Impact of Mixing on the Structural Diversity of Serbian Spruce and Macedonian Pine Endemic to Relict Forest Communities in the Balkan Peninsula

The aim of this paper is to analyze the effect of different degrees of mixing on the diversity structure in stands left to spontaneous development. The research included two communities of species endemic to the Balkan Peninsula—the Serbian spruce (Picea omorika Pančić Purk.) and the Macedonian pine (Pinus peuce Griseb). Data from eight sample plots were used in the research. The changes in diameter and height structure, spatial arrangement of trees, and diameter differentiation were analyzed. The analyzed parameters of structural diversity show relatively low to moderate values. Results showed an increase in mixing was reflected in the width and shape of distributions. A spatial analysis of stands with a higher degree of mixing showed a tendency towards a random to regular distribution of individuals, in contrast to stands with a lower degree of mixing which showed a tendency towards a clump distribution. The pronounced species’ dimensional and spatial diversity confirms their importance to the condition of modern forest management. Significant differences in the change of structure are shown by stands with a share of admixed species of above 20% by volume. The obtained results refer to stands left to spontaneous development, suggesting than an active research and management approach must be assumed to realize the goal of protecting rare forest ecosystems.

Is the double-spined bark beetle Ips duplicatus a new threat to Picea omorika in urban habitats?

The double-spined bark beetle Ips duplicatus (Coleoptera: Curculionidae, Scolytinae) is an invasive forest pest having a broad range of coniferous hosts within Europe. We found this species to be also developing in the Serbian spruce Picea omorika. Ips duplicatus infested 14 (52%) of 27 P. omorika mature trees in an arboretum garden in northern Slovakia in Central Europe during the summer of 2019. Logs from the upper part of stems of P. omorika trees placed in eclectors in the laboratory, yielded a total of 179 individuals of three scolytine species, with prevalence of I. duplicatus. Our results show that I. duplicatus also colonized less likely host such as the Serbian spruce, causing threat to this ornamental tree and contributing to its mortality in urban habitats during hot and dry summer weather.

Seasonal changes in the pigment composition of needles of representatives of the genus spruce in the Nizhny Novgorod region

