Populus Nigra Research Articles

Assessment of environmental pollution with rare-earth metals through bioaccumulation studies using vegetal bioindicators

Environmental pollution by anthropogenic activities has become a global concern as the release of organic and inorganic pollutants into the atmosphere is responsible for important health problems among the population. The rare-earth metals processing sector has raised particular problems due to the bioaccumulation potential of these metals in the food chain. Urban trees are able to retain pollutants from the environment and can be used as bioindicators also for the rare-earth metal pollution. This paper aimed to assess the bioaccumulation of some rare-earth metals, besides other metals and non-metals, in the foliar part of six urban tree species (Populus nigra L., Populus tremula L., Populus x canadensis Moench, Betula pendula Roth, Aesculus hippocastanum L. and Fraxinus excelsior L.) sampled from different areas of the municipality of Bucharest. Laboratory experiments have shown that all tree species used in the study are able to retain rare-earth metals, but the bioaccumulation capacity is species-specific.

Reintroduced Native Populus nigra in Restored Floodplain Reduces Spread of Exotic Poplar Species.

Exotic Populus taxa pose a threat to the success of riparian forest restoration in floodplain areas. We evaluated the impact of exotic Populus taxa on softwood riparian forest development along the river Common Meuse after introducing native Populus nigra and after the re-establishment of the natural river dynamics. We sampled 154 poplar seedlings that spontaneously colonized restored habitat and assessed their taxonomy based on diagnostic chloroplast and nuclear microsatellite markers. Furthermore, by using a paternity analysis on 72 seedlings resulting from six open pollinated P. nigra females, we investigated natural hybridization between frequently planted cultivated poplars and native P. nigra. The majority of the poplar seedlings from the gravel banks analyzed where identified as P. nigra; only 2% of the sampled seedlings exhibited genes of exotic poplar species. Similarly, the majority of the seedlings from the open pollinated progenies were identified as P. nigra. For three seedlings (4%), paternity was assigned to a cultivar of P. × canadensis. Almost two decades after reintroducing P. nigra, the constitution of the seed and pollen pools changed in the study area in favor of reproduction of the native species and at the expense of the exotic poplar species. This study indicates that, although significant gene flow form exotic poplars is observed in European floodplains, restoration programs of the native P. nigra can vigorously outcompete the exotic gene flows and strongly reduce the impact of exotic Populus taxa on the softwood riparian forest development.

Effects of Thermo-Vibro-Mechanic® densification on the density and swelling of pre-treated Uludağ fir and black poplar wood

The radial and tangential swelling as well as the fully dried density of low-density wood materials densified via the Thermo-Vibro-Mechanic® method were evaluated in response to applying wood stain and preservative. The samples obtained from Uludağ fir (Abies bornmüelleriana Mattf.) and black poplar (Populus nigra L.) in the radial and tangential direction were pre-treated with wood stain and preservative before undergoing Thermo-Vibro-Mechanic® densification. Thermo-Vibro-Mechanic® densification was performed at three different temperatures (100 °C ± 3 °C, 120 °C ± 3 °C, and 140 °C ± 3 °C), three different vibration pressures (0.60 MPa, 1.00 MPa, and 1.40 MPa), and three different vibration times (20 s, 60 s, and 100 s). Afterwards, changes in the fully dried density and swelling amounts in the radial and tangential directions of the samples were determined. The fully dried density increased by 15.4% to 38% and the radial and tangential swelling amounts increased by 73.2% to 242.6%, when the densified samples were compared to the control samples. In general, the fully dried density and swelling values increased depending on the Thermo-Vibro-Mechanic® densification parameters; higher values were found as the compression ratio and total application time increased.

