Morphologic variability of the Acer campestre L. populations in Bosnia and Herzegovina

Morphologic variability from 25 populations of Acer campestre L. in Bosnia and Herzegovina was analyzed. Morphometric structure of variability and between-population variability was performed based on 10 fruit-parameter characteristics and 19 leaf-parameter characteristics using multivariate statistical analysis. Results confirmed the separation of three submediterranean populations as a group in relation to other tested populations, from which the Banja Luka population is different. Measured leaf parameters were confirmed as a predominant carrier of the morphologic separation between populations. In other Acer species populations within A. monspessulanum and A. intermedium species are separated mainly by fruit and much less by leaf parameters. The southernmost submediterranean populations from Trebinje, Ljubuški, and Mostar regions have smaller leaf areas, which consequently places them within the same morphologic group; their variability is in tight connection with eco-geo-graphical factors, where the ecological distance is a much better predictor of morphological variability compared to geographical distance. The air temperature had the biggest influence on morphological variability regarding the highest in-between correlation. Achieved results may serve for the continuation of the research in other areas of Acer campestre to determine the interactive effect of ecological, geographical, climatic, and migrational factors on their morphologic population plasticity.

Plant and Wood Area Index of Solitary Trees for Urban Contexts in Nordic Cities

Background: We present the plant area index (PAI) measurements taken for 63 deciduous broadleaved tree species and 1 deciduous conifer tree species suitable for urban areas in Nordic cities. The aim was to evaluate PAI and wood area index (WAI) of solitary-grown broadleaved tree species and cultivars of the same age in order to present a data resource of individual tree characteristics viewed in summer (PAI) and in winter (WAI). Methods: All trees were planted as individuals in 2001 at the Hørsholm Arboretum in Denmark. The field method included a Digital Plant Canopy Imager where each scan and contrast values were set to consistent values. Results: The results illustrate that solitary trees differ widely in their WAI and PAI and reflect the integrated effects of leaf material and the woody component of tree crowns. The indications also show highly significant (P < 0.001) differences between species and genotypes. The WAI had an overall mean of 0.91 (± 0.03), ranging from Tilia platyphyllos ‘Orebro’ with a WAI of 0.32 (± 0.04) to Carpinus betulus ‘Fastigiata’ with a WAI of 1.94 (± 0.09). The lowest mean PAI in the dataset was Fraxinus angustifolia ‘Raywood’ with a PAI of 1.93 (± 0.05), whereas Acer campestre ‘Kuglennar’ represents the cultivar with the largest PAI of 8.15 (± 0.14). Conclusions: Understanding how this variation in crown architectural structure changes over the year can be applied to climate responsive design and microclimate modeling where plant and wood area index of solitary-grown trees in urban contexts are of interest.

ВІКОВА СТРУКТУРА ПІДРОСТУ CARPINUS BETULUS L. У КУЛЬТУРФІТОЦЕНОЗАХ НАЦІОНАЛЬНОГО ДЕНДРОЛОГІЧНОГО ПАРКУ «СОФІЇВКА» НАН УКРАЇНИ

The issue of preserving the dendrological structure in historical parks requires the implementation of a number of agronomic measures aimed at ensuring the decorative and durability of plant communities. The plants of Carpinus betulus L. are included in the vast majority of deciduous plantations of the National Dendrological Park «Sofiyivka» of NASU, form the stands with the participation of Quercus robur L., Acer platanoides L., Acer campestre L. and Fraxinus excelsior L. The question of self-recovery of C. betulus plants in the park is relevant in connection with natural waste and active reduction of its viability identified over the past 10 years. The analysis of the success of natural regeneration of aboriginal plants in the cultural phytocenoses of the National Dendrological Park «Sofiyivka» of NASU has been conducted. As a result of the survey of the dendrological structure, viability of the young growth of the main structure-forming species under the stand was revealed. The prospects of replacing senile plants of C. betulus with the younger generation have been outlined. The young growth of C. betulus is 4.5% of the total number of viable undergrowth in the test plots, which is significantly less compared to A. platanoides – 64.5 % and A. campestre – 20. 7%. There is a sufficient number of viable virginile and young generative plants of C. betulus, which in future is able to form a stand. Prospects for natural regeneration of plants of the C. betulus species are average, similar in quantitative and age characteristics to plants of the Fraxinus excelsior L. The number of virginile plants is 0.5 %, and young generative – 0.1 %, compared with A. platanoides and A. campestre, the results are more than 10 times lower for virginile and 2 times – for young generative plants, which indicates a weak competitiveness of the young growth of C. betulus. Artificial phytocenoses with the participation of C. betulus are one of a few self-regenerating species in the park, as aboriginal species have a higher adaptive potential and are capable of successful renewal. Control over the ratio of species and quantitative composition of undergrowth, timely rational sanitary and landscape felling will create optimal conditions for growth and development of the young growth of C. betulus. Regular removal of aggressive plants of A. platanoides, A. campestre and F. excelsior will help preserve the existing structure of the stand in the historic part of the NDP «Sofiyivka».

