Populus Nigra Research Articles

Antioxidant stone water (human/friendly environment) thermal (thermogravimetric-tga) combustion properties in biohazard (insect/fungus) wood

Abstract In this study, four different wood species walnut (Juglans regia L.), chestnut (Castanea sativa Mill.), Poplar (Populus nigra), scotch pine (Pinus sylvestris L.) were chosen and test samples were prepared according to TS 2470 principles. Especially the pine wood by taking the structure (with fungus, fungus/insect, insect), flawless wood structure is compared with the flawed wood structure. The impregnation process was carried out according to ASTM D 1413 -76 principles. Effects of the chemical characteristics of the determined Stone Water (Firetex) on the thermal decomposition properties of wood (burning degrees, degradation temperature points and residue amount) were determined with TGA (thermogravimetric analysis). According to the results of the experiment; the highest retention value was found in poplar (23.56%) and the lowest retention (12.79%) in chestnut was determined. Amount of residue; 60.84% of the highest on scotch pine wood with fungus and 56.70% of the lowest value was determined on poplar wood. Thermal deterioration was determined between 226.41-405.04 oC on wood .

Effect of the Layer Structure of Wooden Floorings on Dimensional Mobility under Different Relative Humidity and Water Retention Conditions

Abstract This study aimed to determine the effect of different wood flooring layer structures and surface features on water intake, shrinkage, and swelling rates under different relative humidity and water retention conditions. Nine wood flooring sample types were tested: solid wood beech (Fagus orientalis L.) flooring covered with polyurethane varnish, four engineered wood flooring types having different core-layers (solid-wood poplar (Populus nigra L.), 2× medium-density fiberboard, and plywood) covered with ultraviolet dried polyurethane varnish on beech veneer, and four laminated wood flooring types having different core layers (high-density fiberboard, medium-density fiberboard, particleboard, and plywood). The results showed the lowest water retention increase rates for 2 and 24 hours in the high-density fiberboard and medium-density fiberboard core-layered laminated wood floorings. The lowest thickness swelling rate occurred in the laminated wood flooring with a plywood core layer during exposure to high relative humidity, whereas the lowest swelling rate in the width dimension occurred for laminated wood flooring compared with other product types. The lowest thickness shrinkage rate was in the poplar core-layered engineered wood flooring, whereas the lowest shrinkage rate in the width direction was in the medium-density fiberboard core-layered engineered wood flooring and plywood core-layered laminated wood flooring at lower relative humidities. In conclusion, high-density fiberboard and medium-density fiberboard core-layered laminated wood floorings are advisable for flooring exposed to a humid environment. All laminated wood flooring types provided good resistance to swelling. The plywood core-layered laminated wood floorings, poplar, and medium-density fiberboard core-layered engineered wood flooring types performed the best for low-humidity environments.

The content of water-soluble phenolic compounds in the leaves of woody plants growing in the area of sanitary protection zones of enterprises of the industrial region of Zaporizhzhya