The GenTree Leaf Collection: Inter‐ and intraspecific leaf variation in seven forest tree species in Europe

AbstractMotivationTrait variation within species can reveal plastic and/or genetic responses to environmental gradients, and may indicate where local adaptation has occurred. Here, we present a dataset of rangewide variation in leaf traits from seven of the most ecologically and economically important tree species in Europe. Sample collection and trait assessment are embedded in the GenTree project (EU‐Horizon 2020), which aims at characterizing the genetic and phenotypic variability of forest tree species to optimize the management and sustainable use of forest genetic resources. Our dataset captures substantial intra‐ and interspecific leaf phenotypic variability, and provides valuable information for studying the relationship between ecosystem functioning and trait variability of individuals, and the response and resilience of species to environmental changes.Main types of variable containedWe chose morphological and chemical characters linked to trade‐offs between acquisition and conservation of resources and water use, namely specific leaf area, leaf size, carbon and nitrogen content and their ratio, and the isotopic signature of stable isotope 13C and 15N in leaves.Spatial location and grainWe surveyed between 18 and 22 populations per species, 141 in total, across Europe.Time periodLeaf sampling took place between 2016 and 2017.Major taxa and level of measurementWe sampled at least 25 individuals in each population, 3,569 trees in total, and measured traits in 35,755 leaves from seven European tree species, i.e. the conifers Picea abies, Pinus pinaster and Pinus sylvestris, and the broadleaves Betula pendula, Fagus sylvatica, Populus nigra and Quercus petraea.Software formatThe data files are in ASCII text, tab delimited, not compressed.

Fine-scale spatial genetic structure and intra-specific interactions of Populus nigra within a natural river corridor along the lower Allier River (France)

Spatial genetic structure (SGS) studies contribute to our understanding of gene flow and species dispersal. Only a few studies have linked the spatio-temporal pattern of SGS and intra-specific interactions. Black poplar (Populus nigra L.) is a threatened pioneer riparian tree species along many rivers across Europe. We studied its SGS in cohorts of varying ages at a fine-scale (i.e. at distances including the zone of influence between individuals) to better understand local patterns of dispersal and intra-specific interactions during early life-stages. We genotyped 349 P. nigra individuals in three gravel bars along a 1.6 km reach of the Allier River in the Réserve Naturelle du Val d'Allier, central France. We found high genetic diversity values (He = 0.860) thus identifying this site as important for the conservation of P. nigra genetic diversity. We also found significantly more clones in locations exposed to the river flow compared with less exposed locations. These clones offer mechanical protection and habitat improvement (through facilitation) to individuals in close proximity. A significant fine-scale SGS was observed in the youngest cohort at the gravel bar scale while none was observed in the older cohorts or at the river reach scale. This pattern was confirmed by a reanalysis of published data on the Garonne River. A shift in intra-specific interactions, from facilitation to competition through self-thinning, could explain the loss of SGS in older cohorts. This highlights the importance of shifts in intraspecific interactions through life and their consequence on population genetic structure.

Excellent Anti-lung Cancer Activity of Populus nigra and Phylogenetic Analysis.

Lung cancer has the highest incidence rate among malignant tumors all over the world, and it is also the leading cause of death. In this present research, we aimed to evaluate the anti-cancer activity of the Populus nigra extract against the lung cancer and study the genome evolution of the Populus nigra. Firstly, the inhibitory activity of the Populus nigra extract on the NCI-H292 lung cancer cell viability was determined with Cell Counting Kit-8 (CCK-8) assay. The trans-well assay was conducted and the influence of the Populus nigra extract on the NCI-H292 lung cancer cell migration and invasion ability was determined. In addition to this, the chloroplast (cp) genome of Populus nigra was sequenced with high-throughput Illumina pair-end sequencing, which was a classical useful model for genome evolution assessment. The CCK-8 and trans-well assay indicated the Populus nigra extract exhibited excellent inhibitory activity on the NCI-H292 lung cancer cell viability, migration and invasion ability. The circular cp genome of the Populus nigra was 156,354 bp in size, including a large single-copy (LSC) region of 84,528 bp and a small single-copy (SC) region of 16,564 bp, which were separated by two inverted repeat (IR) regions (38,612 bp each). A total of 132 genes were predicted, including 8 ribosomal RNAs (rRNAs), 37 transfer RNAs (tRNAs), and 90 protein-coding genes (PCGs). Furthermore, phylogenetic analysis revealed that Populus nigra has the closest relationship with Populus alba var. pyramidalis. In addition to Populus alba var. pyramidalis, Populus adenopoda and Populus tomentosa are also has closely relationship with Populus nigra.

