Tilia Cordata Research Articles

Species-specific efficiency in PM2.5 removal by urban trees: From leaf measurements to improved modeling estimates

The growing population in cities is causing a deterioration of air quality due to the emission of pollutants, causing serious health impacts. Trees and urban forests can contribute through the interception and removal of air pollutants such as particulate matter (PM). The dry deposition of PM by vegetation depends on air pollutant concentration, meteorological conditions, and specific leaf traits. Several studies explored the ability of different plant species to accumulate PM on leaf structures leading to the development of models to quantify the PM removal. The i-Tree Eco is the most used model to evaluate ecosystem services provided by urban trees. However, fine particulate matter (PM2.5) removal is still calculated with a poorly evaluated function of deposition velocity (which depends on wind speed and leaf area) without differentiating between tree species. Therefore, we present an improvement of the standard model calculation introducing a leaf trait index to distinguish the species effect on PM net removal. We also compared model results with measurements of deposited leaf PM by vacuum filtration. The index includes the effect of morphological and functional leaf characteristics of tree species using four parameters: leaf water storage, deposition velocity, resuspension rate and leaf washing capacity. Leaves of 11 common urban tree species were sampled in representative areas of the city of Ferrara (Italy) and at different times of the year from 2018 to 2021. This includes four deciduous broadleaf trees (Tilia cordata, Platanus acerifolia, Acer platanoides, Celtis australis), three evergreen broadleaf trees (Quercus ilex, Magnolia grandiflora, Nerium oleander), and four conifers (Thuja orientalis, Cedrus libani, Pinus pinaster, Picea abies). The results provide significant advancement in assessing PM removal using decision support tools such as models to properly select tree species for future urban tree planting programs aimed at improving air quality.

ОЦЕНКА УСТОЙЧИВОСТИ ФОТОСИНТЕТИЧЕСКОГО АППАРАТА ЛИПЫ МЕЛКОЛИСТНОЙ TILIA CORDATA MILL. В ГРАДИЕНТЕ ТЕХНОГЕННОГО ЗАГРЯЗНЕНИЯ Г. ВЛАДИКАВКАЗ

The study of the quantitative content of pigments in the leaves of small-leaved linden growing in linear plantings along roads was carried out on 10 sections of the transport network of the capital of the Republic of North Ossetia in Vladikavkaz. The sites are located in the industrial zone of the city, at different distances from stationary sources of air pollution. The complex impact of all sources of pollution with the level of the atmospheric pollution index (API) from 2.0 to 6.4 was assessed. The choice of research objects and sampling for analysis were carried out by the methods of E.V. Nikolaevskaya, N.P. Krasinsky, A.K. Frolova. The content of pigments (chlorophylls "a", "b"; carotenoids) in linden leaves was determined by the photometric method of V.F. Gavrilenko et al. The concentration of pigments was determined on a FEK-56 photocalorimeter. Statistical data processing was carried out using the methods of biological statistics by V.F. Lakin. The amount of green pigments in the leaves of small-leaved linden is not the same, the level of their concentration increases under conditions of the highest level of air pollution. The leading role in the work of the photosynthetic apparatus is played by chlorophyll "a", the content of which determines the overall picture of their joint content with chlorophyll "b". Changes in chlorophylls and their total amount are similar to changes in the content of carotenoids. An analysis of the obtained materials showed that in areas with a high API, the quantitative content of pigments increases, which is consistent with the results of some researchers (Tarabrin, Rachkovskaya, Kim), but not confirmed by others (Aksenova, Kazantseva, Tsandekova Neverova), which may be caused by an individual species reaction plants. The thickness of the leaf tissue decreases with increasing pollution, the ratio of columnar and spongy mesophyll shifts towards spongy, which will negatively affect the process of photosynthesis

Pomniki przyrody i drzewa pomnikowe wybranych gmin powiatu wejherowskiego (województwo pomorskie)

