Acer Campestre Research Articles

Half a century of herb layer changes in Quercus-dominated forests of the Western Carpathians

Species composition of European temperate Quercus forests have undergone dramatic changes in the past century. Observed changes have largely been attributed to anthropogenic environmental changes that drove the processes of thermophilization, eutrophication, or biotic homogenization. However, ecological processes behind these changes can be difficult to explain considering the variability among regions: their history, management, landscape patterns, site properties, and vegetation types. To reveal vegetation change trends and their drivers in the subcontinental Western Carpathians, we analysed vegetation and environmental data from 158 quasi-permanent plots established between 1961 and 1980 in Quercus petraea- dominated forests on the andesite bedrock of the Slovenské stredohorie Mountains in Slovakia (Central Europe), and we resurveyed them again between 2005 and 2020.Among alpha and gamma diversity measures, we found only slight species richness decreases. A significant shift in species composition associated with very high species turnover (64%) and a decrease in herb layer cover (by 24%) resulted in higher spatial heterogeneity of herb understoreys in the resurvey. Winning species were more thermophilous, eutrophic, and mesic/oceanic plants of lower latitudes, replacing original species of open Quercus forests. Increased temperatures was the most significant environmental driver. Climate warming corresponded not only to thermophilization, but, after interaction with management, it was also related to eutrophication of the herb layer. Eutrophication was identified as the main trend of the species composition changes (mean EIV for nutrients of winners was 5.9 compared to 4.1 of losers) even though the effect of anthropic nitrogen depositions was negligible. Successive undergrowing of Quercus canopies by more shade-casting trees (Acer campestre, Carpinus betulus, and Fagus sylvatica) in the period of decreasing management intensity was another major driver. Their increase by 8.6% in the resurveyed plots contributed to decreased species richness and they supported shade-tolerant eutrophic understorey species typical of mesic Carpinus betulus and Fagus sylvatica forests.We concluded that Quercus forests in the Western Carpathians underwent thermophilization and eutrophication, similar to the forests in densely inhabited Western Europe; however, their plant understoreys were not homogenized, and eutrophication was not driven by nitrogen depositions. Eutrophication should be recognised as the next important negative impact of global warming on ecosystems. Dramatic changes in species composition and loss of original characteristic species can only be partly halted by reducing shade-casting trees from lower tree layers in managed stands.

Diversity of acarine fauna (Acari: Parasitiformes, Acariformes) inhabiting ornamental trees and shrubs in Hungary: A review

AbstractThis paper reviews of the recent progress in the acarological researches and knowledge on mites occurring in the canopy of ornamental trees and shrubs. The inventory of Acari includes 444 mite species belonging to 33 families which were recorded from 283 hardwood tree and shrub species of 45 plant families. The highest number of mite families and species were reported from the families Rosaceae (21 mite families), Salicaceae (20) and Oleaceae (17), and Salicaceae (99 mite species), Rosaceae (98) and Fagaceae (63), respectively. The most diverse acarine fauna was found on Acer campestre (37 mite species), Prunus spinosa (37), Acer pseudoplatanus (33), Tilia cordata (33) and Salix alba (31). The most frequently occurring mite species were Euseius finlandicus (on 78 host species), Tydeus californicus (64) and Zetzellia mali (60).

Comparative Analysis of Foliar Diseases of Some Native and Non-Native Tree Species in Belarus and Siberia