Specific features of the response of the antioxidant system of urban trees to mistletoe infection

Urban green spaces are an important component of sustainable urban development. Infestation of urban trees by mistletoe white leads to a decrease in the growth energy of woody plants and their longevity. In the present study, the peculiarities of oxidative stress development and response of antioxidant enzymes (superoxide dismutase and catalase) of three tree species (Tilia cordata, Acer platanoides and Populus nigra) that are most susceptible to mistletoe infestation in Kaliningrad were studied. It was found that in all three species, when severely affected (more than 50 mistletoe bushes per tree), the bark content of malonic dialdehyde and hydrogen peroxide increased, indicating the intensification of oxidative processes in the cells of the affected trees. The catalase reaction was more pronounced compared to superoxide dismutase. The result confirms the fact that mistletoe infestation of trees leads to changes in redox metabolism in the cells of host trees and may indirectly lead to their weakening.

Monitoring of heavy metal pollution by using populus nigra and cedrus libani

Monitoring of heavy metal pollution by using populus nigra and cedrus libani

Variability of seedling survival and growth of different black poplar (Populus nigra L.) clones in the floodplain conditions of the Great War Island

Black poplar (Popuius nigra L.) belongs to endangered species of Serbia that grow in wetlands. This research was conducted on the Great War Island, which is located at the confluence of the Sava and Danube rivers, in Belgrade. This research aimed to determine the survival rate and growth dynamics of seedlings of different black poplar clones in the first year after planting in the flood conditions of the Great War Island. Recording of surviving seedlings and measurements of heights and diameters were performed in 2019, firstly in the spring (April IB, 2019), the second time during the summer (July IS, 2019), after the flooding period, and the third time in the autumn (October 4,2019), at the end of the vegetation period. The results of descriptive statistics, one-way analysis of variance (One-Way ANOVA), and cluster analysis are presented in this paper. Based on the obtained results, the highest survival rate after the flooding period was recorded in clone number 9 (85.70%), in which 78.60% of seedlings survived at the end of the vegetation period. It can be stated that the seedlings of black poplar clone number 9, based on a high survival rate, have the potential to be used for afforestation of wetlands, such as the Great War Island. However, the seedlings of this clone showed significantly lower values of measured heights and diameters, compared to the seedlings of most clones and mostly the seedlings were damaged. On the other hand, seedlings of clone 3 were superior based on the mean values of heights and diameters, obtained after the measurements in all three periods, including the period after flooding. Seedlings of this clone had a satisfactory survival rate, but it was constantly declining. Clone number 1 showed the lowest results, both in terms of survival at the end of the vegetation period and in terms of mean heights and diameters of seedlings. When using this species, special attention should be paid to preserving the gene pool and avoiding the establishment of commercial monoclonal plantations, especially in protected areas such as the Landscape of Outstanding Features "Great War Island".

Plant-mediated detoxification of lead, cadmium, and chromium present in aqueous solution through chemically modified Populus nigra leaves

Plant-mediated detoxification of lead, cadmium, and chromium present in aqueous solution through chemically modified Populus nigra leaves

Removal of heavy metal ions from aqueous solution using Populus nigra sawdust–based activated carbon

Removal of heavy metal ions from aqueous solution using Populus nigra sawdust–based activated carbon

The study of selected properties of black poplar wood (Populus nigra L.) subjected to furfurylation and polymerization in lumen

The study of selected properties of black poplar wood (Populus nigra L.) subjected to furfurylation and polymerization in lumen. The aim of this work was studying black poplar wood (Populus nigra L.) selected properties modified with furfuryl alcohol and styrene. Maleic anhydride and glicydyl methacrylate were used as cross-linking agents. For modified wood samples the index of WPG, density, hardness, water absorbability, colour change and volume swelling were tested. Each test results were compared with values for unmodified black poplar wood. During furfurylation process density of poplar wood samples increased up to 1.3 times. Addition of maleic anhydride to furfurylation process caused increase of WPG index about 5-6 % and at the same time slightly decrease of wood Brinell hardness. Water absorbability and volume swelling of furfurylated poplar wood after 10080 min (168 h) of soaking in water were reduced more than 50% relative to unmodified wood. Polymerization in lumen with using styrene caused increase of density up to 2 times, increase of Brinell hardness up to 1.5 times, while WPG index was in the range from 50.8 to 116.6%. For polymerization in lumen process, water absorbability and volume swelling after 10080 min (168 h) of soaking in water were reduced more than half as well. Furfurylation caused intensive wood darkening when polymerization in lumen changed wood colour slightly. Addition of maleic anhydride to furfuryl alcohol caused an even greater darkening of the wood. The studies proved, that chemical modification significantly improved selected properties of poplar wood.

