Leaf morphometric characteristics variability of different beech provenances in juvenile development stage

The taxonomic status of beech from the Balkan Peninsula is not yet clearly defined. There is no agreement among different authors about the morphological characteristics discriminating between the Balkan and European and/or Eastern beech. For most characteristics, the mean values are different but the ranges of variation overlap considerably. Provenance trial of beech established in Serbia, at the locality Debeli Lug, has provided an opportunity for research of inter-provenance variability at the level of leaf morphometric characteristics in juvenile development stage. Research included 10 provenances originating from the Western Balkans (Serbian provenance 36 and 38; Croatian provenance 24 and 25; Bosnian provenance 30 and 32) and from Central Europe (German provenance 47 and 49; Austrian provenance 56 and Hungarian provenance 42), where following morphometric characteristics were analyzed: leaf length (Ll), leaf width (Lw), petiole lenght (Pl), leaf base width on 1 cm (Blw), number of veins-left (Vl), number of veins - right (Vr), distance between 3(rd) and 4(th) vein - left (Dv 3-4). The results of this research show existence of clear differentiation among provenances from the Western Balkan and from Central Europe, from the point of leaf dimensions, number of veins and leaf base width

Variability of morphological characteristics of leaves and fruits of common hackberry (Celtis occidentalis L.) test trees from Sombor area

Two species of the genus Celtis L. are represented in the city of Sombor, of which the most numerous is Celtis occidentalis L., prevalent in parks and alleys, which became a symbol of the city, with its priceless social, economic and environmental value. Their present situation could be described as alarming. The paper presents the results of the analysis of morphological characteristics of leaves and fruits of common hackberry, investigated at the level of 15 test trees, in order to assess the genetic variability of the available gene pool in the tree alleys at Sombor area. Following parameters were analyzed: total leaf length, lamina width, petiole length, and lamina width at the left and right side from midrib, as well as drupe diameter and weight of 1000 fruits. The descriptive statistics, one-way analysis of variance, LSD test and cluster analysis were done. The largest leaves were recorded at trees 1, 5 and 11, and smallest at the trees 7, 9 and 13, wherein genotype 1 was distanced from the other test trees, on multiple characteristics. The highest average of drupes diameter were recorded at trees number 4, 12, and 3. The obtained results indicate a satisfactory degree of variability of the analyzed characteristics at the level of test trees, which provides a good basis for exploring and proper use of the genetic potential of this species, as well as for conservation of the available gene pool. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TP 31041: Forest plantations in order to increase forestation of Serbia

Genetic diversity and forest reproductive material - from seed source selection to planting

How much of genetic diversity is desirable in mass production of forest reproductive material? How mass production of forest reproductive material reduces genetic diversity? Relation between genetic diversity and mass production of forest reproductive material is discussed in a holistic manner. In industrial forest plantations, narrow genetic diversity is desirable and reproductive material is produced at clone level. On the other hand, in conservation forestry a wide genetic diversity is imperative. Beside management goals, a desirable level of genetic diversity is related to rotation cycle and ontogeny of tree species. Risks of failure are lower in short rotations of fast growing species. In production of slow growing species, managed in long rotations, the reduction of genetic diversity increases the risk of failure due to causes unknown or unexpected at the time of planting. This risk is additionally increased in cases of seed transfer and in conditions of climate change. Every step in production of forest reproductive material, from collection to nursery production, has an effect on genetic diversity mainly by directional selection and should be considered. This review revealed no consistent decrease of genetic diversity during forest reproductive material production and planting

Latewood proportion inside growth rings by bald cypress stems in Serbia

In the paper, there was analyzed participation of the latewood zone inside growth rings of bald cypress from two different locations in Serbia. Its proportion has been monitored depending on three factors growth rings width, age and stem height. Between growth rings width and latewood zone proportion was established negative correlation. For that reason, stems on Backa Palanka, whose growth rings are narrower, have greater latewood zone proportion compared to stems from Veliko ratno ostrvo, that have faster radial increment. Greater latewood proportion contributes to better mechanical and technical properties of the stems from Backa Palanka. As for relations between latewood proportion, from one side, and age and stem height, from the other side, there is also established negative correlation. Bearing on mind that bald cypress belongs to soft conifers, its latewood proportion almost never exceeds more than 1/3 of the whole growth rings width