Juniperus drupacea Labill is a unique representative tree which, nowadays, has limited geographical range. In Greece, it exists only in the southeastern part of the Peloponnese, and it is labeled as endangered according to the IUCN in Europe. In the light of climatic changes, a conservation plan which will secure its adaptation and resilience is important. Knowledge of the genetic and the epigenetic diversity of J. drupacea in Greece can establish a pledge for sustainability. In this study, genetic diversity with amplified fragment length polymorphism (AFLP) markers and epigenetic diversity assessed with methylation-sensitive amplification polymorphism (MSAP) were used for eleven subpopulations of the species. Simultaneously, first assessment between midday water potential (Ψmd) and epigenetic diversity was calculated in order to determine drought response of the species. Results showed that genetic diversity was higher than epigenetic diversity and no subpopulation differentiation was observed. No significant correlations were found between geographic, epigenetic, and genetic diversity, indicating that the genetic diversity is uncoupled from epigenetic diversity. A significant negative correlation between epigenetic Shannon index and Ψmd was found. The holistic research of genetic and epigenetic diversity paves the way for an effective conservation plan for the species.

A first assessment of genetic diversity and expansion of the invasive species Amorpha fruticosa L. was estimated in the 91E0* (Annex I Dir. 92/43/EEC) priority habitat of Nestos. A. fruticosa is a perennial deciduous shrub belonging to the family Fabaceae and is native to the south-western part of North America, which recently was introduced to Europe as an ornamental plant. Its expansion through the cross-border river of Nestos has significant negative effects on the 91E0* habitat (a habitat with Alnus glutinosa, Populus alba, and Ulmus minor). Herein, we studied the genetic diversity with amplified fragment length polymorphisms fragments of eastern and western populations in order to see if there is one genetic pool for the species. Furthermore, we estimated the regeneration index (IR) in order to see the potential expansion of this invasive species. Results showed that eastern and western populations have almost equal heterozygosity (He) and with a slightly higher value for the western population, which was in agreement with the results of the IR. This is an innovative study that discusses the implications of A. fruticosa of 91E0* habitat in Nestos and proposes management measures to eliminate its expansion and improve the resilience of the habitat.

Taxus baccata L. is a tertiary relict, long-lived, wind-pollinated dioecious tree species found throughout Europe. In the rocky mountains of Thasos island, monumental old trees create a unique area of natural beauty. In recent times, the need to implement conservation measures for key endangered species such as Taxus baccata has intensified. Exploring the genetic diversity of the species is a prerequisite for successful forest management decisions aimed at conservation. In this study, 28 monumental trees from two natural populations of Thasos were investigated using eight Simple Sequence Repeat markers in order to assess the levels of genetic diversity and genetic differentiation within the individuals, to estimate the degree of inbreeding and the effective population size of each population, and to discuss the impact this study has on conservation efforts for the species. Although the population size was small (14 individuals per population), the results showed moderate to high genetic diversity parameters. The mean expected heterozygosity was He = 0.649 and the number of effective alleles was Ne = 3.270 for both populations. Moreover, allelic richness (A_R = 3.395) was high, indicating a variable genetic pool which is probably a result of a past established expansion of the species in the area. The results of the present study present a unique genetic pool harbored by specific trees, which is an important advantage for ensuring their conservation and resistance against biotic and abiotic threats. Our study paves the way towards conservation measures, which can be prioritized as follows: (a) in situ conservation, (b) seed bank establishment, and (c) in vitro propagation in order to secure future resilience and sustainability of the species.

Advancements in genetic science and conservation are crucial tools for enhancing the resilience of forest ecosystems against climate change, emphasizing the need for conservation strategies that protect genetic diversity. Strategic management and policy development are imperative to utilize these technologies effectively in conservation efforts, and this is evident in the participation of Greece and Serbia in international organizations, such as the Food and Agriculture Organization (FAO) of the United Nations, the United Nations Environmental Programme (UNEP), and the European Forest Genetic Resources Programme (EUFORGEN). Greece and Serbia are actively engaged within the specified organizations, and as such, their efforts in the conservation of forest genetic resources (FGRs) amidst climate change are structured under the guidance and influence of these stakeholders. Both countries recognize collaborative endeavors between research entities and conservation initiatives and underscore the potential of innovative genetic and biotechnological approaches in FGR management. Genetic monitoring and evaluation play a vital role in pinpointing species and populations at risk and guiding conservation priorities and actions. Examples of successful conservation practices are given both from Serbia and Greece, illustrating that combining traditional methods with modern genetic insights is key to sustaining forest ecosystems. Such comprehensive approaches are essential in countering the adverse effects of climate change on forests, thereby contributing to the conservation of global biodiversity and the stability of natural environments.

