Populus X Canadensis Research Articles

Species features of bioaccumulation of heavy metals in leaves of poplar Populus canadensis Moench and ash Fraxinus americana L. in the urban ecosystem

Species features of bioaccumulation of heavy metals in leaves of poplar Populus canadensis Moench and ash Fraxinus americana L. in the urban ecosystem

Transcriptome Analysis and Reactive Oxygen Species Detection Suggest Contrasting Molecular Mechanisms in Populus canadensis' Response to Different Formae Speciales of Marssonina brunnea.

Revealing plant-pathogen interactions is important for resistance breeding, but it remains a complex process that presents many challenges. Marssonina leaf spot of poplars (MLSP) is the main disease in poplars; in China, its pathogens consist of two formae speciales, namely, Marssonina brunnea f. sp. Monogermtubi (MO) and M. brunnea f. sp. Multigermtubi (MU). However, the mechanism of the molecular interaction between poplars and the two formae speciales, especially for an incompatible system, remains unclear. In this study, we conducted transcriptome sequencing and reactive oxygen species (ROS) staining based on the interactions between Populus canadensis and the two formae speciales. The results show that the gene expression patterns of P. canadensis induced by MO and MU were significantly different, especially for the genes associated with biotic stress. Furthermore, MO and MU also triggered distinct ROS reactions of P. canadensis, and ROS (mainly H2O2) burst was only observed around the cells penetrated by MU. In conclusion, this study suggested that P. canadensis experienced different resistance reactions in response to the two formae speciales of M. brunnea, providing valuable insights for further understanding the host-pathogen interactions of MLSP.

APPLICATION OF FLUCTUATING ASYMMETRY METHODS FOR ENVIRONMENTAL MONITORING IN KAMIANSKE

The city of Kamianske has a hazardous environmental situation due to the long and intensive development of industry, whose enterprises emit large amounts of harmful substances into the atmosphere. Therefore, the implementation of continuous environmental monitoring for the city is an urgent task that can be solved by combining instrumental measurement methods with phytoindication methods. The aim of the study is to test the methods of phytoindication in the environmental monitoring system using the indicator of fluctuating asymmetry of the leaf blade of woody plants of the Populus canadensis species and to assess the quality of the environment, taking into account the functional zones of the urban system. A methodology for assessing the quality of the environment by the integral index of the fluctuating asymmetry of the leaf blade of Populus plants has been developed and an assessment scale with different gradient values has been proposed. The integral indicator of the fluctuating asymmetry of the leaf blades of Populus canadensi plants was calculated for 30 experimental plots covering all functional zones of Kamianske. It was determined that the quality of the environment within the industrial zones is characterised as critically polluted with unfavourable conditions for living organisms, which is confirmed by the integral index of fluctuating asymmetry 0,076¸0,104. Settlement areas are characterised as polluted, with an integral index of 0,063¸0,093. In recreational areas, the state of the environment is assessed by a conditional norm of 0,054¸0,066. The results of the average integral index of leaf asymmetry of Populus canadensi plants for a ten-year period for the city of Kamianske were compared, and the lower (0,038±0,002) and upper (0,106±0,003) limits of the index were determined. The dependence of the integral indicator on the volume of pollutant emissions into the atmosphere has been established, which is confirmed by high correlation coefficients r = 0,8¸0,9 at a significance level of p < 0,05. The modelled polynomial trends predict further growth of the integral indicator of fluctuating asymmetry depending on the increase in pollutant emissions.

Growing (Pleurotus Pulmonarius) on Various Local Substrates in the Kurdistan Region of Iraq

In this study the effect of five locally sourced organic substrates as raw material and supplemented with CaSO4 2%, CaCO3 2% and wheat bran10% and three levels of spawning rates (5, 10, and 15%) on growth, morphological characteristics and chemical composition of Pleurotus Pulmonarius mushrooms were examined. These organic ingredients include: (Wheat straw (WS), Rice straw (RS), cardboard, Populus Canadensis sawdust (PC), and Salix Alba sawdust(WW). The study found that organic substrates, such as wheat straw and rice straw, had a significant effect on the mushrooms’ fresh weight 1087.33g and 1030.67g respectively. Supplements increased the fruit content of crude protein15.3%, nitrogen2.44%, fiber15.44%, and carbohydrates 50.44% without affecting vitamin C 3.38 mg/100 g. It also found that a spawn rate of 15% was optimal for protein19.62%, nitrogen 3.13%, carbohydrates 52.26%, and vitamin C 4.1 mg/100 g content in the fruits, while the lowest content was observed at a spawn rate of 5% protein 8.87%, nitrogen 1.42%, carbohydrates 46.31%, and vitamin C 2.6 mg/100 g content in the fruits.

