Populus Nigra Research Articles

Baccharis dracunculifolia and Dalbergia ecastophyllum, Main Plant Sources for Bioactive Properties in Green and Red Brazilian Propolis.

Nowadays, propolis is used as a highly valuable product in alternative medicine for improving health or treating a large spectrum of pathologies, an ingredient in pharmaceutical products, and also as a food additive. Different vegetal materials are collected by honeybees and mixed with wax and other own substances in order to obtain the final product, called propolis. It is known as the bee product with the widest chemical composition due to the raw material collected by the bees. Different types are known worldwide: green Brazilian propolis (having Baccharis dracunculifolia as the major plant source), red Brazilian propolis (from Dalbergia ecastophyllum), European propolis (Populus nigra L.), Russian propolis (Betula verrucosa Ehrh), Cuban and Venezuelan red propolis (Clusia spp.), etc. An impressive number of scientific papers already demonstrate the pharmacological potential of different types of propolis, the most important activities being the antimicrobial, anti-inflammatory, antitumor, immunomodulatory, and antioxidant activities. However, the bioactive compounds responsible for each activity have not been fully elucidated. This review aims to collect important data about the chemical composition and bioactive properties of the vegetal sources and to compare with the chemical composition of respective propolis types, in order to determine the connection between the floral source and the propolis properties.

The extra-vascular water pathway regulates dynamic leaf hydraulic decline and recovery in Populus nigra.

Leaf hydraulic conductance (Kleaf ) is highly dynamic and typically responds to changes in water status and irradiance. However, the relative contribution of vascular (Kx ) and extra-vascular (Kox ) water pathways to Kleaf changes in response to water potential decline and recovery in function of light conditions remains poorly investigated. We investigated the dynamic responses of leaf hydraulics in Populus nigra L. by measuring Kleaf , Kx , and Kox changes under drought and upon recovery. Measurements were done at both low and high irradiance (LI and HI, respectively). Kleaf increased and became more vulnerable to dehydration under HI conditions than LI, due to marked changes of Kox . After re-watering, Kleaf recovered in parallel with Kox recovery, but Kleaf response to irradiance remained inhibited. Strong correlations between Kleaf and drought-induced membrane damage demonstrated the relevance of the cell-to-cell water pathway in driving the dynamic responses of Kleaf under drought and recovery. Our findings highlight the importance of coordination between water and light availability in modulating the overall Kleaf response to environmental conditions.

Quantifying the Estimation and Abundance of Plant Diversity of Shigar Valley, Gilgit -Baltistan, Pakistan

The studies were carried out from July 2017 to March 2018 in Shigar valley different Union Councils. The area lies between 7444 feet to 11694 feet from Above sea level in the Alpine zone including, Niali Nallah, Laxar Nallah, Nallah, Markuja union, Marapi union, Chorkah union, Gulapur. The study sites were randomly selected based on (1) herbs or shrubs land on the field periphery, (2) open grassland and arable land associated with sparse vegetation on rocks, stones, (3) forest land and open lands associated with sparse tree vegetation catchment of river and (4) forest land and arable land associated with dunes and rocky terrain. The quadrate method was used to record of vegetation from the selected study sites. A total of 59 plants species both medicinally and economically important were recorded at four study sites of CKNP and revealed that 30 herbs followed by 14 trees, 11 kinds of grass, and 4 shrubs respectively the dominant tree species recorded from all habitat types were Juniper sexcelsa, Elaeagnus ambulate, Morus alba, Salix Wilhelmina and Populus nigra. The most common herbs recorded were Artimisa brevifolia, Tanacetum, Echinops echinatus, Capparis sponsia, Ephedra intermedia, Peganum harmala, Daucus carota, Medicago sativa, Typha lotifuliya and Astragalus rhizanthus. The dominant shrubs were Rosa webbina, Hippophae rhamnoides, Sophora Molis and Myricaria germanica. The grasses recorded in the study area were Poa Alpina, Setaria Viridis, Hetropogon contortus, Cynodon dactylon, Taraxacum oritinlis, Trifolium repens and Cascuta reflexa. These plants are also used by local communities for fuelwood and timber. This study will be beneficial for locals and governments for the protection and conservation of this indigenous flora as well as fauna in the future.

