Heavy metal accumulation by Acer platanoides and Robinia pseudoacacia in an industrial city (Northern Steppe of Ukraine)

The role of tree species as a tool for bioaccumulation of heavy metals is an important current issue within the context of the increase of anthropogenic pressure in urban ecosystems. The article presents the results of research on the level of soil contamination with heavy metals and the processes of their accumulation by native and introduced tree species in green spaces of Dnipro city. Inductively coupled plasma mass spectrometry (ICP-MS) was used to detect concentrations of heavy metals (Zn, Cu, Cd, Pb) in soil samples and the assimilation component in trees of black locust (Robinia pseudoacacia) and Norway maple (Acer platanoides). The ranges of mean concentrations of heavy metals at different study sites within the city’s green infrastructure were as follows (mg/kg): 30.7–185.5 for Zn, 5.7–22.4 for Cu, 9.0–31.3 for Pb, and 0.213–0.598 for Cd. With respect to all four of these metals, the soils of the Metallurgists Square location were characterized by the highest concentrations of the metals, and the Pridneprovsky Park in the area of the outskirts of Dnipro city was characterized by the lowest ones. Compared to soils, the two investigated tree species had a significantly lower content of all studied metals in leaves. The heavy metal accumulations in the leaves of both R. pseudoacacia and A. platanoides were observed in the following decreasing order: Zn > Cu > Pb > Cd. Regarding the migration of heavy metals in the soil-plant system, the concentrations of ecopollutants in the plants were found not to be dependent on their content in the soil environment. The calculated bioaccumulation coefficients of heavy metals for both tree species were < 1. However, the results of heavy metal concentration in leaves of both introduced and native tree species evidenced their special role in heavy metal bioaccumulation. Compared to R. pseudoacacia, such native species as A. platanoides can be considered to be a more “sensitive” bioindicator of environmental pollution caused by heavy metals. Planting fast-growing tree species such as R. pseudoacacia and A. platanoides can in a short time be an environmentally appropriate and cost-effective measure to mitigate the unfavourable effects of heavy metals on the environment

Аналіз показників асиміляційної складової у структурі надземної фітомаси деревних порід степових лісостанів України