Changes in Competitors, Stress Tolerators, and Ruderals (CSR) Ecological Strategies after the Introduction of Shrubs and Trees in Disturbed Semiarid Steppe Grasslands in Hulunbuir, Inner Mongolia.

To reveal the changes in the life history characteristics of grassland plants due to vegetation restoration, plant species and communities were analyzed for their competitor, stress tolerator, and ruderal (CSR) ecological strategies after the introduction of woody plants in the damaged steppe grassland and were compared with those in reference sites in Hulunbuir, Inner Mongolia. As a result, it was found that the introduction of the woody plants (Corethrodeneron fruticosum, Caragana microphylla, Populus canadensis, and Pinus sylvestris var. mongolica) into the damaged land greatly increased the plant species diversity and CSR eco-functional diversity as the succession progressed. The plant strategies of the temperate typical steppe (TTS) and woodland steppe (WS) in this Asian steppe are CSR and S/SR, respectively, which means that the plants are adapted to disturbances or stress. As the restoration time elapsed in the damaged lands exhibiting (R/CR) (Corispermum hyssopifolium), the ecological strategies were predicted to change in two ways: (1) →R/CSR (Cynanchum thesioides, Astragalus laxmannii, etc.) → CSR in places (TSS) (Galium verum var. asiaticum, Saussurea japonica, etc.) where only shrubs were introduced, and (2) → S/SR (Allium mongolicum, Ulmus pumila, etc.) → S/SR in sites (WS) (Ulmus pumila, Thalictrum squarrosum, etc.) where trees and shrubs were planted simultaneously. The results mean that the driving force that causes succession in the restoration of temperate grasslands is determined by the life-form (trees/shrubs) of the introduced woody plants. This means that for the restoration of these grasslands to be successful, it is necessary to introduce woody tree species at an early stage.

State of protective forest plantations in the Forest-Steppe zone of Ukraine

This paper analyzes approaches of scholars to the interpretation of the essence of protective forest plantations (PFP) and provides the most appropriate definition. The most significant functions of PFP are analyzed, and their peculiarities in certain regions of Ukraine are highlighted. PFP play an important role in preserving the stability of landscapes, including agricultural ecosystems. They are important for soil improvement and perform significant ecological functions, contributing to the creation and improvement of microclimate in agro-landscapes: reducing wind speed and intensity of wind erosion in the summer, preventing the blowing of the upper, most fertile layer of soil; snow retention and reducing surface runoff, including both snowmelt and rainwater, which helps to preserve soil moisture and prevent water erosion. Existing protective forest plantations in the Forest-Steppe zone of Ukraine are mainly formed from black locust (Robinia pseudoacacia), common oak (Quercus robur L.), common ash (Fraxinus excelsior L.), Canadian poplar (Populus canadensis Moench.), black poplar (Populus nigra L.), Norway maple (Acer platanoides L.), and sycamore maple (Acer pseudoplatanus L.). It is concluded that the Forest-Steppe zone of Ukraine is characterized by a rapid loss of protective forest plantations due to fires and military actions. During 11 months of the war with Russia, 425 cases of forest fires were recorded in PFP on a total area of 754 ha in the occupied Zaporizhia region and 287 ha in the Kherson region. This is three times more than during the same period in 2021, and the average area of one fire has increased by 16 times. Fires in the Forest-Steppe are characterized by the concept of temporary sterilization of the soil, during dry burning, as a result of which the death of worms, insects and microorganisms occurs in these areas. In the post-war period, the development of the forest industry requires scientific support for the implementation of the state policy on sustainable forest management, increasing the forest resource potential, as well as the forest cover of Ukraine to an optimal level, improving the efficiency of forest production through the application of modern scientifically-based methods for forest restoration and cultivation and rational use of forest resources, protecting forests from fires, illegal logging, pests, and diseases.

Differentiation and Identification of Endophytic Bacteria from Populus Based on Mass Fingerprints and Gene Sequences.