The paper presents results of a survey of natural monuments and monumental trees in the Wejherowo County, Poland. During the field research it was found that there are 106 monuments of nature in the community of Gniewino, Linia, Luzino and Łęczyce. Under monument protection are as follows: 1 climber, 69 individual trees, 3 alleys, 18 groups of trees and 15 erratic boulders. The largest number of monuments of nature is located in the Łęczyce community (51 natural monuments), while the smallest monuments number is located in the area of the Linia community (3 monuments). In total, there are 65 monuments of nature in the State Forests, which constitutes as much as 61% of the total number in the studied area. Along the roads, there are 22 monuments in cemeteries and 19 on private land. Manor parks are rich in monuments of nature. There are a total of 23 monuments in them. All natural monuments should be labeled with the word “NATURE MONUMENT”, while only 72 of them are marked as such. During the research work, 7 monument trees were selected as follows: 4 specimens of the common beech Fagus sylvatica L., 2 specimens of Coast Douglas-fir Pseudotsuga menziesii (Mirb.) Franco and 1 specimen of small-leaved lime Tilia cordata Mill. Due to its impressive size and standing out among other trees of the same genus or species, they should be taken under monument protection.

Effect of Salt Treatment on the Growth, Water Status, and Gas Exchange of Pyrus pyraster L. (Burgsd.) and Tilia cordata Mill. Seedlings

Two-year-old seedlings of T. cordata and P. pyraster were exposed to salinity for 50 days, whereby each plant was subject to regular applications of a substrate solution containing 100 mM NaCl, amounting to a cumulative volume of 365 mL per plant. The adaptive reactions of the tree species in coping with salt stress were studied. The measured parameters were the growth and distribution of mass to organs, root to shoot mass ratio (R:S), content of assimilation pigments in the leaves, gas exchange parameters (gs, E, An), and water use efficiency (WUE). The relative increase in biomass was reduced under salt treatment for both species. A significant decrease in the total FW and DW was observed only for T. cordata, which deposited 4.5 times more Na+ ions in the plant tissues compared with P. pyraster. In P. pyraster seedlings, Na+ ions mainly accumulated in the root (75%), and their distribution was limited to aboveground organs. Thus, a balanced content of the assimilation pigments in the leaves was maintained under salt treatment. In the initial (osmotic) phase of salt stress, P. pyraster reduced water consumption and maintained a steady rate of photosynthesis (An) per unit area. T. cordata responded to salinity by regulating stomatal conductance and increasing water use efficiency (WUE). T. cordata was not effective in blocking salt intake and transported Na+ ions to the leaves. Due to the high cumulative salt content in the substrate, the water potential of the leaf tissues and the rate of photosynthesis significantly decreased in salt-treated T. cordata seedlings. The results document the important role of the root system in the resistance of woody plants and in ensuring their survival in conditions of excessive salinity. The investment in root growth improved the water supply of P. pyraster seedlings and enhanced the retention of salt ions in the root system, thus limiting their transfer to leaves.

Antioxidant and reducing activity of Tilia cordata honey produced by Apis mellifera compared to inflorescence Tilia cordata infusion and their mixtures

Herbal and apiculture preparations are examples of products with a very long history of medicine and human body care use. This study aimed to compare the antioxidant activity and reduction potential of Tilia cordata honey solution (TCH) and inflorescence Tilia cordata infusion (ITC) as well as their analysis in the ratio of ITC: TCH 1:1, 2:1, and 1:2 (v/v). All performed tests were done with the use of spectroscopic techniques. It was shown that ITC infusion has stronger antioxidant activity and higher reduction properties than TCH solution and the mixtures with a higher proportion of ITC infusion than TCH solution. The highest antioxidant activity and higher reduction properties had samples within the ratio of ITC: TCH 2:1. A synergistic effect in the area of both antioxidant and reduction potential has been confirmed.

Effects of common European tree species on soil microbial resource limitation, microbial communities and soil carbon

