Forests in the Tolna region (Hungary) are distributed at the xeric limit of broadleaved forest zones and adapted to the arid ecological conditions of the wood-steppe climate. An 85-year-old in situ gene conservation stand of Quercus virgiliana mixed with other taxa of section Quercus was studied, which was regenerated naturally by both seedlings and coppicing. To analyze the phenotypes growing within the stand and the genetic structure of the population, a total of 138 trees were sampled. For taxonomic classification, a complex of morphological traits of oak taxa growing naturally in the region was used. Out of the 12 morphotype groups, only a few trees were classified as Q. virgiliana (eight individuals) or Q. robur (nine individuals), and the majority of the trees (121 individuals) were hybrid or introgressed phenotypes of Q. virgiliana adapted to xeric conditions by its xeromorphic traits. Despite the high number of coppiced trees (89 pcs vegetatively regenerated), the genetic variation was relatively high based on 16 nSSR markers used for analyses. Some of the trees were classified as non-autochthonous with Slavonian oak origin, both by morphological traits and SSR structure. Despite some alleles being lost, the allelic diversity of the seedling trees’ group was similar to that of the group of parent generation (coppiced trees). The spatial structure of trees supported the results of morphologic classification, and Q. virgiliana and hybrid phenotypes were growing on xeric microhabitats of the stand, mostly on southeast-facing slopes or ridges of hills. Consequently, the stand might fulfill all the in situ gene conservation requirements based on the high genetic diversity measured and the high number of xeromorphic phenotypes in the context of climate change as well.

This study examined micromorphological traits on the abaxial surface of leaves using a Scanning Electron Microscope (SEM) to compare pedunculate oak and greyish oak taxa close-up. We selected a pedunculate oak population in Hungary and greyish oak population in Romania. The study randomly selected trees over 100 years old from these populations to investigate the differences between the two taxa based on leaf micromorphological characteristics. We focused mainly on indumentum because observing trichomes can be used in practice. Variation was found in trichome types, trichome-ray lengths, and stomata extent and shape. Stellate and fasciculate trichomes were absent on pedunculate oak leaves and densely developed on greyish oak leaves. The average length of the simple-uniseriate trichomes of pedunculate oak was 49.45 μm and 61.96 μm in greyish oak. On average, stomata surfaces on pedunculate oak leaves were 513.09 μm2 and 440.28 μm2 on greyish oak leaves. The study found no variation in epicuticular wax layer type. Despite the small sample size, in comparing the two populations, we found that the two taxa were distinguishable based on trichome types, and we believe that forestry practice could utilise this trait.

Numerous publications on forest genetic monitoring (FGM) and related topics in genetics and gene conservation have been published over the past three decades. This paper reviews the methods used in FGM and, more broadly, related scientific findings published to date, of which general conclusions can be applied worldwide in FGM. In the strict sense, long-term FGM projects have been established only in a few regions in Europe. The methodological basis (guidelines) for FGM has already been developed, specifically for European tree species and forest communities. In genetic analyses, traditional SSR markers are predominantly used, but SNP markers from new-generation sequencing are increasingly available. Nonetheless, there is a high level of variation in monitoring activities such as biodiversity, forest health, and forest genetics, likely due to the efforts of national (governmental) and international professional organizations. Early evaluation of the first FGM projects has already been published. Scientific evidence for FGM has been limited because of the low number of projects that represent a few geographic regions and species.

In the framework of an ongoing gene conservation programme in the Tolna Hills Region, Hungary, a total of 41 site plots were selected on agricultural land that had recently been used as grassland, meadow or vineyard. Aims of our study were (i) to test the taxonomic status of relic oak trees growing out of forested lands; (ii) to verify the origin of relic trees whether they regenerated by sprouts and suckers or by seeds in order to estimate their age and origin (nativeness); (iii) to test their microhabitats to see if forest-specific plant and fungal species were presented; (iv) and to test species to see if their presence linked to any forest vegetation in the past. Furthermore, the land-use type did not show a significant effect on the abundance of woody, dicot herbaceous, or monocot herbaceous plants recorded on sites based on maps from 1941 or earlier. The follow-up univariate ANOVA revealed a significant direct effect of recent land-use type (of 2022) on monocot herbaceous plants (F(3,33) = 5.21, p < 0.01). Additionally, a significant but weaker effect was observed on woody plants (F(3,33) = 3.22, p < 0.05). The overall past effect of land-use type showed a significantly high positive correlation between the abundance of woody plants and the number of times the maps showed forest or forest boundary land-use types (R = 0.46, p < 0.01). The plots have likely preserved and sustained the microhabitats of the native forest vegetation that was once distributed in the region. The site plots of relic oak trees, considered as flagstone habitats, create opportunities for gene flow, not only for the species with dispersal or discontinuous distribution, but also for the Vergilius oak populations. Therefore, relic trees and their microhabitats might have an important role in the mating system of various species and might also be valuable resources for genetic conservation programmes.

Introduction and Aim: Understanding the spatial distribution of intraspecific genetic variation in trees is essential for conservation and management of forest genetic resources. In pedunculate oak ( Quercus robur ), an economically and ecologically important European tree, southern and southeastern provenances are considered to be putative reservoirs of local adaptations to warm and dry climates, yet remain underrepresented in range‐wide population genetic studies. Herein, we analyse nuclear and chloroplast population genetic structure of Q. robur across central and southeastern Europe, including the subspecies robur and pedunculiflora contact zone, and assess contributions of postglacial recolonization, geographic barriers, fine‐scale topography and human influence to contemporary diversity. Location: Transect from west‐central Europe, north of the Alps to the Black Sea. Methods: We genotyped 1500 individuals from 56 populations using 16 nuclear (nSSRs) and 8 chloroplast (cpSSRs) microsatellites. We assessed nuclear genetic structure and diversity with Bayesian and spatial multivariate analyses, quantified differentiation (AMOVA, F _ST ) and inferred chloroplast lineages/haplotypes differentiation and phylogeographic structure. Results: nSSRs revealed low but significant among‐population differentiation and a pattern with three clusters: west‐central Europe, Dinaric Alps–Pannonian Basin and southeastern Balkans. Genetic diversity increased from west to southeastern Europe. Chloroplast haplotype variation showed pronounced spatial structure congruent with glacial refugia and migration routes. The two subspecies were weakly differentiated, shared chloroplast lineages across the contact zone, indicating substantial gene flow. Main Conclusions: Postglacial recolonization and landscape features structured genetic variation in Q. robur . Southeastern populations retain deep lineage structure and high regional allelic richness with many private haplotypes/alleles, consistent with the rear‐edge position of postglacial expansion. Elevated diversity in contact zones along the northern Alps indicates admixture among recolonization routes, compatible with cryptic late‐glacial microrefugia near the Alpine–Carpathian corridor. Integrating nuclear and chloroplast patterns, we recommend safeguarding southeastern gene pools, maintaining connectivity across contact zones and aligning Genetic Conservation Units with clusters identified.