Acer Platanoides Research Articles

Oviposition selection in spotted lanternfly: impact of habitat and substrate on egg mass size and hatchability.

Oviposition strategies adopted by insects (e.g., habitat selection, substrate preference, egg size, clutch size, structure, arrangement, parental care) are critical to the survival and development of their eggs. The impact of habitat and oviposition substrate on spotted lanternfly egg mass size and hatchability was studied in Pennsylvania through laboratory observations and field monitoring in 2019 and 2021. Eggs were arranged in single layers of 1-13 columns (1-18 eggs/column) on surfaces of various types of oviposition substrates, with the longest column(s) in the middle of the egg mass. Egg mass size was positively correlated with column number, with a mean of 26.6-35.1 (0-105) eggs/egg mass for different samples. Significant differences in egg mass size were observed between study sites, with larger egg masses found at Wertz (44.8), Sam Lewis (40.6), Pinnacle (39.1), Marsh Creek (37.9), Susquehannock (34.5), and Memorial Lake (33.3) and smaller egg masses at Nolde Forest (25.0), Gordon (24.4), and Antietam (21.0). Significant differences were also detected between types of oviposition substrates with smaller egg masses found on American hornbeam (22.7). In general, more (31.6%-48.0%) eggs hatched in the field compared with the laboratory (10.0%). Egg hatch success was positively correlated with egg mass size, with the highest rates recorded on American beech, American hophornbeam, black birch, black cherry, black locust, hackberry, Norway maple, red maple, and sweet cherry at Wertz, Marsh Creek, Memorial Lake, and Pinnacle. Potential (positive or negative) impacts of tree-of-heaven density, initial infestation, treatment history, and incubation conditions are discussed.

Current state of decorative tree plants in ordinary street plantations of Kyiv

An increase in the level of anthropogenic load in urban complexes leads to negative ecological changes in the environment. Urban plantations are able to somewhat smooth out these shortcomings by their influence on the microclimate within the local territory. According to statistical data, every year the indicator of the provision of green spaces for the residents of Kyiv decreases, which, in particular, is caused by the unsatisfactory condition of street plants. The main purpose of the publication is to highlight the results of the research on the assortment of woody plants, to assess their general condition on the busiest streets and avenues of Kyiv, and to provide recommendations for creating a perspective list of plants for urban street landscaping. The article analyzes the data of the inventory, which was conducted within ordinary street plantings in 2021. It was determined that the most common street plantings are Tilia cordata, Aesculus hippocastanum and Populus nigra. A comparative analysis of the main range of plants in the street plantings of Kyiv for 2009 and 2021 was conducted and it was established that the number of and Populus nigra decreased and the percentage of Robinia pseudoacacia, Fraxinus excelsior increased. The assessment of the general state of plants indicates that the largest share of plants is in a satisfactory state – 50%. The best condition was noted in Robinia pseudoacacia, Acer platanoides and Tilia cordata. Attention is drawn to the general condition of woody plants in terms of the percentage of inactive photosynthetic surface and high resistance to urban conditions of Acer platanoides, Fraxinus excelsior and Robinia pseudoacacia is revealed. The analysis of experimental data provides grounds for determining the main and additional range of woody plant species that are recommended for use in street landscaping with further study of their stress resistance

Dynamics of foliar concentrations of photosynthetic pigments in woody and herbaceous plant species in the territory of an industrial city