Urban green spaces are known to be subjected to additional anthropogenic stress. Using native plants in monoculture, i.e., planting trees of the same species, may favour disease outbreaks and plant death. Non-native plants to be used in large cities for creating sustainable plantations are being searched for worldwide. Meanwhile, it is necessary to control plant pathogens in the variable conditions of the region and natural habitat. In Siberian cities, non-native European trees are used, and non-native Siberian plants are introduced in Belarus. This article reports long-term observations of foliar fungal pathogens attacking 21 woody plants (19 European, 2 Siberian) in Siberian and Belarusian cities. In both regions, 48 leaf fungal pathogens were detected, with powdery mildew fungi predominating in Belarus and leaf spotting fungi prevailing in Siberia. In both research regions, the greatest number of fungal species was found on Syringa vulgaris L. In Siberia, many pathogens were found on the non-native European plant Berberis vulgaris (9 species) and native plant Caragana arborescens Lam. (8 species). We have not detected the pathogens on European plants: Acer campestre L., Acer platanoides L., Euonymus europaeus L., Lonicera caprifolium L. in urban green areas in Siberia, while we have identified one to four foliar fungal pathogens on these plants in Belarus. To sum up: more pathogens were found on native plants in Siberia and Belarus; some leaf pathogen species (Sawadaea tulasnei (Fuckel) Homma, Erysiphe alphitoides (Griffon & Maubl.) U. Braun & S. Takam., Cladosporium syringae (Oudem.) Montem., Erysiphe syringae Schwein., Erysiphe palczewskii (Jacz.) U. Braun & S. Takam.) followed their host plants (Acer tataricum L., Syringa vulgaris L., Caragana arborescens Lam.) when introduced into new areas; and some local pathogens were also observed to spread to the non-native plants of closely related species.

Maple species identification based on leaf hyperspectral imaging data

The present study aimed to identify the leaves of Acer campestre L., A. negundo L. and A. saccharinum L. The experiment was carried out under controlled laboratory conditions in 2021. A Cubert UHD-185 camera was used for hyperspectral imaging (HSI). The content of photosynthetic pigments was determined by the spectrophotometric method. HSI and determination of pigments were carried out during the growing season of maples with intervals between experiments of 7–10 days. The time interval in the vegetation of maples was determined, in which the identification of their species by the random forest (RF) method occurs most accurately. Based on the strength of the correlation with photosynthetic pigments, factor loadings of principal component analysis (PCA), results of the t-test and analysis of variance (ANOVA), a group of vegetation indices (VIs) was selected, the values of which are associated with the species characteristics of maples. It has been established that VIs CRI1, Carter4, Datt3, DPI, EVI, Gitelson2, GMI1, Green_NDVI, MTVI, PRI, REP_Li, TCARI, TVI are significant for the identification of A. campestre, A. negundo and A. saccharinum. The OOB estimate of error rate does not exceed 7% when classified by the RF method using selected VIs. When training on the data of Jul 02, the testing error in the time interval from Jul 09 to Aug 24 did not exceed 20%.

Clustering of Field Maple Populations from Different Ecological Conditions in Bosnia and Herzegovina Based on Discriminant Analysis of Morphological Traits

Acer campestre L. is naturally distributed in most of Europe. The species can serve as a valuable model for researching the sensitivity of populations to habitat fragmentation. This research aims to determine whether there is a differentiation of field maple populations based on their division by ecological-vegetation regions, precipitation amounts, temperatures, and altitudes of the populations. The material was collected from 25 populations in Bosnia and Herzegovina, from different ecological-vegetation areas, with twelve trees per population and five fruits and ten leaves per tree. Then, 10 fruit properties and 19 leaf properties were analyzed. A discriminant analysis was performed for population groups based on the ecological-vegetation area, amount of precipitation, average annual air temperature and altitude. The discriminant analysis results showed the distinguishing of groups of populations in the sub-Mediterranean area, and groups of populations with an average annual temperature of 14.00 to 15.99 °C. There was no clear separation of the groups according to the average annual precipitation or altitude. The analysis of the connection established that the influence of environmental factors is more pronounced compared to geographical factors. The key ecological variable that determines morphological separation was temperature and to a lesser extent precipitation. The results of this research will be used in planning of afforestation of suitable, unvegetated land and extreme habitats in the southern and southwestern parts of Bosnia and Herzegovina with Acer campestre.