Diversity of the ‘Candidatus Phytoplasma asteris’ and ‘Candidatus Phytoplasma fraxini’ isolates that infect urban trees in Bogotá, Colombia

Phytoplasmas have been associated with a disease that affects trees of at least 11 species from different botanic families in Bogotá, Colombia. 'Candidatus Phytoplasma asteris' and 'Candidatus Phytoplasma fraxini' are the major groups of phytoplasma in the area of Bogotá. In this study, the genetic diversity within 'Ca. P. asteris' and 'Ca. P. fraxini' was studied in five urban tree species: Croton species (Euphorbiaceae), Fraxinus uhdei (Oleaceae), Magnolia grandiflora (Magnoliaceae), Populus nigra (Salicaceae) and Quercus humboldtii (Fagaceae). Analyses of the 16S rRNA gene using nested PCR, RFLP and sequencing showed that phytoplasmas of 'Ca. P. asteris' could be assigned to: subgroup 16SrI-B; a new subgroup named 16SrI-AF, with a restriction pattern similar to that of 16SrI-B; and a new subgroup named 16SrI-AG, with a restriction pattern similar to that of 16SrI-K and 16SrI-AH with a restriction pattern similar to that of 16SrI-AC. 'Ca. P. fraxini' isolates belonged to a new subgroup named 16SrVII-G, with a restriction pattern similar to that of 16SrVII-A. To complement the identification of the phytoplasma strains, we amplified nonribosomal genes such as leuS and secA. Unexpectedly, it was observed that in 16 trees in which 16S rRNA gene analysis showed the presence of 'Ca. P. fraxini' only, the leuS or secA primers amplified sequences exclusively affiliated to 'Ca. P. asteris. In those plants, sequences belonging to 'Ca. P. fraxini' leuS or secA genes were not amplified. The present work contributes to the identification of novel strains of both species in Colombia, and supports previous suggestions that phytoplasmas in South America are highly variable.

Wood properties and transcriptional responses of poplar hybrids in mixed cropping with the nitrogen-fixing species Robinia pseudoacacia.

Cultivation of fast-growing tree species is often confined to marginal land. Mixed cropping with Robinia pseudoacacia, a legume tree species that forms a symbiosis with N2-fixing bacteria, has been proposed to be a measure to improve soil fertility and to achieve beneficial effects on the cocultivated tree species. The goal of our study was to examine the influence of a Robinia mixture on wood chemistry, anatomy and gene expression in poplar. We hypothesized that annual wood growth is stimulated in species mixtures due to the positive effects of Robinia on nitrogen availability and complementary resource use. Alternatively, we hypothesized that competition, especially for water, has negative effects on the wood growth of poplar. We used two commercial biomass clones, Hybride 275 (H275, Populus trichocarpa×Populus maximowiczii) and Max1 (Populus nigra×P. maximowiczii), which were planted at two locations with contrasting soil fertility in monoculture or mixed plots with Robinia to investigate the annual wood increment, wood nitrogen and δ13C, wood anatomy (length, cell wall thickness, lumina and frequencies of fibers and vessels) and transcriptional profiles in the developing xylem of 4-year-old stems. In a mixture with Robinia, the annual stem increment was reduced, nitrogen in wood was enhanced, δ13C in wood was decreased, vessel and fiber frequencies were increased and fiber lengths and fiber lumina were decreased. Transcriptional profiles showed stronger differences between the genotypes and sites than between mono and mixed cultivation. The transcriptional abundances of only one gene (the putative nitrate transporter, NRT1.2) and one gene ontology term ('immune system process') were significantly enriched in wood-forming tissues in response to the mixture, irrespective of the poplar genotype and growth location. Weighted gene coexpression network analyses extracted gene modules that linked wood nitrogen mainly to vessel traits and wood δ13C with fiber traits. Collectively, molecular and anatomical changes in poplar wood suggest beneficial effects on the water and N supply in response to the mixture with Robinia. These alterations may render poplars less drought-susceptible. However, these benefits are accompanied by a reduced wood increment, emphasizing that other critical factors, presumably light competition or allelopathic effects, overrule a potential growth stimulation.