Изучали характер и масштаб сезонных изменений пигментного состава хвои разных видов ели (Picea A. Dietr.) в условиях интродукции в Нижегородскую область, выявляли содержание и баланс пластидных пигментов фотосинтеза. Объектами исследования выступали 13 видов ели, относящихся к аборигенам и экзотам: ель европейская (Picea abies (L.) H. Karst.); ель сибирская (Picea obovata Ledeb.); ель Глена (Picea glehnii (F. Schmidt) Mast.); ель белая (Picea glauca (Moench) Voss); ель шероховатая (Picea asperata Masters); ель черная (Picea mariana Mill., Britton, Sterns & Poggenburg); ель колючая форма серебристая (Picea pungens Engelm., f. argentea); ель колючая форма голубая (Picea pungens Engelm., f. glauca Regel); ель сербская (Picea omorika (Pančić) Purk.); ель Энгельмана (Picea engelmannii Parry ex Engelm.); ель колючая (Picea pungens Engelm.); ель аянская (Picea jezoensis (Siebold & Zucc.) Carrière); ель корейская (Picea koraiensis Nakai). Отбор проб осуществлен рендомизированно с соблюдением принципа единственного логического различия. Использовали спектрофотометр СФ-2000. Установлено, что содержание и соотношение пластидных пигментов в хвое динамично в течение года. Определена эффективность влияния фаз сезонного развития растений на характеристики пигментного состава: по содержанию хлорофилла-a – 18,86±0,32%; по содержанию хлорофилла-b – 21,26±0,31%; по сумме хлорофиллов – 16,13±0,33%; по каротиноидам – 37,43±0,25%; по доле хлорофилла-a – 39,74±0,24% и доле хлорофилла-b – 39,74±0,24%. Эффект влияния межвидовых различий по показателям содержания и соотношения разных форм хлорофилла и каротиноидов достоверен и в достаточной мере выравнен при максимуме 23,56±0,91%. При общих тенденциях в сезонной динамике представители рода ель обладают заметной видоспецифичностью пигментного состава. We studied the nature and scale of seasonal changes in the pigment composition of needles of different spruce species (Picea A. Dietr.) under the conditions of introduction to the Nizhny Novgorod region, and revealed the content and balance of photosynthetic plastid pigments. The objects of the study were 13 species of spruce belonging to aborigines and exotics: Norway spruce (Picea abies (L.) H. Karst.); Siberian spruce (Picea obovata Ledeb.); Glen spruce (Picea glehnii (F. Schmidt) Mast.); white spruce (Picea glauca (Moench) Voss); Dragon spruce (Picea asperata Masters); black spruce (Picea mariana Mill., Britton, Sterns & Poggenburg); silver prickly spruce (Picea pungens Engelm., f. argentea); blue prickly spruce (Picea pungens Engelm., f. glauca Regel); Serbian spruce (Picea omorika (Pančić) Purk.); Engelman spruce (Picea engelmannii Parry ex Engelm.); Blue spruce (Picea pungens engelm.); Ayan spruce (Picea jezoensis (Siebold & Zucc.) carrière); Korean spruce (Picea koraiensis Nakai). Sampling was carried out in a randomized manner, following the principle of a single logical difference. A spectrophotometer SF-2000 was used. It was found that the content and ratio of plastid pigments in conifers is dynamic throughout the year. The effectiveness of the influence of the phases of seasonal plant development on the characteristics of the pigment composition is determined: by the content of chlorophyll-a-18.86±0.32%; by the content of chlorophyll-b-21.26±0.31%; by the sum of chlorophylls-16.13±0.33%; by carotenoids – 37.43±0.25%; by the proportion of chlorophyll-a – 39.74±0.24% and the proportion of chlorophyll-b – 39.74±0.24%. The effect of interspecific differences in the content and ratio of different forms of chlorophyll and carotenoids is significant and sufficiently equalized at a maximum of 23.56±0.91%. With General trends in seasonal dynamics, representatives of the spruce genus have a noticeable species-specific pigment composition.

MOR and MOE of Serbian Spruce (Picea omorika Pančić/Purkyně) Wood from Natural Stands

The paper presents the results of testing the bending stress of Serbian spruce wood from natural stands. In testing the samples, in addition to the modulus of rupture, the bending stress at the proportionality limit, the ratio between the stress at the proportionality limit and the modulus of rupture as well as the modulus of elasticity of wood were determined. The study included nine trees from natural stands, and a total of 261 samples were tested. Regression analysis determined the dependences of these mechanical properties on the annual ring width, the proportion of late wood and wood density, as well as the dependence of the modulus of elasticity on the modulus of rupture.

ANTIBACTERIAL AND DIELECTRIC PROPERTIES OF TEXTILE MATERIALS MODIFIED WITH HERBAL EXTRACT OF Picea omorika AND THE COPPER FERRITE NANOPARTICLES

In this paper, cotton, polyester and cotton/polyester fabrics were modified by using herbal extract of Picea omorika and copper ferrite nanoparticles and their antibacterial and dielectric properties were investigated. Antibacterial activities of all samples were examined against Escherichia coli and Staphylococcus aureus. Most of the fabrics modified by copper ferrite showed antibacterial activities against Escherichia coli, while the addition of the herbal extract improved their antibacterial protection. Dielectric properties were measured in frequency range from 24 Hz to 75 kHz at room temperature and the results showed that the modification of all three fabrics with copper ferrite caused increase in their electrical conductivity. The obtained results point to the possibility of using investigated fabrics for antibacterial protection as well as for the electromagnetic shielding application.

