Green Ash Research Articles

GEOTOPOLOGICAL JUSTIFICATION FOR THE ESTABLISHMENT OF SHRUBBERY PLANTATIONS

Purpose. Was to substantiate the geotopological paradigm of creating curtin plantings, taking into account the features of the soil and landscape cover of the south of the Volga Upland and northern Ergenes. Materials and methods. Study were carried out during 1988-2020 in the south of the Volga Upland within the Volgograd region. The test site was laid in the former OPH “Kachalinskoye” VNIALMI (now the land use “Kachalinskoye” of the Ilovlinsky district). The meso-and microrelief of the territory was analyzed on the basis of deciphering aerial photographs and ground - based studies. The soil and landscape cover was studied by a comparative geographical method. Based on the data of desk and field decoding with leveling of the terrain, schemes of curtin plantings on meadow-chestnut soils were proposed. Results. The work are obtained. Curtain plantings of dispersed linear-modular type curtain and size 14x22 m, number of trees - 46-50, rows - 6 with placement of 1-2,5 m. The creation technology was based on the author’s patent (SU 1692388). The taxational survey of 2020 showed that the preservation of the curtains of dispersed placement is - 7; of the modular-linear type is - 17, as well as individual tree biogroups have been preserved. The growth rates in the preserved kurtins were higher in the squat elm (Ulmus elfberry) 10.0 ± 0.12 robinia pseudoacia (robinia pseudoacia) 13.9 ± 0.9 m, lanceolate ash (Fraxinus lanceolata). At the same time, in plantings on chestnut saline soils, the height of stands varied from 5.5 m to 8 m. Conclusion. The technology of creating curtin plantings is reduced to the adaptation of the elements of creation to the intra-profile variation of forest suitability, i.e., the adaptation of forest-reclaimed work systems to the spatial heterogeneity of specific lithofacial and morphological conditions associated with the peculiarity of meso- and microrelief.

Watershed and Estuarine Controls Both Influence Plant Community and Tree Growth Changes in Tidal Freshwater Forested Wetlands along Two U.S. Mid-Atlantic Rivers

The tidal freshwater zone near the estuarine head-of-tide is potentially sensitive to both sea-level rise and associated salinity increases as well as changing watershed inputs of freshwater and nutrients. We evaluated the vegetation response of tidal freshwater forested wetlands (TFFW) to changes in nontidal river versus estuarine controls along the longitudinal gradient of the Mattaponi and Pamunkey rivers in the Mid-Atlantic USA. The gradient included nontidal freshwater floodplain (NT) and upper tidal (UT), lower tidal (LT), and stressed tidal forest transitioning to marsh (ST) TFFW habitats on both rivers. Plot-based vegetation sampling and dendrochronology were employed to examine: (1) downriver shifts in plant community composition and the structure of canopy trees, understory trees/saplings/shrubs and herbs, tree basal-area increment (BAI) and (2) interannual variability in BAI from 2015 dating back as far as 1969 in relation to long-term river and estuary monitoring data. With greater tidal influence downstream, tree species dominance shifted, live basal area generally decreased, long-term mean BAI of individual trees decreased, woody stem mortality increased, and live herbaceous vegetative cover and richness increased. Acer rubrum, Fagus grandifolia, Ilex opaca, and Fraxinus pennsylvanica dominated NT and UT sites, with F. pennsylvanica and Nyssa sylvatica increasingly dominating at more downstream tidal sites. Annual tree BAI growth was positively affected by nontidal river flow at NT and UT sites which were closer to the head-of-tide, positively influenced by small salinity increases at LT and ST sites further downstream, and positively influenced by estuarine water level throughout the gradient; nutrient influence was site specific with both positive and negative influences. The counterintuitive finding of salinity increasing tree growth at sites with low BAI is likely due to either competitive growth release from neighboring tree death or enhanced soil nutrient availability that may temporarily mitigate the negative effects of low-level salinization and sea-level increases on living TFFW canopy trees, even as overall plant community conversion to tidal marsh progresses.