WOX genes expression during the formation of new lateral roots from secondary structures in Populus nigra (L.) taproot

Despite the large amounts of data available on lateral root formation, little is known about their initiation from secondary structures. In the present work, we applied a bending treatment to Populus nigra (L.) woody taproots to induce the formation of new lateral roots. The development of lateral roots was monitored by stereomicroscopic examination of cross-sections. Tissues were sampled from the bending zone in the proximity of the vascular cambium before (time 0) and after the application of bending at three different time points (24, 48, and 72 h) and analyzed for the expression of P. nigra WOX homologs. The initiation of new lateral roots was observed to originate from the vascular cambium zone and was followed by primordium formation and root emergence. PnWOX4a, PnWOX4b, PnWOX5a, PnWOX5b, PnWOX11/12a, and PnWOX11/12b were shown to be expressed during the formation of new lateral roots at different developmental stages. The mechanical stress simulated by bending treatment was shown to activate the molecular mechanism leading to the expression of WOX genes, which are hypothesized to control SLR formation in the cambium zone of poplar taproot.

Remote sensing of american maple in alluvial forests: a case study in an island complex of the Loire valley (France)

Due to their particular topographic position between land and river, riparian forests are ecosystems rich in biodiversity. In France, along the Middle Loire (from Nevers to Angers), Black poplar (Populus nigra L.) forests are often in mixtures with the American maple (Acer negundo L.), introduced into the country in the 18th century. We tested the detectability of American maple by LiDAR and very high-resolution multispectral imagery on an island complex. We found that coupling the point cloud height standard deviation with a vegetation index in the red, green and blue spectrums discriminated American maple with a success rate of more than 90%.

Composition and structure of regrowth forests on abandoned agricultural land

Overgrowing of agricultural land by forest in Russia is a large-scale process. This study aims to examine the composition and structure of forests that took over abandoned agricultural lands in Belorechensky district, Krasnodar Krai (Russia). The research on 4 farmland plots was carried out in 2018. At the time of observation agricultural land has been abandoned for 7 to 8 years. Research methodology was developed to determine parameters such as tree and shrub density per ha, height and age at 50 m and up to 100 m from the forest. Two study sites were dominated by mesophytes, whilst the other two sites were invaded by xerophytes. Xerophytic landscapes were co-dominated by downy oaks and dog roses. The stand density of examined plants was 1.7 times lower at 51 to 100 m than near the forest (P ≤ 0.05). There were 3.3 times as many dog roses as downy oaks. The stand density of common ash stand at 51 to 100 m from the forest edge was 10 times lower than that of dog rose (P ≤ 0.01). Mesophytic landscapes were co-dominated by black poplars and crack willows. Black poplar was 4.3 times more frequent than dog rose (P ≤ 0.002) and 130 times more common than elm (P ≤ 0.0001). Natural overgrowth or succession can affect vast areas of land. It was established that dog roses and downy oaks regenerate xerophytic fields within 6 to 7 years, whereas mesophytic fields become dominated by black poplars and crack willows within 5 to 7 years.

Recent Advances Regarding the Phytochemical and Therapeutic Uses of Populus nigra L. Buds.

