Grassland ecosystems are among the most threatened biomes, and their restoration has become common in nature conservation. Yet restoration is rarely applied specifically for reptiles, which are among the most threatened vertebrates. The Meadow Viper (Vipera ursinii) has become extinct in most of lowland Europe, and an endangered subspecies (Vipera ursinii rakosiensis) has been a target of habitat restoration and captive breeding in Hungary since 2004. We quantified vegetation properties and the density of reptiles that either spontaneously colonised (three species) or were reintroduced (V. ursinii) in a grassland restored specifically for this purpose. We used a fine-scale survey to estimate the cover, and compositional and vertical diversity of the vegetation. We characterised sampling units along three habitat gradients: wetness, openness and grass tussock size. Model selection based on data from replicated counts showed that Green Lizards (Lacerta viridis) responded positively to vegetation cover and negatively to tussock area and height, and number of burrows. The Sand Lizard (Lacerta agilis) responded positively to vegetation cover, vertical diversity and wetness, and negatively to openness. The Balkan Wall Lizard (Podarcis tauricus) responded positively to tussock height and negatively to vegetation cover. Finally, V. ursinii responded positively to vegetation cover and tussock height, and negatively to compositional diversity. Our results show the general importance of structural and compositional diversity of vegetation to reptiles. These results suggest that adaptive management should focus on increasing the total cover (for lizards) and the structural diversity of vegetation (for each species) to benefit reptiles in restored grasslands.

The systematic urban floristic research of Budapest was started in 2018 by the authors with detailed methodology. One scope of the research was to gain knowledge on the plant taxa appearing in Budapest and to compile the inventory of the urban flora of Budapest. We have provided the inventory of the urban flora of Budapest, which includes distribution data for all 973 taxa found in Budapest between May 2018 and May 2023. We also provided new detailed occurrence data for 49 species in Budapest. Seven of them are new to the adventive flora of Hungary (Campanula portenschlagiana Roem. & Schult., Clinopodium nepeta (L.) Kuntze, Chasmanthium latifolium (Michx.) H.O.Yates, Cyrtomium fortunei J.Sm., Linaria maroccana Hook.f., Talinum paniculatum (Jacq.) Gaertn.), three were rediscovered in Hungary (Glebionis coronaria (L.) Cass. ex Spach, Lagenaria siceraria (Molina) Standl., Sisymbrium irio L.) and 18 were recorded for the first time in Budapest. We also provided data for two data-poor (Artemisia scoparia Waldst. & Kit., Polygonum rurivagum Jord. ex Boreau) species and we documented the major expansion of six species.

Agriculture has always played a determining role in Hungarian landscapes. Forested areas were also under agricultural use; however, their use changed, starting at least from the Middle Ages when the need for new arable fields resulted in a tremendous decrease in forested areas. The protection of forests started for many reasons, saving them for fuelwood and construction materials. This is the reason why there were periods when forests of the Carpathian Basin suffered from considerable pressure, and even today, this pressure continues; however, the source changed from animal husbandry to tourism, forestry, and wildlife management, or rather hunting. This created the need to search for and analyse former sustainable use of the forests. Furthermore, the consideration of the use of trees/treelines is under the scope of helping the climate adaptation of arable fields. Wooded grasslands have also been mapped and various analyses were done, related to their survival. We wish to introduce some of the ancestral forms of the agricultural use of Hungarian farming, where trees play an important role, their origin, distribution, threatening factors, and their future. Sustainable arable farming systems with trees, including wood-pastures; orchard grasslands and conventional, organic, and permaculture horticultural farms with various proportion of tree cover, will be described.