Studies of tree species effects on soils have revealed a significant impact on soil organic carbon (SOC) stocks and the carbon (C) distribution between forest floor and mineral soil, but the underlying mechanisms including the roles of litter traits, soil properties, and microbiome remain unclear. To address this challenge, we tested the effect of six common European tree species on the quality and nutrient availability of soil organic matter (SOM) as perceived by the naturally assembled microbial communities and explored the possible links between soil enzyme activities (EAs), microbial resource limitation, and microbial community with SOC stocks. The six studied tree species (Acer pseudoplatanus L., Fraxinus excelsior L, Fagus sylvatica L., Quercus robur L., Tilia cordata L., and Picea abies L.) were planted in common garden monocultures more than 40 years ago at six sites across Denmark. In forest floor, microbial biomass C, fungal and total microbial biomass and fungi to bacteria (F/B) ratios decreased with decreasing litter quality. Ecoenzymatic stoichiometry and relative EAs indicated that microbes in spruce forest floor were more limited by phosphorus (P) than in maple, lime, and beech, while microbes in mineral soils were less P limited in spruce than in other monocultures. Mineral soil under the tree species associated with arbuscular mycorrhizal (AM) fungi had higher microbial C and P limitation, bacterial biomass and total microbial biomass than under tree species associated with ectomycorrhizal (EcM) fungi. Our results indicated that tree species with high-quality litter (i.e. AM-associated trees) had (i) higher microbial biomass and less nutrient limitation that were conducive to higher decomposition rates and lower C stocks in the forest floor, and (ii) such tree species could lead to both greater stabilization of mineral soil C by mineral-associated OM formation and greater microbial mineralization of SOM with higher microbial resource demand. The results suggest that tree species-mediated EA, microbial resource limitation and microbial community composition are important drivers of stocks and vertical distribution of SOC among tree species and between the two types of associated mycorrhiza.

Chemical Composition and Related Properties of Lime (Tilia cordata Mill.) Bark and Wood as Affected by Tree Growth Conditions

Tilia cordata Mill. is a favourite tree used in urban spaces. For this reason, it is important to know its sensitivity to environmental stress, which is particularly burdensome for vegetation in urban spaces. The aim of the study was to investigate the properties necessary to control the growth of these trees and their subsequent use, i.e., chemical properties (percentage contents of cellulose, holocellulose, lignin, pentosans and substances soluble in NaOH and EtOH) as well as the chemical elements (K, Na, Mg, Ca and Fe, Zn, Cu, Pb, Cd, B, Ni, Cr, Al, As and Hg) and selected hygroscopic properties (hysteresis and sorption isotherms). Trees of Tilia cordata Mill. growing in environments exposed to environmental stress of varying severity were examined. Regardless of the growth conditions, in terms of its chemical composition, bark differs significantly from wood, showing twice the contents of soluble substances in NaOH and lignin and half the content of polysaccharides. Growth conditions clearly affect the range of selected chemical components in bark, e.g., substances soluble in ethanol, cellulose, or lignin. The main inorganic elements in bark and wood are Na, K, Ca, Mg and Zn. In bark, a relationship was found between the content of most chemical elements and differing environmental growth conditions. It was shown that environmental stress influenced the hygroscopic properties of wood and bark, which are a consequence of the percentage of chemical components.

The influence of sonication times on bioactive compounds, antioxidant activity values, and phenolic compounds of immature and mature types linden blossoms

The total phenolic contents of immature and ripe linden sonicated at different times were measured between 307.74 (10 min) and 365.87 mgGAE/100 g (30 min) to 364.48 (10 min) and 403.97 mgGAE/100 g (30 min), respectively. In addition, total flavonoid contents of immature and ripe linden sonicated were detected between 938.99 (10 min) and 1236.01 mg/100 g (30 min) to 1200.89 (40 min) and 1483.04 mg/100 g (20 min), respectively. The gallic acid contents of sonicated immature and ripe linden were detected between 11.49 (10 min) 14.70 mg/100 g (40 min) to 6.92 (20 min) and 12.62 mg/100 g (10 min), respectively. While 3,4-dihydroxybenzoic acid amounts of immature linden sonicated vary between 19.78 (20 min) and 24.33 mg/100 g (30 min), 3,4-dihydroxybenzoic acid amounts of sonicated-ripe linden were tested between 17.14 (30 min) and 19.62 mg/100 g (20 min). In addition, sonication affected the quantities of phenolic constituents. Practical applications The use of herbal supplements has increased tremendously over the past two decades. The use of herbs has increased due to the lack of side effects compared to synthetics. Linden is rich in phenolic compounds and these compounds. Tilia cordata has sedative, diuretic, and diaphoretic properties in folk medicine. The use of ultrasonic waves is a new processing technology for extraction of foods.