Populus nigra L. (Salicaceae family) is one of the most popular trees that can be found in deciduous forests. Some particularities that characterize the Populus genus refer to the fact that it includes more than 40 species, being widespread especially in Europe and Asia. Many residues, parts of this tree can be used as a bioresource for different extracts as active ingredients in pharmaceuticals next to multiple benefits in many areas of medicine. The present review discusses the latest findings regarding the phytochemical composition and the therapeutic properties of Populus nigra L. buds. The vegetal product has been described mainly to contain phenolic compounds (phenols, phenolic acids and phenylpropanoids), terpenoids (mono and sesquiterpenoids), flavones (e.g., apigenol and crysin), flavanones (e.g., pinocembrin and pinostrombin), caffeic/ferulic acids and their derivates, and more than 48 phytocompounds in the essential oils. The resinous exudates present on the buds have been the major plant source used by bees to form propolis. Several studies depicted its antioxidant, anti-inflammatory, antibacterial, antifungal, antidiabetic, antitumor, hepatoprotective, hypouricemic properties and its effects on melanin production. All these lead to the conclusion that black poplar buds are a valuable and important source of bioactive compounds responsible for a wide range of therapeutic uses, being a promising candidate as a complementary and/or alternative source for a large number of health problems. The aim of the review is to gather the existing information and to bring an up to date regarding the phytochemical and therapeutic uses of Populus nigra L. buds.

The ornithological breeding community in the Oasis of Arcola (Sp)

[The waterways Rivers, especially in lowland areas, often result the elements of highest naturalistic value and play an important role as ecological corridors. Rivers are characterized by high dynamism and biological complexity, and the distribution of several bird species often depends on their physical characteristics and water velocity. During spring 2018, we studied the bird community dwelling in the Arcola Reserve, managed by Lipu, in province of La Spezia (NW Italy), included within the Montemarcello Magra Regional Natural Park (SCZ IT1343502). This site presents a portion of plain woodland with presence of arboreal substrate dominated by Alnus glutinosa, Populus nigra, Populus alba, Salix alba, and a portion consisting of scattered trees, xeric meadows with shrubby formations comprising Rosa canina, Rubus sp., Spartium junceum, Prunus spinosa. Besides, rare reed formations are present. In the 20 hectares of the study area, we carried out field samplings through 8 monitoring sessions since April 23th until June 26th 2018. Overall, we found 62 species of which only 32 were (potentially, probably or certainly) nesting inside the reserve (22 belonging to Passerines and 10 to the non-Passerines species). Nightingale Luscinia megarhynchos (16.87 ± 4.37 individuals), Blackcap Sylvia atricapilla (16 ± 1.41 individuals), Cetti’s Warbler Cettia cetti (13 ± 2.06 individuals), Melodious Warbler (11.88 ± 6.88 individuals), Blackbird Turdus merula (10.75 ± 1.30 individuals) and Great Tit Parus major (9.88 ± 4.04 individuals) were the most abundant species. The density was 62.97 pairs/10 ha, whereas diversity resulted 2.47, this evidencing a considerable degree of complexity, while the evenness value suggests a certain degree of homogeneity in the abundance of the surveyed species. Five dominant species were present. Although the Passerines resulted the most important order in the community, also the non-Passerines showed a value higher than the one reported by other authors, although in less heterogeneous environments. Less than one third of the breeding species resulted to be long migrant species. Results of the present study represent a first step towards the increased knowledge about the avian community of the Arcola Reserve, especially addressed to its administrators as to highlight the need of preserving natural habitats and associated animal and plant species]. [Article in Italian]

Growth dynamics of fast-growing tree species in mixed forestry and agroforestry plantations

