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Określono wpływ ekranów akustycznych na ograniczenie rozprzestrzeniania się metali ciężkich w środowisku. Na teren badań wybrano odcinek Trasy Siekierkowskiej (Łuk Siekierkowski). Kontrola zlokalizowana była na terenie Ogrodu Botanicznego - CZRB w Powsinie. Badania przeprowadzono metodą bioindy­kacyjną polegającą na określeniu stopnia akumulacji metali ciężkich w liściach mniszka lekarskiego (Taraxacum officinale F.H. Wigg.) rosnącego w odległości 10, 150 i 300 m od trasy szybkiego ruchu. Wykazano, że Trasa Siekierkowska to poważne źródło skażenia środowiska metalami ciężkimi, przede wszystkim oło­wiem. Poziom zanieczyszczenia środowiska metalami ciężkimi w rejonie Trasy Siekierkowskiej w porównaniu z terenem kontrolnym był znacznie większy. Ekra­ny akustyczne montowane wzdłuż trasy szybkiego ruchu okazały się skuteczne w zmniejszaniu rozprzestrzeniania się zanieczyszczenia powietrza metalami cięż­kimi. W odległości 10 m od trasy ekrany redukowały zanieczyszczenie środowiska cynkiem i ołowiem średnio o 22%, chromem o około 18%, kadmem i żelazem o 11%, a miedzią o około 2%. Jednak wraz ze wzrostem odległości od trasy szybkiego ruchu ich pozytywny wpływ ulegał zmniejszeniu. Ekrany akustyczne to nie tylko bariery chroniące przed hałasem, ale również ograniczające rozprzestrzenia­nie się zanieczyszczeń w środowisku.
Soil contamination caused by the NaCl used to de-ice slippery roads in winter is now recognized as one of the major causes of nutrient disorders and death in urban trees. It is believed that polyisoprenoids may have a specific role in the adaptation of plants to adverse conditions and habitats; it is further believed that in the cell, they may exhibit a protective effect in response to biotic and abiotic stress. The aim of this study was to evaluate the effect of salt stress on the content of prenol lipids in the leaves of Crimean linden (Tilia ‘Euchlora’). The Cl content in the slightly damaged (“healthy”) leaves averaged 0.96%, while that in the heavily damaged (“sick”) leaves averaged 2.02%. The leaves of control trees contained on average 0.57% Cl. The Na contents in the healthy and damaged leaves were 208 mg/kg and 1038 mg/kg, respectively, and the Na content in the control areas was 63 mg/kg. A mixture of polyprenols consisting of four compounds, prenol-9, prenol-10, prenol-11 and prenol-12, was identified in the leaves of Crimean linden. This mixture was dominated by prenol-10 (2.16–6.90 mg/g). The polyprenol content was highest in the leaves of “healthy” trees (approximately 13.31 mg/g), was lower in the case of “sick” trees (approximately 9.18 mg/g), and was the lowest in the control trees (mean 4.71 mg/g). No changes were observed in the composition of the mixture of polyprenols under these conditions. The results suggest that polyprenols may affect the accumulation of Cl in leaves. This phenomenon is evidenced by the high content of prenols in the leaves of trees considered “healthy” but growing under conditions of increased soil salinity and the lower content of prenols in the leaves of the “sick” and control trees. It is advisable to further investigate the role of prenol lipids in the leaves of trees subjected to salt stress
Application of large amounts of NaCl to control slippery roads in winter leads to soil salinity and consequently to ionic imbalances, changes in pH, changes in physicochemical properties of the soil and the death of roadside trees. The aim of this study was to evaluate the effect of salt stress on the content of microelements in the leaves of roadside trees and on the health trees. The subject of research were trees of the Crimean linden (Tilia ‘Euchlora’) growing in the median strip of one of the main streets in Warsaw. The roadside trees contained much higher amounts of Cl and Na than trees in a park (control). There was a significant correlation between the Cl and Na content in leaves of the trees and their health state. As the content of these elements increased, the health condition of leaves clearly deteriorated. There was no significant effect of soil salinity on the micronutrient content in leaves. The content of Cu, Fe, Zn and Mn in linden tree leaves were on levels considered normal, with values not indicative of any deficiency or toxicity. The presence of Fe and Zn in leaves had no significant effect on the health of leaves of the trees. A statistically significant negative relationship was found between the index of leaf damage and their content of Cu and Mn. This means that a higher degree of leaf damage corresponded to a lower content of Cu and Mn. Based on regression analysis, it was estimated an increase in the Cl content in soil solution by approximately 1000 mg dm-3 caused an average 0.2% increase in the Cl content in leaves.
Unfavorable light conditions in urban areas are one of the most important cause of inappropriate grass communities condition. The possibility to detect the plant stress caused by shade is an important element in shaping the environment. The answer to following questions: what is the ability to detect the stress caused by shade in chosen lawn varieties of Perennial ryegrass by using the chlorophyll a fluorescence (O-J-I-P test) and which of tested varieties has the best properties to create grasslands in reduced light conditions is the aim of this work. Two-factor experimental micro-plot was conducted with three varieties and three different shadowing variants. Chlorophyll a fluorescence measurements were provided and were compared to leaf density. Our results explored significant difference between selected varieties in the terms of their photosynthetic apparatus adaption to light conditions. During May, all tested varieties were characterized by the rise of all fluorescence curve points under lower light intensity. The largest changes under shade conditions were noticed for the variety ‘Taya’. During next months a declining trend of photosynthetic effi ciency for this variety was observed. On the basis of our results, we assume that each variety has unique threshold and needs of light intensity.
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