In the context of forecasted climate change scenarios, the growth of forest tree species at their distribution margin is crucial to adapt current forest management strategies. Analyses of beech (Fagus sylvatica L.) growth have shown high plasticity, but easternmost beech populations have been rarely studied. To describe the response of the marginal beech population to the climate in the far east sites of its distribution, we first compiled new tree ring width chronologies. Then we analyzed climate–growth relationships for three marginal beech populations in the Republic of Moldova. We observed a relatively high growth rate in the marginal populations compared to core distribution sites. Our analyses further revealed a distinct and significant response of beech growth to all climatic variables, assessing for the first time the relationship between growth and vapor pressure deficit (VPD) which described how plant growth responds to drought. These results highlight that accumulated water deficit is an essential limiting factor of beech growth in this region. In conclusion, beech growth in the easternmost marginal population is drought-limited, and the sensitivity to VPD will need to be considered in future studies to update the forest management of other economic and ecologically important species.

Oak species (Quercus spp.) represent one of the most widespread and ecologically important groups of woody plants in the Northern Hemisphere, forming dominant forest ecosystems across temperate, Mediterranean, subtropical, and montane regions. Due to their longevity, high wood density, extensive root systems, and large biomass, oaks play a significant role in terrestrial carbon cycling and long-term carbon storage. However, a comprehensive synthesis of the contribution of oak forests to carbon sequestration remains limited. This review integrates a systematic bibliometric assessment with a qualitative synthesis of the peer-reviewed literature to evaluate the role of oak species and oak-dominated forests in carbon sequestration and climate change mitigation. A total of 656 publications indexed in Scopus and Web of Science were analyzed, revealing increasing research activity after 2008 and a broad geographic distribution of studies, with the highest contributions from the United States, Spain, China, and Germany. The reviewed studies demonstrate that oak ecosystems function as substantial and durable carbon sinks, storing carbon in aboveground biomass, belowground biomass, deadwood, litter, and soil organic carbon pools. Carbon sequestration is influenced by stand age, site conditions, species composition, and management practices. This review highlights oak forests as resilient, multifunctional ecosystems, with a critical role in nature-based climate solutions and sustainable forest management.

Botanical Gardens represent living archives of plant biodiversity originating from various phytogeographic regions of the Earth, but, according to “International Agenda for Botanic Gardens in Conservationun” (2012), a central role of these is the ex situ conservation of native flora in ex vivo collections, germplasm collections and herbarium collections. Ex situ conservation has several purposes, including the saving of the germplasm of the threatened species, by storing genetic material in germplasm collections (seeds, spores, etc.). This conservation method is costeffective due to small storage space and has the following benefits: seeds of many species can be preserved for the long term; provides researchers with easy access to genetic diversity (seeds of the same species collected from different centers of origin); serves as a support for threatened plant populations, contributing with material for reintroduction, repopulation and restoration; provides the opportunity for research into conservation biology; contributes to ecological education in the field of conservation; brings local input to the International Seed Exchange (Index Seminum) between Botanic Gardens and Research Institutions. Within the “Al. Ciubotaru” National Botanical Garden (Institute) (NBGI) the flora of the Republic of Moldova is represented by a number of species, which are framed and maintained in collections and micro-exhibitions such as: Exhibition of the Vegetation of Moldova; Collection of Ornamental Plants; Collection of Medicinal Plants; Collection of Aromatic Plants. These representatives of the native flora, preserved ex situ in the GBNI, represent a potential for collecting genetic material. This opportunity eliminates or reduces the pressure exerted by wild collection on threatened species, with degraded habitats and with fruiting phases compromised by various limiting factors. During 2024-2025, 30 seed samples of the following species were collected from the collections and exhibitions of NBGI, for the conservation in the germplasm collection “Rare Plants of the Republic of Moldova” (PRRM): Adonis vernalis L.; Alnus glutinosa (L.) Gaertn.; Alnus incana (L.) Moench; Amygdalus nana L.; Anemonoides sylvestris (L.) Galasso, Banfi & Soldano; Asparagus officinalis L.; Aurinia saxatilis Desv.; Cephalanthera damasonium (Mill.) Druce; Clematis integrifolia L.; Convallaria majalis L.; Crambe tataria Sebeók; Dictamnus gymnostylis Steven; Digitalis lanata Ehrh.; Dryopteris fi lix-mas (L.) Schott; Galanthus nivalis L.; Helichrysum arenarium (L.) Moench; Iris pumila L.; Leucojum aestivum L.; Lunaria annua L.; Padus avium Mill.; Phyllitis scolopendrium (L.) Newm.; Pontechium maculatum (L.) Böhle & Hilger; Potentilla astracanica Jacq.; Pulsatilla montana Rchb.; Pulsatilla ucrainica (Ugrinsky) Wissjul.; Serratula coronata L. In conclusion, we can mention that the “Al. Ciubotaru” National Botanical Garden (Institute) holds a vast collection of threatened species of native flora, which can be exploited as germplasm sources in the conservation process.