Background. Plants growing in urban ecosystems are negatively affected by anthropogenic activities associated with environmental pollution. Plant photosynthesis is one of the processes that are particularly affected by environmental conditions, including the presence of pollutants in the atmosphere and soil. However, the dynamics of photosynthetic pigments, namely chlorophylls (Chl) and carotenoids, in plant species growing in urban ecosystems have not been sufficiently studied. The aim of this study was to analyze the effect of technogenic load on the content of pigments of photosynthesis in the cells of woody and herbaceous plants common in industrial cities, using the example of the urban ecosystem of Lviv located in the western part of Ukraine. Materials and Methods. The study was carried out at four experimental sites within the city of Lviv with different levels and types of technogenic load. Site S1 selected in the central part of the Stryiskyi park was considered as a control one. Site S2 was chosen in an area with a combined technogenic load, including road and rail traffic, and the operation of the combined heat and power plant-1 (CHPP-1). Sites S3 and S4 were subjected mainly to vehicular traffic. Leaves of six plant species were collected at sites S1–S4, including woody plants (Acer platanoides L., Aesculus hippocastanum L. and Tilia cordata Mill.) and herbaceous plants (Plantago major L., Taraxacum officinale F.H.Wigg. and Urtica dioica L). The concentration of Chl a, Chl b, the total Chl content and the concentration of carotenoids were determined spectrophotometrically. Results. The analyzed plant species growing at site S1 had the highest levels of total Chl and carotenoids compared to other sampling sites. In plant leaves collected at sites S2–S4, the total Chl content was 1.5–3.2 times lower than in the leaves collected at the site S1. The ratio of Chl a and Chl b concentrations was generally lower in plants growing at sites S2–S4 compared to plants from site S1. The concentration of carotenoids in the leaves of woody plants collected from sites S2 and S4 was 1.4–2.4 times lower compared with site S1, while in the leaves of herbaceous plants sampled at sites S2–S4, the concentration of carotenoids was 1.5–2.6 times lower than at site S1. Conclusions. The results of the study suggest that the concentration of both chlorophyll and carotenoids in the leaves of the analyzed herbaceous and woody plant species growing in the territory of an industrial city is influenced by anthropogenic impact associated with atmospheric pollution in the areas of plant growth. These indices are lower in plants growing in areas with technogenic load compared with plants growing in the green zone of the city. At the same time, the concentration of chlorophyll in the leaves of the analyzed plant species growing under urban conditions was found to be more sensitive to anthropogenic load compared to the foliar concentration of carotenoids. Therefore, the concentration of chlorophyll in plant species growing in cities can be one of the biomarkers for assessing the level of pollution caused by anthropogenic load in urban ecosystems.

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.

ЛЕСООБРАЗОВАТЕЛЬНЫЙ ПРОЦЕСС В ПРЕДЕЛЬНО УЗКОЙ ПОЛЕЗАЩИТНОЙ ЛЕСНОЙ ПОЛОСЕ

In the last 30 years, hundreds of thousands of hectares of young shelterbelts in the forest-steppe and steppe zones of Russia were left without proper forest management, and their condition is deteriorating every year. Forest belts are losing their protective and ameliorative functions, while the degradation of agricultural landscapes under the pressure of intensive production continues. For the successful functioning of agricultural landscapes, the presence of forest components is necessary, as stated by the founder of Russian soil science, prof. V.V. Dokuchaev. The article reveals the process of evolution of the forest belt, consisting of a narrow chain of English oak biogroups into a full-fledged forest biocenosis. Forest elements are formed in the forest belt: forest edge, forest litter, self-sowing of oak, Norway maple, red leaved ash, pear, hawthorn and blackthorn. The unsatisfactory condition of 58-year-old oak trees grown per 1 m2 from two to twelve pieces without thinning has been analyzed. The authors came to the conclusion that Yu. Odum's theory of "mutual assistance" among individuals of a biogroup is valid only at the initial period of development of a single plant of a biogroup, after which competition begins. To obtain a viable biogroup, it is necessary to regulate the number of plants, in this case, oak trees. The process of regulation should be started from the moment of closing the crowns in the biogroup

Participation of Rossiulus kessleri (Diplopoda, Julida) in the Formation of Algae Assemblages of Urbanized Territories