Continental-wide population genetics and post-Pleistocene range expansion in field maple (Acer campestre L.), a subdominant temperate broadleaved tree species

Acer campestre L. is a rarely silviculturally managed and poorly investigated European tree species which forms seminatural populations and can thus be considered as a model tree for studying post glacial colonisation and phylogeography. Herein, we studied the genetic structure of Acer campestre L. in order to investigate population and genetic diversity clines over the distribution range and for synthesizing the results into a post-Pleistocene range expansion hypothesis. We characterised the genetic diversity and population structure of 61 Acer campestre populations using 12 microsatellite markers. The three detected gene pools are structured geographically creating a longitudinal pattern corresponding with their proposed refugial origin. The results indicated a longitudinal population cline with three strong but highly admixed gene pools. Based on the possible signal from the structure results, a number of phylogeographic dispersal hypotheses were tested using approximate Bayesian computation, and this analysis supported the three refugia scenario with a simultaneous divergence prior to the last glacial maximum. Acer campestre shows a typical decrease in population diversity with northern and western distribution and signatures of surfing alleles in the western expansion axis in 2% of the included alleles. Acer campestre exhibits a high degree of admixture among populations and typical signatures of isolation by distance with no naturally delimited subpopulations. The population structure is rather impacted by geographically, than climatologically means with surfing alleles and alleles strongly limited to geographical areas. Our data also suggest that the population structure still today harbours signatures of post glacial migrations from Mediterranean as well as northern glacial refugia.

Javori (Acer L.) u ulicama centralnog dela Beograda - stanje i funkcionalnost

This research investigated the existing conditions and functionality of rows of maple trees (Acer L.) (which are traditionally used in our country for urban greening) in the streets that are the most frequent in terms of traffic intensity, ways of use and measures to maintain greenery (streets of the I and II order) on the territory of the municipality of Stari grad (Belgrade). In the investigated area a total of 39 streets of these categories were surveyed. Rows of maple trees are represented in 2 out of 15 streets of the I order and in 10 out of 24 streets of the II order. It was determined that the total number of trees belonging to the species of this genus is 735. Maple species recorded are: Acer pseudoplatanus L, Acer platanoides L, Acer campestre L. and Acer saccharinum L. The most represented species here is A. pseudoplatanus with a total of 442 (60.13%) trees, and an average vitality score of 3.6. They are followed by: A. platanoides with 213 (28.98%) recorded trees and an average vitality score of 3.5, A. campestre with 72 (9.80%) recorded trees and a rating of 3.1 and A. saccharinum with 8 (1.09%) trees and a rating of 2.3. One of the main factors in reducing the functionality of maple tree street rows in the study area was the application of the tree topping care measure.

DYNAMICS OF DISTRIBUTION, AMOUNT OF UNDERGROWTH, TYPE OF FOREST VEGETATION CONDITIONS

Peculiarities of natural regeneration of oak and related species in the conditions of the Northern Steppe were studied. According to the conducted surveys, over the course of 4 years, 21.38–58.19 thousand pcs.•ha-1 of natural renewal of undergrowth of various species were found. In seven-year-old crops, this indicator was somewhat lower and amounted to 40.26 thousand pcs.•ha-1. In six- and nine-year crops, the total amount of natural renewal was approximately the same - 24.1 thousand pcs.•ha-1 and 24.19 thousand pcs.•ha-1, respectively. As for the species composition of the undergrowth, the amount of preserved self-sowing varied greatly by year. Thus, common oak had the largest amount of natural renewal in six-year crops (5.23 thousand pcs.•ha-1). Even in seven-year-old crops, its preservation was 2.54 thousand pcs.·ha-1. In the following years, the conservation of this species was less than one thousand pieces.•ha-1. On the other hand, common ash had the lowest preservation in six-year-old and nine-year-old cultures - 3.52 and 3.84 thousand pcs.•ha-1, respectively. In other years, its preservation was much higher than that of oak, with the maximum amount in 7-year cultures – 19.1 thousand pcs.•ha-1. With the help of statistical data processing, it was found that there is a significant difference in reducing its quantity on one- and two-year-old log cabins. In subsequent years, there is a decrease in the amount of self-sowing oak, which over time completely falls out of the undergrowth. The natural regeneration of common ash, hornbeam, and maple has a significant difference in the age of the logs, but the increase or decrease in regeneration is not monitored due to the systematic cutting of natural regeneration during maintenance felling. There are no significant changes in the undergrowth of acacia, field maple, heart-leaved linden, birch and other species. Significant changes in the total amount of natural renewal were found in log cabins of all years.