Reserve Accumulation Is Prioritized Over Growth Following Single or Combined Injuries in Three Common North American Urban Tree Species

Trees that grow in urban areas are confronted with a wide variety of stresses that undermine their long-term survival. These include mechanical damage to the crown, root reduction and stem injury, all of which remove significant parts of plant tissues. The single or combined effects of these stresses generate a complex array of growth and ecophysiological responses that are hard to predict. Here we evaluated the effects of different individual and combined damage on the dynamics of non-structural carbohydrates (NSC, low weight sugars plus starch) concentration and new tissue growth (diameter increment) in young trees. We hypothesized that (i) tissue damage will induce larger reductions in diameter growth than in NSC concentrations and (ii) combinations of stress treatments that minimally alter the “functional equilibrium” (e.g., similar reductions of leaf and root area) would have the least impact on NSC concentrations (although not on growth) helping to maintain tree health and integrity. To test these hypotheses, we set up a manipulative field experiment with 10-year-old trees of common urban species (Celtis occidentalis, Fraxinus pennsylvanica, and Tilia cordata). These trees were treated with a complete array of mechanical damage combinations at different levels of intensity (i.e., three levels of defoliation and root reduction, and two levels of stem damage). We found that tree growth declined in relation to the total amount of stress inflicted on the trees, i.e., when the combined highest level of stress was applied, but NSC concentrations were either not affected or, in some cases, increased with an increasing level of stress. We did not find a consistent response in concentration of reserves in relation to the combined stress treatments. Therefore, trees appear to reach a new “functional equilibrium” that allows them to adjust their levels of carbohydrate reserves, especially in stems and roots, to meet their metabolic demand under stressful situations. Our results provide a unique insight into the carbon economy of trees facing multiple urban stress conditions in order to better predict long-term tree performance and vitality.

Host plants of Halyomorpha halys in the urban ecosystem on the Azov Sea Coast of Russia

AbstractIn the summer of 2019, the brown marmorated stink bug, Halyomorpha halys (Stål, 1855), was found for the first time in Yeysk city, the northern part of Krasnodar Krai, Southern Russia. A study was performed in 2019 and 2020 to determine presence and assess damage of H. halys on various plants. In the urban ecosystem of the Azov Sea coast of Russia, H. halys fed on 16 plant species, but no significant damage to any crop was observed. The field maple (Acer campestre L.), green ash (Fraxinus pennsylvanica Marshall), London plane (Platanus × hispanica Münchhausen), Persian walnut (Juglans regia L.) and Oregon grape (Berberis aquifolium Pursh), were recorded as the host plants of H. halys for the first time in Russia.

Carbon life cycle assessment of shelterbelts in Saskatchewan, Canada

Shelterbelts are rows of trees planted around farmyards and field for protection against soil erosion, promotion of biodiversity and wildlife habitat. Additionally, to carbon sequestration through growth in tree biomass and carbon sinks in agricultural soil. In recent years, removal of shelterbelts has become more common, as crop land is preferred under higher crop prices, resulting in increased GHG emissions and decreases in carbon sinks. It is likely that landowners are making decisions without the knowledge of carbon sequestered by these trees. In this study, the level of carbon sequestration for the six common shelterbelt tree species found in Saskatchewan (hybrid poplar, green ash, Manitoba maple, Scots pine, white spruce, and caragana) was estimated using a carbon - life cycle analysis method. Net amount of carbon sequestered was estimated for five sequestration/emission stages – 1) seedling production, 2) transportation of seedlings to farm, 3) planting, 4) maintenance, and 5) growth of shelterbelts on farm. Since some landowners are removing shelterbelts, a removal stage was also included. During removal of shelterbelts, CO2 emissions were produced through: (i) physical process of removing the trees and subsequent burning of the wood; and (ii) loss of soil carbon after the removal over a long period of time. The functional unit for the analysis was one linear kilometer of shelterbelt, the normal structure of shelterbelts on agricultural land. All emissions/sequestration levels were measured as carbon dioxide (CO2) by multiplying the molecular weight of carbon dioxide to that of carbon (44/12). Other than the growth stage of shelterbelts, all other stages contributed net greenhouse gas emissions, which offset by carbon sequestration during tree growth. Hybrid poplar is a rapidly growing tree and sequesters the most carbon of the six species in all soil zones. A one km long hybrid poplar shelterbelt sequestered upwards of 1923 t CO2 by age 60 years in the Brown soil zone, compared to 2086 t CO2 over the same period in the Black soil zone. In comparison, in the Brown soil zone, Manitoba maple and white spruce sequestered 756 and 732 t CO2, respectively over the same period. If a landowner decides to remove a 60-year-old shelterbelt, 1205 t CO2 is lost within a short period after removal, whereas 718 t of remaining CO2 is retained as dead organic matter, which is slowly released over a period. Although field shelterbelts may emit greenhouse gases in the earlier stages of development, overall, they are net sinks of carbon and can therefore play a significant role in Canada's plan to reduce GHG emissions from agriculture.

