Leaves of Acer platanoides L., Aesculus hippocastanum L. and Betula pendula Roth. were collected from urban sites with different anthropogenic impact in the city of Plovdiv (Bulgaria). Concentrations of Cd, Cr, Cu, Fe, Pb and Zn in foliage samples were analyzed by ICP–MS. Three studied deciduous trees clearly showed variations in element concentrations depending on the sampling site (Pb, Fe, Cr) and the plant species (Zn). Betula pendula was found to be a better bioaccumulator for the elements Cr, Cd, and especially for Zn. Our approach could be successfully applied in the monitoring of air pollution due to trace elements in urban areas, regardless of their size and topography

In this research, the biosynthetic and biocontrol potential of endophytic yeast to improve the growth and development of tobacco has been elucidated. Three yeast strains were enriched and isolated from different plant tissues. Partial sequence analysis of ITS5-5.8-ITS4 region of the nuclear ribosomal DNA with universal primers identified YD5, YE1, and YSW1 as Saccharomyces cerevisiae (S. cerevisiae), Zygosaccharomyces bailii (Z. bailii), and Saccharomyces kudriavzevii (S. kudriavzevii), respectively. When cultivated in a medium supplemented with 0.1% L-tryptophan, isolated yeast strains produced indole-3-acetic acid (IAA). The capacities of those strains to improve the mobility of phosphorus and synthesize siderophores has been proven. Their antimicrobial activities against several Solanaceae plant pathogenic fungi (Alternaria solani pathovar. tobacco, Rhizoctonia solani, and Fusarium solani pathovar. phaseoli) were determined. S. cerevisiae YD5, Z. bailii YE1, and S. kudriavzevii YSW1 inhibited the growth of all tested pathogens. Yeast strains were tested for endophytic colonization of tobacco by two different inoculation methods: soil drench (SD) and leaf spraying (LS). To establish colonization in the various tissues of tested tobacco (Nicotiana tabaccum L.) plants, samples were taken on the seventh, fourteenth, and twenty-first days after treatment (DAT), and explants were inoculated on yeast malt agar (YMA). Both techniques of inoculation showed a high frequency of colonization from 83.33% to 100%. To determine the effectiveness of the microbial endophytes, their effect on some physiological processes in the plant were analyzed, such as photosynthesis, stomatal conductivity, and transpiration intensity. The effect of single and double treatment with yeast inoculum on the development and biochemical parameters of tobacco was reported. Plants have the ability of structural and functional adaptation to stress effects of different natures. All treated plants had a higher content of photosynthetic pigments compared to the control. Photosynthesis is probably more intense, and growth stimulation has been observed. The chlorophyll a/b ratio remained similar, and the total chlorophyll/carotenoid ratio slightly increased as a result of elevated chlorophyll levels. The most significant stimulating effect was recorded in tobacco plants treated by foliar spraying with Z. bailii YE1 and S. cerevisiae YD5. In contrast, S. kudriavzevii YSW1 had a better effect when applied as a soil drench. Thus, S. cerevisiae YD5, Z. bailii YE1, and S. kudriavzevii YSW1 have a high potential to be used as a biocontrol agents in organic agriculture.

Summary Concentrations of arsenic (As), cadmium (Cd), copper (Cu), nickel (Ni), lead (Pb), and zinc (Zn) were determined in water samples and five fish organs (gills, liver, kidney, spleen, and muscle) of common carp (Cyprinus carpio L.) and common rudd (Scardinius erythrophthalmus L.) from the Topolnitsa reservoir (Bulgaria) in three seasons (spring, summer, and autumn). This water ecosystem is located in a copper mining and metallurgical region. Water metal concentrations were significantly higher in the summer than in the spring (p

Urban areas are facing a range of environmental challenges including air, water and soil pollution as a result of industrial, domestic and traffic emissions. In addition, global climate change is likely to aggravate certain urban problems and disturb the urban ecology by increasing the frequency and severity of extreme weather events. In the context of urbanization growth and the consequent impact on the environment, there is a growing interest in maintaining urban soil quality and functions as they are the medium for green infrastructure development. Furthermore, urban soils are becoming one of the key factors in the delivery of many ecosystem services such as carbon storage, climate regulation, water flow regulation, etc. On the other hand, urban soils are well-known to be a major sink of air pollutants due to the wet and dry atmospheric deposition and recirculation. Soil has the ability to degrade some chemical contaminants but when the levels are high, urban soils could hold on large amounts and pose a risk to human health. A cost-effective technological solution is to use the ability of some plant species to metabolize, accumulate and detoxify heavy metals or other harmful organic or inorganic compounds from the soil layer. The establishment of urban lawns (grass covered surfaces) is a helpful, environmentally friendly, economically sustainable and cost-effective approach to remove contaminants from polluted soils (terrains), which also has some aesthetic benefits. In this paper, an overview of the benefits and limitations of urban lawn construction is presented. The focus is on the perspectives for sustainable management of urban lawns, especially as buffer green patches in the road network surroundings, that can represent strategies to provide ecological and social multifunctionality of urban soils, and thus, increasing their ecosystem services capacity. Specifically, the paper highlights (i) the possibilities for phytoremediation of urban soils, (ii) potential of some perennial grasses and (iii) key issues that should be considered in the planning and design of urban lawns.

The rehabilitation and restoration of land-based ecosystems is a key strategy for recovering the services (goods and resources) ecosystems offer to humankind. The use of nature-based solutions (NBSs) to restore degraded soil functions and improve soil quality can be a sustainable and successful strategy to enhance their ecosystem services by working together with the forces of nature and using well-designed measures that require less maintenance, are more cost-effective, and if constructed in the right way may even be more effective over long periods because nature’s forces can increase the structural efficiency. In this study, we aimed to (i) evaluate the bioremediation capacity of some grasses and their suitability for lawn planting in settlements (in residential and non-residential areas, along roads, etc.) and (ii) propose technological solutions for their practical application in an urban environment. Emphasis was placed on the potential of some perennial grasses and their application for the bioremediation of polluted urban soils, including perennial ryegrass (Lolium perenne L.), crested wheatgrass (Agropyron cristatum L.), tall fescue (Festuca arundinacea Schreb), and bird’s foot trefoil (Lotus corniculatus L.). A case study from the city of Plovdiv (Bulgaria) is presented, together with an effective technological solution for the establishment of urban lawns and the roadside green buffer patches.