velikost temeljni
nega prirastka. To je najverjetneje posledica neugodnega 
razmerja med son
nimi in sen
nimi listi, saj gorski javor v zrelem obdobju postaja vse 
bolj zahteven glede svetlobe. 
 
Vpliva preskrbljenosti z dušikom na rast presenetljivo nismo ugotovili, izkazal pa se je 
velik pomen fosforja, ki ga na karbonatni mati
ni podlagi praviloma primanjkuje in zato 
pove
uje tako proizvodno sposobnost rastiš
a kot tudi temeljni
no rast pri gorskem 
javorju. Na tleh s hitrejšo razgradnjo oziroma hitrejšim kroženjem hranil je višji višinski 
prirastek.  
 
Vpliv karakteristik A horizonta na rast odraslih javorjev je relativno skromen, nekoliko 
presenetljivo smo potrdili le pozitivni vpliv nasi
enosti z bazami oziroma koncentracije 
kalcija na temeljni
no rast. Pa
 pa je proizvodna sposobnost mo
no povezana z globino 
tal, kjer globlja tla nakazujejo boljšo produktivnost. Ta je ve
ja tudi pri višjih deležih 
grobega melja v kambi
nem horizontu. Z višjimi deleži peš
ene frakcije v taistem 
horizontu pa se dosega ve
ji višinski prirastek. Temeljni
ni prirastek je v negativni 
povezavi z deležem finega melja v kambi
nem horizontu in z razmerjem med kapaciteto 
tal za zrak ter rastlinam dostopno vodo.  
117 
Kadunc, A., Kotar, M.: Factors influencing growth of mature sycamore … 
 
 
Izkazalo se je, da pri odraslem javorju temeljni
ni prirastek še (mo
no) reagira na 
parametre sestoja (gostota, katere posledica so ve
je ali manjše krošnje) in dejavnike 
rastiš
a. V nasprotju s tem pa je rast v višino pod mo
nejšim nadzorom starosti in le 
šibko odseva razmere.  
 
Raziskava je pokazala tudi na razmeroma šibko vlogo talnih parametrov, kar je v najve
ji 
meri posledica ozkega ekološkega intervala analize.  
 
Dodati je treba, da je raziskava potekala v realnih gozdnih razmerah in pri odraslem 
drevju, kjer je nemogo
e izlo
iti vpliv kompleksa interakcij. Omejenost prispevka na 
karbonatno mati
no podlago narekuje tudi veliko previdnost pri prenosu rezultatov 
oziroma zaklju
kov.  
 
 
6 REFERENCES 
VIRI 
 
AREND, T., 1982. Untersuchungen zum Höhenwachstum von Bergahorn im Vergleich 
mit Esche in vier verschieden alten Mischbeständen. Diplomarbeit, Göttingen, 
Forstliche Fakultät der Universität Göttingen, 62 s. 
BAUER, G. A. / PERSSON, H. / PERSSON, T. / MUND, M. / HEIN, M. / 
KUMMETZ, E. / MATTEUCI, G. / OENE, H. von / SCARASCIA-
MUGNOZZA, G. / SCHULZE, E. D., 2000. Linking Plant Nutrition and 
Ecosystem Processes. In: SCHULZE ED (ed) Carbon and Nitrogen Cycling 
in European Forest Ecosystems. Ecological Studies, 142, Springer Verlag, 
Berlin Heidelberg New York Barcelona Hong Kong London Milan Paris 
Singapore Tokyo: 63-98. 
BRAUN, H., 1976. Rhythmus und Grösse von Wachstum, Wasserverbrauch und 
Produktivität des Wasserverbrauchs bei Holzpflanzen. Allgemeine Forst- und 
Jagdzeitung, 147, 8: 163-168. 
CORNELISSEN, J. H. C. / CARNELLI, A. L. / CALLAGHAN, T. V., 1999. 
Generalities in the growth, allocation and leaf quality response to elevated 
CO2 in eight woody species. New Phytologist 141, 3: 401-409. 
118 
Zbornik gozdarstva in lesarstva, 78 
 