Using saline water drip irrigation and soil matric potential control for tree establishment in coastal saline soil

Soil salinization and freshwater shortage are important factors restricting urban and peri-urban landscaping in coastal regions of China, where rapid industrialization and urbanization have expanded. This study explores saline water resources and soil matric potential control as a part of functional irrigation management to cope with the landscaping on salt-affected soils. A 4-year field experiment was carried out in coastal saline soil of North China, to establish four ornamental tree species (Fraxinus pennsylvanica, Crataegus cuneata, Broussonetia papyrifera, and Diospyros kaki) using saline water with five salinity levels (ECi of 0.8, 3.1, 4.7, 6.3, and 7.8 dS·m−1) by drip irrigation scheduled by yearly-lowered soil matric potential thresholds. Periodic monitoring results show that the survival rates of 100% were observed in the first post-transplant year for all ECi treatments and tree species, but survival rates decreased both as ECi increased and as matric potential thresholds decreased. The DBH, height, and canopy diameter of the surviving trees deteriorated as ECi increased and simultaneously increased each year. The initial soil salinity (ECe > 27 dS·m−1) at the 0–1 m depth decreased to 2.6, 2.1, 2.1, 3.4, and 6.3 dS·m−1 for five ECi treatments, respectively. Severe saline soil was reclaimed to non-saline and mildly saline soils. A performance indicator (PI) combining survival and growth rates was developed and applied to quantitatively assess performance of trees. According to the linear relationship between PI and ECi and the acceptable reduction of PI, F. pennsylvanica, C. cuneata, and B. papyrifera are recommended for landscaping with saline water, with threshold ECi of 6.1, 4.1, and 2.5 dS·m−1, respectively. The sustainability and implications for landscaping of irrigation management are discussed.

Intersexual segregation in winter foraging of great spotted woodpecker Dendrocopos major in riparian forests infested with invasive tree species

ABSTRACT We investigated the pre-breeding intersexual foraging habitat preferences of the great spotted woodpecker Dendrocopos major in six old, unmanaged riparian forest stands in Central Hungary, which are composed mainly of the invasive North American green ash Fraxinus pennysylvanica and boxelder Acer negundo, and native poplar Populus sp. and willow Salix sp. trees in lower abundances. With the influence of river management, the two invasive species have usurped native tree species in numerous Central European riparian forests. We studied the intersexual utilization of tree species, tree condition, stem diameter, foraging height, horizontal sections, substrate diameter, substrate condition, and foraging technique. The birds showed intersexual segregation in numerous studied variables despite the high niche overlap between sexes. Similar patterns were also found in other woodpecker species as well. We think that the most important part of this segregation could be the difference revealed in the choice of tree species, as males tended to be more specialized for native softwood tree species with rougher bark structure. Despite the high abundance of invasive tree species, neither sex preferred them. The further population decrease of native tree species could increase within-species competition and negatively affect the studied bird species.

Transcriptomic and Metabolomic Data Reveal the Key Metabolic Pathways Affecting Streltzoviella insularis (Staudinger) (Lepidoptera: Cossidae) Larvae During Overwintering.

Streltzoviella insularis (Staudinger) (Lepidoptera: Cossidae) is a woodboring insect feeding on Fraxinus pennsylvanica, Sophora japonica, and Ginkgo biloba, as well as many other species used for urban greening and plain afforestation in northern China, including the temperate north. There is also a risk that S. insularis could spread through the transportation of seedlings, thereby increasing urban greening costs. However, how S. insularis increases the cold tolerance then reduces it to survive winter temperature below 0°C remains unclear. In the transcriptomic of S. insularis, we identified three profiles (profile 25, 27, and 13) whose trends related to the cold tolerance. We detected 1,783 differentially expressed genes (in profile 25) and identified 522 genes enriched in the AMPK signaling pathway. The metabolome analysis identified 122 differential metabolites. We identified four co-pathways, among which “Glycerophospholipid metabolism” was the pathway most enriched in differentially expressed genes and differential metabolites. The AMPK signaling and glycerophospholipid metabolism pathways play key roles in the natural overwintering physiological process of S. insularis larvae.