Uspevanje omorike (Picea omorika (Pančić) Purk.) v generativnem semenskem nasadu Počivalnik pri Postojni

Serbian spruce (Picea omorika (Pančić) Purk.) is an endemic tree species from the Balkan Peninsula. The species also thrives in Slovenia and would be an interesting minority alternative to Norway spruce (Picea abies (L.) Karst.) on some sites. This study was carried out in a Serbian spruce plantation below Počivalnik hill, between Unec and Postojna. The trees were planted in 1988 and are currently classified as a pole stand. We measured the diameters of the trees and systematically evaluated the vitality of each tree throughout the plantation. Data processing consisted of calculating the percentage of trees of each health status for each provenance and phenotype present in the plantation, creating a plantation model, and performing an analysis of variance and Tukey's post-hoc test. We found that provenance has a significant effect on the vitality of trees but not on tree diameter. Phenotype affects both the vitality of trees and tree diameter. The correlation between phenotype and tree diameter is significant within phenotypes B (type %semidichotomy%) and C (type %serbica%). Also, the impact of phenotype on diameter increment varies between the different provenances. According to our investigations, the most suitable seed material for the Dinaric karst region of Slovenia is from the Šargan provenance (read Shargan). In terms of phenotype, types C ('serbica') and F ('argentea') seem to be the most suitable. They are also the most desirable for horticultural use.

Headspace volatiles isolated from twigs of Picea omorika from Serbia

The variability of volatiles isolated from twigs by the static headspace (HS) method in seven natural populations of Picea omorika from Serbia was investigated for the first time. In the overall chemical profile, monoterpenes strongly dominated hydrocarbons as the most volatile compounds (95.7%). The dominant compounds were ?-pinene (29.5 %), ?-pinene (25.7%) and myrcene (13.0%), totaling 68.2% of the volatiles on average. The following nine volatiles were found to be present in medium-to-high amounts (0.5-10%): tricyclene, camphene, ?-phellandrene, ?-3-carene, p-cymene, ?-phellandrene, terpinolene, (E)-caryophyllene, and germacrene D. Out of the 78 volatiles detected, the six most abundant (?-pinene, ?-pinene, myrcene, ?-3-carene, ?-phellandrene and camphene) were selected for principle component analysis (PCA) and cluster analyses (CA). PCA revealed a high degree of similarity between populations, while CA showed a degree of separation of two populations from the others. The presented results are in agreement with previous phytochemical and molecular analyses of this species that confirm high variability in both specialized metabolites and genetic markers.

Variability of morphological and anatomical characteristics of Serbian spruce (Picea omorika /Panc./ Purkyne) needles of natural population located in the Milesevka river canyon

Serbian spruce (Picea omorika /Panc./ Purkyne) is rare and endangered tertiary relict and endemic species in the Balkan Peninsula. Its natural distribution is fragmented and restricted to western Serbia and eastern Bosnia and Herzegovina, mainly in the canyon of middle course of the Drina river. Since the mid-19th century, the number and size of populations have been steadily decreasing accompanied by a decline in the number of mature individuals, endangering natural regeneration is endangered. The objective of this study is to determine variability within Serbian spruce (Picea omorika /Panc./ Purkyne) natural population in the canyon of the Milesevka river on the basis of morphological and anatomical characteristics of needles and, thus, to broaden knowledge on this rare and endangered species. Twigs with needles collected from all mature individuals that represent the population were used as material for the study. The following morphological and anatomical characteristics were measured: NL- needle length; NH - needle height; NW - needle width; CT+EH - cuticle + epidermis height; HH - hypodermis height; VB - vascular bundle diameter; No of SC - number of resin channels; SC diameter - resin channel diameter. The average values of the measured characteristics are: needle length 13.23 mm; needle width 1239.93 ?m; needle height 608.63 ?m; cuticle + epidermis height 11.49; hypodermis height 17.59 ?m; vascular bundle diameter 220.64 ?m; number of resin channels 0.74; resin channel diameter 52.36 ?m. The characteristics with the highest variability are as follows: number of resin channels (161.64%); resin channel diameter (25.35%); hypodermis height (20.79%), while the needle width is a characteristic with the lowest variability (6.39%). The results of the analysis of variance showed very high statistical differences within population for all studied characteristics (p<0.01; ?=0.05). In order to make the results clearer, it is necessary to investigate the genetic diversity and population structure by analyzing various phenotypic characteristics in specially designed experiments (e.g. progeny tests) as well as by analyzing appropriate DNA markers. The studied population must be involved in continuous conservation and breeding processes, especially through appropriate forms of ex situ conservation.