DIACI, J., 1997. Experimentelle Felduntersuchungen zur Naturverjüngung 
künstlicher Fichtenwälder auf Tannen-Buchenwaldstandorten (Homogyno 
sylvestris-Fagetum) in den Savinja-Alpen (Slowenien) mit besonderer 
Berücksichtung der Ansamungsphase und unter dem Einfluss der Faktoren 
Licht, Vegetation, Humus und Kleinsäuger. Beiheft zur Schweizerischen 
Zeitschrift für Forstwesen 80, Zürich, 197 s. 
DITTMAR, C. / ZECH, W. / ELLING, W., 2003. Growth variations of Common 
beech (Fagus sylvatica L.) under different climatic and environmental 
conditions in Europe - A dendroecological study. Forest Ecology and 
Management 173, 1-3: 63-78.  
ECE-ICP, 1993. Manual for Integrated Monitoring. Programme Phase 1993-
1996. Helsinki, UN ECE-ICP, Environment Data Center, National Board of 
Waters and the Environment, 114 s. 
EIBERLE, K., 1985. Bergahorn und Esche: Belastungsgrenzen für den 
Wilderviss. Schweizerische Zeitschrift für Forstwesen 136: 849-856. 
FAUST, H., 1963. Waldbauliche Untersuchungen am Bergahorn in 
mitteldeutschen Muschelkalkgebiet, im hessischen Basaltbergland und in 
den süddeutschen Rheinauen. Dissertation, Hann. Münden, Forstliche 
Fakultät der Georg-August-Universität zu Göttingen, 146 s.  
FELIKSIK, E. / NIEDZIELSKA, B. / WILCZYNSKI, S., 2000. Proba oceny 
oddziaywania opadow atmosferycznych i temperatury powietrza na przyrost 
grubosci jaworu (Acer pseudoplatanus L.). Sylwan 144, 6: 63-72. 
FINNERN, H. / GROTTENTHALER, W. / KÜHN, D. / PÄLCHEN, W. / 
SCHRAPS, W. / SPONAGEL, H., 1994. Bodenkundliche Kartieranleitung. 
E. Schweizerbart’sche Verlagsbuchhandlung, Hannover, 392 s.  
FRANC, A. / RUCHAUD, F., 1996. Autécologie des feuilles précieux: frêne 
commun, merisier, érable sycomore, érable plane. Cemagref, Riom, 170 s.  
GADOW, A. von, 1975. Ökologische Untersuchungen an Ahorn-Eschenwäldern. 
Dissertation, Göttingen, Mathematisch-Naturwissenschaftliche Fakultät der 
Georg-August-Universität zu Göttingen, 76 s.  
HEGI, G., 1927. Illustrierte Flora von Mittel-Europa. Band V, 1. Teil, München, 
Carl Hanser Verlag München: 274-280. 
119 
Kadunc, A., Kotar, M.: Factors influencing growth of mature sycamore … 
 