Plant endophytic bacteria play important roles in plants' growth and resistance to stress. It is important to characterize endophytic bacteria to be able to understand their benefits. Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) has become a powerful technique for bacterial identification due to its high throughput and simple procedures. In this study, the endophytic bacteria separated from Populus (the leaves, roots and stems of Populus tomentosa Carrière; stems of Populus nigra Linn. var. nigra; and stems of Populus canadensis Moench) were identified and classified based on MALDI-TOF MS data and 16S rRNA gene sequencing. The sampling and preparation of bacteria were optimized to obtain meaningful protein mass fingerprints. The composite correlation index (CCI) values of the inter-genera and inter-species protein mass fingerprints demonstrated sufficient differences between the strains. In the CCI value matrix for ten species in the same genus, all the CCI values were less than 0.5. Among the species, 95.6% of all the CCI values were less than 0.5. After data processing, the classification capacity of the protein mass fingerprints was verified using inter-specific and inter-generic PCoA. To compare different methods' potential for differentiation and phylogenetic analysis, a dendrogram of the MS profiles and a phylogenetic tree based on the 16S rRNA gene sequences were constructed using 61 endophytic bacteria found in Populus. The clustering and grouping results show that the phylogenetic analysis based on MALDI-TOF MS is similar to that based on 16S rRNA gene sequencing. This study provides a valuable reference for differentiating and identifying endophytic bacteria according to their protein mass fingerprints.

Evaluation of the Optimal Conditions for Oxygen-Rich and Oxygen-Lean Torrefaction of Forestry Byproduct as a Fuel

Wood biomass is an alternative to fossil fuels. However, biomass use has several limitations. Torrefaction, in which reduction conditions prevail to overcome these limitations, has been suggested. Here, torrefaction using different wood chips (Liriodendron tulipifera, Populus canadensis, Pinus rigida, and Pinus koraiensis) was conducted under oxygen-rich and oxygen-lean conditions to determine the effects of oxygen. Torrefaction was conducted at 230–310 °C for 1 h. A mass yield difference of 3.53–20.02% p (percentage point) was observed between oxygen-lean and oxygen-rich conditions. The calorific value increased by a maximum of 50.95% and 48.48% under oxygen-rich and oxygen-lean conditions, respectively. Decarbonization (DC), dehydrogenation (DH), and deoxygenation (DO) occurred in the following order because of dehydration and devolatilization during biomass torrefaction: DO > DH > DC. The calorific value of the torrefied biomass increased linearly with the extent of all three processes. The combustibility index and volatile ignitability were calculated based on proximate composition to suggest the optimal conditions for replacing anthracite and bituminous coal. This study provides suggestions for stable operation in a standard boiler design.

Effects of Drought Stress and Ca Supply on the Biomass Allocation Strategies of Poplar and Mulberry

In order to investigate the effect of Ca on the biomass allocation strategies of tree species with different growth rates under drought conditions, we treated poplar (Populus canadensis cv) cuttings and mulberry (Morus alba) seedlings with two soil moisture levels (40 ± 5% and 80 ± 5% maximum water holding capacity) and two soil Ca levels (0 and 200 mg·kg−1 Ca2+) in a greenhouse experiment, and then measured the Ca uptake, growth, gas exchange parameters, biomass allocation, and leaf traits. Drought induced a reduction in biomass accumulation of poplar cuttings and mulberry seedlings, and the cuttings and seedlings exhibited different biomass allocation patterns in response to drought stress. Under Ca0 treatment, poplar cuttings allocated more biomass to leaves and less biomass to stems under drought conditions, leading to an increased leaf/stem (L/St) ratio and higher SLA than under moist conditions in order to maintain higher Pn, and had enhanced WUE to cope with drought stress. Under the same treatment, mulberry seedlings allocated more biomass to roots and less biomass to stems, leading to an increased root/shoot (R/S) ratio and lower SLA, to improve drought resistance. Ca200 treatment decreased the growth of poplar cuttings and mulberry seedlings, whereas it enhanced the WUE, root growth, and R/S ratio of poplar cuttings and the WUE of mulberry seedlings, and alleviated drought stress in both species.