The article presents the results of studying the accumulation of water-soluble phenolic compounds in the leaves of woody plants growing in the area of sanitary protection zones of a number of enterprises of Zaporizhzhya: Zaporizhzhya Titanium & Magnesium Combine, Zaporizhzhya Aluminium Plant, Zaporizhzhya Abrasive Plant, Zaporizhstal, Zaporizhcoke, Zaporizhzhya Ferroalloy Plant, Zaporizhvohnetryv, Ukrgrafit and Zaporizhtransformator. The concentration of phenolic compounds was found to be significantly higher under the technogenic conditions compared to the relatively "clean" area. Their highest concentration was found in the leaves of woody plants growing in the forest belt near the Zaporizhcoke plant. For the level of accumulation in the organs of assimilation of trees, and thereby for the degree of air pollution by the phenolic compounds, enterprises can be ranked as follows: Zaporizhcoke > Zaporizhstal ≥ Zaporizhzhya Ferroalloy Plant > Zaporizhvohnetryv > Ukrgrafit > Zaporizhzhya Aluminium Plant > Zaporizhzhya Titanium & Magnesium Combine > Zaporizhzhya Abrasive Plant > Zaporizhtransformator. Depending on the level of accumulation of phenolic compounds in the leaves, the plants have been divided into three groups. The largest amount of the pollutant, compared to the other species of woody plants, is being accumulated by the leaves of the following species: Ailanthus altissima, Betula pendula, Juglans regia, Populus alba, Populus nigra, Populus piramidalis, Populus simonii, Elaeagnus angustifolia, and the least amount – by Morus alba, Robinia pseudoacacia, Tilia cordata, Ulmus carpinifolia, Armeniaca vulgaris, Fraxinus lanceolata. The following species occupy the intermediate position between the two groups: Acer negundo, Acer platanoides, Aesculus hippocastanum, Catalpa bignonioides, Salix alba, Ulmus laevis. The tree species that can be characterized by their capacity to accumulate the highest concentration of water-soluble phenolic compounds may be recommended for the purpose of purification of atmospheric air. The following plant species, which turned to be the most sensitive indicators of air pollution, have been listed in a descending order according to the value of the coefficient of relative accumulation of phenolic compounds. Such species include Betula pendula, Catalpa bignonioides, Elaeagnus angustifolia, Ailanthus altissima, Populus simonii, Acer negundo, Ulmus laevis and Fraxinus lanceolata.

Variability and adaptability of selected poplar (Populus nigra) clones, based on stability parameters and AMMI model

Poplars are among the most important wood trees that play a key role for provision of raw material for the cellulose industry. In order to study the genetic diversity, selection and introduction of superior and compatible clones in the west of Iran, this research was carried out. The experiment was set up based on randomized complete block design (RCBD) with three replications in eight years (2007 to 2014) at the Agricultural and Natural Resources Research Center of Kermanshah, Iran. From each clone 25 seedlings were planted with 3 × 3 meter spacing. The studied traits included: diameter at breast height, total height, current annual volume increment and wood volume. The results of mean comparison by Duncan test showed a significant difference between the clones at the level of 5%. The clon 62/154 had the greatest height, diameter, and wood volume. Combined analysis of variance revealed significant effect of Year I Clone interaction for all traits at 5% probability. Based on the cluster analysis, ten clones were grouped into three clusters. The clones 62/149 and 62/154 had the greatest distance of all all clones. Based on the AMMI model, and other stability parameters the clones P. nigra 56/75, P. nigra betulifolia, P. nigra mehregan, P. nigra 63/135, P. nigra 56/72 were selected as the highest productive clones and recommended to cultivation.

State o Phytocenosis in Beremytske Nature Park

Purpose. Botanical analysis of existing vegetation in the territory of the “Beremitske” Nature Park for further zoning and selection of individual territories where reproduction of the original state of the phytocenosis is planned. Methods. Field research methods for the analysis of the taxonomic composition of the flora in the park, cartographic methods for zoning the area and historical analysis of the land use of the former landowners. Results. The conducted flora monitoring showed that in the studied territories the adventitious and synanthropic species predominated, in particular in the meadow-steppe areas the invasive and synanthropic vegetation was represented by Ambrosia artemisiifolia, Asclepias syriaca, Amaranthus retroflexus, Arctium lappa, Sonchus arvensis, Tanacetum vulgare, Medicago lupulina, Verbascum phlomoides, Urtica dioica. Among the wood forms Betula pendula, Robinia pseudoacacia, Picea abies, Pinus sylvestris, Pinus sylvestris Populus nigra, Alnus glutinosa, Carpinus betulus predominated. Among the rare plants we identified the accumulation of Iris sibirica in some meadow-swamp areas. The scheme of the park has been developed and the starting points at which flora reproduction is planned to be identified. Conclusions. The species composition of the phytocenosis showed the predominance of invasive vegetation species in some areas of the park. The growth sites of the endangered species of Iris sibirica have been found, and in the future will allow to design new ecological trails in the park and to reintroduce it to other suitable sites. The data obtained will allow to develop a scheme of restoration of the original floral biodiversity in the park, taking into account the identified features.

