This research investigated the existing conditions and functionality of rows of maple trees (Acer L.) (which are traditionally used in our country for urban greening) in the streets that are the most frequent in terms of traffic intensity, ways of use and measures to maintain greenery (streets of the I and II order) on the territory of the municipality of Stari grad (Belgrade). In the investigated area a total of 39 streets of these categories were surveyed. Rows of maple trees are represented in 2 out of 15 streets of the I order and in 10 out of 24 streets of the II order. It was determined that the total number of trees belonging to the species of this genus is 735. Maple species recorded are: Acer pseudoplatanus L, Acer platanoides L, Acer campestre L. and Acer saccharinum L. The most represented species here is A. pseudoplatanus with a total of 442 (60.13%) trees, and an average vitality score of 3.6. They are followed by: A. platanoides with 213 (28.98%) recorded trees and an average vitality score of 3.5, A. campestre with 72 (9.80%) recorded trees and a rating of 3.1 and A. saccharinum with 8 (1.09%) trees and a rating of 2.3. One of the main factors in reducing the functionality of maple tree street rows in the study area was the application of the tree topping care measure.

Greening urban ruins represents an innovative approach to the revitalization of abandoned built structures. This process merges greenery with ruins or abandoned structures, creating synergy between natural and built elements of the space. The goal of greening ruins is not only ecological but also aesthetic, as it transforms neglected buildings into green "oases" that promote biodiversity and improve microclimatic conditions in urban environments. As a part of urban green infrastructure revitalized ruins can become an effective way in adaptation cities to climate changes, especially in the terms of rainwater regulation and minimaze urban heat island. Additionally, revitalization contributes to social cohesion, creating spaces that can become gathering places for various community activities. Case studies at both European and global levels, such as the MFO Park, Qiaotou Ruin Garden, and others, provide examples of good practices that offer insights into the benefits and challenges of revitalizing abandoned structures. This paper explores the potential for revitalizing ruins through the application of plant materials, emphasizing the benefits greenery can contribute to the renewal of abandoned urban spaces, as well as analyzing various greening possibilities, including the use of different techniques such as vertical greening systems, rooftop gardens, green walls, and interior greening of buildings. Greening ruins also contributes to preserving cultural identity, as it allows old buildings, through the appropriate use of plant materials, to become integral parts of contemporary urban ecosystems. The potential for revitalization depends on the structural stability of the buildings, the maintenance and care requirements for green areas, potential legal issues, and financial considerations, which highlight the need for careful planning and implementation. Further research in this area can contribute to the understanding and making practices and specific solutions for the future revitalization of urban spaces through greening.

This study assesses the potential risk of soil pollution in Belgrade by cadmium (Cd) in relation to the city’s urban development zones and different land use types. Cadmium is considered a typical anthropogenic element with toxic and carcinogenic properties. A total of 126 urban soil samples were investigated in this study. Soil pollution by Cd was evaluated based on the determined concentrations with background values (BV), maximum limit values (MLV), and remediation values (RV) established by national regulations. The contamination potential was assessed using the number and percentage of samples relative to the total number of analyzed samples, and the results were analyzed in relation to the degree of urbanization, and different land uses. The concentration of Cd was determined by atomic absorption spectroscopy (AAS) following aqua regia digestion (SRPS-ISO 14870:2005). The results indicate localized but significant risks of Cd contamination in urban soils, particularly in the central and suburban zones of Belgrade, as well as in soils of industrial complexes and traffic junctions. These findings highlight the need for systematic monitoring, targeted identification of contamination sources, and the implementation of zone-specific remediation strategies to mitigate long-term impacts on the urban environment and public health.