Drought tolerance differs between urban tree species but is not affected by the intensity of traffic pollution

Key MessageIn an urban area, resistance and resilience of stem diameter growth differ substantially between tree species. Traffic emissions are reflected in wood nitrogen isotopes, but do not affect drought tolerance.With increasing drought and heat, the benefits of urban trees such as shading and cooling become more important. Yet, it is necessary to identify tree species able to withstand such extreme climatic conditions. We studied the resistance and resilience of stem diameter growth of five deciduous tree species in an urban area in Southwest Germany to three exceptional drought periods (2003, 2011 and 2015) for differences between and within species, especially considering the intensity of traffic emissions (NOx). Analyses of the stable isotopic composition of carbon (δ13C) and oxygen (δ18O) as well as the intrinsic water-use efficiency (WUEi) in the tree rings were carried out. Further, we investigated the stable isotopic composition of nitrogen in the wood (δ15N) to assess its potential as an indicator of NOx emissions from traffic. Stem diameter growth in all species was strongly limited by low water availability in spring, as was also reflected in elevated δ13C and δ18O values in Acer platanoides and Tilia cordata, which were particularly sensitive to drought. In contrast, growth of Platanus × hispanica and Quercus robur was less affected by drought, and resistance of Carpinus betulus ranged in between. Across species, δ15N was higher in trees located closer to roads and exposed to higher NOx traffic emissions. Unexpectedly, these conditions did not significantly affect drought resistance/resilience. Our study demonstrates the potential and interpretative challenges of coupled dendroecological and isotope analyses. It also indicates clear species-specific differences in drought tolerance and thus helps to identify suitable urban tree species.

Cenopopulation of Epipactis helleborine (Orchidaceae) in forest ecosystems that have been anthropogenically transformed to various degrees

Because of developed symbiotic connections of the root system of trees, mycorrhiza-forming fungi and the orchid family Orchidaceae in forest ecosystems of the northeast Polissia Region – cultivated Pinus sylvestris, which are now 100–120 years old, recovery of cenopopulations of Epipactis helleborine has been observed in locations of mixed and broad-leaved forests. In natural plant cover of mature pines of the region, indigenous vegetation is gradually recovering – there occur young Quercus robur, Tilia cordata, Acer platanoides of various ages, crown density of understory formed by Coryllus avellana has reached 0.6, above-ground organic leaf foliage that is able to sustain moisture and increase fertility of soil accumulates, creating sufficient conditions of shading for seedlings and juvenile individuals of forest orchids. Special studies revealed a relationship between density of E. helleborine specimens and crown density of the tree stand, shrub strata, structure of soil cover, expressed in cenoses under various degrees of recreational pressure. Density of individuals of forest orchids in the studied populations ranges 10.0 to 0.1 ind./10 m2. Dynamics were seen in groupings of Betuleto-Pineta corylosa, Querceta (roboris) corylosa, Querceto-Pineta corylosa, Acereto (platanoidis) –Tilieto (cordatae) – Quercetum (roboris) aegopodiosum in the territory of the nature-reserve fund and structurally similar anthropogenically pressurized cenoses. We determined that all examined cenopopulations in old indigenous zonal cenoses in the territory of the nature reserve fund are normal, they may be considered relatively stable, ontogenetic spectra are incomplete, mostly with right-sided age spectrum – maximum numbers of virgin and generative individuals of various stages. Low density of individuals and incomplete spectra of cenopopulations in light oak forests are natural, and now the largest share of generative and virgin individuals is concentrated in this area. Impact of recreation, unavoidable due to proximity to a road, is a negative factor directly decreasing their density. Ontogenetic spectra of all cenopopulations are incomplete – no seedlings were found in the natural conditions due to underground type of germination. Much more interesting data may be obtained by monitoring studies of age and morphometric dynamic changes during several years.

Volatile Constituents of Some Selected Plant Species Traditionally Used as Tea in the Sharri Mountains (Kosovo).

The study evaluates the chemical composition of the volatile constituents of ten plant species traditionally used as herbal tea in the Sharri Mountain regions (Kosovo and North Macedonia). Volatile constituents responsible for the flavour and fragrance of selected species (Crataegus monogyna, Cydonia oblonga, Malus sylvestris, Matricaria chamomilla, Morus alba, Morus nigra, Rosa canina, Sambucus nigra, Tilia cordata, and Vaccinium myrtillus) were separated and then identified using GC-MS, whereas GC-FID is employed for the quantitative analysis. Experimental data revealed different patterns of volatile constituents depending on plant species. Monoterpenes, sesquiterpenes, diterpenes, and norisoprenoids were the most abundant volatile constituents. Principal component analysis (PCA) was deployed for data analysis and resulted in grouping these ten species in four principal clusters. The combination of various volatile constituents present in specific plant species may play an important role in the specific aroma and taste sensation of these species used as recreational teas.