Climate change has been projected to negatively affect genetic resources of the forests worldwide. Thus, integrating biotechnological innovations with traditional forest conservation strategies offers as a promising pathway to enhance the resilience of forest genetic resources. Biodiversity informatics plays a crucial role in managing and analysing data, supporting informed decision-making in forest management and conservation. Advancements in genomics and sequencing technologies, such as next-generation sequencing (NGS) and whole genome sequencing (WGS), have revolutionized the understanding of complex traits in forest trees. These technologies facilitate the identification of genetic markers, aiding breeding programmes and management strategies. Clustered regularly interspaced short palindromic repeats (CRISPR, in our study referring to CRISPR-Cas9 system) technology and the development of transgenic trees offer new possibilities for improving traits like growth, stress tolerance, and wood quality in forest species, though the potential ecological impacts warrant careful evaluation. Epigenetic research in forest trees provides insights into adaptation mechanisms to environmental changes through gene expression and phenotypic variation. The synergy between biotechnological advances and conservation practices is vital for sustaining forest ecosystems amidst rapid environmental shifts. Recommendations call for fostering interdisciplinary collaborations, enhancing biodiversity informatics infrastructure, engaging stakeholders, prioritizing epigenetic research, and developing regulatory frameworks for genome editing. These steps are imperative for a holistic approach to forest conservation, ensuring the adaptive capacity of forests and safeguarding their genetic resources against the backdrop of climate change.

Background/Objectives: The stone pine (Pinus pinea L.) is an evergreen coniferous species valued for its edible seeds, which provide significant economic benefits to local populations. Remarkable phenotypic plasticity but low genetic variation characterizes the species. In Greece, natural populations of P. pinea are part of the Natura 2000 network and are protected under Annex I Priority Habitat type 2270. These populations, located across six Natura 2000 sites (including two islands), face increasing threats from tourism and climate change, leading to ecosystem degradation. Genetic and epigenetic studies are critical for the conservation of forest species because they provide insights into the genetic diversity, adaptive potential, and resilience of species, helping to inform effective management strategies and protect biodiversity in changing environments. This study aims to assess the genetic and epigenetic diversity of P. pinea in four Natura 2000 sites using molecular markers and to propose conservation strategies to ensure the species’ long-term sustainability. Additionally, a preliminary investigation of water potential under maximum daily water demand was conducted to evaluate the species’ adaptive response. Methods: Genetic analysis was performed using Amplified Fragment Length Polymorphism (AFLP) markers, while epigenetic analysis was conducted using Methylation-Susceptible Amplified Polymorphism (MSAP) markers. Sampling was carried out in four Natura 2000 areas, where genetic and epigenetic diversity patterns were examined. Furthermore, a preliminary study on water potential under peak daily water demand conditions was conducted to assess the species’ physiological adaptation to environmental stress. Results: The results of this study provide valuable insights into conservation strategies by highlighting the potential role of epigenetic variation in the adaptability of P. pinea, despite its low genetic variability. Understanding the species’ epigenetic flexibility can inform conservation efforts aimed at enhancing its resilience to environmental stressors, such as climate change. Additionally, the preliminary water potential analysis contributes to identifying physiological traits that may help predict the species’ survival under varying environmental conditions, guiding the development of more targeted conservation practices and management plans. Further research could refine these findings and strengthen their application in conservation efforts. Conclusions: The conclusions emphasize the critical importance of this research in informing conservation efforts for P. pinea in Greece, particularly considering climate change and human pressures. The results highlight the need for both in-situ and ex-situ conservation strategies to ensure the long-term sustainability of the species. The key recommendations include the protection of natural habitats, the implementation of controlled seed collection practices, and further research into the epigenetic mechanisms that may enhance the species’ resilience to environmental stress. Future studies should focus on deepening our understanding of these epigenetic factors and their role in the adaptability of P. pinea, which will be essential for developing more effective conservation measures.