In recent years, plantations of fast-growing tree species have emerged as a possible way to meet the increasing demand for biomass for renewable energy in Europe. Agroforestry plantations including fast-growing tree species could be an attractive option because they reduce land competition for biomass and food production while providing forest benefits. Today, the species interactions that determine whether a given mixture will be more productive than the corresponding monocultures are still poorly understood. Our objective was to assess the performance of fast-growing trees, i.e. poplar (Populus nigra × P. deltoides) and alder (Alnus glutinosa), in association with herbaceous species either N2-fixing species (succession alfalfa (Medicago sativa) and clover (Trifolium pratense)) or graminoids (succession of wheat (Triticum aestivum) – triticale (Triticosecale) – temporary grassland consisting of mixtures of perennial ryegrass (Lolium perenne) and fescue (Festuca ovina)), respectively, and in association together. We compared tree growth in mixed stands to growth in the respective tree monocultures. An experimental plantation composed of three blocks including the different treatments was set up in 2014 in northeastern France. In the forest mixture, poplar and alder were planted in alternating rows, and in the agroforestry plots, every second line of trees was replaced by the crops. No fertilizers (of any kind) were used during the experiments. During six growing seasons, tree growth (height and diameter at breast height) was monitored monthly in the agroforestry stands, the forest mixture stand and the two tree monocultures. By the end of 2019, poplar stem height in association with N2-fixing crops (alfalfa, then clover) was higher than in the forest mixture and the monoculture. During the warmest growing season with a marked dry period in June-July (2018), poplar height growth rate in the agroforestry treatment was between three and five times higher than for the poplars in the monoculture and the forest mixture. A facilitation process in the agroforestry plantations could explain this result due to a significant enrichment of the soil in nitrogen by the N2-fixing crops. This result only appeared several years after tree planting, and management actions were necessary in order to control the strong competition between crops and trees during the early stages. In the forest mixture, poplars associated with alders were smaller than in their monoculture, in spite of a stratification of the canopies of the two species. For alders, tree growth did not appear to be affected by either an association with graminoids or with poplar.

Populus nigra Italica Leaves as a Valuable Tool for Mineralogical and Geochemical Interpretation of Inorganic Atmospheric Aerosols’ Genesis

The Olmaliq industrial area in Uzbekistan is believed to represent a risk to the environment and to human health due to the dispersal of contaminants into the air and soil. This study was undertaken to delineate the track of airborne contaminants’ migration and to assess the distribution of such particles deposited on Populus nigra L. cv Italica leaves and soils. Particles were identified using scanning electron microscopy–energy-dispersive X-ray spectroscopy (SEM-EDX), while bulk soil composition was quantified by applying inductively coupled plasma mass spectrometry (ICP-MS). The results of this study confirmed the research hypothesis, indicating the industrial center as a source of pollution and human exposure to metallic contaminants. The Olmaliq area in particular is strongly influenced by atmospheric pollutants from local industries. The spread of ultra-fine particles is mainly governed by the industrial output and the direction of prevailing winds.

Afforestation may influence changes in tailing heaps in a long time

A soil and plant survey was carried out in a tailing heap afforested 30 years ago to gain information about the changes in the tailing and metal uptake by plants. A poor development of Technosol was found. It was observed accumulation of OM spatio temporarily. Metal concentrations in the soil profile varied between plots. Extractable Pb concentrations ranged from 0.4 to 2.9%; extractable Cd varied 9.7–46% of the total concentration. PCA analysis shows DTPA-Zn and DTPA-Cu, Na, K, and OM have the widest concentrations range between soil layers. Casuarina equisetifolia and Pennisetum clandestinum formed a pristine uniform litter layer, whereas Eucalyptus camaldulensis did not form a litter layer. Casuarina equisetifolia has a higher population density (756 p ha−1) compared to Populus nigra (528 p ha−1) and E. camaldulensis (621 p ha−1). Pennisetum clandestinum grew successfully and covered the tailing, but Cd and Pb concentrations were above the domestic animal toxicity limits, 0.5 and 10 mg kg−1, respectively. Populus nigra absorbed more Zn than Casuarina equisetifolia and Eucalyptus camaldulensis. Trees species did not accumulate high foliar Cu and Zn concentrations, but Pb (47.7–124.3 mg kg−1) and Cd (5.7–26.8 mg kg−1) concentrations are over those reported for mature leaf tissues. Highlights Pennisetum clandestinum formed soil cover on remediated plots. Casuarina equisetifolia was efficient in forming a litter soil horizon. Trasdescantia fluminensis accumulated Pb. Populus nigra accumulated Zn and Cd from the tailing heap.