Plant Diversity and Quantitative Characteristics Of Wetland Community on the North Bank of Hanjiang River in Cheng GU, Shaanxi Province, China

Four water ecological surveys were carried out on the north bank of Hanjiang river in two seasons from 2020 to 2021. Based on the field wetland quadrat survey and literature data, the species diversity index was determined. The research showed that there are 360 species of wetland plants belonging to 108 families and 264 genera on the north bank of Hanjiang river, and the geographical composition of seed plants is at the genus level, mainly temperate distribution types, with 160 species. In the community species diversity index, the mean value of Patrick index was 18.80 ± 5.19. The mean Shannon Wiener diversity index was 2.15 ± 0.39. The mean value of Simpson dominance index was 0.81 ± 0.10. The average Pielou evenness index was 0.75 ± 0.10. The mean value of Margalef index was 3.44 ± 0.87. The Patrick index and Margalef index of the Bidens pilosa form were the lowest. The Shannon-Wiener diversity index，the Simpson index，and the Pielou index of the Potamogeton malaianus form were the lowest. The Patrick index of the Colocasia esculenta form was the highest,and the Pielou of the Sapium sebiferum form was the highest. The Shannon- Wiener diversity index and Simpson index of the Populus canadensis form group were the highest, and the Margalef index of the Flueggea virosa form was the highest. The research results provide basic data and scientific basis for the protection and restoration of wetland ecosystems and management of wetland resources in Yuan'an and similar areas. Bangladesh J. Bot. 51(4): 839-848, 2022 (December) Special

Microbial community dynamics during the storage of industrial-scale wood chip piles of Picea abies and Populus canadensis and the impact of an alkaline stabilization agent

Storage of woody biomass in large wood chip piles is unavoidable for biotechnological applications, but comes along with considerable biomass-, energy- and thus, economic losses due to exothermic reactions and microbial degradation. The homogeneous amendment of the storage piles with an alkaline stabilization agent, calcium hydroxide (Ca(OH)2), was found to decrease dry matter loss in Picea abies; for Populus canadensis piles the effects cannot clearly be deduced. Here we investigated the bacterial and fungal communities of industrial-scale wood chip piles (250 m3) of these two different tree species and related them to physicochemical conditions and enzymatic activities after 35 and 120 d, representing short- and long-term storage of the wood chips, respectively. Coming from different wood types (hard vs. softwood), we expected the communities to converge over time, due to similar storage conditions. Despite pH posing selective pressure, we expected a minor Ca(OH)2 effect as already known from previous studies.We found that the effectiveness of Ca(OH)2 addition depended on the wood type that determined both the native microbial seeding community and temperature pattern of all piles, thereby exerting selective forces of differing strength. Generally, a thermophilic community consisting of single fungal and variable bacterial taxa were identified. As expected, the microbial communities from P. abies and P. canadensis converged over time. Biomass loss was connected to C-cycle related enzymatic activities and to the abundance and composition of fungal communities. Chaetomium sp. was identified as potential key taxon determining biomass degradation under the given storage conditions.

Response of Poplar and Associated Fungal Endophytic Communities to a PAH Contamination Gradient.

Microbial populations associated to poplar are well described in non-contaminated and metal-contaminated environments but more poorly in the context of polycyclic aromatic hydrocarbon (PAH) contamination. This study aimed to understand how a gradient of phenanthrene (PHE) contamination affects poplar growth and the fungal microbiome in both soil and plant endosphere (roots, stems and leaves). Plant growth and fitness parameters indicated that the growth of Populus canadensis was impaired when PHE concentration increased above 400 mg kg−1. Values of alpha-diversity indicators of fungal diversity and richness were not affected by the PHE gradient. The PHE contamination had a stronger impact on the fungal community composition in the soil and root compartments compared to that of the aboveground organs. Most of the indicator species whose relative abundance was correlated with PHE contamination decreased along the gradient indicating a toxic effect of PHE on these fungal OTUs (Operational Taxonomic Units). However, the relative abundance of some OTUs such as Cadophora, Alternaria and Aspergillus, potentially linked to PHE degradation or being plant-beneficial taxa, increased along the gradient. Finally, this study allowed a deeper understanding of the dual response of plant and fungal communities in the case of a soil PAH contamination gradient leading to new perspectives on fungal assisted phytoremediation.

Populus canadensis x Populus 'HB6'

This datasheet on Populus canadensis x Populus 'HB6' covers Identity.

Populus canadensis (hybrid black poplar)

This datasheet on Populus canadensis covers Identity, Overview, Associated Diseases, Pests or Pathogens, Distribution, Biology & Ecology, Environmental Requirements, Uses, Management, Genetics and Breeding, Economics, Further Information.