Constituents of Populus nigra Leaves

Constituents of Populus nigra Leaves

Рост корней трансгенных растений табака с конститутивной экспрессией гена экспансина PnEXPA3 при действии стрессовых факторов

Plant α-expansin genes are of great interest for genetic engineering, since they can be used to improve the growth of the roots of agricultural plants. Previously, we obtained transgenic tobacco plants Nicotiana tabacum overexpressing the PnEXPA3 expansin gene from black poplar Populus nigra. In this work, the growth of roots of transgenic plants was studied under normal conditions and under the influence of stress factors such as hypothermia, salinity and heavy metals. Constitutive expression of the PnEXPA3 gene improved the growth of roots of transgenic tobacco plants as compared to the wild type under normal conditions and under hypothermia (+10°C), salinity (50 and 100 mM NaCl) and the action of heavy metals (200 and 400 μM acetate cadmium). The totality of the obtained data suggests that the constitutive expression of the PnEXPA3 gene can be used to improve the growth of roots of cultivated plants both under normal conditions and the action of stress factors.

The Effects of Some Synthetic Adhesives on the Formaldehyde Emission of the Particleboard

The formaldehyde emission is the one of the major problems of the particleboard industry that harms to human health and environment. The purpose of this study was to determine the effect of the adhesive type on the formaldehyde emission of three-layered particleboard. The urea formaldehyde (UF), phenol formaldehyde (PF) and melamine-urea formaldehyde (MUF) adhesives were used as adhesives. Black poplar (Populus nigra) was used as wood raw material. The panels produced with PF and MUF adhesives had the required level of formaldehyde emission value specified in EN 312-2 (1996) and these panels could be classified as E-1 grade particleboard. The particleboard samples produced with UF adhesive had more than the formaldehyde emission value required for E-1 class particleboards.

Tree avenues as reservoir for epiphytic lichens in deforested landscapes

Kubiak, D. & Osyczka, P. 2019. Tree avenues as reservoir for epiphytic lichens in deforested landscapes. – Herzogia 32: 398 – 420.Old tree avenues are a disappearing traditional element in European landscapes. Roadside trees constitute an important habitat for many groups of organisms and support the maintenance of biodiversity in deforested areas, but they are often neglected in conservation strategies. This study describes and analyses the conservation value of planted trees along rural roads in NE Poland for epiphytic lichens. A total of 105 trunks of seven deciduous tree species were examined. Lichen species inventories were assembled for trunks at a height up to two meters from the ground. A total of 99 lichen species was recorded. Lichen species richness and cover were dependent primarily on tree species. Diameter of trees was not significantly correlated with the number of species. Ulmus laevis and, to a lesser extent, Fraxinus excelsior and Acer platanoides, were be the most valuable tree species in terms of lichen species richness. Quercus robur as a roadside tree did not have above-average species numbers. Lichen species with a preference for eutrophicated or alkaline bark occurred in their largest numbers on Populus nigra agg. Betula pendula hosted the largest number of species avoiding eutrophication. Each tree species had its own set of exclusive lichens and hosted taxa which are red-listed in Poland; however, no single tree species alone guarantees preservation of the entire range of epiphytic lichens on roadside trees in the study area. Since tree avenues, especially those composed of multiple species, provide a suitable habitat for various rare and endangered lichens, potentially high conservation value should always be attributed to this element of local landscapes in low pollution areas.