Reconstructing the history (spatio-temporal patterns) of biological invasions at a small spatial scale is challenging, notably because the required data are often not available in sufficient quantity and quality. In this study, we present a mixed approach using six different data sources to explore the spreading history of four non-native invasive tree species, Ailanthus altissima, Celtis occidentalis, Prunus serotina and Acer negundo in a high conservation value foreststeppe habitat with an area of 1000 ha (Peszér Forest, Central Hungary). We carried out a literature search, compiled all the archived and currently valid data of the National Forestry Database (NFD) in a GIS database, conducted a full-coverage field survey, mapped all the large/old tree specimens and carried out annual ring counts, performed a hotspot analysis on the abundance data provided by the field survey and gathered local knowledge. Each of these approaches proved indispensable and their complementary use made it possible to reconstruct the invasion history of all four tree species. According to the available source literature, P. serotina was first planted in the area in 1937 and the first known occurrence of A. altissima could also be traced back to the 1930s. The examination of large specimens of C. occidentalis and querying the NFD for data related to A. negundo provided evidence that these species have been present in the area since at least the 1940s. However, based on the NFD and local knowledge, it is certain that the rapid expansion of the four tree species occurred simultaneously and only around the turn of the millennium, with a lag of at least 60-70 years. The exploration of local knowledge revealed three possible explanations, which interestingly also coincided in time. With the change in the political regime, the intensity of forest use started to decrease in the 1990s, the population of game was drastically reduced at the end of the decade and droughts became more frequent from 2000 onwards. The field survey clearly showed that these tree species were 2-3 times more prevalent and abundant than the relevant NFD data indicated. Finally, the primary hotspots of A. altissima and A. negundo overlapped with the locations of their first known occurrences, while in the case of C. occidentalis and P. serotina, they did not. However, local knowledge revealed that the former two had been ignored since at least the 1950s, while the latter two were occasionally planted until the 1990s. It is likely that the primary hotspots of C. occidentalis and P. serotina indicate the locations of these undocumented plantations.

Ancient trees are important habitats, confer vital ecological roles and function as cultural legacies. Old trees with large girth are keystone structures in various ecosystems. We aim to present which species amongst the greatest Hungarian trees (and some other phanerophyte plants) are damaged by polypores (the most important agents of wood decay), Agrobacterium tumefaciens (usually causing root tumour) or ivy (competing against the native vegetation and causing windthrow damage) and at what extent and frequency; and whether there is a relationship between these types of damage and the origin of the species (native or adventive) or its situation (solitary or surrounded by other trees). We measured 2,000 trees, belonging to 29 native and 43 non-native species. Polypore infection could be detected in 12.2% of the observed 531 settlements, 22.8% are damaged by Agrobacterium and 29.6% by ivy, while 51.2% by other types of pests and diseases. Altogether, one third of the observed 2000 ancient or veteran trees suffered from one or more types of damage. A total of 33.5% of the native species (519 specimens out of 1550) and 28.7% of the adventives (129 trees out of 450) are damaged by any (or more than one) of the mentioned infections or ivy. Mostly, damage occurred to those old trees that stand in a park or forest, while the single (solitary) trees were usually healthy. The most infected regions are the western and south-western counties, while the Northern Hungarian Mountain Range is much less affected, despite its great sample size. Low damage was detected in the Great Hungarian Plain, but the number of sample areas and veteran trees was also low here. The damage to old trees remains without any management or healing in Hungary, since the only effective solution would be prevention.

Nowadays, forest management focuses on nature- and environmentally-friendly methods in Europe with less fossil fuel use; however, animal-powered logging is rarely covered by scientific papers despite the fact that it is considered to be less harmful to topsoil, wood stands, saplings, and natural values than heavy machines. The main goal of this study is to determine its characteristics, advantages, and disadvantages based on structured and semi-structured interviews with loggers and foresters in every Hungarian state-owned forest area. Our results show that while 39 out of the total 116 Hungarian forest districts hired teams that applied horses for logging in 2013, their number fell to 24 in 2021. Despite this negative tendency, 34 out of the 44 forest districts that operate in hilly and mountainous areas still find horses to be useful for timber extraction. Five forest districts own horses, but none of them use animal power for logging (only for touristic and hunting activities). The productivity of a logging team depends on the timber extraction distance, terrain slope, number of workers, and cut timber volume per turn. The average logging capacity of a brigade with horses is 0.78 m³ per load, 15 m³ per day, and 2413 m³ per year. The average terrain slope angle is 15°, situated 350–450 m above sea level. The average timber extraction distance is 185 m, and the width of a track made by a horse is 96 cm. The average distance from the barn to the cut-block area is 11 km. Lower impact of horse logging on the affected area is more important than the amount of the harvested wood. Therefore, from a nature conservation aspect, it is essential to maintain animal logging and promote it with training and financial incentives.