One-step preparation of green tea ash derived and polymer functionalized carbon quantum dots via the thiol-ene click chemistry

In this work, we developed a simple, economical and forthright strategy for synthesis of polyethylene glycol functionalized CQDs (PEG@CQDs) through a one-pot thiol-ene click reaction using mercapto polyethylene glycol and green tea ash. These PEG@CQDs displayed excellent waterdispersibility and intense blue-green fluorescence. The fluorescence emission wavelengths of these PEG@CQDs are depended on the excitation wavelengths. Furthermore, cell viability and cell internalization of PEG@CQDs were examined by MTT assay and confocal laser scanning microscopy. The results demonstrated that PEG@CQDs showed low cytotoxicity towards HepG2 cells and strong green fluorescence could be detected after HepG2 cells were excited with a 405 nm laser. All the above results demonstrated that PEG@CQDs possess small size, high water dispersibility and fluorescence properties and could be potentially utilized for cell fluorescent imaging. We hope the method will provide some novel ideas for preparation of functional CQDs and inspired the biomedical applications of these functional CQDs.

Point Zero Charge Determination and Fluoride Adsorption on Natural Red Ash (Metal Oxide)

The PZC is essential parameter for the characterization of certain materials used for the treatment of organic or inorganic wastes in the environment, particularly from waste water and industrial sludge. Potentiometric titration and batch experimentation method was used to determine PZC value and type of adsorption isotherm behavior observed. Red ash is the natural metal oxides collected from the rift valley of Ethiopia which have PZC values of 3.35 for 0.5g, 1g and 1.5g adsorbent dose studied. On the adsorbent surface, monolayer and homogeneous adsorption process of fluoride observed. Therefore, based on the interest of the researcher and the adjustment of the pH of red ash solution might used for the treatment of ionic wastes.

Field Response of Green Ash (Fraxinus pennsylvanica) and Honey Locust (Gleditsia triacanthos) to Aminocyclopyrachlor1

AbstractField trials were conducted to assess the impact of aminocyclopyrachlor on green ash (Fraxinus pennsylvanica Marshall) and honey locust (Gleditsia triacanthos L.) trees in an urban environment. Aminocyclopyrachlor is a relatively new, selective, plant-growth-regulator herbicide in the pyrimidine carboxylic acid family. Treatments were applied to Kentucky bluegrass (Poa pratensis L.) sod growing with and without trees present. Evaluations included determination of a safe spraying distance from target trees and the effect of application timing on tree response. This multi-year study showed that green ash was highly tolerant to aminocyclopyrachlor while honey locust developed severe injury in trees closest to applications. Honey locust trees up to 7 m (23 ft) from the tree trunk to the edge of the application displayed moderate to severe injury symptoms and fall treatment in October and November had the lowest tree injury compared to all other application timings. Honey locust trees exhibiting moderate to severe cosmetic injury would not be acceptable to landowners; recovery over time was minimal. Trees located 13 m (43 ft) away displayed no injury for any treatment timing. Soil analysis demonstrated that aminocyclopyrachlor dissipation was the same underneath green ash and honey locust trees, and that dissipation was faster in the presence of growing trees. Taken together, these results provide a basic groundwork necessary for improving aminocyclopyrachlor labels, and a better understanding of this herbicide's effect on certain woody species.Index words: Herbicide injury, aminocyclopyrachlor, herbicide fate, tree safety.Species used in this study: Green ash, Fraxinus pennsylvanica Marshall, honey locust, Gleditsia triacanthos L.Chemicals used in this study: Aminocyclopyrachlor.

Emerald Ash Borer Approaches the Borders of the European Union and Kazakhstan and Is Confirmed to Infest European Ash

Emerald ash borer (EAB), Agrilus planipennis, native to East Asia, is an invasive pest of ash in North America and European Russia. This quarantine species is a threat to ash trees all over Europe. Survey in ten provinces of European Russia in 2019–2020 showed that EAB had spread faster and farther than was previously thought. The new infested sites were first detected in St. Petersburg (110–120 km from the EU border: Estonia, Finland) and Astrakhan Province (50 km from the Kazakhstan border). The current range of EAB in Europe includes Luhansk Province of Ukraine and 18 provinces of Russia: Astrakhan, Belgorod, Bryansk, Kaluga, Kursk, Lipetsk, Moscow, Orel, Ryazan, Smolensk, St. Petersburg, Tambov, Tula, Tver, Vladimir, Volgograd, Voronezh, and Yaroslavl. Within these, only seven quarantine phytosanitary zones in five provinces are declared by the National Plant Protection Organization of Russia. EAB was not found in the regions along the Middle Volga: Mari El, Chuvash and Tatarstan republics, Nizhny Novgorod, Samara and Saratov provinces. The infested sites in St. Petersburg and in the Lower Volga basin are range enclaves separated from the core invasion range by 470 and 370 km, correspondingly. It is possible that new enclaves can appear in the cities of Eastern Europe and Kazakhstan far from the current known range. All previously known infestations in European Russia were in green ash (Fraxinus pennsylvanica), which was introduced from North America, and individual trees of European ash (F. excelsior). A first confirmed case of mass decline of several thousand of EAB-infested European ash trees in Moscow province is provided. Therefore, there is no more doubt that under certain conditions EAB can seriously damage native ash trees in European forests.