"Poplars and Cypresses” – that is the phenomenon of popularity of Populus Italica in the Kingdom of Poland in the 19th century

Lombardy poplar is a tree with a distinctive cypress shape, which grows very fast and has little soil requirements. The species probably originated at the turn of the 17th and 18th century in Lombardy, where it spread via France and Germany, arriving at the territory of the Crown in the second half of the 18th century.
 However, it was only in the 19th century that its popularity reached its peak. The Lombardy poplar was being planted as a popular avenue plant. It was also an important part of the park complexes designed in a sentimental landscape style inspired by the work of Jean Jacques Rousseau. The article analyses the phenomenon of the popularity of poplar trees on the territory of the Kingdom of Poland in the context of the then literary and philosophical programme of the garden, whose two key sources are to be found in Arcadian literature – J. Milton's Paradise Lost, J. J. Rousseau's works such as New Heloise or Jacques Dellille's Gardens.

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.

A comparative study on some mechanical properties of black pine and black poplar woods

Pine and poplar wood types grow in many places in Turkey. Each tree species has different physical and mechanical properties due to its anatomical structures. In this study, some physical and mechanical properties of black pine (Pinus nigra) and black poplar (Populus nigra L.) wood were investigated, and compared with each other. According to the results of the research, moisture content, air-dried density, bending strength, modulus of elasticity, compression strength and impact bending strength of black pine wood were 9.77%, 508 kg/m3, 118.7 N/mm2, 9789 N/mm2, 57 N/mm2, 0.416 kgm/cm2, respectively. In addition, moisture content, air-dried density, bending strength, modulus of elasticity, compression strength and impact bending strength of black poplar wood were 9.81%, 396 kg/m3, 75.1 N/mm2, 5438 N/mm2, 42 N/mm2, 0.438 kgm/cm2, respectively.

Root shape adaptation to mechanical stress derived from unidirectional vibrations in Populus nigra.

While it is known that plant roots can change their shapes to the stress direction, it remains unclear if the root orientation can change as a means for mechanical reinforcement. When stress in form of a unidirectional vibration is applied to cuttings of Populus nigra for 5 min a day over a period of 20 days, the root system architecture changes. The contribution of roots with a diameter larger than 0.04 cm increases, while the allocation to roots smaller than 0.03 cm decreases. In addition to the root diameter allocation, the root orientation in the stem proximity was analyzed by appearance and with a nematic tensor analysis in an attempt to calculate the average root orientation. The significant different allocation to roots with a larger diameter, and the tendency of roots to align in the vicinity of the stress axis (not significantly different), are indicating a mechanical reinforcement to cope with the received strain. This work indicates an adaptive root system architecture and a possible adaptive root orientation for mechanical reinforcement.

Split-root investigation of the physiological response to heterogeneous elevated Zn exposure in poplar and willow

Essential and toxic ions are often heterogeneously distributed within a soil landscape. This fact may complicate phytoextraction efforts to remove toxic ions such as heavy metals from the soil as the roots of some plants instead may colonize more favorable microenvironments and avoid heavy metal accumulation. In this study a split-root hydroponic experiment was used to test whether root-level exposure to zinc (Zn) stress to none, half or all of the root systems of Populus deltoides Bart. ex Marshall x Populus nigra L. (poplar) and Salix matsudana L. (willow) plants alters root and shoot physiology. Cuttings of both species were split to create two root system halves that were exposed to either control (-Zn) or stress (+1 mM Zn) solutions for 42 days. Weekly measurements of gas exchange, photosystem fluorescence parameters and pigments showed that poplar was more sensitive to the half stress (-Zn/+Zn) treatment than willow, with lower gas exchange rates and total chlorophyll and carotenoid values relative to their respective controls (-Zn/-Zn). Half stress willow plants had increased root growth in the half without Zn, demonstrating a reallocation of carbon to compensate with no negative impact to shoot physiology as compared to poplar. Water consumption was also reduced in half stress willow but not in poplar, suggesting an increase in water-use efficiency in response to heterogeneous Zn exposure that was not derived from dramatic reductions in transpiration rate. These significant differences between these two species in response to patchy distribution of toxic Zn concentration may impact the efficiency of phytoremediation efforts and suggests additional criteria to consider in the pre-selection process.