Models of protective forest stands with shrubs in conditions of chestnut soils

Дан научный анализ возможностей использования кустарников, как адаптивной жизненной формы для создания возобновляемой системы лесных насаждений, при ландшафтном обустройстве малолесной территории. Объекты исследований: таксоны геоксильного кустарника рода Corylus разных возрастных этапов, которые произрастают в Волгоградской области: в условиях южных черноземов (C. avellana L.), каштановых почв (С. pontica C. Koch. – формы ‘Президент’, ‘Футкурами’, ‘Черкесский-2’; кад. № 34:34:000000:122). Использован биометрический метод в определении таксационных величин и установлении отклонений от оптимальных размеров. Цель исследований – разработать модели защитных лесных насаждений на основе изучения специфики роста таксонов Corylus L. в условиях каштановых почв. Установлен пик интенсивности роста основных, крону образующих побегов Corylus pontica - 5-7 летний возраст. Развитие надземной части в последующие десять лет (этап кустовидного роста) описывается уравнениями регрессии. Они показали взаимосвязь изменения таксационных характеристик с возрастом. Приведены показатели освещенности (от 77,0 до 108,8 kLx) в период вегетации. Установлено интенсивное формирование побеговых систем, сокращение их длительности роста, ранний переход от моноподиального (этап древовидного роста) к симподиальному типу ветвления (этап кустовидного роста) побегов. С учетом анализа структуры и морфогенеза побеговых систем построена графическая модель их возрастного состава и расположения. Критериями выделения возрастных этапов роста - равномерность размещения, возраст побегов, способность к возобновлению. Разработаны эскизные модели защитных лесных насаждений (многорядных, в том числе на склонах крутизной 4-7°) с участием Corylus avellana, Acer campestre, Quercus, Betula pendulaдля повышения устойчивости и обогащения защитных лесных насаждений на каштановых почвах. Таксоны Corylus L. образуют лесную подстилку – один из факторов, влияющих на стокорегулирующие свойства насаждений. В условиях южных черноземов более чем за тридцатилетний период произрастания Corylus сформировало лесную подстилку до 2,0 см (масса 12,0 т/га). Установлены декоративные качества и экологические свойства кустарников Corylusдля озеленительных насаждений. A scientific analysis of the possibilities of using shrubs as an adaptive life form for creating a renewable system of forest stands, in the landscape arrangement of a low-forest area, is given. Objects of research: taxa of the geoxyl shrub of the genus Corylusof different age stages, which grow in the Volgograd region: in the conditions of southern chernozems (C. avellana L.), chestnut soils (C. pontica C. Koch. - forms 'President', 'Futkurami', 'Circassian-2'; kad. № 34:34:000000:122). The biometric method is used in determining the taxational values and determining deviations from the optimal size. The aim of the research is to develop models of protective forest stands based on the study of the specific growth of Corylus L. taxa. in conditions of chestnut soils. The peak growth rate of the main, crown - forming shoots of Corylus pontica is 5-7 years old. The development of the aboveground part in the next ten years (the stage of bush-like growth) is described by regression equations. They showed the relationship of changes in taxation characteristics with age. The indicators of illumination (from 77.0 to 108.8 kLx) during the growing season are given. Intensive formation of shoot systems, reduction of their growth duration, early transition from monopodial (tree-like growth stage) to sympodial branching type (bush-like growth stage) of shoots were established. Taking into account the analysis of the structure and morphogenesis of shoot systems, a graphical model of their age composition and location is constructed. The criteria for identifying the age stages of growth are the uniformity of placement, the age of shoots, and the ability to resume. Sketch models of protective forest stands (multi-row, including on slopes with a steepness of 4-7°) with the participation of Corylus avellana, Acer campestre, Quercus, Betula pendula were developed to increase the stability and enrich the protective forest stands on chestnut soils. Corylus L. taxa form the forest floor-one of the factors influencing the flow-regulating properties of plantings. In the conditions of southern chernozems, Corylus has formed forest litter up to 2.0 cm (weight 12.0 t/ha) for more than thirty years of growth. The decorative qualities and ecological properties of Corylus shrubs for landscaping are established.

Height to Crown Base Modelling for the Main Tree Species in an Even-Aged Pedunculate Oak Forest

The height to crown base (hcb) is a critical measure used in many investigations as an input variable to investigate the vigour of the stands, the social position of the trees, and to evaluate the behaviour of forest fires, among other uses. Though measuring height-related variables in the field is always time-consuming, the foremost benefits offered by modelling hcb are that it permits to generalize and average a very uneven attribute and, furthermore, provides insights about which tree and stand variables have a significant impact on hcb. However, there are many species in which models of the crown base height have not been developed in Croatia. The objective of this research was to develop a height to base crown model for each of the main species present in the two-layered mixed stands of this study. According to previous investigations, logistic models provide the highest precision and require the lowest inventory cost owing to less frequent measurements. Tree- and plot-level variables with distance-independent competition indexes were studied in the fitting model. In this research, we obtained models for the main stand species: Acer campestre (root mean squared error (RMSE) = 2.28 m, R2 = 82.80%); Alnus glutinosa (RMSE = 1.78 m, R2 = 85.36%); Carpinus betulus (RMSE = 2.47 m, R2 = 67.55%); Fraxinus angustifolia (RMSE = 2.46 m, R2 = 82.45%); Quercus robur (RMSE = 2.60 m, R2 = 80.57%); Tilia sp. (RMSE = 2.01 m, R 2 = 89.07%); and Ulmus laevis (RMSE = 1.71 m, R2 = 92.42%). The combination of the total height, tree, and plot-level variables with distance-independent competition indexes contributed to the prediction accuracy of proposed model significantly.