The purpose this research is to study the parameters of leaf (needle) share in the trees’ greenery fraction and the content of absolutely dry matter in fresh leaves of black locust and Scots pine. The leaf (needle) share in the trees greenery fraction and the content of absolutely dry matter were determined by their quantitative measures (weight and volume). The results of the research reveal that the leaf share in the structure of a tree’s greenery fraction has a broad range of values: 43.0–72.8% for black locust and 49.1–75.4% for Scots pine. The minimum value of this parameter was recorded for an overmature Robinia specimen of 41 years of age, while the maximum was for a 3-year-old tree. For pine trees the lowest values of the given parameter were registered for the spcimens aged 38, 49 and 84, the maximum – for 30–31-year-old trees. For both investigated species it should be noted that there is a consistent pattern indicated by the following trend line: with the increase of tree age, height and trunk diameter, there is a decrease of leaf share value in the trees’ greenery fraction. Such characteristic parameter as absolutely dry mass has a sufficient range of values from 0.321 to 0.524, with the extreme values for the trees belonging to the young stock group in the case of the black locust. The absolutely dry matter content in Scots pine needles showed a significant variability of values from 0.426 to 0.620. The trend line shows a tendency of increase in the value of absolutely dry matter mass in the leaves of both investigated species with the increase in the values of the tree taxation parameters. There is no statistically proven dependency of the parameter indicating leaf share in the trees greenery fraction on the age, trunk diameter and height of trees. The most important biometric indicator, which shows a moderate relationship with the greenery fraction of a tree is the average diameter of the trunk of model trees of the two studied species. This is confirmed by values of correlation coefficients. The indicator of greenery fraction is inversely dependent on the height, trunk diameter and tree age, i.e. the increase in the values of these parameters leads to the decrease in the share of the photosynthetic active component of  trees of the studied tree species in the steppe zone. The value of leaf (needle) share in trees’ greenery fraction decreases with the increasing age, height and diameter values, which is quite natural. Correlation indices of absolutely dry matter according to age, height and diameter of sample trees have negative values, while the index of leaf (needle) share of trees’ greenery fraction has a direct correlation with all the studied influence factors. Подано результати досліджень асимілювальної складової надземної фітомаси – частка листя (хвої) та вміст абсолютно сухої речовини у листі (хвої) у фракції деревної зелені головних лісотвірних порід лісостанів Північного Степу України – Pinus sylvestris L. та Robinia pseudoacacia L. Значення показників частки листя (хвої) у структурі асимілювальної складової робінії звичайної та сосни звичайної перебувають у певному діапазоні, який демонструє їх залежність від основних таксаційних показників деревостанів. Спостерігається зменшення даного показника зі збільшенням віку та зі зростанням середнього діаметра та висоти стовбура для двох досліджуваних деревних порід. Виявлено тренди, що демонструють зміни значень вмісту абсолютно сухої речовини у листі робінії звичайної та у хвої сосни звичайної. Висока варіабельність абсолютних значень вмісту сухої речовини у листі робінії зафіксована за умов однакових значень віку, діаметра стовбура та висоти модельних дерев. Показники вмісту абсолютно сухої речовини у хвої сосни звичайної, навпаки, мають тенденцію до підвищення відносно досліджуваних таксаційних параметрів. Подано результати досліджень асимілювальної складової надземної фітомаси – частка листя (хвої) та вміст абсолютно сухої речовини у листі (хвої) у фракції деревної зелені головних лісотвірних порід лісостанів Північного Степу України – Pinus sylvestris L. та Robinia pseudoacacia L. Значення показників частки листя (хвої) у структурі асимілювальної складової робінії звичайної та сосни звичайної перебувають у певному діапазоні, який демонструє їх залежність від основних таксаційних показників деревостанів. Спостерігається зменшення даного показника зі збільшенням віку та зі зростанням середнього діаметра та висоти стовбура для двох досліджуваних деревних порід. Виявлено тренди, що демонструють зміни значень вмісту абсолютно сухої речовини у листі робінії звичайної та у хвої сосни звичайної. Висока варіабельність абсолютних значень вмісту сухої речовини у листі робінії зафіксована за умов однакових значень віку, діаметра стовбура та висоти модельних дерев. Показники вмісту абсолютно сухої речовини у хвої сосни звичайної, навпаки, мають тенденцію до підвищення відносно досліджуваних таксаційних параметрів.

Особенности продуктивности сосновых древостоев в лесонасаждениях Северной Степи Украины