Ландшафтно-історичний аналіз території парку у смт Поморяни

На підставі архівних документів проаналізовано генезис створення та формування парку біля замку в смт Поморяни на Львівщині. Узагальнено первісні особливості планувальної, просторової та функціональної структури території парку, подано стильову характеристику загальної композиції об'єкт. Встановлено трансформацію початкового пейзажного планування парку в регулярно-пейзажний стиль, який поєднував партерну частину перед центральним входом у будівлю з пластичними вигинами прогулянкових доріжок, що було характерним прийомом композиції маєтків того часу. З'ясовано, що планувальна структура об'єкта ні періоду закладання, ні періоду розквіту практично не збереглася. Виявлено залишки колишніх земляних укріплень та окремі фрагменти доріжок, які добре збереглися під гумусним нашаруванням. Простежено незначну подібність сучасної об'ємно-просторової структури насаджень деяким періодам функціонування об'єкта. Виявлено зростання близько 400 дерев, які представляють 15 видів з 11 родів та 8 родин. Переважають у складі деревостану здебільшого вікові Tilia cordata Mill., Fraxinus excelsior L., та Acer platanoides L., які, ймовірно, були основою паркових насаджень у часи його закладання. З цієї причини більшість дерев (74,4 %) мають задовільний стан. Серед багатовікових виявлено два величні дерева-довгожителі з відповідною історичною та науковою цінністю, тому потребують відповідного охоронного статусу. Узагальнено наявні проблеми та важливість подальших різнобічних досліджень замкової території для розроблення проектів її реконструкції.

Populus nigra as a phytoremediator for Cd, Cu, and Pb in contaminated soil

The contamination of agricultural soil with heavy metals is a complex phenomenon that causes negative consequences for various organisms. Poplars may have considerable phytoremediation potential, and this plant species can tolerate Cd, Cu, and Pb up to 15.6, 63.6, and 173.3 mg kg-1 soil, respectively, with 100% survival. The analyzed data revealed significant reduction in vegetative growth traits and leaf N, P, K, and carbohydrate (%) and leaf green color degree. However, a simultaneously significant increase in enzymatic activities and electrolyte leakage were recorded in comparison to control plants. A bioconcentration factor of plant organs was ˂ 1, and the translocation factors (TF) of Cd and Cu were ˂ 1 ( ˂100%) under various concentrations of each heavy metal, while TF of Pb was ˃ 1(>100%), except for the first level. More Cd, Cu, and Pb contents were localized in roots compared to leaves or stems. Thus, the risk of contamination through leaf can be minimized. Populus nigra has defense mechanisms against Cd, Cu, and Pb up to 7.8, 29.8, and 91.1 mg/kg soil, respectively because the tolerance index (TI) of either biomass or root was >0.8. Finally, it is a good candidate for research of phytoremediation and phytoextraction.

The Biological Durability of Thermally- and Chemically-Modified Black Pine and Poplar Wood Against Basidiomycetes and Mold Action

Wood of black pine and poplar species were subjected to thermal modification under variant conditions, while subsequently, a number of the thermally-modified black pine specimens were subjected to surface modification with organosilane solutions, and the biological resistances of the different materials were examined using laboratory agar block tests against the action of basidiomycetes and microfungi. Thermally-modified pine specimens were exposed to the brown rot fungi Coniophora puteana and Oligoporus placenta, whereas poplar wood was exposed to the white rot fungus Trametes versicolor and O. placenta. Regarding the biological durability of thermally-chemically-treated pine wood with organosilanes, it was tested against the action of C. puteana. Additionally, both of the thermally-treated wood species, as well as thermally-chemically-treated pine wood were exposed to a microfungi mixture, so that the wood treatments efficacy would be evaluated through a visual assessment of fungal growth on the specimen’s surface The thermal treatments seem to increase the biological resistance of black pine against C. puteana by 9.65–36.73% compared to unmodified wood. The most significant increase in biological durability among all the thermally-treated wood categories was recorded by O. placenta, with 28.75–68.46% lower mass losses in treated pine specimens and 31.98–64.72% in thermally-treated poplar, respectively, compared to unmodified wood. The resistance of treated poplar against T. versicolor was also found increased (13.25–46.08%), compared to control. Thermal modification affected positively the biological resistance of both species, though it did not manage to protect effectively pine and poplar wood from the microfungi action. The combination of thermal and organosilanes treatment revealed a significant improvement of the durability of pine wood compared to? control (45.68–87.83% lower mass losses against C. puteana), as well as against the microfungi action, with the presence of benzin to have a positive effect on the silanes solutions performance and protective action.