Crown Shapes of Urban Trees-Their Dependences on Tree Species, Tree Age and Local Environment, and Effects on Ecosystem Services

Crown shapes of common European urban tree species differ from tree species to tree species and are modified by the age of a tree and its local environment. A tree’s crown shape has a great influence on the crown volume and thus on the ecosystem service provision of a tree such as the shade area or the shade density. We used the data of 3852 tree individuals from eight German cities and the crown shape data of 528 trees for the species Acer platanoides, Acer pseudoplatanus, Aesculus hippocastanum, Fraxinus excelsior, Platanus × acerifolia, Robinia pseudoacacia and Tilia cordata to analyze tree structural dimensions and the crown volume and shade dependency on a tree’s crown shapes. Ovoid (57% of all tree individuals) and spherical (24%) crown shapes were mostly observed. However, columnar shape was observed for light-demanding R. pseudoacacia in close proximity of objects. The greatest shade areas were measured for spherical shape and the highest shade density for ovoid shape. Logistic regression analysis showed significant effects of age and distance to objects on crown shapes. Significant probability of crown shapes was found for different tree species, e.g., A. hippocastanum strongly showed half-ellipsoid crown shapes.

The Importance of Flavonoids and Phytochemicals of Medicinal Plants with Antiviral Activities

Abstract: In this mini-review article, we have mentioned the key roles of some of the most important herbal plants medicine containing flavonoids and phytochemicals with antiviral activities. All relevant information was searched by using the terms, influenza, phytochemicals, SARS, SARSCov- 2, flavonoids, and traditional medicinal plants uses, from reliable databases, such as PubMed, Science Direct, and Google Scholar. The most important medicinal herbs which contain flavonoids with antiviral activities are Limonium densiflorum, Oroxylum indicum, Tribulus terrestris L., Paulownia tomentosa Steud., Allophylus africanus, Houttuynia cordata, Moslea Herba, Mosla scabra, Scutellaria baicalensis, Berries, Genus Psoralea, Sophora tonkinensis, Trollius chinensis, Tilia cordata, Hippophae rhamnoides L. (Seabuckthorn), Paulownia tomentosa steud, and C. swietenia. Phytochemicals are chemicals of plant origin produced by plants through primary or secondary metabolism. The most important medicinal plants, which contain phytochemicals with antiviral activities are Blue honeysuckle (Lonicera caerulea L.), Forsythia suspense, Ligustrum lucidum, Radix Paeoniae Alba (Bai Shao), Banlangen (Radix Isatidis), Lysiphyllum strychnifolium, Phellinus baumii, Mesona chinensis, Sanguinaria Canadensis, Dodonaea viscosa, Isatis indigotica, Pelargonium sidoides, Entada Africana Guill., Pomegranate (Punica granatum), Goldenseal (Hydrastis canadensis), Lychee fruit extract, Lycoris radiate, Cistus incanus, Chaenomeles sinensis Koehne (Chinese quince), Geranium sanguineum L., and Tea polyphenols. Natural products from traditional herbal medicines, especially traditional Chinese and Persian medicines, have been found to exert antiviral impacts against influenza and human coronaviruses. The natural plant-derived compounds that have been used for treating various diseases are flavonoids and phytochemicals.

Reproductive strategy of a temperate canopy tree Tilia cordata Mill. (Malvaceae) is related to temperature during flowering and density of recent recruits

Facultative clonality is extremely common in plants, but the relative emphasis on sexual versus asexual reproduction varies both between and within species, which in turn may influence individual fitness and population persistence. Tilia cordata is a temperate, entomophilous canopy tree that is partially clonal. Favourably warm climatic conditions have been linked with successful sexual reproduction in the species with clonality being suggested as the reason for population persistence in colder periods. Despite this the extent, character and structure of asexual reproduction in the species have never been described, nor has its relationship with climate. Fine-scale spatial genetic structure was assessed in 23 stands across a latitudinal gradient. The proportion of individuals that are of clonal origin has a wide range with a mean of ~43%. Genetic diversity is high, with even mostly clonal stand possessing several distinct genotypes. A beta regression model shows that historic summer temperatures and density of recent recruits are predictors of the proportion of clonal recruitment. Clonal reproduction is less important in stands that experience higher temperatures during flowering while stands with more saplings have more clones. Additional factors likely affect the balance between the two reproductive modes. The climatic relationship suggests a trend towards a higher proportion of recruitment from seed in a warming climate, although factors such as herbivory may prevent this.