The aim of this work is the comparative analysis of the productivity of Scots pines in pure and mixed plantations with main and accompanying species in the Northern Steppe of Ukraine We analysed the taxation parameters such as height, diameter, stand density, which vary with the age of the stand and composition of the plantation. Within the study area pines grow mainly in pure stands (81.9%). The share of mixed forest stands in the study area is only 18.1%. The analysis of representation of age structure showed the presence of the same proportion of the young age group in pure and mixed stands, the dominant share being taken up by middle-aged monoculture stands, and thus a smaller area taken up by mature and overmature pines. The average stand density per 1 ha in pure stands of all age groups is 17% higher than in mixed stands. The dynamics of variations of such biometric data as average height, diameter and density for the different compositions of Scots pine stands were measured for 14 age classes. The mean heights of the pure and mixed stands are vere close, while the average diameter gradually increased with age, reaching its maximum in overmature plantations. The research results showed that there is an excess of this parameter in the mixed compared with the pure stands. We did not find significant differences between middle age pure and mixed stands in accumulation of stand density. But pure pine stands show a clear tendency to dominate in wood accumulation in all age classes through the period of growth. The greatest difference between pure and mixed stands in the mean stand density was observed for those of middle-age. The average stand density in the pure stands was up to 32% higher than the mixed. The area distribution of Scots pine stands according to productivity was as follows. The largest area for both pure and mixed stands was occupied by trees of quality class I, which took up 54.3% of the total pure pine acreage and 41.9% of the mixed stand acreage. The second position was occupied by quality class II, which occupied 27.6% of total pure pine acreage and 36.6% of mixed stand acreage with the perecentage of total stand density at 23.6% and 35.1% respectively. In general, the value of the average stand density falls as the quality class decreases, and essentially depends on the composition of plantations: in pure stands, it is higher than in mixed. The investigated values of the biometric parameters are statistically significant for both the pure and the mixed stands. Проанализирована возрастная структура древостоев сосны обыкновенной (PinussylvestrisL.) в чистых и смешанных лесонасаждениях Северной Степи Украины. Показано превалирование доли средневозрастных монокультур сосны. Средний запас древесины на 1 га во всех исследуемых возрастных группах однопородных насаждений превышает таковую в смешанных максимум на 17%. Приведена динамика изменений биометрических показателей (высоты, диаметра и запаса древесины) для разных по составу сосновых насаждений. По сравнению со средней высотой, показатель средного диаметра имеет большую зависимость от возраста, что особенно характерно для древостоев смешанного типа. Наблюдается тенденция доминирования формирования древесины в чистых по составу насаждениях во всех исследуемых классах возраста на 3–32 %. Показано падение величины среднего запаса по мере снижения бонитетного класса, которое в чистых насаждениях выше, сравнительно со смешанными. Приведены статистически достоверные значения зависимости таксационных параметров древостоев от возраста, как в чистых, так и смешанных. Проанализирована возрастная структура древостоев сосны обыкновенной (PinussylvestrisL.) в чистых и смешанных лесонасаждениях Северной Степи Украины. Показано превалирование доли средневозрастных монокультур сосны. Средний запас древесины на 1 га во всех исследуемых возрастных группах однопородных насаждений превышает таковую в смешанных максимум на 17%. Приведена динамика изменений биометрических показателей (высоты, диаметра и запаса древесины) для разных по составу сосновых насаждений. По сравнению со средней высотой, показатель средного диаметра имеет большую зависимость от возраста, что особенно характерно для древостоев смешанного типа. Наблюдается тенденция доминирования формирования древесины в чистых по составу насаждениях во всех исследуемых классах возраста на 3–32 %. Показано падение величины среднего запаса по мере снижения бонитетного класса, которое в чистых насаждениях выше, сравнительно со смешанными. Приведены статистически достоверные значения зависимости таксационных параметров древостоев от возраста, как в чистых, так и смешанных.

Effect of antigibberellins on morphogenesis, photosynthetic apparatus, productivity and their residual content in tomato fruits