Comparative analysis of artificial and natural plantations in the Kurdjipsky subdivision of Maikop forest area in Republic of Adygea

The Republic of Adygea is one of the southern entities located in the northwestern part of the North Caucasus. The northern part of the republic stretches across the Kuban lowlands and the southern part along the slopes of the Greater Caucasus. Climatic conditions are favourable for the growth of heat-loving woody and shrub vegetation. The area covered by forests is 285.7 thousand hectares, including 278.4 thousand hectares covered by forests. The forests of the republic are distributed unevenly; most of the forests are concentrated in the piedmont and mountainous areas. The main forest-forming species are oriental beech and English oak. The forests of the Republic have an important water and soil protection function. The area of forests is insignificant, more widespread are forest shelter belts and boles scattered among the fields, often confined to river valleys, reservoirs, and low-lying places. Plantings include English oak, common ash, Caucasian hornbeam, field maple, poplar, willow, grey alder and black alder. Plantations located in forest shelter belts perform water protection, water protection, sanitary-hygienic, and aesthetic functions [1]. The work provides a comparative analysis of plantations of natural and artificial origin of the same age, growing in the same forest and vegetation conditions.

Thirty Years of Growth of Woody Plants in a Biocorridor Established on Agricultural Land: Case Study From Vracov (Czech Republic)

Abstract In the 1970s and 1980s, the concept of ecological networks was developed in the Czech Republic. The first biocorridors were established on arable land in the beginning of the 1990s. One of them was the Vracov biocorridor. This paper deals with the growth and development of trees on two permanent research plots in the period from 1993–2021. In the biocorridor, repeated inventories of woody plants and monitoring of biometrical parameters of trees and shrubs were carried out. The number of woody plants has been decreasing as the level of stand canopy has increased. Moreover, mean heights and diameters of skeleton (Quercus robur, Tilia cordata) and filling (Acer campestre, Prunus avium) trees and shrubs (Cornus sanguinea, Ligustrum ovalifolium) were compared. Under the given conditions, the growth of these tree species can be positively evaluated.

Selection of Plant Species for Particulate Matter Removal in Urban Environments by Considering Multiple Ecosystem (Dis)Services and Environmental Suitability

To select plant species for particulate matter (PM) removal from urban environments, it is important to consider the plant species’ ecosystem (dis)services and environmental suitability in addition to their effectiveness in PM removal. In this study, 61 plant species were ranked for PM removal using three separate models: (i) leaf traits, (ii) leaf saturation isothermal remanent magnetization (SIRM), and (iii) ecosystem services and disservices. The plant species’ effectiveness in PM accumulation and the effective leaf traits were identified using leaf SIRM. In each model, plant species were assigned scores and weights for each criterion. The weighted average or the product (Π)-value was calculated for each plant species. The weighted average of each plant species was multiplied by the scores of leaf longevity and leaf area index (LAI) to scale up to a yearly basis and per unit of ground surface area. The preference ranking organization method for enrichment of evaluations (PROMETHEE) method was employed for the services and disservices model because of the lack of precise weights for the included criteria in the model. A scenario analysis was performed to determine a change in the ranking of plant species when the weights of the criteria were modified in the services and disservices model. The plant species with increased ecosystem services and reduced ecosystem disservices were Tilia cordata (Mill.), Tilia platyphyllos (Scop.), Alnus incana (L.), Acer campestre (L.), and Picea abies (L.). The findings of this study can be relevant to urban planners for recommending suitable choices of plant species for the development of urban green spaces.

Investigation of leafy shoots and tea products of European mistletoe (Viscum album L.) with special focus on their antioxidant capacity

Abstract Antioxidants are compounds that inhibit combustion (oxidation) processes. Antioxidants are vital components of our body, which can be obtained in part through plant nutrition. Therefore, it is very important to study species that have significantly higher antioxidant capacity than other species. The aim of the study was to investigate the antioxidant capacity of total polyphenols (TPC) of European mistletoe (Viscum album L.) leafy shoots collected from different species of trees (black locust, European ash, white poplar, field maple and black walnut) based on different methods; DPPH (2,2-diphenyl-1-picrylhydrazyl), FRAP (ferric reducing antioxidant power) and TPC (total phenolic contents). The results proved that the antioxidant effect of leafy shoots from European ash (Fraxinus excelsior) against hydroxyl radicals (ROS) showed significantly higher values than those of the other four tree species. We found that the DPPH, FRAP and TPC methods show significant differences in antioxidant effect of European white mistletoe leafy shoots on the studied tree species and tea brands. However, the FRAP method shows higher sensitivity for trees but for tea brands, the DPPH method is more sensitive. The reason for the difference might be explained by the different methods of drying. In the future, we consider it feasible to plant ash groves at an altitude of at least 80 m above sea level in a closed area, where we can start growing European white mistletoe as an herb. Based on the results obtained European white mistletoe can be recommended as an herb to natural medicine for supplementary treatment of several cancer diseases.

