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ŠUMARSKI LIST 11-12/2014 str. 29     <-- 29 -->        PDF

Richens, R. H., J. N. R. Jeffers, 1986: Numerical taxonomy and ethnobotany of the elms of northern Spain, An. Jard. Bot. Madr., 42: 325–341.
StatSoft, Inc. 2001: STATISTICA (data analysis software system), version 8.0.
Sokal, R. R., F. J. Rohlf, 1989: Biometry, Freeman and Co., 887 str., San Francisco.
Škvorc, Ž., 2006: Florističke i vegetacijske značajke Dilja, Disertacija, Šumarski fakultet Zagreb.
Škvorc, Ž., J. Franjić, M. Idžojtić, 2005: Population structure of Quercus pubescens Willd. (Fagaceae) in Croatia according to morphology of leaves., Acta Bot. Hung., 47(1-2): 193–206.
Tutin, T. G., 1962: Ulmus L., U: A. R. Clapham, T. G. Tutin i E. F. Warburg (ur.): Flora of the British Isles, Cambridge University Press, 562–566 str., New York.
Tutin, T. G., 1964: Ulmus L., U: T. G. Tutin, V. H. Heywood, N. A. Burges, D. H. Valentine, S. M. Walters, D. A. Webb (ur.): Flora Europaea, 1: 65, Cambridge University Press, New York.
Vukelić, J., D. Baričević, 1998: Sukcesija šumskih zajednica na području sušenja hrasta lužnjaka u Hrvatskoj, U: B. Prpić (ur.): Održivo gospodarsko korištenje nizinskih rijeka i zaštita prirode i okoliša, Hrvatsko šumarsko društvo Zagreb i EURONATUR, 23–37 str., Zagreb.
Vukelić, J., Đ. Rauš, 1998: Šumarska fitocenologija i šumske zajednice u Hrvatskoj, Šumarski fakultet Zagreb, 310 str., Zagreb.
WinFOLIA TM, 2001: Regent Instruments Inc., Quebec, Canada, version PRO 2005b.
Zebec, M., M. Idžojtić, I. Poljak, I. Mihaldinec, 2010: Varijabilnost nizinskog brijesta (Ulmus minor Mill. sensu latissimo) na području hrvatske Podravine prema morfološkim svojstvima listova, Šum. list, 134 (11–12): 569–580.
Zlatarić, B., 1952: Forme nizinskog brijesta, njegovo rasprostranjenje i šumsko-uzgojno značenje kod nas, Manuskript, Zagreb.
The European field elm (Ulmus minor Mill. sensu latissimo), our native noble broad-leaved species is known for having very valuable and highly prized wood. The favorable characteristics of this tree are not limited solely to its economic usefulness, since it also has more important, invaluable role in preserving the stability of lowland forest ecosystems. Unfortunately, European elm trees have suffered enormous losses due to Dutch elm disease pandemics, which resulted in significant dieback of adult trees. Nay, threats to morphological and genetic diversity of U. minor s.l. are manifold and expressed in terms of anthropogenic-induced destruction of habitat, introduction of new elm species and spontaneous hybridization with ornamental species, as well as extremely high susceptibility of elms of the Ulmus Heybr. section to the said Ophiostoma novo-ulmi Brasier pathogenic fungus. Giving the fact that in Croatia elm trees are also severely affected by the disease, abundance of healthy, adult individuals in the field is rather low. Accordingly, it is presumed that genetic and consequently morphological diversity of U. minor s.l. in Croatia as well as throughout Europe has been exceedingly negatively affected.
The study of morphological variability of leaves encompassed six elm populations (Ulmus minor Mill. sensu latissimo) from continental Croatia: Bilogora, Dilj, Donji Miholjac, Jastrebarsko, Nova Kapela and Zagreb (Figure 1). Quantification of the intra- and interpopulational variability was done on the basis of 10 morphological leaf traits (Figure 2). In order to describe the pattern of variability, descriptive statistics and multivariate methods were used. Analysed morphological traits showed high variability, despite hypothesized negative impact of Dutch elm disease on morphological variability of the studied species. The variability coefficient for populations in total ranged from 17,05 % for the trait of number of secondary and tertiary veins in the subapical region to 45,24 % for the trait of leaf base asymmetry (Table 1).
There were significant differences among trees within populations and among populations for all measured leaf traits (Tables 2 and 3), except for four traits on populational level: leaf blade area (LA), leaf blade breadth at its widest point (HW), leaf blade length, measured along the shorter side of lamina, starting from the leaf base to the point of maximum leaf breadth (PMPW) and leaf blade width at 50 % of leaf blade length, measured along the shorter side of lamina (PW1).
Partitioning of variance showed that differences among trees in a single population accounted for 1/2-2/3 of total variability, whereas the amount of variation attributable to differences among populations was considerably smaller. However, interpopulation variability proved high for the trait of number of secondary and tertiary veins in the subapical region and the trait of petiole length (Table 4). Application of cluster analysis revealed grouping of populations regarding ecological site conditions (Table 5 and Figure 3). However, negative impact of anthropogenic activities on environmental conditions in terms of land use alteration and hydroregulation processes as a basis for population differentiation was also confirmed. Thus, the first group of the most similar populations involved Bilogora, Donji Miholjac, Zagreb and the second group Jastrebarsko and Nova Kapela. The reasons for the Dilj population differentiation can be sought in its affiliation to the Central European vegetation zone thermofilic forests of the alliance Quercion pubescentis-petraeae Br. – Bl. 1931.