Effect of volatiles emitted from wilted Populus nigra L. leaves on the mating and oviposition of Helicoverpa armigera (Hübner)

Wilted black poplar, Populus nigra ‘Italica’ L., leaves are very attractive to a vast number of noctuid moth species. This provides an opportunity for the development of effective trapping methods for the integrated management of pest species, such as Helicoverpa armigera, a major global and economically important insect pest.In the present study, we investigated the (1) nocturnal attraction patterns of H. armigera males and females to wilted P. nigra leaves; (2) effects of P. nigra volatiles on the mate-searching behavior of males through laboratory serial-chamber bioassays and field trapping; and (3) effects of P. nigra volatiles on the ovipositional choice and reproductive performance of females. Females and males, when tested alone, could be attracted by wilted P. nigra leaves, and the time periods of the first two attraction peaks were largely overlapped between sexes. Streams consisting of wilted P. nigra leaves and virgin females were not more attractive than virgin females alone, regardless of the stream sequence in a serial chamber. However, a stream of virgin females passed through wilted P. nigra leaves was more attractive than wilted P. nigra leaves alone. The addition of P. nigra extracts and its major aromatic components to the sex lure of H. armigera did not attract more moths than the sex lure alone. The volatiles from wilted P. nigra leaves were significantly more attractive to ovipositing females than those from cotton, tomato, and corn leaves, but equally attractive to tobacco leaves. Females exposed to volatiles from different leaves (P. nigra, cotton, and tobacco) showed similar fecundities. In summary, the attraction of moths to wilted P. nigra leaves may be attributable to multiple mechanisms, including the adsorption of sex pheromones, ovipostional attraction, and possible feeding attraction.

Bacterial Canker Disease on Populus × euramericana Caused by Lonsdalea populi in Serbia

Populus × euramericana (Dode) Guinier clone (cl.) “I-214” is a fast-growing interspecific hybrid between Eastern cottonwood (P. deltoides Bartr. ex Marsh) and European black poplar (Populus nigra L.). Populus × euramericana was introduced into Serbia in the 1950s and has become one of the most widely grown poplar species. In September 2019, cankers were observed on stems and branches of P. × euramericana cl. “I-214” trees in a two-year-old poplar plantation in the province of Vojvodina, Serbia. The canker tissue was soft and watery, and a colorless fluid that smelled rotten flowed from the cracks in the bark, suggesting possible bacterial disease. After two weeks, diseased trees experienced crown die-back and oozing of foamy, odorous exudates and this study aimed to identify the causal agent of the disease. Canker margins and exudates were collected from 20 symptomatic trees. The associated bacterium was isolated and identified using biochemical characteristics, phylogenetic analyses based on 16S rRNA gene sequences, and multilocus sequence analyses (MLSA) based on partial sequencing of three housekeeping genes (gyrB, infB, and atpD). The pathogen was identified as Lonsdalea populi. Pathogenicity tests were conducted on rooted cuttings of P. × euramericana cl. “I-214” in an environmental test chamber and demonstrated that the isolated bacterial strain was able to reproduce symptoms of softened, water-soaked cankers and exudation. To the best of our knowledge, this is the first report of L. populi causing bacterial canker disease on P. × euramericana cl. “I-214” in Serbia and in southeastern Europe (SEE). It is also the first report of a bacterial disease on hybrid poplars, including P. × euramericana in this country and in SEE. If the disease spreads into new areas, selection for L. populi resistance may need to be integrated into future poplar breeding programs.