Reaction Wood Anatomical Traits and Hormonal Profiles in Poplar Bent Stem and Root.

Reaction wood (RW) formation is an innate physiological response of woody plants to counteract mechanical constraints in nature, reinforce structure and redirect growth toward the vertical direction. Differences and/or similarities between stem and root response to mechanical constraints remain almost unknown especially in relation to phytohormones distribution and RW characteristics. Thus, Populus nigra stem and root subjected to static non-destructive mid-term bending treatment were analyzed. The distribution of tension and compression forces was firstly modeled along the main bent stem and root axis; then, anatomical features, chemical composition, and a complete auxin and cytokinin metabolite profiles of the stretched convex and compressed concave side of three different bent stem and root sectors were analyzed. The results showed that in bent stems RW was produced on the upper stretched convex side whereas in bent roots it was produced on the lower compressed concave side. Anatomical features and chemical analysis showed that bent stem RW was characterized by a low number of vessel, poor lignification, and high carbohydrate, and thus gelatinous layer in fiber cell wall. Conversely, in bent root, RW was characterized by high vessel number and area, without any significant variation in carbohydrate and lignin content. An antagonistic interaction of auxins and different cytokinin forms/conjugates seems to regulate critical aspects of RW formation/development in stem and root to facilitate upward/downward organ bending. The observed differences between the response stem and root to bending highlight how hormonal signaling is highly organ-dependent.

Comparative Studying of Leaf Trichomes, Teeth and Glands in Populus nigra L., Populus deltoides W. Bartram ex Marshall and Their Hybrids

Poplars from Aigeiros Duby section are very widespread in the world. A range of morphological characters were studied in such species of this section as Populus deltoides Bartram ex Marshall, P. nigra L. and their hybrid P. × canadensis Moench. However, there is little information about micromorphological characters of their leaves. The aim of this work was to study these characters and understand their species-specific potential. Thus, the morphological features, density and distribution of non-glandular trichoms, marginal glandular trichomes (salicoid teeth or coleters), epiglandular trichomes and basilaminar nectaries-glands were ontogenetically examined by both light and scanning electron microscopy in the certified by molecular markers P. deltoides, P. nigra and P. × canadensis samples. Non-glandular trichomes belong to the uni-, multicellular, uniseriate category. Marginal glandular trichomes can be classified as coleter types. Other morphological and anatomical trichome features are discussed with regard to their possible function. In summary, some variations in leaf morphology may be useful for the P. nigra, P. deltoides and their hybrid P. × canadensis species identification. These species differ in shape and number of basilaminar glands, as well as non-glandular trichome types and their distribution on the leaf.

Simultaneous Real-Time Measurement of Isoprene and 2-Methyl-3-Buten-2-ol Emissions From Trees Using SIFT-MS.

The C5 hemiterpenes isoprene and 2-methyl-3-buten-2-ol (MBO) are important biogenic volatiles emitted from terrestrial vegetation. Isoprene is emitted from many plant groups, especially trees such as Populus, while emission of MBO is restricted to certain North American conifers, including species of Pinus. MBO is also a pheromone emitted by several conifer bark beetles. Both isoprene and MBO have typically been measured by proton-transfer reaction mass spectrometry (PTR-MS), but this method cannot accurately distinguish between them because of their signal overlap. Our study developed a method for using selective ion flow tube mass spectrometry (SIFT-MS) that allows simultaneous on-line measurement of isoprene and MBO by employing different reagent ions. The use of m/z(NO+) = 68 u for isoprene and m/z(O2+) = 71 u for MBO gave minimal interference between the compounds. We tested the suitability of the method by measuring the emission of young trees of Populus, Picea, and Pinus. Our results largely confirm previous findings that Populus nigra, Picea glauca, and Picea abies emit isoprene and Pinus ponderosa emits MBO, but we also found MBO to be emitted by Picea abies. Thus SIFT-MS provides a reliable, easy to use, on-line measuring tool to distinguish between isoprene and MBO. The method should be of use to atmospheric chemists, tree physiologists and forest entomologists, among others.