Epi- and endozoochory are well explored phenomena that contribute to the distribution patterns of plant seeds, spores or fruits by vertebrates. It is less known how soil algae may be redistributed due to analogous interactions. We describe the participation of saprophage Rossiulus kessleri (Julidae, Diplopoda) in soil algae redistribution. The research was carried out in a park area of a large industrial megacity in the Dnipro steppe region (Ukrainian North Steppe subzone), Dnipro city. Research material was collected according to zoological and algological methods. The leaf litter of tree species (ash maple Acer negundo, Italian poplar Populus deltoides, locust Robinia pseudoacacia, European white elm Ulmus laevis, Norway maple Acer platanoides) and living diplopods were collected within 1 m2 quadrats along transects. Millipedes were maintained without feeding for five days, after which they were fed with the litter collected previously. Identification of algoflora was conducted in washes from the surface of diplopods’ bodies, its gut washes, in diplopods’ excretions and leaf litter washes. In the leaf litter, as R. kessleri’s feeding base, 14 soil algae species were identified—Nostoc punctiforme, Bracteacoccus minor, Mychonastes homosphaera, Neospongiococcum sp., Chlamydomonas sp., Chlorella vulgaris, Stichococcus bacillaris, Pseudococcomyxa simplex, Desmococcus olivaceus, Trebouxia spp., Klebsormidium flaccidum, Nephrodiella phaseolus, Navicula pelliculosa and Vischeria magna. In body surface washes, five soil algae species were identified, in gut washes seven algae species were found, while in excretions, just four were observed. It was established that not all algae species from the gut washes of R. kessleri were present in excretions. The presence of some representatives of soil algae, for example, Chlorella vulgaris and Vischeria magna, in natural park litter, body surface washes, gut washes and in excretions of R. kessleri, suggests that the given species pass through the diplopod’s gut and stay undamaged. This indicates that soil saprophage R. kessleri contributes to the dispersal of some soil algae representatives through epi- and endozoochory. Our results represent novel contributions to the knowledge of zoochory. It was shown that animals can be involved in dispersal of not only plant parts but also entire organisms, although it is unknown at what scale diplopods contribute to the diversity and dispersal of algae.

Ecological Characterization and Bio-Mitigation Potential of Heavy Metal Contamination in Metallurgically Affected Soil

Heavy metals (HMs) remain persistent in soil for a long time and thus present a long-term threat of environmental pollution. In this study, the concentrations of some HMs (As, Cu, Zn, Pb, and Mo) in soil, potentially affected by the ex-operation of a metallurgical plant—specifically, a copper smelter in Alaverdi Town, northeastern Armenia—were measured, based on which, the HM contamination and its ecological, biological, and health effects were assessed. Concentrations of HMs (Cu, Zn, and Pb) were also measured in different plant (leaves) and invertebrate species that occur in the soil over the metallurgical factory site in order to assess the potential for the bioremoval of HMs from the soil. The results showed that the ex-operation of the metallurgical facility created such contamination in the soil that it caused a noticeable loss of invertebrate biomass in the soil and posed ecological, non-carcinogenic (for children), and carcinogenic health hazards. The investigated plant and invertebrate species were characterized by different capacities for the accumulation of HMs from the soil, based on which the plant species Fraxinus excelsior, Acer platanoides, Robinia pseudoacacia, and Aesculus hippocastanum and the invertebrate species Deroceras caucasicum, Limax flavus, and Eisenia rosea are recommended to be used for the selective removal of HMs (Cu, Zn, and Pb) from the soil.

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.

Flowering behavior of clones in a Norway maple (Acer platanoides) seed orchard and mating system analysis using nuclear SSR markers

Norway maple (Acer platanoides L.) is a tree species native to Central Europe and occurs in scattered or in small populations mixed with other tree species. Since Norway maple is considered to be adaptable to climate change, it has increasingly become a focus of forestry as one of the so-called alternative tree species to diversify species composition in forests. However, little knowledge exists on the phenotypic variation in the natural range, and no studies on the reproductive behavior of this monoecious and insect-pollinated tree species. The sexual system of Norway maple is known as heterodichogamous, with male-first and female-first flowering individuals mixed in a population. In a first step, we conducted a mating system analysis in a seed orchard. We used a recently developed set of species-specific SSR markers to genotype the parental clones and respective seed samples. The total seed had proportions of 68% outcrossed offspring between clones of the seed orchard, 11% selfing and 20% external pollination. Four flower types were observed, with protogynous and hermaphrodite types contributing more female gametes, while the protandrous type is highly variable in its female or male contributions. The number of ramets per clone in the seed set has a significant impact on the proportion of genetic contribution per clone to total seed yield. Conclusions are drawn for the establishment of new seed orchards and for further research.