Monitoring of a long term phytoremediation process of a soil contaminated by heavy metals and hydrocarbons in Tuscany.

The purpose of this study was to monitor and model indicators of soil contamination, organic matter evolution and biochemical processes involved in a long-term phytoremediation process. Populus nigra L., Paulownia tomentosa Steud., Cytisus scoparius L. and natural vegetation were used in differently contaminated areas (high, medium and low levels of contamination). Parameters indicating contamination (total petroleum hydrocarbons (TPH) and heavy metals) and agronomic (C, N and P) and functional (enzyme activities) soil recovery were monitored for 3.5 years. Three subareas with different levels of contamination (high, medium and low) were identified according to the Nemerow Index. A considerable decrease in TPH (52% on average) over time in the whole site was measured, while the metal reduction was only of about 22% at surface level. A stimulation in metabolic soil processes and improvement in the chemical quality of the soil was also observed throughout the experimental site. Statistical analysis modelling showed that the contaminant content decreased following a one-phase decay model, while the dramatic increase in enzyme activities could be represented by an exponential growth equation. On the basis of our data, it is possible to conclude that the initial contamination level affected neither the decontamination process nor the improvement in soil quality, which occurred similarly in the three different contaminated areas.

Combined Multi-assay Evaluation of the Antioxidant Properties of Tree Bark

Abstract Wood logging generates considerable amounts of bark by-product, which are a potential antioxidant source well worth extracting and using. The present work compares the antioxidant properties of the bark of the following selected Hungarian forest tree species: white poplar (Populus alba L.), black locust (Robinia pseudoacacia L.), sessile oak (Quercus petraea Liebl.), black poplar (Populus nigra L.), silver birch (Betula pendula Roth), European larch (Larix decidua Mill.), scots pine (Pinus sylvestris L.), wild cherry (Prunus avium L.), European hornbeam (Carpinus betulus L.) and sweet chestnut (Castanea sativa Mill.). Inner and outer bark were investigated separately. Total polyphenol content (TPC) was determined by the Folin-Ciocâlteu method, whereas antioxidant capacity was assayed using the ferric reducing ability of plasma (FRAP), 2.2-diphenyl-1-picrylhydrazyl (DPPH), and ABTS (2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)) methods. The overall antioxidant power of the samples was evaluated using a scoring system that combined the FRAP, DPPH, and ABTS assay results. The TPC levels did not always follow the FRAP, DPPH, and ABTS assay values. Differing reaction mechanisms and sample compositions are possible reasons for this. The presented scoring evaluation was suitable for the assessment and comparison of complex antioxidant properties of tree bark samples. According to the scores, inner bark showed higher scores compared to outer bark for most species with the exceptions of black poplar, black locust, white poplar, sweet chestnut, and European larch. The highest overall antioxidant capacities were determined in the inner bark of wild cherry and the outer bark of sweet chestnut. The species with the overall lowest scores were black locust and black poplar.

Study of Growth Function of Black Poplar (Populus Nigra) With Kermanshah and Zanjan Origin in Karaj Research Station

Study of Growth Function of Black Poplar (Populus Nigra) With Kermanshah and Zanjan Origin in Karaj Research Station

A New Type of Anatolian Propolis: Evaluation of Its Chemical Composition, Activity Profile and Botanical Origin.