HEIN, S., 2004. Zur Steuerung von Astreinigung und Dickenwachstum bei Esche 
(Fraxinus excelsior L.) und Ahorn (Acer pseudoplatanus L.). Freiburg 
(Breisgau): Albert-Ludwigs-Universität und Forstliche Versuchs- und 
Forschungsanstalt Baden-Württemberg, Schriftenreihe Freiburger Forstliche 
Forschung; Band 25, 200 s.  
HELLIWELL, D. R., 1965. Factors influencing the growth of Sycamore and 
Norway maple. Quarterly Journal of Forestry 59: 327-337. 
HENNECKE, W., 1977. Untersuchungen über das Jugendwachstum von 
Bergahorn im Vergleich zu Buche in künstlich begründeten 
Mischbeständen. Diplomarbeit. Forstliche Fakultät der Universität 
Göttingen, Göttingen, 56 s.  
HOFFMANN, E., 1960. Der Ahorn. VEB Deutscher Landwirtschaftsverlag, 190 s.  
HÖLSCHER, D. / SCMITT, S. / KUPFER, K., 2002. Growth and Leaf Traits of 
Four Broad-Leaved Tree Species along a Hillside Gradient. 
Forstwissenschaftliches Centralblatt 121: 229-239. 
JÖRNS, O., 2000. Holzmesskundlich-ertragskundliche Untersuchungen an 
Bergahorn (Acer pseudoplatanus L.). Beiträge für die Forstwirtschaft und 
Landschaftsökologie 34, 2: 81-82. 
KADUNC, A., 2003. Vloga gorskega javorja (Acer pseudoplatanus L.) v 
gozdnih ekosistemih. Disertacija, Univerza v Ljubljani, Ljubljana, 196 s.  
KENNEL, R. / WEHRMANN, J., 1967. Ergebnis eines Düngungsversuchs mit 
extrem hohen Stickstoffgaben in einem Kiefernbestand geringer Bonität. 
Proceedings XIV. IUFRO-Congress Referate VI. Deutscher Verband 
Forstliche Forschungsanstalten, Munich: 216-231. 
KIMMINS, J. P., 1997. Forest ecology. Prentice-Hall, Second Edition, New 
Jersey, 596 s.  
KJÖLBY, V. / SABROE, A. / MOLTESEN, P., 1958. AER (Acer 
pseudoplatanus). Dansk Skovforening, Kopenhagen, 126 s.  
KLINKA, K., 1976. Ecosystem units, classification, interpretation and maping in 
the UBC Research Forest, Ph.D. thesis, Univ. of British Columbia, 
Vancouver, 120 s.  
KOTAR, M., 2002. Spremembe proizvodne sposobnosti bukovih gozdov v 
Sloveniji v zadnjih desetletjih. Gozdarski vestnik 60, 4: 179-191.  
120 
Zbornik gozdarstva in lesarstva, 78 
 
KOZLOWSKY, T. T. / PALLARDY, S. G., 1997. Physiology of Woody Plants. 
Second Edition, Academic Press, San Diego, 411 s.  
LYR, H. / DREYER, E. / AUSSENAC, G., 1996. Effect of the root temperature 
on growth parameters of various European tree species. Annales des 
Sciences Forestieres 53, 2-3: 317-323.  
MARSCHNER, H., 1998. Mineral nutrition of Higher Plants. Academic Press, 
Harcourt Brace & Company Publishers, London San Diego New York 
Boston Sydney Tokyo Toronto, 887 s.  
MILLARD, P. / PROE, M. F., 1991. Leaf demography and the seasonal internal 
cycling of nitrogen in sycamore (Acer pseudoplatanus L.) seedlings in 
relation to nitrogen supply. New Phytologhist 117: 587-596. 
NAGEL, J., 1985. Wachstumsmodell für Bergahorn in Schleswig-Holstein. 
Dissertation, Universität Göttingen, 124 s.  
NEIRYNCK, J. / MIRTCHEVA, S. / SIOEN, G. / LUST, N., 2000. Impact of 
Tilia plathyphyllos Scop., Fraxinus excelsior L., Acer pseudoplatanus L., 
Quercus robur L. and Fagus sylvatica L. on earthworm biomass and 
physico-chemical properties of a loamy topsoil. Forest ecology and 
management 133: 275-286.  
NÜSSLEIN, S., 1995. Struktur und Wachstumsdynamik jüngerer Buchen-
Edellaubholz-Mischbestände in Nordbayern. Forstliche Forschungsberichte 
München, Nr. 151, Forstwissenschaftliche Fakultät der Universität 
München, Freising, 295 s.  
OKALI, D. U. U., 1966a. A comparative study of the ecologically related tree 
species Acer pseudoplatanus and Fraxinus excelsior. I. The analysis of 
seedling distribution. Journal of Ecology 54 (1): 129-141. 
OKALI, D. U. U., 1966b. A comparative study of the ecologically related tree 
species Acer pseudoplatanus and Fraxinus excelsior. II. The analysis of 
adult tree distribution. Journal of Ecology 54 (2): 419-425.  
PLAUBORG, K. U., 2004. Analysis of radial growth responses to changes in 
stand density for four tree species. Forest Ecology and Management 188: 
65-75.  
PRETZSCH, H., 1992. Konzeption und Konstruktion von Wuchsmodellen für 
Rein- und Mischbestände. Forstliche Forschungsberichte München, Nr. 115, 
Forstwissenschaftliche Fakultät der Universität München, Freising, 332 s.  
121 
Kadunc, A., Kotar, M.: Factors influencing growth of mature sycamore … 
 