Understorey light quality affects leaf pigments and leaf phenology in different plant functional types.

Forest understorey plants receive most sunlight in springtime before canopy closure, and in autumn following leaf‐fall. We hypothesised that plant species must adjust their phenological and photoprotective strategies in response to large changes in the spectral composition of the sunlight they receive. Here, we identified how plant species growing in northern deciduous and evergreen forest understoreys differ in their response to blue light and ultraviolet (UV) radiation according to their functional strategy. We installed filters in a forest understorey in southern Finland, to create the following treatments attenuating: UV radiation below 350 nm, all UV radiation (< 400 nm), all blue light and UV radiation (< 500 nm), and a transparent control. In eight species, representing different functional strategies, we assessed leaf optical properties, phenology, and epidermal flavonoid contents over two years. Blue light accelerated leaf senescence in all species measured in the understorey, apart from Quercus robur seedlings, whereas UV radiation only accelerated leaf senescence in Acer platanoides seedlings. More light‐demanding species accumulated flavonols in response to seasonal changes in light quality compared to shade‐tolerant and wintergreen species and were particularly responsive to blue light. Reduction of blue and UV radiation under shade reveals an important role for microclimatic effects on autumn phenology and leaf photoprotection. An extension of canopy cover under climate change, and its associated suppression of understorey blue light and UV radiation, may delay leaf senescence for understorey species with an autumn niche.

STRUCTURE OF SEQUESTERED CARBON IN THE BIOMASS OF FOREST STANDS IN THE GARDEN ART PARK-MONUMENT OF NATIONAL SIGNIFICANCE “FEOFANIA”

-The state of forest ecosystems and processes of carbon sequestration have both global and local significance upon investigating the influence of natural and anthropogenic factors on biogeochemical cycles. The study of the consequences of their impact on forest stands is initiated by international and state environmental programs aimed at solving the problems of climate change. Sequestration of carbon in the biomass of forest stands depends on the productivity of stands, the formation of tree mortality and the conduct of economic activities. The purpose of the study was to establish the regularities of changes in the reservoir of sequestered carbon in the biomass components of the stands in the garden art park-monument “Feofania”. The processes of transformation of forest ecosystems were investigated on permanent experimental plots of the “Feofania” Park territory using the methods of forest inventory. The observations results confirmed the general increase in the reservoir of sequestered carbon in the biomass of tree stands and the multi-vector dynamics of the sequestered carbon structure in the live biomassand mortmass of tree stands. Evidence of decrease in the carbon-sequestering potential of stands under intense mortality and lesser increase in the live biomass of stands was obtained. From an ecological standpoint, a positive trend towards an increase in the share of coarse woody debris (mortmass) in the biomass structure of permanent plots was established. The main carbon structure of biomass, according to the species composition, is represented by common oak, common hornbeam, and Norway maple. Nature protection decisions and measures implemented in the territories of the natural reserve fund should increase the intensity of carbon sequestration in biomass and the resistance of forest ecosystems to the influence of environmental factors. Given the priority of carbon sequestration in the biomass of tree stands as an ecological function, it is necessary to practice measures to promote current increment in carbon sequestered in the biomass and increase the resistance of trees to natural and anthropogenic disturbance

Tree Composition and Size Structure Based on Nativity and Deer Resistance at an Urban Forest in Southeast Pennsylvania