How light pollution can affect spring development of urban trees and shrubs

While artificial light at night (ALAN) is gaining more attention in view of its proven negative effect on animals, including humans, it remains a little-known matter when it comes to plants. Street lamps emit light that can be perceived by plants, and therefore disturb their natural photoperiod. In the present work we examine two different light treatments considered as low intensity (L-LP) and medium intensity (M-LP) light pollution (1 μmol·m−2·s−1 and 30 μmol·m−2·s−1 during the night, respectively) both comparable to different street lamps parameters (based on own field measurements). We have studied the influence of those LP treatments on the spring phenology and physiology of 4 tree species and 4 shrub species. The experiment involved species commonly used in European urban areas: Tilia tomentosa, Betula pendula, Fagus sylvatica, Acer campestre, Cornus alba, Lonicera pileata, Kerria japonica and Spiraea ×cinerea. All the investigated species were influenced by ALAN and developed buds faster than the control group. However, the changes were visible at different stages of bud development depending on species. The light pollution treatments resulted in a reduction of soluble sugars, measured in apical twigs of T. tomentosa, S. ×cinerea, K. japonica and A. campestre. In contrast, the soluble sugar content increased in branches of light-polluted L. pileata and C. alba when compared to the control group. These results prove, that light pollution affects the spring phenology and physiology of deciduous species. Long-term consequences of such reactions require more detailed studies.

Determination of the species structure of phytocenoses of the natural age oak forest of the Dendrological Park "Olexandria" of the National Academy of Sciences of Ukraine

The modern species composition of woody plants of the centuries-old oak grove of the State Dendrological Park "Olexandria" of the National Academy of Sciences of Ukraine was studied.
 The work was carried out as part of the study of the dynamics of stands of oak phytocenoses under conditions of anthropogenic load, technogenic pollution and weather fluctuations.
 It has been established that the oak grove of the arboretum with an area of 446 hectares out of 2000 oaks is a complex multi-species planting. The floristic core of the oak forest consists of the main forest-forming species characteristic of the Right-Bank Forest-Steppe of Ukraine: Quercus robur, Acer platanoides L. and Acer campestre L., Fraxinus excelsior L., Tilia cordata Mill., Carpinus betulus L., Ulmus scabra Mill. The role of the dominant species and edificator was retained by Quercus robur. In the worst growing conditions, monodominant stands are formed. In more favorable ecotopes in the upper tree layer, the participation of Quercus robur is 70–100 %, and its codominant satellites (Acer platanoides, Tilia cordata, Fraxinus excelsior) are 10 % each. All oak forest phytocenoses have a well-developed multi-species second tree layer: Acer platanoides (15–80 % in various phytocenoses), Acer campestre (10–30 %), Tilia cordata (10–60 %), in some phytocenoses Fraxinus excelsior (10–20 %), Ulmus scabra (10–20 %), Carpinus betulus (30 %).
 The group of asectators is diverse and is represented by small species, local and adventive species, introducers, including invasive species.
 A characteristic feature of the oak forest is its exorbitant crushing, which, along with the massive introduction of introduced species, caused a powerful ecotonization of the oak forest and formed the cells of the greatest mortality of Quercus robur.
 The conducted studies establish the modern species composition of the oak forest and are the basis for the study of succession processes in oak forest phytocenoses.

Plant species selection by hybrid multiple-attribute decision-making model for promoting green mining in the Sungun copper mine, Iran.

