This paper presents the 2024 research results from the Danube Delta Biosphere Reserve (DDBR), including reed bed mapping and typology for fire management, assessment of sustainable use of vegetal resources, conservation status of invertebrates, fish, reptiles, amphibians, colonial waterbirds, and mammals of Community interest, evaluation of species invasiveness under climate change, and studies on human well-being and ecotourism within a sustainable development framework.

Iris brandzae is one of the most threatened plant species in Romania. The current distribution of this species is very fragmented, and the population size has been reduced in the last 30 years. Information on the habitat preferences of the species has not been summarized yet. In this context, this study aimed to identify the habitat preferences of the species I. brandzae in Romania. The study was carried out in the NE (Moldova) and SE (Muntenia) regions of Romania. For the vegetation analysis, a total of 46 relevés were used. To classify the vegetation, we applied the hierarchical agglomerative clustering method, using the ß-flexible algorithm with ß = -0.25 and the Bray-Curtis dissimilarity. The data were represented as mean percentage values, according to the the Braun-Blanquet scale . Relationships between floristic composition and environmental variables were analyzed with Detrended Correspondence Analysis (DCA) and Canonical Correspondence Analysis (CCA). The vegetation analysis showed that I. brandzae grows in xerophilous, mesophilous and halophilous grasslands and ash-alpine alluvial forests. The species occurs in the communities of the Stipion lessingianae alliance, of the Festucetalia valesiacae order, mainly. The results of the CCA analysis indicate that the variation of the floristic composition of I. brandzae is influenced by the annual mean temperature (BIO1).

The palatability of a plant refers to the degree of attraction or preference that animals show toward that particular plant. Various factors can influence palatability, including the plant’s chemical composition, texture, taste, aromas, and the circumstances under which herbivorous animals consume it. The study aims to assess the plant species composition in grasslands and pastures within the Danube Delta, Romania. Both old or new references on palatability were considered. The evaluation of plant composition and degree of plant palatability was carried out in 12 grazing areas in the Danube Delta and the surrounding region. The study revealed 121 plant species identified in some pastures. Of these, 31 were “Non-Palatable”, 16 were “Highly Palatable”, 32 were “Mostly Palatable”, 16 were “Less Palatable”, and 26 were “Rarely Palatable”. Animals preferred 60 plant species in their fresh condition, with 29 preferred in fresh and dry. Most animals consumed whole plants (48 species), followed by leaves (43 species), fruits (three species), and inflorescences (two species). By analysing the feeding preferences of animals, it was found that cows exhibited a preference for the broadest range of plants (75 species), followed by sheep (67 species), goats (59 species), and horses (34 species). Domestic animals like goats, sheep, cows, and horses may prefer certain plants based on nutritional content or digestibility while avoiding toxic plants. The study showed that the investigated areas have a diverse flora with a varied supply of plants, including palatable species. The palatability index is essential in assessing the quality of pastures, especially in obtaining average daily gains based on the species of animals living on the pastures. Considering the dynamic climatic conditions and poor pasture quality in the Danube Delta, more detailed and interdisciplinary studies are needed to understand the deltaic biocenoses comprehensively.

Context: Habitat fragmentation contributes to population isolation and threatens the survival of plant species listed on the Red List. Effective conservation measures require considering both suitable habitats and landscape permeability. Species Distribution Models (SDMs) are valuable for identifying suitable habitats. These models gain utility when combined with landscape permeability analyses for conservation planning. Objectives: This study aims to (1) model the potentially suitable habitat distribution for five threatened plant species in Romania, (2) assess landscape permeability, and (3) identify priority areas for conservation based on the overlay of the habitat and permeability. Methodology: We applied an integrated approach that combined SDM modelling (MaxEnt) and GIS analysis. We used the Continuum Suitability Index (CSI) to quantify landscape permeability. By mapping the spatial overlap of habitat suitability and permeability, we classified areas into four categories for ecological interventions. Results: A significant proportion of the identified suitable habitats have low permeability, which limits species dispersal and persistence. Areas combining high suitability and high permeability are limited and are mostly outside protected areas (PAs). This highlights the urgent need for conservation actions. Measures such as optimal grazing management, reduced fragmentation, and maintaining traditional agro-pastoral mosaics should be prioritized in these critical zones beyond formal protected area boundaries. Conclusion: Including landscape permeability in habitat analyses gives a more realistic view of the requirements of threatened species. It supports more explicit decision-making for conservation management. The study also proposes a replicable method for other fragmented regions, with direct applications in land-use policy and biodiversity conservation.