Understanding stand structure and regeneration dynamics is essential for assessing the functioning, resilience, and conservation status of Mediterranean forest ecosystems. Atlas cedar (Cedrus atlantica), a keystone species of high conservation concern, has experienced significant decline across its natural range. This study examines the structural dynamics and regeneration patterns of C. atlantica in the Tala Guilef forest (northwestern Djurdjura, Algeria) under varying local ecological conditions and disturbance regimes. Field data were collected from 32 square stands (625 m2 each), representing a range of elevations, slopes, exposures, vegetation cover classes, and stand compositions. Structural attributes were assessed using dendrometric measurements (diameter at breast height, total height, crown dimensions, basal area, and density), while regeneration was evaluated across four developmental stages. Cone production was quantified as an indicator of reproductive potential, and disturbance factors were recorded through direct field observations.The results indicate that C. atlantica dominates all stands and is associated with low to moderate woody species diversity. Regeneration was present across all sites, although its density varied significantly with ecological conditions. Seedlings were more abundant on north-facing slopes, whereas advanced regeneration stages were more frequent on south-facing slopes. Regeneration density peaked at higher elevations and under intermediate vegetation cover (25-50%). Cone production was widespread and did not limit regeneration. Diameter distributions consistently exhibited an inverted J-shaped structure, indicating continuous recruitment. Structural attributes such as diameter, height, and basal area were generally higher in mixed stands and at medium elevations. Grazing was identified as the dominant disturbance factor, affecting more than 80% of the surveyed stands and likely constraining regeneration success. Despite these pressures, the overall structural patterns suggest that C. atlantica populations in Tala Guilef maintain active dynamics and regeneration capacity. Reducing anthropogenic pressure, particularly grazing, and prioritizing the protection of stands with high regeneration potential may enhance natural regeneration processes and support sustainable forest management.
Pedunculate oak forests have prominent historical value from commercial, biological, and social aspects for both countries. Recently, these forests have been exposed to rising threats, which raised both the concern of practical foresters and the importance of forest restoration efforts. Reports from both Croatia and Serbia over the past decade indicate an increase in the frequency and intensity of biotic and abiotic threats. To preserve the forests and their numerous benefits for nature and society, as well as to prevent their further degradation, it is essential to undertake the restoration. However, defferenet barriers and constraints are associated with restoring pedunculate oak forests in practical forestry. Therefore, our goal was to facilitate restoration of pedunculate oak forests by analysing current scientific knowledge and by identifying: 1) threats posed to pedunculate oak forests, 2) constraints and barriers, and 3) enablers and guidelines for forest restoration. Reviewing the available literature, we identified the most reported threats affecting pedunculate oak forests in Croatia and Serbia, among which lace bug, powdery mildew, wind damage, and the complex interplay of harmful biotic and abiotic factors stand out. Forest restoration is challenged by a range of systemic and practical barriers. The most common barriers are economic, legal, political, environmental, technical, and social. For each barrier, a description and binding issue for the restoration of pedunculate oak forests is given, as well as possible enablers for addressing them. Identifying and comprehending the barriers and enablers is essential for creating effective forest restoration strategies. Given that both the science and practice of restoration are still in a developmental phase, such insights are vital for advancing and improving restoration outcomes.