Adopting the most suitable plant species selection is a multi-dimensional problem. Many parameters affect judges' decisions. Accordingly, the present study aimed to develop a multi-attribute platform for plant species selection consisting of parameters such as aesthetic outlook, resistance in front of insects, plant disease resistance, economic efficiency, pollution prevention, erosion reduction, and growth rate. The plant species selection was performed according to the primary factors. Along with the priorities mentioned above, a multi-attribute decision-making (MADM) model was presented to define the selected species based on the secondary factors. This study used two methods (Entropy and AHP) to attribute weighting because plant species selection is highly case sensitive, and global weighting was fundamental. Therefore, attribute weighting was calculated by two objective and subjective methods, respectively. Then, the ELECTRE method was applied for ranking plant species in acidic and alkaline soil types in the Sungun copper mine of Iran. This case study results showed that Acer campestre, Robinia pseudoacacia, Juniperus communis, Betula pendula, Ulmus minor, and Rhus coriria had more priority in acidic soil type, respectively. Similarly, Juglans regia was the best type for alkaline soil, and either Ficus carica or Fraxinus excelsior is located in the following ranking. When the number of possible options was more significant, the outranking result taken by the ELECTRE method was more reliable.

Romanian Viscum album L.-Untargeted Low-Molecular Metabolomic Approach to Engineered Viscum-AuNPs Carrier Assembly.

Viscum is one of the most famous and appreciated medicinal plants in Europe and beyond. The symbiotic relationship with the host tree and various endogenous and ecological aspects are the main factors on which the viscum metabolites’ profiles depend. In addition, European traditional medicine mentions that only in two periods of the year (summer solstice and winter solstice) the therapeutic potential of the plant is at its maximum. Many studies have investigated the phytotherapeutic properties of viscum grown on different species of trees. However, studies on Romanian viscum are relatively few and refer mainly to the antioxidant and antiproliferative activity of mistletoe grown on Acer campestre, Fraxinus excelsior, Populus nigra, Malus domestica, or Robinia pseudoacacia. This study reports the first complete low-molecular-weight metabolite profile of Romanian wild-grown European viscum. A total of 140 metabolites were identified under mass spectra (MS) positive mode from 15 secondary metabolite categories: flavonoids, amino acids and peptides, terpenoids, phenolic acids, fatty acids, organic acids, nucleosides, alcohols and esters, amines, coumarins, alkaloids, lignans, steroids, aldehydes, and miscellaneous. In addition, the biological activity of each class of metabolite is discussed. The development of a simple and selective phyto-engineered AuNPs carrier assembly is reported and an evaluation of the nanocarrier system’s morpho-structure is performed, to capitalize on the beneficial properties of viscum and AuNPs.

СЕЗОННАЯ ДИНАМИКА ФОТОСИНТЕТИЧЕСКИХ ПИГМЕНТОВ У КЛЕНОВ ACER CAMPESTRE L., A. NEGUNDO L. И A. SACCHARINUM L. В РОСТОВЕ-НА-ДОНУ

The objective of the study carried out at Botanical Garden of Southern Federal University (Rostov-on-Don, Russia) was to assess the seasonal changes in photosynthetic pigments contents in the leaves of the maples Acer campestre L., A. negundo L., and A. saccharinum L. Leaves samples were collected from selected maple trees once a week. The contents of chlorophylls and carotenoids were determined spectrophotometrically and expressed per leaf area (mg/dm2). Similar seasonal changes in chlorophylls a and b in A. campestre, A. saccharinum, and A. negundo have been found. At the same time, the seasonal changes in carotenoids contents in A. campestre differs from those in A. saccharinum and A. negundo. The qualitative and quantitative parameters of the seasonal changes in chlorophylls a and b and carotenoids differ from each other, regardless of species. All maple species differ significantly in the mean contents of photosynthetic pigments, the highest one featured by A. campestre. Using the analysis of variance, variations in the contents of photosynthetic pigments during a season were assessed. Chlorophyll variability is highest in A. campestre and lowest in A. negundo. A very large difference of A. campestre from A. saccharinum and A. negundo was found in the variation of carotenoid contents. The response of photosynthetic pigments to changes in climatic factors is higher in A. campestre than in A. saccharinum and A. negundo. These findings suggest that drought adaptation strategy of A. campestre is active, whereas that of A. saccharinum and A. negundo is passive. Keywords: chlorophyll, carotenoids, maple, adaptation, climatic factors.