Urban forests of northeastern North America are often seen as degraded ecosystems with little ecological diversity or value. This is especially true given that native tree species declines in these forests have resulted from low recruitment caused by abundant exotic species, mortality from pathogens and pests, and severe deer browse. This study assessed tree composition and size structure of species found at the Robert B. Gordon Natural Area for Environmental Studies, an urban 51 ha forest fragment located 36 km west of Philadelphia, Pennsylvania. The study quantified and compared tree species from 15 plots located in mid- to late-successional forest stands. Species were categorized as native or exotic and resistant or nonresistant to deer browse. We quantified tree densities per species and measured diameter at breast height of all individuals > 2.5 cm and used this information to quantify relative importance values and assign trees to size classes. Natives Liriodendron tulipifera and Fagus grandifolia, and exotic Acer platanoides, dominated composition (i.e., 45.3% of total relative importance), with L. tulipifera most dominant. Natives had significantly greater densities than exotics in all size classes that included both categories, except for a 10–20 cm class, regardless of whether F. grandifolia, a prolific root sprouter, was included or excluded from comparisons. When F. grandifolia was excluded, nonresistant species had significantly greater densities than resistant ones in classes ranging from the smallest to larger classes. The prominence of nonresistant species in the smallest classes was unexpected given intense deer browsing.

Effects of environmental factors and management on dynamics of mixed calcareous forests under climate change in Central European lowlands

Mixed lowland forests reserved for natural succession are sparse in the Czech Republic. However, their development provides essential insights into the natural processes of these forests and recommendations for forest management in a changing climate. The research describes the dynamics, productivity, structure, diversity, dead wood, and radial growth of hornbeam-oak groves and calcareous beech-dominated forests in the Karlštejn National Nature Reserve (Czechia) based on inventory in 2002, 2008, 2014 and 2020. The objective was to evaluate changes in differently managed stands (high forest, coppice with standards, and coppice) after leaving the stands to spontaneous development in 2004. The tree density increased by 2–10% from 2002 to 2014 and decreased by 6–18% in 2020. In the high forest, an increase in the stand volume was observed during the whole period, while in the coppice with standards and coppice, only until 2014. The stand volume ranged from 190 (coppice) to 630 (high forest) m³ ha−1 in 2020 and increased by an average of 28% over 18 years. Overall diversity of tree layer showed an uneven structure in the high forest and a substantially diverse structure in the other variants. The deadwood volume has been steadily increasing (18–35 m³ ha−1 in 2020), accumulating an average of 1 m³ ha−1 yr−1. A lack of precipitation and high temperatures from June to August were the main limiting factors of the radial growth of tree species, while the number of negative pointer years has increased in the last decade. European beech (Fagus sylvatica L.) was the most sensitive tree species to climate compared to the resilient European ash (Fraxinus excelsior L.). The lowest fluctuations in the diameter increment were recorded in Norway maple (Acer platanoides L.) and the highest in beech in the temperature cycles of 7–15 years. Over the last 20 years, sessile oak [Quercus petraea (Matt.) Liebl.] showed an increase in radial growth by 7%, while other tree species reported a decrease with a maximum in beech (by −38%). The forest stands managed as high forest, characterized by a higher production potential and lower diversity, had slower dynamics when compared to coppice with standards and coppice.

Population Differentiation in Acer platanoides L. at the Regional Scale—Laying the Basis for Effective Conservation of Its Genetic Resources in Austria

