Historic allées and urban avenues reflect a far-sighted and forward-thinking design attitude. These compositions are the living witnesses of olden times, suggesting permanence. However, the 20th century’s urban development severely damaged the environment, therefore hundred-year-old mature trees are relatively rare among city avenues’ stands. Due to the deteriorated habitat conditions, replantation may be necessary from time to time. However, there are a large number of replanted allées and urban avenues considered historical monuments, according to the relevant international literature in urban and living heritage’s preservation. The renewal often results in planting a different, urban tolerant taxon, as seen in several examples reviewed. Nevertheless, the allée remains an essential urban structural element, though often with a changed character. The Budapest Andrássy Avenue, a city and nature connection defined in the late 19th century’s urban landscape planning, aimed to offer a splendid link between city core and nature in Városliget Public Park. The 19–20th century’s history and urban development are well documented in Hungarian and several English publications, though current tree stock stand and linear urban green infrastructure as part of the urban landscape need a detailed survey. The site analyses ran in 2020–early 2021 created a basis for assessing the allées and the whole avenue as an urban ecosystem and a valuable case study of contemporary heritage protection problems. Andrassy Avenue, the unique urban fabric, architecture, and promenades have been a world heritage monument of cultural value since 2002. The allées became endangered despite reconstruction type maintenance efforts. The presented survey analyses the living heritage’s former renewal programs and underlines the necessity of new reconstruction concepts in urban heritage protection. We hypothesize that urban green infrastructure development, the main issue in the 21^st century to improve the urban ecological system and human liveability, may support heritage protection. The Budapest World Heritage Site is worthwhile for a complex renewal where the urban green ecosystem supply and liveable, pedestrian-friendly urban open space system are at the forefront to recall the once glorious, socially and aesthetically attractive avenue.

Examining the history of garden art since ancient times, we find many examples of linear tree layouts supporting orientation or being used for the purpose of composition. Allées gained special significance during the Baroque as dynamic and grandiose space-forming garden design elements. They mostly consist of trees of taxonomically similar species planted along a regular line equidistant from each other in single or multiple rows. The two-dimensional compositional elements of the layout form three-dimensional longitudinal space forms. During their evolution, both their proportions and openness constantly change. Analyses of the compositional role and functions of allées of exemplary Hungarian Baroque garden complexes in the 18th century provided a basis for setting up a novel typology. Five compositional types have been defined as the primary result of archival research. The significance of the still-subsisting historic Hungarian allées calls for unique protection similar to European heritage protection. Taking a summary of significant, surviving examples of Hungarian Baroque allées into account, methods for allée renewal are defined along with the core question of whether allées are natural landscape elements or strict architectural compositions where authenticity may be an important criterion. The methodological research is partially based on three plans for the renewal of Baroque allées in Hungary that have been worked out by the Author as the chief landscape architect of the projects.

Az éghajlatváltozás hatással van környezetünk alakítására és súlyos fenntarthatósági, esztétikai problémát jelenthet minden régióban. A történeti kertek növényállományában, különösen a fák esetén aggasztó károsodások figyelhetők meg, melyeket a heves viharok, a csapadék és a talajvíz csökkenése, a kritikus hőségperiódusok, valamint az új kártevők és növénybetegségek megjelenése okoz. A történelmi kertek, örökségi és tájképi helyszínek magas kulturális, társadalmi és környezeti értékeket képviselnek. Az évszázados élő örökség, a legértékesebb ökoszisztéma elem, időről időre rendszeres fenntartást és részleges vagy teljes helyreállítást igényel a hagyományos felújítási programok keretében. A megőrzésnek és a szakszerű fenntartásnak figyelembe kell vennie a regionális és helyi sajátosságokat, a megváltozott klimatikus adottságokat is. Bár Magyarország viszonylag kis területű ország, a helyi és kistérségi klímatípusok változatosak, ezért két történelmi kertet (Nagycenk, Szép-halom) választottunk esettanulmányi helyszínnek. Az egyik a nyugati, a másik a keleti régióban található, két különböző éghajlati adottságot reprezentálva. A kutatás az idős faállomány körében kihívást jelentő állapotokat tárt fel. A levont tanulságok hasznosak lehetnek a kertrekonstrukciós programok során a telepítések tervezésében, valószínűleg nem csak Magyarországon, hanem nagyobb európai léptékben is.

As discussions around climate change intensify and as a response to the biodiversity crisis, botanic gardens have shown their fundamental role in the active conservation of biodiversity. Being a living collection of native and exotic plant species, botanic gardens are subject to potential threats from climate change. This paper investigates and analyses the climate change mitigation and adaptation solutions implemented by two leading botanic gardens: Kew Gardens and the Royal Botanic Gardens Victoria in Melbourne. The study first identifies the major challenges that botanic gardens face in the shadow of climate change and its potential risks. Second, it explores and highlights the applied sustainable solutions in the two case studies, aiming to enhance the ecosystem's resilience and foster biodiversity. Lastly, the research presents the potential results of the applied strategies on the ecological and managemental aspects of the gardens. Furthermore, the findings of this study emphasise the relevance of these conservation strategies in shaping future conservation initiatives extending beyond botanic gardens.