Uncertainty in the modelled mortality of two tree species (Fraxinus) under novel climatic regimes

AbstractAimBased upon species distribution models (SDMs), many studies have predicted that climate change will cause regional extinctions of tree species within the next 50–100 years. SDM‐based predictions have been challenged on procedural and theoretical grounds, but for tree species they are largely beyond the practical reach of direct experimental validation. Here we report the experimental consequences of moving seedlings from ~50 natural populations of each of two ash (Fraxinus) species to experimental sites spanning a range of 10°C colder to 10°C warmer (mean annual temperature) than home environments.LocationEastern North America.MethodsWe measured population‐by‐test‐site survival percentages and mean trunk diameters at an average age of 35 years. We then used linear, mixed‐effect models to develop transfer functions for each species and predict survival and mean annual growth as functions of fixed and random effects including, especially, the climatic distance (CD) between test site and home environment.ResultsSurvival and growth were highest at CD ≈ 0 and declined as populations were moved to warmer or colder environments, indicating that survival and growth were optimal when populations were in home‐like climates. However, variance around the model fit was substantial, and we could not statistically detect, even at α = .50, elevated mortality following displacements into environments 3.5°C (white ash) and 4.1°C (green ash) warmer in mean annual temperature. Survival rates of 80%–100% were common even within populations subjected to warming conditions greater than those predicted to cause meso‐scale extinctions in this century. We show that within‐population genetic variance, phenotypic plasticity and idiosyncratic aspects of the non‐climatic environment and its interaction with genotype each likely contributed to these unexpected responses to climatic displacement.Main conclusionsResults emphasize the uncertainty that underlies predictions of climate‐induced extinctions of long‐lived woody plants over time frames of 50 to perhaps 100 years into the future.

Responses of two introduced larval parasitoids to the invasive emerald ash borer (Coleoptera: Buprestidae) infesting a novel host plant, white fringe tree: Implication for biological control

Emerald ash borer (EAB), Agrilus planipennis is a buprestid species native to Asia, where it is a pest of ash trees, Fraxinus spp. Since it was accidentally introduced to the United States in the 1990s, this beetle has become one of the most destructive invasive pests of North American ash trees. In 2015 it was found attacking the white fringe tree, Chionanthus virginicus, indicating the potential for host range expansion. This study evaluates the responses of two introduced larval parasitoids, Spathius agrili and S. galinae, to EAB larvae infesting this novel host plant. Third to fourth instar EAB larvae reared with tropical ash in the laboratory were inserted into green ash and white fringe tree bolts. Infested bolts were exposed to gravid females of both Spathius spp. under no-choice and S. galinae under choice testing conditions. No-choice testing indicated no difference in parasitism rate on EAB larvae between white fringe and green ash for either parasitoid species. Two-choice testing with S. galinae also indicated no difference in parasitism rate when green ash was an option. Sex ratio and brood size were unaffected by host substrate for EAB, but both species emerged sooner on EAB in white fringe tree under no-choice conditions. EAB larvae can be successfully parasitized in white fringe tree under laboratory conditions. These results indicate that S. agrili and S. galinae have potential to attack EAB larvae infesting white fringe tree.