Norway maple (Acer platanoides L.) is a widespread forest tree species in Central and Northern Europe but with a scattered distribution. In the debate on climate change driven changes in species selection in the forest, Norway maple has recently received raised interest because of its comparatively high drought resistance (higher than in sycamore maple). Therefore, it is an interesting species for sites high in carbonates and where other native tree species have become devastated by pathogens (e.g., elm, ash). In Austria, the demand on saplings is currently rising, while there is only very little domestic reproductive material available (on average more than 95% of saplings are imported from neighboring countries). This study was undertaken to identify genetic diversity and population structure of Norway maple in Austria to lay the foundation for the establishment of respective in situ and ex situ conservation measures. In addition, samples from planted stands and imported reproductive material from other countries were included to study the anthropogenic influence on the species in managed forests. We used 11 novel microsatellites to genotype 756 samples from 27 putatively natural Austrian populations, and 186 samples derived from two planted stands and five lots of forest reproductive material; in addition, 106 samples from other European populations were also genotyped. Cross species amplification of the new markers was tested in 19 Acer species from around the world. Population clustering by STRUCTURE analysis revealed a distinct pattern of population structure in Austria and Europe, but overall moderate differentiation. Sibship analysis identifies several populations with severe founding effects, highlighting the need for proper selection of seed sources of sufficient genetic diversity in the species.

Integrating Tree Species Identity and Diversity in Particulate Matter Adsorption

The amount of PM bound by tree canopies depends on leaf traits, but also the leaf area available, both of which are dependent on tree identity. We investigated four species (Acer platanoides L., Tilia cordata Mill., Quercus robur L., Carpinus betulus L.) grown in monocultures and in two and four species polycultures. The amount of PM on the leaves of these species was determined by washing and fractionation of the PM into PM2.5, PM10 and PM100 size classes using a filtering method. The leaf area index was estimated by litter collection. The amount of PM2.5 per m2 leaf area was significantly higher in T. cordata compared to Q. robur and A. platanoides, and in C. betulus compared to A. platanoides. The leaf area index in monocultures was similar for all species except T. cordata which was considerably lower. Overyielding of LAI was shown in the two species polyculture of T. cordata and A. platanoides, and also in the four species polyculture. In polyculture, higher amounts of PM were determined in the two species polyculture of Q. robur and C. betulus and also in the four species polyculture. The result show that both tree identity and mixture influence the amount of PM in the canopy, and this is related to tree leaf traits, and also to overyielding of LAI in the polyculture.

THE IMPACT OF EARTHWORKS ON OLDER TREES IN HISTORICAL PARKS

The publication aims to investigate the quantitative impact of linear earthworks in urban parks, e.g. during roads’ and pavements’ modernization in the old trees’ root zones, on the increment in their external parameters (e.g. trunk circumference). Pilot studies (Warsaw, Poland) were carried out 2003–2019 in two historical parks: Ursynów and Królikarnia. The dataset of trees’ parameters is based on detailed dendrological inventories. Test groups consisted of trees exposed to damage and not exposed to damage (Ursynów) and the control group – trees growing in unchanged site conditions (Królikarnia). Among the three most abundant species of dendroflora, Norway maples (Acer platanoides L.) show the most visible difference (&gt;1.8 cm) between the normal and the inhibited growth in trunk circumference. Two other species – black locusts (Robinia pseudoacacia L.) and small-leaved limes (Tilia cordata Mill.) – also revealed statistically significant differences in the increment of the trunk circumference (respectively: &gt;1.3 cm and &gt;1.4 cm). In general, the reaction of affected trees was a significant reduction of circumference increments from 2.6 to 4.0 times concerning trees not exposed to damage. The verification made with the resistograph in 2019 confirmed a statistically significant decrease in radial increments of trees remaining in the impact zone of the earthworks.