The study inventoried and analyzed the presence of 34 strictly protected and 11 threatened species of vascular flora within the forest vegetation of Plitvice Lakes National Park. The inventory was conducted on the basis of previously relevant findings and the authors'own field observations across 323 complete or partial 1 & times; 1 km grid squares. Species occurrences within the grid squares were classified into five categories, ranging from very rare distribution (<= 10 grid squares, Category I) to wide ranges extending over more than 60 % of the Park's area (>= 201 grid squares, Category V). It was found that 14 species have a very limited distribution, occurring on less than 3% of the total forest area (<= 10 grid squares). A further 11 species were recorded in 11-50 grid squares (covering less than 17% of the area), whereas the remaining 20 species showed considerably higher frequencies and broader distributions within the Park's forest ecosystems. The categories of very rare and rare species include taxa with narrow ecological valence (habitat specialists). They inhabit specific, sensitive, and spatially restricted habitats such as wet and flood-prone areas, more open limestone slopes and hillsides, ecotones, and non-forest areas. Since this group also includes species whose abundance decreases along the transition from non-forest habitats to closed and shaded forest stands, they are certainly present in the surrounding successional and open habitats as well. The category of rarely distributed taxa includes several typical forest species, primarily orchids (Cypripedium calceolus, Corallorhiza trifida, Epipactis sp.), as well as Ilexaquifolium and Taxus baccata. Based on the available data, their current distribution is considered stable, although it is assumed that yew and holly historically occupied a wider range that has been reduced over time due to long-term anthropogenic influence. Alongside these rare taxa, a substantial share of the Park's flora is composed of widely distributed forest species that provide it with a distinctive natural identity. The analysis of the distribution and threat status of the inventoried taxa indicates that they currently occupy stable ranges within Plitvice Lakes National Park. The maintenance of this condition is expected, as no interventions are carried out in the Park that would lead to fragmentation, degradation, or alteration of forest habitats. Nevertheless, long-term threats, particularly for habitat specialists, include potential changes in the hydrological regime, progressive succession on non-forest areas, and the cumulative effects of climate change. Therefore, it is necessary to establish systematic monitoring of sensitive species on permanent plots and to implement targeted conservation measures. The results provide a relevant professional basis for improving management strategies and ensuring the long-term protection of the Park's biodiversity.
Bay laurel (Laurus nobilis L., Lauraceae) is an economically and ecologically important non-timber forest product widely distributed across Mediterranean and sub-Mediterranean ecosystems. This study assessed phenotypic variation in two-year-old seedlings originating from six natural populations in the Southwestern Black Sea Region. Seedlings were grown under uniform open-field nursery conditions and evaluated using fourteen phenotypic and quality-related traits, including growth parameters, biomass components, and composite seedling quality indices. Univariate and multivariate analyses revealed significant population-level differentiation and supported the emergence of two well-defined distinct phenotypic groups. The first group exhibited higher biomass accumulation, larger root collar diameter, and more balanced quality index values, indicating stronger structural development and superior seedling quality. In contrast, the second group showed lower biomass production and higher slenderness, reflecting a more limited growth pattern. Mantel tests revealed moderate correlations between phenotypic distances and both geographic and environmental distances; however, these relationships were not statistically significant, suggesting that spatial and environmental gradients alone do not fully account for the observed phenotypic structure. Our results highlight the critical influence of population origin in shaping seedling morphology and quality under uniform nursery conditions. These findings provide a scientific basis for provenance-based seed source selection and contribute to sustainable cultivation, breeding, and conservation strategies for bay laurel, with practical implications for horticulture and urban
Historic parks in European urban environments have multiple values: they serve as hotspots of biodiversity, spaces of historical and cultural significance, sites of horticultural experimentation, and important elements in shaping urban identity.The city of Zagreb inherits a series of such parks created in the 19th century, among which Ribnjak, located beneath the cathedral, occupies a special place. Its present appearance has been shaped over nearly two centuries of change-from a romantic landscape with water surfaces, through modernist interventions after World War II, to contemporary uses. In 19th-century parks, plants were important design elements, transforming space into an idealized natural landscape that combined aesthetic beauty, botanical enthusiasm for exotic species, and social prestige. Because of this important role of plants, a woody plant inventory of Ribnjak Park was conducted from spring 2025 to spring 2026. A total of 99 taxa were recorded, dominated by trees, with a smaller number of shrubs and climbers. Although deciduous species prevail, evergreen plants, particularly conifers, ensure continuity during winter months. Notable among them are specimens of yew, a species of historical and conservation importance. Biogeographical analysis revealed a high proportion of non-native taxa, a characteristic feature of parks designed in the 19th century. Comparison with the 1958 list, which recorded 113 taxa, confirmed 58 taxa and indicated losses in woody flora over the past decades. At the same time, several species planted in Zagreb's parks and gardens during the 19th century remain present today, including individual solitaires and groups of old trees, demonstrating the long-term continuity of historical horticultural choices.The diversity of woody plants shapes ambiences and vistas that complement the spatial elements of the park. Paths, resting areas, flower beds, meadows, and sculptures together create a layered spatial experience, while views toward the cathedral reinforce Ribnjak as a cultural landscape. Ribnjak Park thus emerges as a space where historical continuity, plant diversity, and spatial elements intertwine to form a recognizable historic environment of Zagreb.