A preliminary study on change of mistletoe (Viscum albüm L.) silage quality according to collection time and host tree species

In this study, it was aimed to determine the silage quality of mistletoe (Viscum album L.) collected from wild pear (Pyrus amygdaliformis) and poplar trees (Populus canadensis) in January, July, August, and December. The fresh samples were chopped in 2 cm size and ensiled in 2 kg plastic bags then stored at 25 ± 2 °C conditions for 45 days. Silage samples were investigated for dry matter ratio, pH, crude protein ratio, crude ash ratio, condensed tannin, acid detergent fiber, neutral detergent fiber, lactic acid, acetic acid, butyric acid, malic acid, citric acid, succinic acid, potassium, phosphorus, calcium, and magnesium contents. All quality traits of mistletoe silages were significantly different between host trees, collected times, and the interactions of host tree x collection time. It has been determined that mistletoe can be used as silage in terms of all the traits investigated. Besides, the silage of mistletoe collected from wild pear in December is better than other treatments. Mistletoe can be considered as an alternative roughage source due to its high content of crude protein, nutrient composition, easy digestibility, and organic acid content.

Biogeochemistry of Dominant Plants and Soils in Shewushan Gold Lateritic Deposit, China

This paper describes the effect of mineral elements on dominant plants in the Shewushan lateritic gold deposit, China. For this purpose, 30 soil profile samples at different depths and 3 kinds of dominant plants including Populus canadensis (Populus X canadensis Moench), Cinnamomun camphora (Cinnamomum camphora (L.) Presl.) and Rhus chinensis (Rhus chinensis Mill.) were collected. The concentration of ore-forming elements including Au, Ag, Pb, Zn, Cu, As, Fe, and S were analyzed. Based on the investigation of two mine profiles, it can be found that Au, Pb, As, and Fe were mainly enriched in laterite layer and the brown clay layer at a depth of 5–11 m. Moreover, the biological accumulate coefficient (BAC) and the contrast coefficient (CM) were calculated to assess the sensitivity and concentrating ability of Populus canadensis and Cinnamomun camphora. To investigate the response of the two species to metal stress, the contents of chlorophyll, malondialdehyde (MDA), and activities of superoxide dismutase (SOD) and peroxidase (POD) were determined. The result showed that Populus canadensis and Cinnamomun camphora have a high tolerance to metal stress and that both of the two species can indicate the content of Au, As, Pb, and Co in topsoil.

ECOLOGICAL AND GEOCHEMICAL SPECIFICS OF SOIL AND PLANT COVERING OF URBAN LANDSCAPES (IN THE TOWN OF BROVARY AS AN EXAMPLE)

The results of the pollutants content research in urbanized landscapes soils of Ukraine (on the example of Brovary city, Kyiv region) were shown. The total and mobile contents data of chemical elements (Ni, Co, Zn, V, Pb, Cr, Cu) were obtained and analyzed using the methods of landscape-geochemical studies, analytical and statistical methods. The dependences of the vegetation resistance in cities to the level of soil cover contamination and the degree of heavy metals income have been established. The geochemical characteristics (such as the value of the accumulation coefficients; concentration of soil and vegetation cover; index of biogeochemical activity of the species within Brovary city) were analyzed.
 Throughout most of the city territory, the level of soil contamination is above average. Soils are characterized by the following association of heavy metals: Cu> Pb> Zn> Co> Cr> V> Mo> Mn> Ni. The dominant association is distributed heterogeneous throughout the city, forming geochemical anomalies depending on the source of contamination. The maximum technogenic load was recorded in urban soils areas within zones of transport infrastructure, production and communal-warehouse facilities.Woody vegetation is the most actively absorbed copper, manganese from the soil, and the least intensively absorbed chromium, vanadium and nickel. The biogeochemical activity coefficient of the research species is the following: Acer platanoides - 7,26, Betula pendula Roth. - 7,07, and Populus deltoides - 7,05, Pínus sylvestris - 1.32 and Alnus incana - 3.37. The biological absorption coefficients of manganese and copper are high because these metals have the ability to form strong complexes with organic matter. Biological absorption coefficients of vanadium and chromium is low for the researched plant species because these chemical elements are immobile in soils.
 For the city of Brovary, the presence of polyelemental contamination of soil and vegetation has been established. According to the indicators of the gross content of VM, the main pollutants are Cu, Zn, Pb and Mn. Concentrations of gross and mobile forms of VM exceed background values ​​and maximum concentration limits in 17-28 times. The maximum of man-caused load was recorded in the urban soils of the transport infrastructure zone and the zone of production and communal-warehouse facilities.
 Regularities of formation of elemental composition of plants of urban areas undergo significant changes in comparison with natural conditions, which is due to the strengthening of the role of foliar absorption of pollutants from the air and their high content in soils. The greatest ability to bioaccumulate has a male thyroid (Dryopteris filix-mas Schott) and birch (Convolvulus arvensis). The highest coefficient of biogeochemical activity of the studied species is Acer platanoides - 7.26, hanging birch (Betula pendula Roth.) - 7.07 and Canadian poplar (Populus deltoides) - 7.05, the lowest - Scots pine (Pínus sylvеstris ) - 1.32 and gray alder (Alnus incana) - 3.37. Weakly and very weakly, most of the studied plant species capture vanadium and chromium, which are relatively sedentary in the soil.
 Further research is needed to analyze the physicochemical parameters of soils, the coefficients of transition of metals to plants relative to their content in organic and mobile form in order to establish the relationships that characterize the process of translocation of chemical elements.
 Keywords: landscape-geochemical conditions, heavy metals, soils, vegetation.