In a constantly moving and developing world, measures to save and conserve genetic resources are becoming imperative. The collection and storage of plant germplasm is a modern system for biodiversity conservation, which allows the storage of a large number of samples in a relatively small space. The stability of plant biodiversity is ensured by the synergy of in situ and ex situ conservation strategies. In 2024, within the National Botanical Garden (Institute) “Al. Ciubotaru”, the germplasm collection “Rare Plants of the Republic of Moldova” (PRRM) was established, which has a primary role in ensuring the ex situ conservation of rare species of native flora. This collection presents, in essence, a scientific basis for a subsequent assessment of the preservation of quality indices, as well as the regeneration-multiplication-repopulation of species at high risk of endangerment. Protected areas are selected as target points for the collection of biological material from in situ conditions, where rare species are widespread, including the “Dobrușa” landscape reserve. Within the PRRM germplasm collection, seeds of species that represent rare taxa protected by the state are preserved through: The Red Book of the Republic of Moldova (1); The Law on the Fund of State Protected Natural Areas (2); The Law on the Plant Kingdom (3). Germplasm collections on the territory of the Dobrușa Landscape Reserve were carried out in 2024-2025, through field trips. The collections were sustainable and conscious, aligned with the principles of nature conservation. During the reference period, germplasm of the following species were collected and preserved: Cephalanthera damasonium (Mill.) Druce (1, 2); Epipactis helleborine (L.) Crantz (2); Epipactis purpurata Smith (1, 2); Fritillaria montana Hoppe ex W.D.J.Koch (2, 3); Galanthus nivalis L. (1, 2, 3); Lilium martagon L. (2); Lunaria annua L. (2); Scopolia carniolica Jacq. (1, 2, 3); Staphylea pinnata L. (2). In conclusion, we can state that the “Dobrușa” landscape reserve has potential for collecting germplasm of rare native species, specific to forest coenoses. Ex situ conservation of species with high conservation value in germplasm collections ensures their long-term protection

Cephalanthera damasonium (Mill.) Druce is a rare species for the flora of the Republic of Moldova, categorized as vulnerable in the Red Book (2015), grows sporadically in beech, sessile oak and pedunculate oak forests with cherry. The distribution area of the species includes North Africa, Europe, the Caucasus and Asia Minor. Due to the difficulties of natural regeneration, which depends on the specific presence of mycorrhiza and appropriate habitat conditions, studies on in vitro germination and multiplication become crucial for ex situ conservation strategies and reintroduction into the natural environment. Previous studies have demonstrated that in vitro germination of orchid seeds is influenced by several factors: the physiological state of the seeds, sterilization treatments, the type and composition of the nutrient medium, as well as incubation conditions. For the genus Cephalanthera, the specialized literature is relatively limited, but there are reports on the success of germination in MS-type media (Murashige & Skoog) with minimal hormonal adjustments. The study used mature seeds of Cephalanthera damasonium (Mill.) Druce, collected from natural populations (Landscape Reserve “Dobrusa”), for the purpose of assessing germination capacity under in vitro conditions. The seeds of the studied species are very small in size (m1000 ≃0.01 mg), and usually do not have a welldeveloped endosperm. Each seed represents an embryo surrounded by a transparent coverage. The structure is adapted for anemochorous dispersal. The biomorphometric parameters of the seeds, determined with the Levenhuk Med D40 Microscope, are the following: length – 146.332±6.947 μm; width – 25.288±3.964 μm; embryo perimeter – 83.666±3.115; embryo area – 523.830±10.186 μm². For their asepsis, two sterilizing agents were applied: mercuric chloride (0.01 %) and sodium hypochlorite (ACE, 7 %). After sterilization, the seeds were inoculated on Murashige & Skoog (MS) media in two variants: MS + 0.5 mg/L BAP and MS (without phytohormones). The protocol with HgCl₂ 0.01 % showed the lowest contamination rate (below 10 %), compared to the protocol with sodium hypochlorite (~25 %). In addition, seeds treated with HgCl₂ demonstrated a survival rate of approximately 70 %, and in combination with MS + BAP medium, they showed clear beginnings of germination and differentiation of protocorms. Sodium hypochlorite, although more easily accessible and less toxic, partially affected the viability of the seeds and did not completely prevent the development of fungi, especially in samples collected from areas with soils rich in mycorrhizal spores. The results obtained are consistent with those reported for other terrestrial orchids, where mercuric chloride was effective in low doses. Although no clear germination processes have been observed so far, the seeds remain viable in the environment, and the protocorms have not visibly differentiated. Observations will continue to monitor the evolution over time. The proposed protocol can be successfully used in the initiation of sterile cultures of Cephalanthera damasonium, representing an essential step towards the ex situ conservation and artificial propagation of this rare species.

The article elucidates the retrospective of the breeding of flowering plants in the Laboratory of Ornamental Plants of the National Botanical Garden (Institute) for about six decades, and also the recent results obtained in the field. The mobilization and introduction into culture of thousands of intraspecifi c taxa generated unique collections of ornamental flowering plants, which served as a basis for obtaining new varieties. More than 300 cultivars have been obtained by: the method of induction of mutations, directed hybridization, selection of spontaneous mutations and natural pollination. Approximately 150 varieties have been certified, homologated, and some patented with the support of the State Agency on Intellectual Property, and also abroad. Currently, 56 ornamental varieties are registered and maintained in the Catalog of Plant Varieties of the Republic of Moldova. In the last decade, more than 60 cultivars were selected, of which 12 were patented. The work of the breeders was appreciated with gold and silver medals, diplomas for participation in national and international inventions exhibitions.