Invasive alien species of woody and shrubby plants and assessment of their phytocenotic aggressiveness in the State Regional Nature Park “Medeu”

The aim of the work was to determine the species composition of woody and shrubby plants of the State Natural Park “Medeu” and to identify invasive species. For the first time, an assessment of the aggressiveness of invasive species and their impact on the ecosystem was carried out. The article provides an analysis of the dendroflora of the GRPP “Medeu”. The species composition of native and invasive species was revealed, the degree of aggressiveness of the latter and the peculiarities of their distribution were analyzed using the species abundance assessment scale. It is shown that the uncontrolled spread by self-seeding and overgrowth of particularly aggressive plant species such as Acer campestre, Acer negundo, Fraxinus excelsior has a depressing effect on the local natural flora, leads to the homogenization of ecosystems and a decrease in the biodiversity of cenoses, by reducing the number of individual species and reducing their ranges. This may further lead to the complete destruction of wild fruit forests growing in this region, and disruption of the ecosystem of plant communities in which red Book plants grow. During the survey conducted on the territory of the Medeu State Regional Natural Park were identified 35 naturally growing species of trees and shrubs 5 of which are red-listed, 27 alien species, three of which are classified as aggressive, and 13 invasive species that may eventually become aggressive.

Varijabilnost generativnog potomstva klena (Acer campestre L.) u rasadničkom testiranju

Field maple (Acer campestre L.) is naturally distributed in most of Europe, with the exception of its northern parts. Field maple can serve as a valuable model for researching the sensitivity of its populations to habitat fragmentation, considering lack of silvicultural treatments in its stands. The research aims to determine interpopulation and intrapopulation variability of field maple populations from Bosnia and Herzegovina in the nursery test. The authors researched measured root collar diameter, height, observed forkness and calculated slenderness coefficient of the one-year-old generative material from 18 Bosnian-Herzegovinian populations of field maple, produced in the nursery of Žepče. The descriptive statistics and variance analysis was performed. All analyzed traits showed a high degree of intra-population as well as interpopulation variability, as confirmed by the analysis of variance. The highest average height had provenance Bosanski Brod (46.08 cm) and the smallest Bosanska Dubica (19.11 cm). Kreševo provenance had the highest average root neck diameter (8.27 mm) and Bosanska Dubica (5.24 mm) the lowest. A very low percentage of forkness (6.86%) was determined, and the values of the slenderness coefficient were acceptable for all provenances. The results indicate need for further systematic research on this ecologically valuable species.

Crown allometry and growing space requirements of four rare domestic tree species compared to oak and beech: implications for adaptive forest management

Rare domestic tree species are increasingly being viewed as promising alternatives and additions to current main tree species in forests facing climate change. For a feasible management of these rare species, it is, however, necessary to know their growth patterns and space requirements. This information has been lacking in management and science up to now. Our study investigated the basic crown allometries of four rare domestic tree species (European hornbeam, European white elm, field maple and wild service tree) and compared them to the more established and assessable European beech and oak (sessile oak and pedunculate oak). For our analysis, we used data from eight temporary research plots located on seven sites across south-eastern Germany, augmented by data from long-term plots. Using quantile regression, we investigated the fundamental relationships between crown projection area and diameter, and height and diameter. Subsequently, we used a mixed-effect model to detect the dependence of crown allometry on different stand variables. We derived maximum stem numbers per hectare for each species at different stand heights, thus providing much-needed practical guidelines for forest managers. In the early stages of stand development, we found that European white elm and field maple can be managed with higher stem numbers than European beech, similar to those of oak. European hornbeam and wild service tree require lower stem numbers, similar to European beech. However, during first or second thinnings, we hypothesise that the rare domestic tree species must be released from competitors, as shade tolerance and competitiveness decrease with age. Furthermore, we argue that thinnings must be performed at a higher frequency in stands with admixed European beech because of the species’ high shade tolerance. When properly managed, rare species can reach target diameters similar to oak and beech.