Oil in Water Nanoemulsions Loaded with Tebuconazole for Populus Wood Protection against White- and Brown-Rot Fungi

Eugenol in water nanoemulsions loaded with tebuconazole appear as a very promising alternative formulations for wood protection against xylophagous fungi that are the main species responsible for different rots in wood structures. The dispersions as prepared and upon dilution (impregnation mixtures) were characterized by the apparent hydrodynamic diameter distribution of the oil droplets loaded with tebuconazole and their long-term stability. The impregnation mixtures were applied on wood of Populus canadensis I-214 clone by using a pressure-vacuum system, and the effectiveness against fungal degradation by Gloeophyllum sepiarium and Pycnoporus sanguineus fungi was determined. The retention of tebuconazole in wood was about 40% of the amount contained in the impregnation mixtures. The results showed that the impregnation process leads to a long-term antifungal protection to the wood, with the mass loss after 16 weeks being reduced more than 10 times in relation to the control (untreated poplar wood) and the reference wood (untreated beech wood).

The Role of Lysobacter antibioticus HS124 on the Control of Fall Webworm (Hyphantria cunea Drury) and Growth Promotion of Canadian Poplar (Populus canadensis Moench) at Saemangeum Reclaimed Land in Korea.

Populus canadensis Moench forests established in Saemangeum-reclaimed land have been invaded by Hyphantria cunea Drury, causing defoliation and stunted growth. This study investigated the biocontrol potential of cuticle degrading chitinase and protease secreted by Lysobacter antibioticus HS124 against H. cunea larvae. In addition, L. antibioticus HS124 was examined for indole-3-acetic acid phytohormone production for plant growth promotion. To determine the larvicidal activity in the laboratory experiments, crude enzymes, bacteria culture, CY medium, and water (control) were sprayed on the larvae reared on natural diet in insect rearing dishes. Treatment with crude enzymes and bacteria culture caused 76.7% and 66.7% larvae mortality, respectively. The larvae cuticle, mainly composed of chitin and proteins, was degraded by cuticle-degrading enzymes, chitinase, and protease in both the bacteria culture and crude enzyme treatments, causing swelling and disintegration of the cuticle. Field application of the bacteria culture was achieved by vehicle-mounted sprayer. Bacterial treatment caused morphological damage on the larvae cuticles and subsequent mortality. Foliar application of the bacteria culture reduced tree defoliation by H. cunea and enhanced growth compared to the control. Especially, L. antibioticus HS124 produced auxins, and increased growth of poplar trees.

Оценка физиологических показателей растений рода Populus в аридных условиях Жезказгана

The creation of modern green spaces should be based on the selection of a sustainable assortment. Resistance is evaluated on the basis of a number of physiological indicators. Preliminary testing is of particular value for industrial regions with difficult climatic conditions. The purpose of this study was to study the resistance of 4 species of poplars to drought, winter conditions, the effects of diseases and pests, and atmospheric pollution. Resistance assessment was carried out for the species Populus alba, Populus balsamifera, Populus canadensis, Populus nigra, covering the period from 2015 to 2019. The results of visual observations showed that all species of poplars have high winter resistance — 4–5 points. Maximum winter resistance is noted for white poplar, minimum — for canadian poplar. The gas stability of poplars is estimated at 3–5 points. The greatest stability is noted in balsamic poplar, the minimum — in canadian poplar. Drought resistance among poplar species is estimated at 3–4 points. White and canadian poplar showed the least resistance to drought, while canadian poplar showed the maximum. Estimated scores of resistance to diseases and pests were 4–5 points, the highest indicators were noted for balsamic poplar, the minimum — for black poplar. On the basis of the identified indicators, the directions of poplar use in green construction are proposed.