Changes in demography and carrying capacity of green ash and black ash ten years after emerald ash borer invasion of two ash-dominant forests

Quantifying changes in ash (Fraxinus spp.) demography and emerald ash borer (EAB; Agrilus planipennis) carrying capacity in forested ecosystems is essential for understanding impacts of this invader and projecting future species composition in aftermath forests in North America. We inventoried green ash (F. pennsylvanica) and black ash (F. nigra) trees in two ash-dominated Michigan forests invaded by EAB, estimated phloem area, and potential EAB adult production before tree mortality occurred in 2007 and 2008. We re-inventoried both areas approximately a decade later to assess post-invasion ash demographics and EAB carrying capacity. Ash distribution by size class initially followed a negative exponential function. In the Pre-EAB inventories, small trees (2.5–13 cm dbh) accounted for more than 70% of the stems but comprised less than 20% of the ash phloem. Mid-sized trees (26–42 cm dbh) represented <10% of stems but accounted for at least 40% of the phloem. In Post-EAB inventories, nearly all ash >13 cm dbh were dead and EAB carrying capacity was reduced by 94% and 99% in the two areas. Live stump sprouts were present on 25–30% of EAB-killed green ash trees but were absent on dead black ash trees. Ash sapling and recruit density varied within and between forests, but newly germinated ash seedlings were absent. Whether green or black ash will function as overstory species in post-invasion forests in North America may be jeopardized by the near extirpation of seed sources and endemic EAB populations likely to limit recruitment of ash saplings and seedlings.

Preliminary results on narrow-leaved ash (Fraxinus angustifolia Vahl) and green ash (Fraxinus pennsylvanica Marshall) seed entomofauna in Croatia

Native narrow-leaved ash (Fraxinus angustifolia Vahl) and introduced green ash (F. pennsylvanica Marshall) are two most common ash (Fraxinus spp.) species in Croatian lowland forests, taking a significant place in these ecosystems. In the recent past it has been observed that narrow-leaved ash seed yields have reduced, emphasising the importance of good health status of those collected, as they are used for seedling production and consecutive regeneration of forest stands or afforestation. Given that insects could be an important factor affecting ash seed health status, the aim of this research was to gain insight into the species being present and their frequency in the ash seeds. In total 2.500 narrow-leaved ash and 1.000 green ash seeds from seven different locations were screened for insect presence. Analysed seeds were categorized as undamaged, insect damaged or empty, and observed insect specimens were identified by morphological and molecular genetic analysis. Green ash seeds revealed higher insect infestation in comparison with native ash species, with weevil Lygniodes bischoffii being the most numerous pest found. Narrow-leaved ash seeds were mostly occupied by the native weevil species, L. enucleator. Besides these pests, larval, pupal, and adult stages of parasitoid wasps (Hymenoptera) and larval stage of the seed eating moth Pseudargyrotoza conwagana (Lepidoptera) were found in both ash species. However, given that pests detected in this study prefer urban areas or were present in a very small number of seeds, where they were often followed by parasitoids, it can be concluded that insects currently do not have a significant negative impact on the reproduction of narrow-leaved ash and green ash in forest stands.

North-Westward Expansion of the Invasive Range of Emerald Ash Borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) towards the EU: From Moscow to Saint Petersburg

Agrilus planipennis is a devastating invasive pest of ash trees in European Russia, Ukraine, and North America. To monitor the north-western limit of its European invasive range, in June 2018 we established 10 study plots along the federal highway M10 (Russia) that runs between Moscow and Saint Petersburg through Tver’ City (approx. 180 km from Moscow), and lined with ash trees. On each plot, 2–4 Fraxinus pennsylvanica trees with heights ranging 6.1–17.0 m and diameters ranging 7.0–18.0 cm were girdled, i.e., 50 cm of their bark were removed. The study plots were visited and girdled trees were examined in September and November, 2018, and in October, 2019. Observations revealed that the current continuous north-western limit of A. planipennis range in European Russia coincides with the north-western border of Tver’ City and this range limit has not distinctly shifted north-westward during 2015–2019. In spite of the rich food supply (due to abundant F. pennsylvanica and F. excelsior plantings) in Tver’ City and along roads going to and from, the population density of A. planipennis in the area is currently low. Recent (September 2020) sudden detection of a spatially isolated A. planipennis outbreak approx. 520 km far north-westward from Tver’ (in Saint Petersburg) suggested that A. planipennis most likely had arrived at Saint Petersburg not by gradual stepwise (flying tree-to-tree) expansion of its continuous invasive range in Tver’ City, but as a result of its accidental introduction by means of, e.g., “insect-hitchhiked” vehicles, transported plants for planting, and/or other commodities. The proximity of the reported A.planipennis outbreak to the borders of the EU (approx. 130 km to Estonia and Finland) requires urgent measures for its containment and control, and constant monitoring.

