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Potential of Selected Species of Spiraea L. for Phytoremediation of Heavy Metals from Soils of Urban Areas
Four taxa of Spiraea were selected for this study: S. × cinerea Zabel ‘Grefsheim’, S. nipponica Maxim. ‘Snowmound’, S. splendens É. N. Baumann ex K. Koch and S. × vanhouttei (Briot) Carrière growing for a minimum of 5 years along heavily trafficked traffic routes. This study included the genus Spiraea due to its popularity in horticultural practice (commercial availability, widespread in urban environments). In addition, the use of ornamental shrubs for phytoremediation in urban green spaces effectively combines the aesthetic needs of residents with those of caring for the urban environment. This study was conducted in Poznań (population 550,000, the fifth largest city in Poland). Soils and foliage were examined in spring and autumn. Soil pH and specific electrolytic conductivity (EC) were determined. The content of micronutrients (Cu, Fe, Mn, Ni, Zn) and toxic heavy metals (Cd, Cr, Pb) in soil dry matter and leaves was determined. The uptake capacity of bioavailable forms of heavy metals by Spiraea from the soil was analyzed by determining the bioconcentration factor (BCF). It was found that the studied taxa meet the basic requirements for plants used for soil phytoremediation processes, especially for chromium phytoextraction. The degree of salinity of the tested soils did not pose a threat to the shrubs growing there, and most of the sites, despite the alkaline reaction, are suitable for their cultivation. S. × cinerea and S. × vanhouttei have BCFs for lead <1. The remaining taxa are characterized by strong concentrations of all analyzed elements. A particularly high BCF, above 10, was recorded for chromium and high for manganese and nickel.
Assessment of the Antioxidative Properties of Extracts from the Fruits of Pyrus pyraster (L.) Burgsd and Pyrus ×myloslavensis Czarna & Antkowiak Grown under Natural Environmental Conditions
Analyses were conducted on extracts from the fruits of P. pyraster and P. ×myloslavensis. Extraction with 80% methanol was performed at room temperature. The total phenolic content was determined by spectrophotometry using the Folin–Ciocalteu reagent, with gallic acid as the reference standard. Phenolic compounds and organic acids were identified on a liquid chromatograph. The antioxidative activity of the extracts was tested in relation to linoleic acid incubation of the emulsions for 19 h based on the neutralization of the DPPH radical (2,2-diphenyl-1-picrylhydrazyl) and the ABTS cation radical (2,2′-azino-bis[3-ethylbenzothiazoline-6-sulfonic acid]) as well as by the ferric reducing antioxidant power (FRAP) assay. The analyses showed that the extract from P. pyraster fruits is characterized by a higher content of phenolic compounds and a higher antioxidative potential compared with that from P. ×myloslavensis. In extracts of both pear species, seven phenolic compounds and four organic acids were identified. The total fiber content in pears of P. pyraster and P. ×myloslavensis was determined at 36.45 g and 24.74 g/100 g d.m. of the pear fruits, of which most comprised the insoluble fraction (32.49 g and 20.86/100 g, respectively). The results of the conducted research are highly significant, as they confirm that pears contain many valuable nutrients and biologically active compounds, including antioxidants and dietary fiber. Adding pear extracts to food products may offer a way to boost their health benefits while also broadening the variety of items that have appealing sensory characteristics. Moreover, research has shown that fruit extracts can help to prolong the shelf life of food products by safeguarding them against lipid oxidation and the decline in their nutritional value.
Assessment of the Influence of Aluminum, Iron, and Manganese Forms on the Phytocenoses of Post-Mining Lands in the Lengerskoye Brown Coal Mine
Post-mining land in areas where mineral extraction has occurred may constitute a significant portion of the land used for various purposes. Such land serves as soil-forming parent material for developing anthropogenic soils, which sometimes exhibit unfavorable physicochemical properties. The toxicity of the waste generated during lignite mining is due to a number of factors, whose determination permits the identification of its origin for the subsequent design of technologies for the waste reclamation. The purpose of the study, in consistence with sustainable development, is to identify the causes of the toxicity of brown coal waste from the Lengerskoye deposit, in southern Kazakhstan. These studies have provided the results essential for planning remedial actions necessary to improve the well-being of the local population, in accordance with the principles of sustainable development. The studies were performed using single extraction; forms of Al, Fe, and Mn; soil texture; elemental analysis; phytocoenosis analysis; and diffractometric, IR spectroscopic, SEM, route reconnaissance, and comparative statistical methods. A decrease in the biodiversity of plant species was noted, with a gradual increase with distance from the waste storage sites. The most resistant plant species in the vicinity of the waste dump were Cynodon dactylon (L.) Pers and Alhagi pseudalhagi (M. Bieb.) Desv. ex B. Keller & Shap., while Dodartia orientalis (L.) was the only plant species found at the edge of the waste dump. The high toxicity of lignite waste is determined by such factors as low pH values, about 3.0; high content of active forms of aluminum, iron, and manganese (344.0, 0.90, and 20 mg/kg); high electrical conductivity—2835 µS/cm; waste composition poor in nutrients; and climate aridity. It has been observed that a content of exchangeable aluminum above 100 mg/kg resulted in an almost complete lack of vegetation.
Changes in physiological features of undergrowth indicator species of old forest
The study concerns the study of selected physiological features of three indicator species of the undergrowth of the oak-hornbeam forest (Anemone nemorosa L., Galeobdolon luteum Huds. emend. Holub and Stellaria holostea L.), after the forest canopy closure. Las Wolski, an isolated forest complex located within the city of Cracow (Southern Poland), was selected for the study. The plant material was collected at two points in the season – right after the forest canopy closure and a month later. Under laboratory conditions, the physiological characteristics of the indicator species were analysed. Light stress may play a smaller role here, and physiological parameters are probably most affected by the phenology of undergrowth species, which is adapted to seasonal changes in habitat conditions. However, these issues require more research.