HPLC Assay of Rutin Content in the Leaves of the Black Poplar

A method for assay of rutin content in the leaves of the black poplar (Populus nigra L.) using HPLC at a wavelength of 360 nm was developed; this used an Elsico column (No. 10302, 2 mm × 80 mm; Silasorb C18 7 μm), with a mobile phase consisting of acetonitrile-water (2:8) supplemented with 1% glacial acetic acid. The suitability of the method for analysis of standard rutin samples was confirmed. Rutin content in black poplar leaves ranged from 0.67% to 1.05%. Statistical analysis of the experimental results provided evidence that the error level in single determinations of rutin in black poplar leaves with a 95% confidence interval was ± 4.6%.

Impact of biased sex ratio on the genetic diversity, structure, and differentiation ofPopulus nigra(European black poplar)

Effective population size is a crucial concept of conservation biology. It is reduced by biased sex ratio, consequently causing loss of genetic variation. To evaluate genetic diversity related to gender, and investigate the possible effects of biased sex ratio, we analyzed available microsatellite DNA markers from 120 samples of Populus nigra L. (European black poplar) originating from five geographical regions in Turkey. Using 12 microsatellite markers, we detected 60 clones of the same genotype, out of 120 trees. The clone genotype was observed both in males and females, which might suggest that P. nigra deviates from dioecism. Three genetic clusters were detected, two of which possibly correspond to commercially available trees. Overall allelic richness was found to be similar for both genders, whereas heterozygosity was slightly higher in males. Additionally, a simulation software prototype was developed to see the effects of sex ratio on diversity and allele frequency trends in future generations, given the available molecular data. Results showed that if biased sex ratio persists, allele loss and fixation might occur in a higher rate, causing loss of variation.

Study of forest strip systems agrolandscapes structure

The aim of the scientific work is to investigate the forest bands system structure of agrolandscapes with the aim of establishing the duration of periods of its development for determining the main forest species. Research Methodology: complete counting of trees on temporary test plots laid in typical forest belts, analysis of main tree trunks and obtaining equations of relationships between heights and ages; modeling the development of the structure of forest belts using these equations and formulas for determining the distance between forest belts. It was found out that forest lane systems in their development consistently go through certain periods: unsteady, stationary, post-stationary and decaying functioning. The main criterion for choosing the main species when creating forest belt systems is the longest duration of the stationary and post-stationary functioning of the system. For forest strips created from Quercus robur, this duration is 81 years, Fraxinus lanceolata - 63 years; Robinia pseudoacacia - 55 years. According to this criterion, it is not advisable to create forest strips from such main species as Populus nigra and Ulmus pumila on southern chernozems.

Esterification of cellulose isolated from black poplar (Populus nigra L.) sawdust with octanoyl chloride

Esterification of cellulose isolated from black poplar (Populus nigra L.) sawdust with octanoyl chloride

Experimental Determination of Sound Transmission Loss of Some Wood Species

Aim of study: To determine the sound transmission losses of 16 different wood species with the different density in the range of 100-1000 Hz frequencies, and the relationship between density and transmission loss was. Material and methods: In this study sound transmission loss values of Ash (Fraxinus excelsior), Acacia (Robinia pseudoacacia L.), Beech (Betula pendula), Black pine (Pinus nigra), Black poplar (Populus nigra), Canadian poplar (Populus x euramaricana), Chestnut (Castanea sativa Mill.), Cypress (Cupressus sempervirens), Oriental beech (Fagus orientalis Lips,) Eucalyptus C. (E, camaldulensis Dehnh), Eucalyptus G. (Eucalyptus grandis), Juniper (Juniperus excelsa), Plane (Platanus orientalis L.), Scotch pine (Pinus sylvetris L), Turkish Red pine (Pinus brutia Ten) and White Oak (Quercus alba) wood specimens were determined by using the impedance tube kit. Main results: Sound transmission loss is observed in lower density wood material species with the increasing frequency. However, a clear relationship has not been established between the mean sound transmission loss and density. Highlights: It is important to determine the frequency-related acoustic performance parameters of the wood material and to its relationship with density.