This study was undertaken to analyze the phenolic profiles of 19 propolis samples from Turkey by using a high-performance thin-layer chromatographic (HPTLC) method in order to identify their plant origins. Furthermore, their antioxidant and antimicrobial activity profiles were comparatively evaluated. For the appraisal of antioxidant potential, total phenolic (TPC) and total flavonoid contents (TFC) of propolis samples were firstly determined and then their effects on free radicals were evaluated by FRAP, ABTS.+ , CUPRAC, DPPH. and HPTLC-DPPH. methods. Antimicrobial activity of propolis samples against Staphylococcus aureus (ATCC 6538), Pseudomonas aeruginosa (ATCC 15442), Escherichia coli (ATCC 11229) and Candida albicans ATCC 10231 were determined by disc diffusion and broth dilution methods. HPTLC fingerprinting analyses revealed that O-type (botanical origin from Populus nigra L.) was the primarily available propolis type in Turkey. Moreover, 3-O-methylquercetin (3MQ) rich propolis was identified as a new propolis type for the first time. Principal component analysis (PCA) indicated that 3MQ-type propolis differs from the O-type. Antioxidant activity studies showed that O-type of propolis possesses higher antioxidant effect than the other tested propolis types. Quercetin, caffeic acid, caffeic acid phenethyl ester (CAPE) and galangin were determined to contribute significantly to the antioxidant potential of O-type propolis among others. Propolis extracts exerted moderate antimicrobial activity against the tested microorganisms with MIC values between the ranges of 128-512 μg/mL.

Accumulation of Catechin and Proanthocyanidins in Black Poplar Stems After Infection by Plectosphaerella populi: Hormonal Regulation, Biosynthesis and Antifungal Activity.

Flavan-3-ols including the monomeric catechin and the polymeric proanthocyanidins (PAs) are abundant phenolic metabolites in poplar (Populus spp.) previously described to protect leaves against pathogen infection. However, it is not known whether stems are also defended in this way. Here we investigated flavan-3-ol accumulation, activity, and the regulation of formation in black poplar (P. nigra) stems after infection by a newly described fungal stem pathogen, Plectosphaerella populi, which forms canker-like lesions in stems. We showed that flavan-3-ol contents increased in P. populi-infected black poplar stems over the course of infection compared to non-infected controls. Transcripts of leucoanthocyanidin reductase (LAR) and anthocyanidin reductase (ANR) genes involved in the last steps of flavan-3-ol biosynthesis were also upregulated upon fungal infection indicating de novo biosynthesis. Amending culture medium with catechin and PAs reduced the mycelial growth of P. populi, suggesting that these metabolites act as anti-pathogen defenses in poplar in vivo. Among the hormones, salicylic acid (SA) was higher in P. populi-infected tissues compared to the non-infected controls over the course of infection studied, while jasmonic acid (JA) and JA-isoleucine (JA-Ile) levels were higher than controls only at the early stages of infection. Interestingly, cytokinins (CKs) were also upregulated in P. populi-infected stems. Poplar saplings treated with CK showed decreased levels of flavan-3-ols and SA in stems suggesting a negative association between CK and flavan-3-ol accumulation. Taken together, the sustained upregulation of SA in correlation with catechin and PA accumulation suggests that this is the dominant hormone inducing the formation of antifungal flavan-3-ols during P. populi infection of poplar stems.

Noninvasive Analysis of Tree Stems by Electrical Resistivity Tomography: Unraveling the Effects of Temperature, Water Status, and Electrode Installation.

The increasing demand for tree and forest health monitoring due to ongoing climate change requires new future-oriented and nondestructive measurement techniques. Electrical resistivity (ER) tomography represents a promising and innovative approach, as it allows insights into living trees based on ER levels and ER cross-sectional distribution patterns of stems. However, it is poorly understood how external factors, such as temperature, tree water status, and electrode installation affect ER tomograms. In this study, ER measurements were carried out on three angiosperms (Betula pendula, Fagus sylvatica, Populus nigra) and three conifers (Larix decidua, Picea abies, Pinus cembra) exposed to temperatures between −10 and 30°C and to continuous dehydration down to −6.3 MPa in a laboratory experiment. Additionally, effects of removal of peripheral tissues (periderm, phloem, cambium) and electrode installation were tested. Temperature changes above the freezing point did not affect ER distribution patterns but average ER levels, which increased exponentially and about 2.5-fold from 30 to 0°C in all species. In contrast, freezing of stems caused a pronounced raise of ER, especially in peripheral areas. With progressive tree dehydration, average ER increased in all species except in B. pendula, and measured resistivities in the peripheral stem areas of both angiosperms and conifers were clearly linearly related to the tree water status. Removal of the periderm resulted in a slight decrease of high ER peaks. Installation of electrodes for a short period of 32–72 h before conducting the tomography caused small distortions in tomograms. Distortions became serious after long-term installation for several months, while mean ER was only slightly affected. The present study confirms that ER tomography of tree stems is sensitive to temperature and water status. Results help to improve ER tomogram interpretation and suggest that ER analyses may be suitable to nondestructively determinate the hydraulic status of trees. They thus provide a solid basis for further technological developments to enable presymptomatic detection of physiological stress in standing trees.