Antibacterial and antioxidant activity of flavonoid, glycoside and alkaloid extracts of Tilia Cordata

About 12,000 chemical compounds isolated from medicinal plants and used to conduct crucial biological functions. These phytochemicals offer long-term health benefits for humans, thus they can be used effectively for treat a variety of human ailments. The goal of this study was to assess the in vitro free radical scavenging and antibacterial activities of glycoside, flavonoid and alkaloid extracts of Tilia cordata plant. According to the findings, flavonoid extract exhibits strong inhibitory action against Staphylococcus aureus but no activity against Escherichia coli. The free radical scavenging activity exhibited that the flavonoid extract was more effective in inhibiting lipid peroxidation more than alkaloid extract, whereas the glycoside extract had no antioxidant activity.

Effects of Controlled Mycorrhization and Deficit Irrigation in the Nursery on Post-Transplant Growth and Physiology of Acer campestre L. and Tilia cordata Mill.

The goal of this work was to assess the effects of mycorrhizal inoculation and deficit irrigation applied in the nursery on the post-transplant growth and physiology of Acer campestre L. and Tilia cordata Mill. For this purpose, 144 preconditioned plants were planted in an experimental plot in northern Italy and were monitored for three growing seasons. Controlled inoculation in the nursery enhanced the root colonization rate three years after transplanting only in Acer campestre. Inoculated Acer campestre showed higher survival, shoot length, turgor potential and leaf gas exchange than non-inoculated plants throughout the experiment. By contrast, in Tilia cordata, no difference in root colonization by mycorrhizal fungi was observed between plants inoculated or not in the nursery three years after transplanting. Indeed, the survival, growth and physiology of Tilia cordata after transplanting were little affected by inoculation. Deficit irrigation in the nursery determined higher survival, growth and CO2 assimilation rate and more favorable water relations in newly transplanted Acer campestre. By contrast, Tilia cordata exposed to deficit irrigation in the nursery showed lower growth and unaffected survival after transplanting compared to plants which received full irrigation in the nursery. The overall results suggest that nursery preconditioning through mycorrhizal inoculation and deficit irrigation can affect post-transplant performances, although their effectiveness depends on species’ mycorrhizal dependency and water use strategy.

Are Trees Planted along the Roads Sustainable? A Large-Scale Study in the Czech Republic

Trees provide a wide variety of ecosystem services to society and form the character of the environment and landscape. The analyses of tree populations and their resistance to changing conditions related to climate change typically focus on urban tree communities or forest trees. Similar studies on non-forest trees in the open landscape are largely missing; even the evidence on tree species abundance and distribution is sporadic. The article aims to expand the current evidence by a large-scale study on roadside trees in the Czech Republic. Using an extensive dataset that covers 91.2% of the total tree population along roads in nine NUTS3 regions, we assess the state and observed practices in selecting tree genera for roadside planting and discuss the implications for sustainable tree planning and management. Our survey documented 133,169 tree individuals belonging to 116 species and 40 genera. The results show that 75% of the total roadside plantings along second-class motorways and first-class roads are represented by seven main genera of deciduous trees (Acer, Fraxinus, Tilia, Malus, Betula, Populus, and Quercus), the distribution of which is similar across most Czech regions. New plantings have shifted only a little from the original species distribution. Traditional roadside species are becoming a more popular choice among new plantings, and the effort not to let the invasive trees outgrow into the mature stage is apparent. Most of the original and newly planted species are relatively suitable for emerging risks related to climate change. To achieve more sustainable patterns in roadside tree species composition in the future, especially the susceptibility of some commonly planted roadside tree species to emerging pests and diseases (e.g., Fraxinus excelsior) and to unfavorable site conditions typical for roadside tree stands (Tilia cordata) is of relevance to tree managers. The relative abundance of tree genera was proven to be similar in most studied regions, which makes the recommendations equally relevant for roadside tree managers across the country.

