Plants know no political borders and some of them are restricted to small geographical territories of different countries in which they are endemic. In this study, we prioritized plants (PPs) of the cross-border area of Greece and the Republic of North Macedonia that are already threatened or nearly so (PPA), those which occur exclusively on either side of borderline and/or nearby countries (PPB), or those which are uncommon and rare in this region (PPC) with the aim to document in-situ the species-specific risks-threats; offer ex-situ conservation for them as a back-up solution for future re-introductions and sustainable exploitation; and raise public awareness and alertness about the importance of local biodiversity. In the framework of the project Conse-pp, 20 botanical expeditions were performed in 75 selected areas to collect samples and suitable propagation material from 130 PPs (147 accession numbers), also recording all types of threats-identified in-situ for each of them. No ex-situ conservation was detected for 40 PPs worldwide while for another 12 PPs only limited attempts have been made to date. The fully documented PPs are currently maintained under ex- situ conservation and acclimatization in the Balkan Botanic Garden of Kroussia (BBGK). In total, 156 propagation trials (sexual or asexual) have been made for these PPs to develop species-specific propagation protocols. Consequently, the production of new plant stocks raised ex-situ was achieved (n = 3254 individuals; first-time ex-situ conservation for 40 taxa), and this has enabled the establishment of three awareness-raising sites with PPs: (i) 1000 plants of 70 PPs in the newly designed Kardia Botanical Park in Thermi (Greece); (ii) 850 plants of 104 PPs in the phytodiversity awareness spot in BBGK and 130 individual PPs in the Garden of Environmental Awareness; and (iii) 42 plants of 14 PP taxa delivered to the botanic garden of Ss. Cyril and Methodius University in Skopje. This project outlines the necessity of the development of common plant conservation strategies for threatened plants in cross-border areas of neighboring countries and presents an integrated approach allowing for sustainable development and future in-situ protection measures and actions in the studied cross-border area.

Although nanotechnology is increasingly applied in plant tissue culture in many parts of Europe, its use in the Balkans remains limited, revealing a regional gap with untapped potential for advancing in vitro propagation and preservation of woody plant species. Building upon a recently published regional review covering 2001–2024, which analyzed in vitro biotechnology progress in nine Balkan countries, this paper introduces the concept of a “nano gap”, referring to the limited connection between existing nanotechnology research potential and its use in in vitro woody plant biotechnology. In Serbia, Greece, Bulgaria, Croatia, and Albania, significant progress has been made in optimizing micropropagation and in vitro conservation strategies by introducing temporary immersion systems, synthetic seed technology, adapting genotype-specific sterilization and multiplication protocols, and modifying established cryopreservation methods for regional woody species. However, the integration of nanotechnology into these systems remains largely unexplored. To date, there are no published results or validated applications for nano-enhanced media or nanoscale delivery systems for micropropagation and in vitro conservation of woody species. The limited integration of nanotechnology may be due to insufficient funding, lack of specialized infrastructure, and limited interdisciplinary expertise. Nevertheless, many Balkan countries possess growing capacities in nano-applications within agriculture and environmental sciences and are ready to advance toward interdisciplinary research and innovation. By mapping both scientific readiness and structural barriers, this review provides a strategic framework for bridging the “nano gap” and offers a novel regional perspective with broader implications for European research policy, sustainable agriculture, biodiversity preservation, and green innovation.

Summary: Increasing population, expansion of urban areas and rapid urbanization are the main causes of losing green spaces, which results in many environmental problems and threatens the quality of urban life. Urban green spaces are of great importance and urban planning issues nowadays gain increasing popularity. It is realized that biological methodologies need to be used in urban planning, otherwise the quality of life will be more threatened. In order to discover the meaning and importance of green corridors in urban areas, a literature review was undertaken. Boulevards, as green corridors, are very important linear parts in the structures of dense modern cities. If planned and designed properly, they mitigate the negative effects of densely built urban environment. Green corridors provide numerous environmental benefits, they are an essential factor of sustainability and have a significant impact on biodiversity. Green corridors also provide social benefits, by enhancing well-being through contact with nature. They decrease health problems and improve the quality of life. The importance of urban green corridors was observed and presented on the example of Blvd. Bosnia and Herzegovina and Blvd. Hristijan Todorovski Karposh, which form an important ecological network in the northern part of Skopje, North Macedonia. The emphasis is on planning, designing and improving green corridors in urban areas like Skopje. Although these two boulevards are well designed as green corridors, with preserved old line greenery, planted with many different plant species (trees, shrubs, perennials), covered by grass, with bicycle and pedestrian paths, there is still potential for improvement. Linear parks on both sides of the new part of the Blvd. Hristijan Todorovski Karposh would be a great idea.