Nitrate Leaching from Continuous Corn, Perennial Grasses, and Poplar in the US Midwest

Leaching from annual corn (Zea mays L.) crops is a primary source of nitrate (NO3−) pollution of ground and surface waters. Here, we compare NO3− losses from no‐till corn with losses from various alternative perennial cropping systems (switchgrass [Panicum virgatum L.], miscanthus [Miscanthus ×giganteus J.M. Greef & Deuter ex Hodkinson & Renvoiz], a native grass mixture, and restored prairie), as well as hybrid poplar (Populus nigra L. × P. maximowiczii A. Henry ‘NM6’), all grown on a well‐drained soil in Michigan. Soil water was sampled from below the root zone using suction cup samplers during nonfrozen periods (March–November) between 2009 and 2016. Leaching was estimated from NO3− concentrations in soil water and modeled drainage (percolation) rates. Drainage rates were not significantly different among crops, constituting ∼30% of total annual precipitation. Aboveground net primary production (Mg ha−1 yr−1) averaged across the 7 yr was highest in poplar (30.8 ± 1.9 [SE]) followed by miscanthus (23.9 ± 2.4) and corn (20.4 ± 0.9). Volume‐weighted mean NO3− concentrations (mg N L−1) and NO3− leaching (kg ha−1 yr−1) averaged across the 7 yr were 9.2 and 34.1, 2.3 and 5.9, and 3.0 and 7.2, respectively, for corn, perennial grasses and poplar. Approximately 10 to 32% of applied N was lost as NO3− from these crops, with the highest percent losses from poplar (32%) followed by corn (20%). Perennial cropping systems leached considerably more NO3− in first few years after planting, but over 7 yr they lost much less NO3− than corn. Perennial crops may therefore help ameliorate NO3− pollution in agricultural landscapes even if they receive modest N fertilization.Core Ideas Over 7 yr, perennial grasses and poplar trees leached much less nitrate than corn Nitrate leaching from grasses and poplar was comparable with corn for 1–2 yr after planting. Perennial crops can ameliorate nitrate pollution in agricultural landscapes.

Poplar testing and breeding in the Central Chernozem region of Russia

Poplar – Populus L. is a widely-distributed major forestry species in the north hemisphere. Here we investigated poplars selected in the local forests, introduced from different regions, and hybrids during the last 60 years. More than 300 clones and varieties were introduced from 30 locations of the former USSR and more than 4,000 new poplar hybrids were bred in the Voronezh region and maintained in the field collections and field tests of the Central Chernozem region. Based on the variety testing, we selected the most promising clones and varieties as well as developed the assortment for different target forest plantations. Also, the tested varieties were patented by the Federal Registration including the black and white poplars: ‘Steppe Lada’, ‘Breeze’, ‘Surprise’, ‘Bolide’, ‘Veduga’. We developed a new series of hybrids with P. tremula by collaborating with the Germany Ministry of Food and Agriculture. In these series the factorial crossings included the hybrids between the heart rot stable and fast-growing parental forms with unstable to decay parents. Our study will build the way of developing the heart rot stable genotypes of aspen based on the genetic architecture. Our varieties will strengthen the local timber supply and the reclamation of the disturbed lands as well as to replenish the assortments for landscaping in the region and other territories.