PRETZSCH, H., 2002. Grundlagen der Waldwachstumsforschung. Parey 
Buchverlag, Berlin, 414 s.  
REHFUESS, K. E. / ÅGREN, G. I. / ANDERSSON, F. / CANNELL, M. G. R. / 
FRIEND, A. / HUNTER, I. / KAHLE, H. P. / PRIETZEL, J. / SPIECKER, 
H., 1999. Relationships Between Recent Changes of Growth and Nutrition 
of Norway Spruce, Scots Pine and European Beech Forest in Europe 
(RECOGNITION). European Forest Institute, Working Paper 19, 180 s.  
RÖHRIG, E., 1967. Wachstum junger Laubholzpflanzen bei unterschiedlichen 
Lichtverhältnissen. Allgemeine Forst- und Jagdzeitung 138: 224-239.  
SPETHMANN, W. / NAMVAR, K., 1985. Der Bergahorn und die Gattung Acer. 
Allgemeine Forstzeitschrift 42: 1126-1131.  
SPIECKER, H. / MIELIKÄINEN, K. / KÖHL, M. / UNTHEIM, H., 1994. 
Growth trends in European forests – Has site productivity changed? 
European Forest Institute Working Paper 4, 68 s.  
SPIECKER, H. / MIELIKÄINEN, K. / KÖHL, M. / SKOVSGAARD, J., 1996. 
Growth Trends in European Forests. Studies from 12 Countries. European 
Forest Institute, Research Report No. 5, Springer Verlag, 352 s.  
THIES, M. / HEIN, S., 2000. Expertenbefragung zur Bedeutung und 
Bewirtschaftung von Edellaubbäumen im deutschsprachigen Raum. Sektion 
Ertragskunde im Deutschen Verband Forstlicher Forschungsanstalten, 
Jahrestagung 2000, Kaiserslautern, 5.-7. June 2000: 256-269.  
THOROE, C. / OLLMANN, H., 2001. Die zukünftige Entwicklung des Holzmarktes in 
Deutschland, Europa und weltweit – Chancen für schnellwachsende Baumarten? 
Forst und Holz 56: 75-80.  
UN ECE-ICP Programme Coordinating Centers, 1994. Manual on methods and 
criteria for harmonized sampling, assessment, monitoring and analysis of the 
effects of air pollution on forests, Hamburg  
WEBER, G., 1999. Warum versagen Esche und Bergahorn auf stark versauerten Böden? 
Allgemeine Forstzeitschrift/Der Wald 16: 848-850. 
WEBER, G. / BAHR, B., 2000a. Wachstum und Ernährungszustand junger 
Eschen (Fraxinus excelsior L.) und Bergahorne (Acer pseudoplatanus L.) 
auf Sturmwurfflächen in Bayern in Abhängigheit vom Standort. 
Forstwissenschaftliches Centralblatt 119: 177-192.  
122 
Zbornik gozdarstva in lesarstva, 78 
 
WEBER, G. / BAHR, B., 2000b. Eignung bayerischer Standorte für den Anbau 
von Esche (Fraxinus excelsior L.) und Bergahorn (Acer pseudoplatanus L.). 
Forstwissenschaftliches Centralblatt 119: 263-275.  
WEBER-BLASCHKE, G. / CLAUS, M. / REHFÜSS, K. E., 2002. Growth and 
nutrition of ash (Fraxinus excelsior L.) and sycamore (Acer pseudoplatanus 
L.) on soils of different base saturation in pot experiments. Forest Ecology 
and Management 167: 43-56.  
ZEIDE, B., 1993. Analysis of growth equations. Forest Science 39, 3: 594-616.