Optimizing reduction pruning under electrical lines: The influence of tree vitality before pruning on traumatic responses

Reduction pruning of main tree stems is commonly performed in the maintenance of an electricity distribution network to encourage the growth of scaffold limbs away from the wires. Understanding both the initiation and growth of epicormic branch after reduction pruning interventions, as well as the area of discolored wood at the cutting point are important for optimizing the pruning cycle and maintaining safe trees. In this study, we investigated post-pruning traumatic responses in relation to tree vitality before pruning in 116 hackberries (Celtis occidentalis L.) and 86 green ash (Fraxinus pennsylvanica Marsh.) growing in a controlled environment of a nursery. Four years before pruning, each tree of both species was assigned a degree of damage commonly occurring in urban areas, including root injury, defoliation, and stem injury, for a total of 18 treatment combinations arranged in a random block design. In both species, trees that had lower vitality prior to pruning had a reduced number, height, and volume of the epicormic branches at the cutting point two years after main stem pruning. Interestingly and contrary to expectations, a positive relationship was found between the area of discolored wood at the cutting point and tree vitality prior to pruning. However, below a vitality threshold, the area of wood discoloration was exacerbated by crown dieback and retrenchment. Celtis showed a less efficient ability to compartmentalize and produced fewer epicormic branches compared to Fraxinus, and epicormic branches were of reduced height and volume when low growth was observed. From a management perspective, although both species can survive after several damage events and after reduction of the main stem, the results suggest to conduct an assessment of tree vitality before pruning to identify trees with lower vitality and better predict the return pruning time.

Checklist of the flora of the vicinity of Balakliya (Kharkiv region, Ukraine): native and alien taxa, distribution of rare plants, new findings

For the first time, information on the flora of the Siverskyi Donets basin in the vicinity of Balakliya town (Kharkiv region of Ukraine) was summarized based on the comprehensive analysis of published data, herbarium material, and own field examinations. Field surveys were conducted during September 2015 and March-July 2016. The surveyed areas were located mainly in the valleys of the Sіverskyi Donets river and some of its tributaries within the former Balakliуa district. The conspectus of flora comprising 933 taxa of vascular plants (including 798 recorded during field surveys) has been prepared. In particular, 739 taxa of native and 194 taxa of alien plants were recorded. The habitats of 14 species from the Red Book of Ukraine were found. The locations of other protected, uncommon and new for the flora of the region plant species were also identified. Several taxa (i.e., some of the calciphytes like Astragalus albicaulis, Linum czernjajevii, Odontarrhena tortuosa subsp. cretacea, Scutellaria supina, and Silene supina) were found out of their previously known ranges. Newly established locations of some other species (e.g., Ephedra distachya, Onosma simplicissima, and Ornithogalum boucheanum) significantly complement previously known chorological data. Finally, information about new findings of such alien taxa actively expanding new areas as Cornus sanguinea subsp. australis, Fraxinus pennsylvanica, Sedum sexangulare, Ulmus pumila, and Vitis vulpina is provided.It has been established that the flora of the Siverskyi Donets basin in the vicinity of Balakliya town is a rich natural center of phytodiversity being under active adventisation. Forest reclamation plantations play a significant role in spreading the alien plants. Railway and the pine terrace of the Siverskyi Donets also serve the migration corridors for many of such alien plants.

A Mixture of Green Waste Compost and Biomass Combustion Ash for Recycled Nutrient Delivery to Soil

The use of major nutrient-containing solid residuals, such as recycled solid waste materials, has a strong potential in closing the broken nutrient cycles. In this work, biofuel ash (BA) combined with green waste compost (GWC) was used as a nutrient source to improve soil properties and enhance wheat and triticale yields. The main goal was to obtain the nutrient and heavy metal release dynamics and ascertain whether GWC together with BA can potentially be used for concurrent bioremediation to mitigate any negative solid waste effects on the environment. Both BA and GWC were applied in the first year of study. No fertilization was performed in the second year of the study. The results obtained in this work showed the highest spring wheat yield when the GWC (20 t ha−1) and BA (4.5 t ha−1) mixture was used. After the first harvest, the increase in the mobile forms of all measured nutrients was detected in the soil with complex composted materials (GWC + BA). The content of heavy metals (Cd, Zn, and Cr) in the soil increased significantly with BA and all GWC + BA mixtures. In both experiment years, the application of BA together with GWC resulted in fewer heavy metals transferred to the crops than with BA alone.