Population Structure and Regeneration Status of Woody Plants in Relation to the Human Interventions, Arasbaran Biosphere Reserve, Iran

Proper understanding of the diversity and natural structure of woody species and the impacts of human interventions are prerequisites for maintaining the remaining forests as well as restoration of deforested and degraded areas. This research was conducted to document the impact of human interventions on the population structure and the species diversity in the Arasbaran biosphere reserve in Iran due to the limited research and insufficient knowledge. The study area was divided into three adjacent sampling areas of low, medium, and high destruction intensity. Thirty fixed area 0.1-hectare plots were sampled to evaluate the composition, diversity, and species richness. Oak (Quercus macranthera), hawthorn (Crataegus meyeri), and maple (Acer campestre) were the top three dominant tree species at all the sites. The relative dominance of the top three species comprised 87.8% of the basal area of all species. The relative abundance of the top three species accounted for 68.1% of the species. The mean density and basal areas per tree across all three destruction statuses were 145 ± 59 stems ha−1 and 0.01 ± 0.005 m2 ha−1, respectively. The mean height of trees was different at low and high disturbance sites (4.6 ± 0.96 m and 3.37 ± 1.74 m, respectively). Due to the impact of human interventions on forest structure, composition, and diversity, conservation programs are recommended for implementation and in collaboration with local communities to employ management aimed at providing services for local people while restoring these forests. Basic ecological studies such as this study are the foundation to begin developing policies and management that meet multiple ecological and social goals.

Mixed mesophilic mountain beech forest (Fagetum submontanum serbicum) on the Vidlič Mountain

On the Vidlič mountain, mixed mesophilic mountain beech forests (Fagetum submontanum serbicum) have been recorded at altitudes of 700 - 1000 m, at the following localities: Crni vrh, Vazganica, Kranjci, Planinarski dom, and Visočka Ržana. Phytocenological research was performed on the mentioned localities by the Braun-Blanquet method (Braun-Blanquet, 1964). It was taken 11 phytocenological plots. Beech (Fagus moesiaca) and turkey oak cer (Quercus cerris) were the main edificators and have the highest degree of presence in the examined phytocenoses on the tree floor. In the floor of shrubs, the following species: Viburnum lantana, Crataegus monogyna, Rosa canina, Daphne mezereum, Clematis vitalba, and Ligustrum vulgare have been noticed with the highest degree of presence. Acer campestre has been dominated with the highest degree from the shoots of trees. In the floor of herbaceous plants, the species: Viola alba, Cruciata glabra, Brachypodium sylvaticum, Euphorbia amygdaloides, Helleborus odorus, Fragaria vesca were with the highest degree of presence.

Epiphytic bryophytes of the State Dendrological Park “Olexandria” of the NAS of Ukraine

Investigations of the species diversity of epiphytic bryophytes of the State Dendrological Park “Olexandria” (the historical part and the “Budynok Lisnyka” plot) were conducted in 2017–2019 and revealed 40 species representing 22 genera, 17 families, seven orders, two classes, and two divisions. This corresponds to 46.51 % of the total number of detected bryophytes in the park. The leading families in the bryoflora of the park are Orthotrichaceae (9 species), Brachytheciaceae (6), Amblystegiaceae (3), Anomodontaceae (3), Dicranaceae (3), Hypnaceae (3), and Pottiaceae (2). The leading genera are Orthotrichum (9 species), Anomodon (3), and Dicranum (3).Among the identified taxa, five species (Dicranum tauricum, Orthotrichum lyellii, Porella platyphylla, Sciuro-hypnum reflexum, and Syntrichia virescens) are regionally rare within the Forest-Steppe zone of Ukraine. Most of the recorded epiphytic mosses were found on the bark of Acer platanoides (28 species), Fraxinus excelsior (27), Quercus robur (26), Acer campestre (23), and Tilia cordata (22). The least epiphytic mosses were found on the bark of conifers (Pinus sylvestris, P. strobus, Picea abies, Larix decidua, etc.).The surveyed trees in the State Dendrological Park “Olexandria” were also found such epigeal mosses as Plagiomnium cuspidatum, Ceratodon purpureus, Dicranella heteromalla, and Pohlia nutans, as well as epixilic moss Dicranum flagellare, etc.The “Budynok Lisnyka” plot hosts three species that do not occur in the park’s historical part. In particular, Lophocolea heterophylla and Sciuro-hypnum curtum were found there on Quercus robur trunks and Sciuro-hypnum reflexum on Quercus rubra bark. At the same time, the historical part of the park is characterized by the number of expansive bryophytes.