The application of growth and development regulators on crops in order to optimize their production process is one of the leading tasks of modern plant physiology. Retardants – gibberellin inhibitors are widely used for this purpose. We investigated the effect of foliar treatment with EW-250, ССС-750 and 2-СEPA on morphogenesis, leaf apparatus, content of photosynthetic pigments, indices of chlorophyll fluorescence induction, CO2 gas exchange, and residual amounts of drugs in the fruits of tomato (Lycopersicon esculentum Mill.) Bobcat hybrid. The field experiment was laid on plots with an area of 33 m2. The treatment of the plants was carried out at the budding stage. Morphometric indices were determined at the stages of flowering and fruit formation. The chlorophylls content was determined in the raw material by the spectrophotometric method. Indices of photosystem II (PSII) photochemical activity were determined according to the parameters of chlorophyll fluorescence induction after a half-hour exposure of plants in the dark using a portable single-beam fluorimeter "Floratest". The determination of the residual content of retardants in the fruits was carried out on a Shimadzu GC gas chromatograph with a mass spectrometric detector – GCMS- QP2020 EI. All gibberellin inhibitors reduced linear plant size. The number of leaves on the plants decreased under 2-CEPA treatment, and increased after the application of EW-250. Treatment with 2-CEPA decreased, EW-250 significantly increased, and CCC-750 practically did not change the leaves’ fresh and dry weight. Leaf area and leaf index decreased under 2-CEPA treatment, but practically did not change when EW-250 and ССС-750 were applied. All antigibberellin drugs increased the leaf specific leaf weight and thickened the leaf lamina due to the growth of chlorenchyma cells. At the same time, growth inhibitors increased the volume of columnar parenchyma cells and practically did not change the size of spongy parenchyma cells. Retardants increased the chlorophylls content in leaves, while the ethylene producer 2-CEPA did not change this index. The plants’ chlorophyll index after treatment with drugs increased significantly. The whole plant dry weight increased under EW-250 treatment, decreased after 2-CEPA application, and did not change under CCC-750. It was established that the photosynthetic rate increased under the EW-250 treatment, both in the flowering stage and in the stage of fruit formation, while when using 2-CEPA and CCC-750, it occurred only at the stage of fruit formation. The most significant positive changes of PSII photochemical activity indices were observed under the use of EW-250. Under the action of the drug, the maximum and actual quantum efficiency of PSII increased, the linear electron transport accelerated, and the fraction of reaction centers that did not transfer electrons from the primary acceptor QA to QB decreased, at the same time the chlorophyll fluorescence decay coefficient significantly increased, which indicates an increase in the CO2 assimilation intensity. Retardants increased the proportion of the fruit in the whole plant dry weight. All growth regulators increased net photosynthetic efficiency. A significant increase in fruit yield occurred under EW-250 treatment. When using CCC-750, the index tended to increase, while under the influence of 2-CEPA the yield decreased. The residual amounts of EW-250 and CCC-750 in the fruits did not exceed the maximum permissible concentrations

Crystal Phase Transitions in the Shell of PbS CdS Core Shell Nanocrystals Influences Photoluminescence Intensity

ABSTRACT We reveal the existence of two different crystalline phases, i.e., the metastable rock salt and the equilibrium zinc blende phase within the CdS shell of PbS CdS core shell nanocrystals formed by cationic exchange. The chemical composition profile of the core shell nanocrystals with different dimensions is determined by means of anomalous small angle X ray scattering with subnanometer resolution and is compared to X ray diffraction analysis. We demonstrate that the photoluminescence emission of PbS nanocrystals can be drastically enhanced by the formation of a CdS shell. Especially, the ratio of the two crystalline phases in the shell significantly influences the photoluminescence enhancement. The highest emission was achieved for chemically pure CdS shells below 1 nm thickness with a dominant metastable rock salt phase fraction matching the crystal structure of the PbS core. The metastable phase fraction decreases with increasing shell thickness and increasing Exchange times. The photoluminescence intensity depicts a constant decrease with decreasing metastable rock salt phase fraction but Shows an abrupt drop for shells above 1.3 nm thickness. We relate this effect to two different transition mechanisms for changing from the metastable rock salt phase to the equilibrium zinc blende phase depending on the shell thicknes

ЕКГ – картина при позалікарняних пневмоніях у дітей підліткового віку

The present article analyses the ECG-results of 75 adolescents, suffering from the community-acquired pneumonia. 61,33 % patients have been established to have changes in electromechanical function of the heart such as rhythm disorder, disturbance of conductivity and metabolic changes. Comparison to ECG-findings of healthy adolescents has proved the significant predominance of changes caused by pneumonia.Проанализированы результаты ЭКГ-обследования 75 подростков, больных внебольничной пневмонией. У 61,33 % установлены изменения электромеханической функции сердца в виде нарушений ритма, проводимости и метаболических изменений. Сравнение с показателями ЭКГ здоровых подростков показало существенное преобладание изменений на фоне пневмонии.Проаналізовані результати ЕКГ-обстеження 75 підлітків, хворих на позалікарняну пневмонію. У 61,33 % встановлено зміни електромеханічної функції серця у вигляді порушень ритму, провідності та метаболічних змін. Порівняння з показниками ЕКГ здорових підлітків довело суттєве переважання змін на тлі пневмонії