Analyzing Air Pollutant Reduction Possibilities in the City of Zagreb

This paper aims to present possible areas to plant different vegetation types near traffic jams to reduce air pollution in the capital of Croatia, the city of Zagreb. Based on main traffic road and random forest machine learning using WorldView-2 European cities data, potential areas are established. It is seen that, based on a 10 m buffer, there is a possible planting area of more than 220,000 square meters, and based on 15 m buffer, there is a possible planting area of more than 410,000 square meters. The proposed plants are Viburnum lucidum, Photinia x fraseri, Euonymus japonicus, Tilia cordata, Aesculus hippocastanum, Pinus sp., Taxus baccata, Populus alba, Quercus robur, Betula pendula, which are characteristic for urban areas in Croatia. The planting of proposed trees may result in an increase of 3–5% in the total trees in the city of Zagreb. Although similar research has been published, this paper presents novelty findings from combined machine learning methods for defining green urban areas. Additionally, this paper presents original results for this region.

Herbivore‐induced branching increases sapling survival in temperate forest canopy gaps

Abstract Tree architectures reflect the main abiotic and biotic selection pressures determining tree growth and survival. Studies have shown that trees growing in herbivore‐dominated ecosystems, such as savannas, develop denser, more divaricate ‘cage’‐like architectures in response to chronic browsing pressure (also known as ‘brown world’ architectures). In contrast, trees growing under resource‐limited conditions develop traits that allow them to better compete for abiotic resources (referred to as ‘green world’ architectures); for example, light limitation can induce trees to form more pole‐like structures that allow them to grow faster in height. In temperate forests, abiotic drivers have traditionally been assumed to be the main factors affecting plant architecture. However, gap dynamics typically characterize old‐growth temperate forests, where disturbances such as storms create gaps with temporary high‐light availability, but also attracting intense mammalian browsing. Under such conditions, one would expect tree saplings to exhibit high architectural plasticity enabling them to develop a ‘cage’ in response to high herbivore pressure, but when herbivore pressure declines switch to a more pole‐like structure that allows them to grow quickly in height and compete for light. We tested the ability of five dominant European tree species to induce a ‘cage’ architecture (hereafter referred to as ‘cage plasticity’) under contrasting light and herbivory regimes in a full‐factorial experiment in Białowieża Forest. We planted 720 young tree saplings in six replicated blocks in which we manipulated ungulate browsing (exclosure vs. control) and light levels (gap vs. closed forest). Two out of the five species (hornbeam Carpinus betulus and lime Tilia cordata) were able to develop a cage when exposed to ungulate herbivores but only under high‐light conditions. These two species had the highest survival rates in the herbivory treatment over a 10‐year period. Synthesis. Cage plasticity in temperate forest tree species may reflect an overlooked adaptation to mammal herbivory originating in a past when large mammals exerted strong selection pressures in European ecosystems. Our findings challenge the view of closed‐canopy forest communities being solely driven by abiotic drivers and call for a re‐evaluation of the importance of large herbivores in shaping the functional traits of temperate tree species.

Genotyping-by-Sequencing Analysis Shows That Siberian Lindens Are Nested within Tilia cordata Mill

Tilia sibirica and T. nasczokinii are considered to be endemic Siberian linden species. They have very small distributions located hundreds to thousands of kilometers away from other lindens. It is unclear how closely these species are related to the widespread Tilia cordata: according to the current hypotheses, they could be pre-Pleistocene relicts or remnants of the recent continuous range of T. cordata that existed during the Holocene climatic optimum. Earlier studies detected significant differences between T. sibirica, T. nasczokinii, and T. cordata in microsatellite loci, but not in plastid sequences. Here we performed a phylogenetic analysis of several linden species based on GBS data. The obtained GBS sequences were assembled to create phylogenetic trees based on 16,000–294,000 variable sites. We found that T. cordata and the two putative Siberian species formed a monophyletic group. It consisted of three clades: the basal clade containing specimens from the Caucasus, and two sister clades representing populations from the East European Plains+the Urals and Siberia, respectively. Neither of the Siberian species was related to the Far Eastern T. amurensis, as was hypothesized earlier. Our study suggests that the colonization of Europe and Siberia after the Last Glacial Maximum occurred from different glacial refugia.