Diverging conditions of current and potential future urban forest patches

AbstractForested natural areas in cities provide a range of social, ecological, economic, and health benefits. Ensuring the delivery of these benefits requires an understanding of current and potential future forest conditions, yet urban forest dynamics are not well‐understood. Here, we address this knowledge gap by examining forest structure and composition in 126 plots distributed across three forest patch sizes (large [95–126 ha], medium [1–19 ha], and small [0.05–0.65 ha] patches) in the city of New Haven, CT. We detected significant shifts in forest structure and composition suggesting a suite of distinct successional trajectories within each patch size. Large patches comprised 95% native tree species in the canopy (&gt;5 cm dbh), sapling (1–5 cm dbh), and seedling (&lt;1 cm dbh) layers, suggesting that these large patches will continue to be native‐dominated in the future—a primary objective for urban forest management. Moreover, in these large patches, shifts in the dominant species in each stratum suggest that as large patches move through succession they will transition from moderately shade‐tolerant forest types (i.e., oaks) to shade‐tolerant types (i.e., American beech)—a similar successional trajectory to surrounding second‐growth forests in the region. Medium patches were the most heterogeneous patch size sampled. Despite this heterogeneity, they generally resembled large patches in the canopy and sapling layers but diverged in the seedling layer. In medium patches, the invasive Norway maple replaced American beech as primary seedling species suggesting a future shift toward non‐native‐dominated forest in the future. Small patches were the most compositionally and structurally distinct patch size sampled. Only 36% of the canopy trees and saplings in small patches were native species; however, this increased to 71% native in the seedling layer. Additionally, the most important seedling species included those that are bird‐dispersed highlighting the potentially valuable role that these small, non‐native, forest fragments play as wildlife corridors. Collectively, our study demonstrates that multiple forest types, dynamics, and conditions can be found within a single city and that forest patch size offers a helpful framework to begin to parse out these differences.

Host plant identity and condition shape phytophagous insect communities on urban maple (Acer spp.) trees

By mitigating the negative effects of urbanization, urban trees contribute significantly to the well-being of urban citizens. However, trees themselves are also exposed to urban stress that can influence tree condition and tree-herbivore interactions. Maple species (Acer spp.) are among the most commonly planted trees in urban areas throughout North America and Europe. Among these species, field, sycamore, and Norway maple are native to Europe, but tolerate environmental stress to varying degrees. Here, we compared the phytophagous insect communities in the canopy of these tree species in the city of Budapest, Hungary. We also examined the stress level [expressed as peroxidase (POD) enzyme activity], and physiological condition (expressed as degree of leaf necrosis and leaf fall) of the maple trees, and their relationship to herbivore abundance. We observed higher total abundance of phytophagous insects on field and sycamore maple compared to Norway maple. Most herbivorous species were associated with field maple, sycamore had the highest aphid densities, and Norway maple harbored the least specific phytophagous insect community. Field maple trees were in the best condition while Norway maple trees in the worst condition, i.e., with the highest proportion of necrotic leaf surface area. The super-abundant planthopper species, Metcalfa pruinosa positively affected the POD activity of trees, but did not influence their condition. On the contrary, M. pruinosa abundance was driven by tree condition, with higher numbers on healthier trees. Our findings suggest that the abundance of phytophagous insects in the canopy of maple trees is highly determined by tree condition, and in this study field maple had the highest and Norway maple the lowest tolerance for urban stress.

Biochemical indicators of woody plants in the diagnosis of air condition

It is found that anthropogenic pollution has a significant effect on the change in the content of total nitrogen, glutathione and vitamin E, which increases the resistance of woody plants to stress. A series of woody plants with regard to their sensitivity to aerosol pollution has been compiled: according to the degree of decrease in total nitrogen – Picea abies > Thuja occidentalis > Syringa vulgaris > Acer platanoides > Tilia cordata > Sorbus aucuparia; the degree of decrease in glutathione content – Picea abies > Thuja occidentalis > Syringa vulgaris > Acer platanoides > Tilia cordata > Sorbus aucuparia; the degree of decrease in the content of vitamin E – Picea abies > Thuja occidentalis > Sorbus aucuparia > Tilia cordata > Syringa vulgaris > Acer platanoides. A positive correlation was revealed between the biochemical parameters of woody plants and the monitoring complex indices proposed by the Russian meteorological service. A close direct regression dependence of the air pollution index and the average stability coefficient for the content of total nitrogen, vitamin E and glutathione in the biomass of model woody plants was revealed: with an increase in the degree of air pollution, the average stability coefficient for certain biochemical indicators increases.